xattr.c

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/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * xattr.c
 *
 * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
 *
 * CREDITS:
 * Lots of code in this file is copy from linux/fs/ext3/xattr.c.
 * Copyright (C) 2001-2003 Andreas Gruenbacher, <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/sched.h>
#include <linux/splice.h>
#include <linux/mount.h>
#include <linux/writeback.h>
#include <linux/falloc.h>
#include <linux/sort.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/security.h>

#include <cluster/masklog.h>

#include "ocfs2.h"
#include "alloc.h"
#include "blockcheck.h"
#include "dlmglue.h"
#include "file.h"
#include "symlink.h"
#include "sysfile.h"
#include "inode.h"
#include "journal.h"
#include "ocfs2_fs.h"
#include "suballoc.h"
#include "uptodate.h"
#include "buffer_head_io.h"
#include "super.h"
#include "xattr.h"
#include "refcounttree.h"
#include "acl.h"
#include "ocfs2_trace.h"

struct ocfs2_xattr_def_value_root {
    struct ocfs2_xattr_value_root   xv;
    struct ocfs2_extent_rec     er;
};

struct ocfs2_xattr_bucket {
    /* The inode these xattrs are associated with */
    struct inode *bu_inode;

    /* The actual buffers that make up the bucket */
    struct buffer_head *bu_bhs[OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET];

    /* How many blocks make up one bucket for this filesystem */
    int bu_blocks;
};

struct ocfs2_xattr_set_ctxt {
    handle_t *handle;
    struct ocfs2_alloc_context *meta_ac;
    struct ocfs2_alloc_context *data_ac;
    struct ocfs2_cached_dealloc_ctxt dealloc;
    int set_abort;
};

#define OCFS2_XATTR_ROOT_SIZE   (sizeof(struct ocfs2_xattr_def_value_root))
#define OCFS2_XATTR_INLINE_SIZE 80
#define OCFS2_XATTR_HEADER_GAP  4
#define OCFS2_XATTR_FREE_IN_IBODY   (OCFS2_MIN_XATTR_INLINE_SIZE \
                     - sizeof(struct ocfs2_xattr_header) \
                     - OCFS2_XATTR_HEADER_GAP)
#define OCFS2_XATTR_FREE_IN_BLOCK(ptr)  ((ptr)->i_sb->s_blocksize \
                     - sizeof(struct ocfs2_xattr_block) \
                     - sizeof(struct ocfs2_xattr_header) \
                     - OCFS2_XATTR_HEADER_GAP)

static struct ocfs2_xattr_def_value_root def_xv = {
    .xv.xr_list.l_count = cpu_to_le16(1),
};

const struct xattr_handler *ocfs2_xattr_handlers[] = {
    &ocfs2_xattr_user_handler,
    &ocfs2_xattr_acl_access_handler,
    &ocfs2_xattr_acl_default_handler,
    &ocfs2_xattr_trusted_handler,
    &ocfs2_xattr_security_handler,
    NULL
};

static const struct xattr_handler *ocfs2_xattr_handler_map[OCFS2_XATTR_MAX] = {
    [OCFS2_XATTR_INDEX_USER]    = &ocfs2_xattr_user_handler,
    [OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS]
                    = &ocfs2_xattr_acl_access_handler,
    [OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT]
                    = &ocfs2_xattr_acl_default_handler,
    [OCFS2_XATTR_INDEX_TRUSTED] = &ocfs2_xattr_trusted_handler,
    [OCFS2_XATTR_INDEX_SECURITY]    = &ocfs2_xattr_security_handler,
};

struct ocfs2_xattr_info {
    int     xi_name_index;
    const char  *xi_name;
    int     xi_name_len;
    const void  *xi_value;
    size_t      xi_value_len;
};

struct ocfs2_xattr_search {
    struct buffer_head *inode_bh;
    /*
     * xattr_bh point to the block buffer head which has extended attribute
     * when extended attribute in inode, xattr_bh is equal to inode_bh.
     */
    struct buffer_head *xattr_bh;
    struct ocfs2_xattr_header *header;
    struct ocfs2_xattr_bucket *bucket;
    void *base;
    void *end;
    struct ocfs2_xattr_entry *here;
    int not_found;
};

/* Operations on struct ocfs2_xa_entry */
struct ocfs2_xa_loc;
struct ocfs2_xa_loc_operations {
    /*
     * Journal functions
     */
    int (*xlo_journal_access)(handle_t *handle, struct ocfs2_xa_loc *loc,
                  int type);
    void (*xlo_journal_dirty)(handle_t *handle, struct ocfs2_xa_loc *loc);

    /*
     * Return a pointer to the appropriate buffer in loc->xl_storage
     * at the given offset from loc->xl_header.
     */
    void *(*xlo_offset_pointer)(struct ocfs2_xa_loc *loc, int offset);

    /* Can we reuse the existing entry for the new value? */
    int (*xlo_can_reuse)(struct ocfs2_xa_loc *loc,
                 struct ocfs2_xattr_info *xi);

    /* How much space is needed for the new value? */
    int (*xlo_check_space)(struct ocfs2_xa_loc *loc,
                   struct ocfs2_xattr_info *xi);

    /*
     * Return the offset of the first name+value pair.  This is
     * the start of our downward-filling free space.
     */
    int (*xlo_get_free_start)(struct ocfs2_xa_loc *loc);

    /*
     * Remove the name+value at this location.  Do whatever is
     * appropriate with the remaining name+value pairs.
     */
    void (*xlo_wipe_namevalue)(struct ocfs2_xa_loc *loc);

    /* Fill xl_entry with a new entry */
    void (*xlo_add_entry)(struct ocfs2_xa_loc *loc, u32 name_hash);

    /* Add name+value storage to an entry */
    void (*xlo_add_namevalue)(struct ocfs2_xa_loc *loc, int size);

    /*
     * Initialize the value buf's access and bh fields for this entry.
     * ocfs2_xa_fill_value_buf() will handle the xv pointer.
     */
    void (*xlo_fill_value_buf)(struct ocfs2_xa_loc *loc,
                   struct ocfs2_xattr_value_buf *vb);
};

/*
 * Describes an xattr entry location.  This is a memory structure
 * tracking the on-disk structure.
 */
struct ocfs2_xa_loc {
    /* This xattr belongs to this inode */
    struct inode *xl_inode;

    /* The ocfs2_xattr_header inside the on-disk storage. Not NULL. */
    struct ocfs2_xattr_header *xl_header;

    /* Bytes from xl_header to the end of the storage */
    int xl_size;

    /*
     * The ocfs2_xattr_entry this location describes.  If this is
     * NULL, this location describes the on-disk structure where it
     * would have been.
     */
    struct ocfs2_xattr_entry *xl_entry;

    /*
     * Internal housekeeping
     */

    /* Buffer(s) containing this entry */
    void *xl_storage;

    /* Operations on the storage backing this location */
    const struct ocfs2_xa_loc_operations *xl_ops;
};

/*
 * Convenience functions to calculate how much space is needed for a
 * given name+value pair
 */
static int namevalue_size(int name_len, uint64_t value_len)
{
    if (value_len > OCFS2_XATTR_INLINE_SIZE)
        return OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
    else
        return OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_SIZE(value_len);
}

static int namevalue_size_xi(struct ocfs2_xattr_info *xi)
{
    return namevalue_size(xi->xi_name_len, xi->xi_value_len);
}

static int namevalue_size_xe(struct ocfs2_xattr_entry *xe)
{
    u64 value_len = le64_to_cpu(xe->xe_value_size);

    BUG_ON((value_len > OCFS2_XATTR_INLINE_SIZE) &&
           ocfs2_xattr_is_local(xe));
    return namevalue_size(xe->xe_name_len, value_len);
}


static int ocfs2_xattr_bucket_get_name_value(struct super_block *sb,
                         struct ocfs2_xattr_header *xh,
                         int index,
                         int *block_off,
                         int *new_offset);

static int ocfs2_xattr_block_find(struct inode *inode,
                  int name_index,
                  const char *name,
                  struct ocfs2_xattr_search *xs);
static int ocfs2_xattr_index_block_find(struct inode *inode,
                    struct buffer_head *root_bh,
                    int name_index,
                    const char *name,
                    struct ocfs2_xattr_search *xs);

static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
                    struct buffer_head *blk_bh,
                    char *buffer,
                    size_t buffer_size);

static int ocfs2_xattr_create_index_block(struct inode *inode,
                      struct ocfs2_xattr_search *xs,
                      struct ocfs2_xattr_set_ctxt *ctxt);

static int ocfs2_xattr_set_entry_index_block(struct inode *inode,
                         struct ocfs2_xattr_info *xi,
                         struct ocfs2_xattr_search *xs,
                         struct ocfs2_xattr_set_ctxt *ctxt);

typedef int (xattr_tree_rec_func)(struct inode *inode,
                  struct buffer_head *root_bh,
                  u64 blkno, u32 cpos, u32 len, void *para);
static int ocfs2_iterate_xattr_index_block(struct inode *inode,
                       struct buffer_head *root_bh,
                       xattr_tree_rec_func *rec_func,
                       void *para);
static int ocfs2_delete_xattr_in_bucket(struct inode *inode,
                    struct ocfs2_xattr_bucket *bucket,
                    void *para);
static int ocfs2_rm_xattr_cluster(struct inode *inode,
                  struct buffer_head *root_bh,
                  u64 blkno,
                  u32 cpos,
                  u32 len,
                  void *para);

static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
                  u64 src_blk, u64 last_blk, u64 to_blk,
                  unsigned int start_bucket,
                  u32 *first_hash);
static int ocfs2_prepare_refcount_xattr(struct inode *inode,
                    struct ocfs2_dinode *di,
                    struct ocfs2_xattr_info *xi,
                    struct ocfs2_xattr_search *xis,
                    struct ocfs2_xattr_search *xbs,
                    struct ocfs2_refcount_tree **ref_tree,
                    int *meta_need,
                    int *credits);
static int ocfs2_get_xattr_tree_value_root(struct super_block *sb,
                       struct ocfs2_xattr_bucket *bucket,
                       int offset,
                       struct ocfs2_xattr_value_root **xv,
                       struct buffer_head **bh);

static inline u16 ocfs2_xattr_buckets_per_cluster(struct ocfs2_super *osb)
{
    return (1 << osb->s_clustersize_bits) / OCFS2_XATTR_BUCKET_SIZE;
}

static inline u16 ocfs2_blocks_per_xattr_bucket(struct super_block *sb)
{
    return OCFS2_XATTR_BUCKET_SIZE / (1 << sb->s_blocksize_bits);
}

#define bucket_blkno(_b) ((_b)->bu_bhs[0]->b_blocknr)
#define bucket_block(_b, _n) ((_b)->bu_bhs[(_n)]->b_data)
#define bucket_xh(_b) ((struct ocfs2_xattr_header *)bucket_block((_b), 0))

static struct ocfs2_xattr_bucket *ocfs2_xattr_bucket_new(struct inode *inode)
{
    struct ocfs2_xattr_bucket *bucket;
    int blks = ocfs2_blocks_per_xattr_bucket(inode->i_sb);

    BUG_ON(blks > OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET);

    bucket = kzalloc(sizeof(struct ocfs2_xattr_bucket), GFP_NOFS);
    if (bucket) {
        bucket->bu_inode = inode;
        bucket->bu_blocks = blks;
    }

    return bucket;
}

static void ocfs2_xattr_bucket_relse(struct ocfs2_xattr_bucket *bucket)
{
    int i;

    for (i = 0; i < bucket->bu_blocks; i++) {
        brelse(bucket->bu_bhs[i]);
        bucket->bu_bhs[i] = NULL;
    }
}

static void ocfs2_xattr_bucket_free(struct ocfs2_xattr_bucket *bucket)
{
    if (bucket) {
        ocfs2_xattr_bucket_relse(bucket);
        bucket->bu_inode = NULL;
        kfree(bucket);
    }
}

/*
 * A bucket that has never been written to disk doesn't need to be
 * read.  We just need the buffer_heads.  Don't call this for
 * buckets that are already on disk.  ocfs2_read_xattr_bucket() initializes
 * them fully.
 */
static int ocfs2_init_xattr_bucket(struct ocfs2_xattr_bucket *bucket,
                   u64 xb_blkno)
{
    int i, rc = 0;

    for (i = 0; i < bucket->bu_blocks; i++) {
        bucket->bu_bhs[i] = sb_getblk(bucket->bu_inode->i_sb,
                          xb_blkno + i);
        if (!bucket->bu_bhs[i]) {
            rc = -EIO;
            mlog_errno(rc);
            break;
        }

        if (!ocfs2_buffer_uptodate(INODE_CACHE(bucket->bu_inode),
                       bucket->bu_bhs[i]))
            ocfs2_set_new_buffer_uptodate(INODE_CACHE(bucket->bu_inode),
                              bucket->bu_bhs[i]);
    }

    if (rc)
        ocfs2_xattr_bucket_relse(bucket);
    return rc;
}

/* Read the xattr bucket at xb_blkno */
static int ocfs2_read_xattr_bucket(struct ocfs2_xattr_bucket *bucket,
                   u64 xb_blkno)
{
    int rc;

    rc = ocfs2_read_blocks(INODE_CACHE(bucket->bu_inode), xb_blkno,
                   bucket->bu_blocks, bucket->bu_bhs, 0,
                   NULL);
    if (!rc) {
        spin_lock(&OCFS2_SB(bucket->bu_inode->i_sb)->osb_xattr_lock);
        rc = ocfs2_validate_meta_ecc_bhs(bucket->bu_inode->i_sb,
                         bucket->bu_bhs,
                         bucket->bu_blocks,
                         &bucket_xh(bucket)->xh_check);
        spin_unlock(&OCFS2_SB(bucket->bu_inode->i_sb)->osb_xattr_lock);
        if (rc)
            mlog_errno(rc);
    }

    if (rc)
        ocfs2_xattr_bucket_relse(bucket);
    return rc;
}

static int ocfs2_xattr_bucket_journal_access(handle_t *handle,
                         struct ocfs2_xattr_bucket *bucket,
                         int type)
{
    int i, rc = 0;

    for (i = 0; i < bucket->bu_blocks; i++) {
        rc = ocfs2_journal_access(handle,
                      INODE_CACHE(bucket->bu_inode),
                      bucket->bu_bhs[i], type);
        if (rc) {
            mlog_errno(rc);
            break;
        }
    }

    return rc;
}

static void ocfs2_xattr_bucket_journal_dirty(handle_t *handle,
                         struct ocfs2_xattr_bucket *bucket)
{
    int i;

    spin_lock(&OCFS2_SB(bucket->bu_inode->i_sb)->osb_xattr_lock);
    ocfs2_compute_meta_ecc_bhs(bucket->bu_inode->i_sb,
                   bucket->bu_bhs, bucket->bu_blocks,
                   &bucket_xh(bucket)->xh_check);
    spin_unlock(&OCFS2_SB(bucket->bu_inode->i_sb)->osb_xattr_lock);

    for (i = 0; i < bucket->bu_blocks; i++)
        ocfs2_journal_dirty(handle, bucket->bu_bhs[i]);
}

static void ocfs2_xattr_bucket_copy_data(struct ocfs2_xattr_bucket *dest,
                     struct ocfs2_xattr_bucket *src)
{
    int i;
    int blocksize = src->bu_inode->i_sb->s_blocksize;

    BUG_ON(dest->bu_blocks != src->bu_blocks);
    BUG_ON(dest->bu_inode != src->bu_inode);

    for (i = 0; i < src->bu_blocks; i++) {
        memcpy(bucket_block(dest, i), bucket_block(src, i),
               blocksize);
    }
}

static int ocfs2_validate_xattr_block(struct super_block *sb,
                      struct buffer_head *bh)
{
    int rc;
    struct ocfs2_xattr_block *xb =
        (struct ocfs2_xattr_block *)bh->b_data;

    trace_ocfs2_validate_xattr_block((unsigned long long)bh->b_blocknr);

    BUG_ON(!buffer_uptodate(bh));

    /*
     * If the ecc fails, we return the error but otherwise
     * leave the filesystem running.  We know any error is
     * local to this block.
     */
    rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &xb->xb_check);
    if (rc)
        return rc;

    /*
     * Errors after here are fatal
     */

    if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {
        ocfs2_error(sb,
                "Extended attribute block #%llu has bad "
                "signature %.*s",
                (unsigned long long)bh->b_blocknr, 7,
                xb->xb_signature);
        return -EINVAL;
    }

    if (le64_to_cpu(xb->xb_blkno) != bh->b_blocknr) {
        ocfs2_error(sb,
                "Extended attribute block #%llu has an "
                "invalid xb_blkno of %llu",
                (unsigned long long)bh->b_blocknr,
                (unsigned long long)le64_to_cpu(xb->xb_blkno));
        return -EINVAL;
    }

    if (le32_to_cpu(xb->xb_fs_generation) != OCFS2_SB(sb)->fs_generation) {
        ocfs2_error(sb,
                "Extended attribute block #%llu has an invalid "
                "xb_fs_generation of #%u",
                (unsigned long long)bh->b_blocknr,
                le32_to_cpu(xb->xb_fs_generation));
        return -EINVAL;
    }

    return 0;
}

static int ocfs2_read_xattr_block(struct inode *inode, u64 xb_blkno,
                  struct buffer_head **bh)
{
    int rc;
    struct buffer_head *tmp = *bh;

    rc = ocfs2_read_block(INODE_CACHE(inode), xb_blkno, &tmp,
                  ocfs2_validate_xattr_block);

    /* If ocfs2_read_block() got us a new bh, pass it up. */
    if (!rc && !*bh)
        *bh = tmp;

    return rc;
}

static inline const char *ocfs2_xattr_prefix(int name_index)
{
    const struct xattr_handler *handler = NULL;

    if (name_index > 0 && name_index < OCFS2_XATTR_MAX)
        handler = ocfs2_xattr_handler_map[name_index];

    return handler ? handler->prefix : NULL;
}

static u32 ocfs2_xattr_name_hash(struct inode *inode,
                 const char *name,
                 int name_len)
{
    /* Get hash value of uuid from super block */
    u32 hash = OCFS2_SB(inode->i_sb)->uuid_hash;
    int i;

    /* hash extended attribute name */
    for (i = 0; i < name_len; i++) {
        hash = (hash << OCFS2_HASH_SHIFT) ^
               (hash >> (8*sizeof(hash) - OCFS2_HASH_SHIFT)) ^
               *name++;
    }

    return hash;
}

static int ocfs2_xattr_entry_real_size(int name_len, size_t value_len)
{
    return namevalue_size(name_len, value_len) +
        sizeof(struct ocfs2_xattr_entry);
}

static int ocfs2_xi_entry_usage(struct ocfs2_xattr_info *xi)
{
    return namevalue_size_xi(xi) +
        sizeof(struct ocfs2_xattr_entry);
}

static int ocfs2_xe_entry_usage(struct ocfs2_xattr_entry *xe)
{
    return namevalue_size_xe(xe) +
        sizeof(struct ocfs2_xattr_entry);
}

int ocfs2_calc_security_init(struct inode *dir,
                 struct ocfs2_security_xattr_info *si,
                 int *want_clusters,
                 int *xattr_credits,
                 struct ocfs2_alloc_context **xattr_ac)
{
    int ret = 0;
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
    int s_size = ocfs2_xattr_entry_real_size(strlen(si->name),
                         si->value_len);

    /*
     * The max space of security xattr taken inline is
     * 256(name) + 80(value) + 16(entry) = 352 bytes,
     * So reserve one metadata block for it is ok.
     */
    if (dir->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE ||
        s_size > OCFS2_XATTR_FREE_IN_IBODY) {
        ret = ocfs2_reserve_new_metadata_blocks(osb, 1, xattr_ac);
        if (ret) {
            mlog_errno(ret);
            return ret;
        }
        *xattr_credits += OCFS2_XATTR_BLOCK_CREATE_CREDITS;
    }

    /* reserve clusters for xattr value which will be set in B tree*/
    if (si->value_len > OCFS2_XATTR_INLINE_SIZE) {
        int new_clusters = ocfs2_clusters_for_bytes(dir->i_sb,
                                si->value_len);

        *xattr_credits += ocfs2_clusters_to_blocks(dir->i_sb,
                               new_clusters);
        *want_clusters += new_clusters;
    }
    return ret;
}

int ocfs2_calc_xattr_init(struct inode *dir,
              struct buffer_head *dir_bh,
              umode_t mode,
              struct ocfs2_security_xattr_info *si,
              int *want_clusters,
              int *xattr_credits,
              int *want_meta)
{
    int ret = 0;
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
    int s_size = 0, a_size = 0, acl_len = 0, new_clusters;

    if (si->enable)
        s_size = ocfs2_xattr_entry_real_size(strlen(si->name),
                             si->value_len);

    if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
        acl_len = ocfs2_xattr_get_nolock(dir, dir_bh,
                    OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT,
                    "", NULL, 0);
        if (acl_len > 0) {
            a_size = ocfs2_xattr_entry_real_size(0, acl_len);
            if (S_ISDIR(mode))
                a_size <<= 1;
        } else if (acl_len != 0 && acl_len != -ENODATA) {
            mlog_errno(ret);
            return ret;
        }
    }

    if (!(s_size + a_size))
        return ret;

    /*
     * The max space of security xattr taken inline is
     * 256(name) + 80(value) + 16(entry) = 352 bytes,
     * The max space of acl xattr taken inline is
     * 80(value) + 16(entry) * 2(if directory) = 192 bytes,
     * when blocksize = 512, may reserve one more cluser for
     * xattr bucket, otherwise reserve one metadata block
     * for them is ok.
     * If this is a new directory with inline data,
     * we choose to reserve the entire inline area for
     * directory contents and force an external xattr block.
     */
    if (dir->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE ||
        (S_ISDIR(mode) && ocfs2_supports_inline_data(osb)) ||
        (s_size + a_size) > OCFS2_XATTR_FREE_IN_IBODY) {
        *want_meta = *want_meta + 1;
        *xattr_credits += OCFS2_XATTR_BLOCK_CREATE_CREDITS;
    }

    if (dir->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE &&
        (s_size + a_size) > OCFS2_XATTR_FREE_IN_BLOCK(dir)) {
        *want_clusters += 1;
        *xattr_credits += ocfs2_blocks_per_xattr_bucket(dir->i_sb);
    }

    /*
     * reserve credits and clusters for xattrs which has large value
     * and have to be set outside
     */
    if (si->enable && si->value_len > OCFS2_XATTR_INLINE_SIZE) {
        new_clusters = ocfs2_clusters_for_bytes(dir->i_sb,
                            si->value_len);
        *xattr_credits += ocfs2_clusters_to_blocks(dir->i_sb,
                               new_clusters);
        *want_clusters += new_clusters;
    }
    if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL &&
        acl_len > OCFS2_XATTR_INLINE_SIZE) {
        /* for directory, it has DEFAULT and ACCESS two types of acls */
        new_clusters = (S_ISDIR(mode) ? 2 : 1) *
                ocfs2_clusters_for_bytes(dir->i_sb, acl_len);
        *xattr_credits += ocfs2_clusters_to_blocks(dir->i_sb,
                               new_clusters);
        *want_clusters += new_clusters;
    }

    return ret;
}

static int ocfs2_xattr_extend_allocation(struct inode *inode,
                     u32 clusters_to_add,
                     struct ocfs2_xattr_value_buf *vb,
                     struct ocfs2_xattr_set_ctxt *ctxt)
{
    int status = 0, credits;
    handle_t *handle = ctxt->handle;
    enum ocfs2_alloc_restarted why;
    u32 prev_clusters, logical_start = le32_to_cpu(vb->vb_xv->xr_clusters);
    struct ocfs2_extent_tree et;

    ocfs2_init_xattr_value_extent_tree(&et, INODE_CACHE(inode), vb);

    while (clusters_to_add) {
        trace_ocfs2_xattr_extend_allocation(clusters_to_add);

        status = vb->vb_access(handle, INODE_CACHE(inode), vb->vb_bh,
                       OCFS2_JOURNAL_ACCESS_WRITE);
        if (status < 0) {
            mlog_errno(status);
            break;
        }

        prev_clusters = le32_to_cpu(vb->vb_xv->xr_clusters);
        status = ocfs2_add_clusters_in_btree(handle,
                             &et,
                             &logical_start,
                             clusters_to_add,
                             0,
                             ctxt->data_ac,
                             ctxt->meta_ac,
                             &why);
        if ((status < 0) && (status != -EAGAIN)) {
            if (status != -ENOSPC)
                mlog_errno(status);
            break;
        }

        ocfs2_journal_dirty(handle, vb->vb_bh);

        clusters_to_add -= le32_to_cpu(vb->vb_xv->xr_clusters) -
                     prev_clusters;

        if (why != RESTART_NONE && clusters_to_add) {
            /*
             * We can only fail in case the alloc file doesn't give
             * up enough clusters.
             */
            BUG_ON(why == RESTART_META);

            credits = ocfs2_calc_extend_credits(inode->i_sb,
                                &vb->vb_xv->xr_list,
                                clusters_to_add);
            status = ocfs2_extend_trans(handle, credits);
            if (status < 0) {
                status = -ENOMEM;
                mlog_errno(status);
                break;
            }
        }
    }

    return status;
}

static int __ocfs2_remove_xattr_range(struct inode *inode,
                      struct ocfs2_xattr_value_buf *vb,
                      u32 cpos, u32 phys_cpos, u32 len,
                      unsigned int ext_flags,
                      struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;
    u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
    handle_t *handle = ctxt->handle;
    struct ocfs2_extent_tree et;

    ocfs2_init_xattr_value_extent_tree(&et, INODE_CACHE(inode), vb);

    ret = vb->vb_access(handle, INODE_CACHE(inode), vb->vb_bh,
                OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_remove_extent(handle, &et, cpos, len, ctxt->meta_ac,
                  &ctxt->dealloc);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    le32_add_cpu(&vb->vb_xv->xr_clusters, -len);
    ocfs2_journal_dirty(handle, vb->vb_bh);

    if (ext_flags & OCFS2_EXT_REFCOUNTED)
        ret = ocfs2_decrease_refcount(inode, handle,
                    ocfs2_blocks_to_clusters(inode->i_sb,
                                 phys_blkno),
                    len, ctxt->meta_ac, &ctxt->dealloc, 1);
    else
        ret = ocfs2_cache_cluster_dealloc(&ctxt->dealloc,
                          phys_blkno, len);
    if (ret)
        mlog_errno(ret);

out:
    return ret;
}

static int ocfs2_xattr_shrink_size(struct inode *inode,
                   u32 old_clusters,
                   u32 new_clusters,
                   struct ocfs2_xattr_value_buf *vb,
                   struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret = 0;
    unsigned int ext_flags;
    u32 trunc_len, cpos, phys_cpos, alloc_size;
    u64 block;

    if (old_clusters <= new_clusters)
        return 0;

    cpos = new_clusters;
    trunc_len = old_clusters - new_clusters;
    while (trunc_len) {
        ret = ocfs2_xattr_get_clusters(inode, cpos, &phys_cpos,
                           &alloc_size,
                           &vb->vb_xv->xr_list, &ext_flags);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        if (alloc_size > trunc_len)
            alloc_size = trunc_len;

        ret = __ocfs2_remove_xattr_range(inode, vb, cpos,
                         phys_cpos, alloc_size,
                         ext_flags, ctxt);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        block = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
        ocfs2_remove_xattr_clusters_from_cache(INODE_CACHE(inode),
                               block, alloc_size);
        cpos += alloc_size;
        trunc_len -= alloc_size;
    }

out:
    return ret;
}

static int ocfs2_xattr_value_truncate(struct inode *inode,
                      struct ocfs2_xattr_value_buf *vb,
                      int len,
                      struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;
    u32 new_clusters = ocfs2_clusters_for_bytes(inode->i_sb, len);
    u32 old_clusters = le32_to_cpu(vb->vb_xv->xr_clusters);

    if (new_clusters == old_clusters)
        return 0;

    if (new_clusters > old_clusters)
        ret = ocfs2_xattr_extend_allocation(inode,
                            new_clusters - old_clusters,
                            vb, ctxt);
    else
        ret = ocfs2_xattr_shrink_size(inode,
                          old_clusters, new_clusters,
                          vb, ctxt);

    return ret;
}

static int ocfs2_xattr_list_entry(char *buffer, size_t size,
                  size_t *result, const char *prefix,
                  const char *name, int name_len)
{
    char *p = buffer + *result;
    int prefix_len = strlen(prefix);
    int total_len = prefix_len + name_len + 1;

    *result += total_len;

    /* we are just looking for how big our buffer needs to be */
    if (!size)
        return 0;

    if (*result > size)
        return -ERANGE;

    memcpy(p, prefix, prefix_len);
    memcpy(p + prefix_len, name, name_len);
    p[prefix_len + name_len] = '\0';

    return 0;
}

static int ocfs2_xattr_list_entries(struct inode *inode,
                    struct ocfs2_xattr_header *header,
                    char *buffer, size_t buffer_size)
{
    size_t result = 0;
    int i, type, ret;
    const char *prefix, *name;

    for (i = 0 ; i < le16_to_cpu(header->xh_count); i++) {
        struct ocfs2_xattr_entry *entry = &header->xh_entries[i];
        type = ocfs2_xattr_get_type(entry);
        prefix = ocfs2_xattr_prefix(type);

        if (prefix) {
            name = (const char *)header +
                le16_to_cpu(entry->xe_name_offset);

            ret = ocfs2_xattr_list_entry(buffer, buffer_size,
                             &result, prefix, name,
                             entry->xe_name_len);
            if (ret)
                return ret;
        }
    }

    return result;
}

int ocfs2_has_inline_xattr_value_outside(struct inode *inode,
                     struct ocfs2_dinode *di)
{
    struct ocfs2_xattr_header *xh;
    int i;

    xh = (struct ocfs2_xattr_header *)
         ((void *)di + inode->i_sb->s_blocksize -
         le16_to_cpu(di->i_xattr_inline_size));

    for (i = 0; i < le16_to_cpu(xh->xh_count); i++)
        if (!ocfs2_xattr_is_local(&xh->xh_entries[i]))
            return 1;

    return 0;
}

static int ocfs2_xattr_ibody_list(struct inode *inode,
                  struct ocfs2_dinode *di,
                  char *buffer,
                  size_t buffer_size)
{
    struct ocfs2_xattr_header *header = NULL;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    int ret = 0;

    if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL))
        return ret;

    header = (struct ocfs2_xattr_header *)
         ((void *)di + inode->i_sb->s_blocksize -
         le16_to_cpu(di->i_xattr_inline_size));

    ret = ocfs2_xattr_list_entries(inode, header, buffer, buffer_size);

    return ret;
}

static int ocfs2_xattr_block_list(struct inode *inode,
                  struct ocfs2_dinode *di,
                  char *buffer,
                  size_t buffer_size)
{
    struct buffer_head *blk_bh = NULL;
    struct ocfs2_xattr_block *xb;
    int ret = 0;

    if (!di->i_xattr_loc)
        return ret;

    ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc),
                     &blk_bh);
    if (ret < 0) {
        mlog_errno(ret);
        return ret;
    }

    xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
    if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
        struct ocfs2_xattr_header *header = &xb->xb_attrs.xb_header;
        ret = ocfs2_xattr_list_entries(inode, header,
                           buffer, buffer_size);
    } else
        ret = ocfs2_xattr_tree_list_index_block(inode, blk_bh,
                           buffer, buffer_size);

    brelse(blk_bh);

    return ret;
}

ssize_t ocfs2_listxattr(struct dentry *dentry,
            char *buffer,
            size_t size)
{
    int ret = 0, i_ret = 0, b_ret = 0;
    struct buffer_head *di_bh = NULL;
    struct ocfs2_dinode *di = NULL;
    struct ocfs2_inode_info *oi = OCFS2_I(dentry->d_inode);

    if (!ocfs2_supports_xattr(OCFS2_SB(dentry->d_sb)))
        return -EOPNOTSUPP;

    if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
        return ret;

    ret = ocfs2_inode_lock(dentry->d_inode, &di_bh, 0);
    if (ret < 0) {
        mlog_errno(ret);
        return ret;
    }

    di = (struct ocfs2_dinode *)di_bh->b_data;

    down_read(&oi->ip_xattr_sem);
    i_ret = ocfs2_xattr_ibody_list(dentry->d_inode, di, buffer, size);
    if (i_ret < 0)
        b_ret = 0;
    else {
        if (buffer) {
            buffer += i_ret;
            size -= i_ret;
        }
        b_ret = ocfs2_xattr_block_list(dentry->d_inode, di,
                           buffer, size);
        if (b_ret < 0)
            i_ret = 0;
    }
    up_read(&oi->ip_xattr_sem);
    ocfs2_inode_unlock(dentry->d_inode, 0);

    brelse(di_bh);

    return i_ret + b_ret;
}

static int ocfs2_xattr_find_entry(int name_index,
                  const char *name,
                  struct ocfs2_xattr_search *xs)
{
    struct ocfs2_xattr_entry *entry;
    size_t name_len;
    int i, cmp = 1;

    if (name == NULL)
        return -EINVAL;

    name_len = strlen(name);
    entry = xs->here;
    for (i = 0; i < le16_to_cpu(xs->header->xh_count); i++) {
        cmp = name_index - ocfs2_xattr_get_type(entry);
        if (!cmp)
            cmp = name_len - entry->xe_name_len;
        if (!cmp)
            cmp = memcmp(name, (xs->base +
                     le16_to_cpu(entry->xe_name_offset)),
                     name_len);
        if (cmp == 0)
            break;
        entry += 1;
    }
    xs->here = entry;

    return cmp ? -ENODATA : 0;
}

static int ocfs2_xattr_get_value_outside(struct inode *inode,
                     struct ocfs2_xattr_value_root *xv,
                     void *buffer,
                     size_t len)
{
    u32 cpos, p_cluster, num_clusters, bpc, clusters;
    u64 blkno;
    int i, ret = 0;
    size_t cplen, blocksize;
    struct buffer_head *bh = NULL;
    struct ocfs2_extent_list *el;

    el = &xv->xr_list;
    clusters = le32_to_cpu(xv->xr_clusters);
    bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
    blocksize = inode->i_sb->s_blocksize;

    cpos = 0;
    while (cpos < clusters) {
        ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
                           &num_clusters, el, NULL);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);
        /* Copy ocfs2_xattr_value */
        for (i = 0; i < num_clusters * bpc; i++, blkno++) {
            ret = ocfs2_read_block(INODE_CACHE(inode), blkno,
                           &bh, NULL);
            if (ret) {
                mlog_errno(ret);
                goto out;
            }

            cplen = len >= blocksize ? blocksize : len;
            memcpy(buffer, bh->b_data, cplen);
            len -= cplen;
            buffer += cplen;

            brelse(bh);
            bh = NULL;
            if (len == 0)
                break;
        }
        cpos += num_clusters;
    }
out:
    return ret;
}

static int ocfs2_xattr_ibody_get(struct inode *inode,
                 int name_index,
                 const char *name,
                 void *buffer,
                 size_t buffer_size,
                 struct ocfs2_xattr_search *xs)
{
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
    struct ocfs2_xattr_value_root *xv;
    size_t size;
    int ret = 0;

    if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL))
        return -ENODATA;

    xs->end = (void *)di + inode->i_sb->s_blocksize;
    xs->header = (struct ocfs2_xattr_header *)
            (xs->end - le16_to_cpu(di->i_xattr_inline_size));
    xs->base = (void *)xs->header;
    xs->here = xs->header->xh_entries;

    ret = ocfs2_xattr_find_entry(name_index, name, xs);
    if (ret)
        return ret;
    size = le64_to_cpu(xs->here->xe_value_size);
    if (buffer) {
        if (size > buffer_size)
            return -ERANGE;
        if (ocfs2_xattr_is_local(xs->here)) {
            memcpy(buffer, (void *)xs->base +
                   le16_to_cpu(xs->here->xe_name_offset) +
                   OCFS2_XATTR_SIZE(xs->here->xe_name_len), size);
        } else {
            xv = (struct ocfs2_xattr_value_root *)
                (xs->base + le16_to_cpu(
                 xs->here->xe_name_offset) +
                OCFS2_XATTR_SIZE(xs->here->xe_name_len));
            ret = ocfs2_xattr_get_value_outside(inode, xv,
                                buffer, size);
            if (ret < 0) {
                mlog_errno(ret);
                return ret;
            }
        }
    }

    return size;
}

static int ocfs2_xattr_block_get(struct inode *inode,
                 int name_index,
                 const char *name,
                 void *buffer,
                 size_t buffer_size,
                 struct ocfs2_xattr_search *xs)
{
    struct ocfs2_xattr_block *xb;
    struct ocfs2_xattr_value_root *xv;
    size_t size;
    int ret = -ENODATA, name_offset, name_len, i;
    int uninitialized_var(block_off);

    xs->bucket = ocfs2_xattr_bucket_new(inode);
    if (!xs->bucket) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto cleanup;
    }

    ret = ocfs2_xattr_block_find(inode, name_index, name, xs);
    if (ret) {
        mlog_errno(ret);
        goto cleanup;
    }

    if (xs->not_found) {
        ret = -ENODATA;
        goto cleanup;
    }

    xb = (struct ocfs2_xattr_block *)xs->xattr_bh->b_data;
    size = le64_to_cpu(xs->here->xe_value_size);
    if (buffer) {
        ret = -ERANGE;
        if (size > buffer_size)
            goto cleanup;

        name_offset = le16_to_cpu(xs->here->xe_name_offset);
        name_len = OCFS2_XATTR_SIZE(xs->here->xe_name_len);
        i = xs->here - xs->header->xh_entries;

        if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
            ret = ocfs2_xattr_bucket_get_name_value(inode->i_sb,
                                bucket_xh(xs->bucket),
                                i,
                                &block_off,
                                &name_offset);
            xs->base = bucket_block(xs->bucket, block_off);
        }
        if (ocfs2_xattr_is_local(xs->here)) {
            memcpy(buffer, (void *)xs->base +
                   name_offset + name_len, size);
        } else {
            xv = (struct ocfs2_xattr_value_root *)
                (xs->base + name_offset + name_len);
            ret = ocfs2_xattr_get_value_outside(inode, xv,
                                buffer, size);
            if (ret < 0) {
                mlog_errno(ret);
                goto cleanup;
            }
        }
    }
    ret = size;
cleanup:
    ocfs2_xattr_bucket_free(xs->bucket);

    brelse(xs->xattr_bh);
    xs->xattr_bh = NULL;
    return ret;
}

int ocfs2_xattr_get_nolock(struct inode *inode,
               struct buffer_head *di_bh,
               int name_index,
               const char *name,
               void *buffer,
               size_t buffer_size)
{
    int ret;
    struct ocfs2_dinode *di = NULL;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_xattr_search xis = {
        .not_found = -ENODATA,
    };
    struct ocfs2_xattr_search xbs = {
        .not_found = -ENODATA,
    };

    if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
        return -EOPNOTSUPP;

    if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
        ret = -ENODATA;

    xis.inode_bh = xbs.inode_bh = di_bh;
    di = (struct ocfs2_dinode *)di_bh->b_data;

    ret = ocfs2_xattr_ibody_get(inode, name_index, name, buffer,
                    buffer_size, &xis);
    if (ret == -ENODATA && di->i_xattr_loc)
        ret = ocfs2_xattr_block_get(inode, name_index, name, buffer,
                        buffer_size, &xbs);

    return ret;
}

/* ocfs2_xattr_get()
 *
 * Copy an extended attribute into the buffer provided.
 * Buffer is NULL to compute the size of buffer required.
 */
static int ocfs2_xattr_get(struct inode *inode,
               int name_index,
               const char *name,
               void *buffer,
               size_t buffer_size)
{
    int ret;
    struct buffer_head *di_bh = NULL;

    ret = ocfs2_inode_lock(inode, &di_bh, 0);
    if (ret < 0) {
        mlog_errno(ret);
        return ret;
    }
    down_read(&OCFS2_I(inode)->ip_xattr_sem);
    ret = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
                     name, buffer, buffer_size);
    up_read(&OCFS2_I(inode)->ip_xattr_sem);

    ocfs2_inode_unlock(inode, 0);

    brelse(di_bh);

    return ret;
}

static int __ocfs2_xattr_set_value_outside(struct inode *inode,
                       handle_t *handle,
                       struct ocfs2_xattr_value_buf *vb,
                       const void *value,
                       int value_len)
{
    int ret = 0, i, cp_len;
    u16 blocksize = inode->i_sb->s_blocksize;
    u32 p_cluster, num_clusters;
    u32 cpos = 0, bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
    u32 clusters = ocfs2_clusters_for_bytes(inode->i_sb, value_len);
    u64 blkno;
    struct buffer_head *bh = NULL;
    unsigned int ext_flags;
    struct ocfs2_xattr_value_root *xv = vb->vb_xv;

    BUG_ON(clusters > le32_to_cpu(xv->xr_clusters));

    while (cpos < clusters) {
        ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
                           &num_clusters, &xv->xr_list,
                           &ext_flags);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);

        blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);

        for (i = 0; i < num_clusters * bpc; i++, blkno++) {
            ret = ocfs2_read_block(INODE_CACHE(inode), blkno,
                           &bh, NULL);
            if (ret) {
                mlog_errno(ret);
                goto out;
            }

            ret = ocfs2_journal_access(handle,
                           INODE_CACHE(inode),
                           bh,
                           OCFS2_JOURNAL_ACCESS_WRITE);
            if (ret < 0) {
                mlog_errno(ret);
                goto out;
            }

            cp_len = value_len > blocksize ? blocksize : value_len;
            memcpy(bh->b_data, value, cp_len);
            value_len -= cp_len;
            value += cp_len;
            if (cp_len < blocksize)
                memset(bh->b_data + cp_len, 0,
                       blocksize - cp_len);

            ocfs2_journal_dirty(handle, bh);
            brelse(bh);
            bh = NULL;

            /*
             * XXX: do we need to empty all the following
             * blocks in this cluster?
             */
            if (!value_len)
                break;
        }
        cpos += num_clusters;
    }
out:
    brelse(bh);

    return ret;
}

static int ocfs2_xa_check_space_helper(int needed_space, int free_start,
                       int num_entries)
{
    int free_space;

    if (!needed_space)
        return 0;

    free_space = free_start -
        sizeof(struct ocfs2_xattr_header) -
        (num_entries * sizeof(struct ocfs2_xattr_entry)) -
        OCFS2_XATTR_HEADER_GAP;
    if (free_space < 0)
        return -EIO;
    if (free_space < needed_space)
        return -ENOSPC;

    return 0;
}

static int ocfs2_xa_journal_access(handle_t *handle, struct ocfs2_xa_loc *loc,
                   int type)
{
    return loc->xl_ops->xlo_journal_access(handle, loc, type);
}

static void ocfs2_xa_journal_dirty(handle_t *handle, struct ocfs2_xa_loc *loc)
{
    loc->xl_ops->xlo_journal_dirty(handle, loc);
}

/* Give a pointer into the storage for the given offset */
static void *ocfs2_xa_offset_pointer(struct ocfs2_xa_loc *loc, int offset)
{
    BUG_ON(offset >= loc->xl_size);
    return loc->xl_ops->xlo_offset_pointer(loc, offset);
}

/*
 * Wipe the name+value pair and allow the storage to reclaim it.  This
 * must be followed by either removal of the entry or a call to
 * ocfs2_xa_add_namevalue().
 */
static void ocfs2_xa_wipe_namevalue(struct ocfs2_xa_loc *loc)
{
    loc->xl_ops->xlo_wipe_namevalue(loc);
}

/*
 * Find lowest offset to a name+value pair.  This is the start of our
 * downward-growing free space.
 */
static int ocfs2_xa_get_free_start(struct ocfs2_xa_loc *loc)
{
    return loc->xl_ops->xlo_get_free_start(loc);
}

/* Can we reuse loc->xl_entry for xi? */
static int ocfs2_xa_can_reuse_entry(struct ocfs2_xa_loc *loc,
                    struct ocfs2_xattr_info *xi)
{
    return loc->xl_ops->xlo_can_reuse(loc, xi);
}

/* How much free space is needed to set the new value */
static int ocfs2_xa_check_space(struct ocfs2_xa_loc *loc,
                struct ocfs2_xattr_info *xi)
{
    return loc->xl_ops->xlo_check_space(loc, xi);
}

static void ocfs2_xa_add_entry(struct ocfs2_xa_loc *loc, u32 name_hash)
{
    loc->xl_ops->xlo_add_entry(loc, name_hash);
    loc->xl_entry->xe_name_hash = cpu_to_le32(name_hash);
    /*
     * We can't leave the new entry's xe_name_offset at zero or
     * add_namevalue() will go nuts.  We set it to the size of our
     * storage so that it can never be less than any other entry.
     */
    loc->xl_entry->xe_name_offset = cpu_to_le16(loc->xl_size);
}

static void ocfs2_xa_add_namevalue(struct ocfs2_xa_loc *loc,
                   struct ocfs2_xattr_info *xi)
{
    int size = namevalue_size_xi(xi);
    int nameval_offset;
    char *nameval_buf;

    loc->xl_ops->xlo_add_namevalue(loc, size);
    loc->xl_entry->xe_value_size = cpu_to_le64(xi->xi_value_len);
    loc->xl_entry->xe_name_len = xi->xi_name_len;
    ocfs2_xattr_set_type(loc->xl_entry, xi->xi_name_index);
    ocfs2_xattr_set_local(loc->xl_entry,
                  xi->xi_value_len <= OCFS2_XATTR_INLINE_SIZE);

    nameval_offset = le16_to_cpu(loc->xl_entry->xe_name_offset);
    nameval_buf = ocfs2_xa_offset_pointer(loc, nameval_offset);
    memset(nameval_buf, 0, size);
    memcpy(nameval_buf, xi->xi_name, xi->xi_name_len);
}

static void ocfs2_xa_fill_value_buf(struct ocfs2_xa_loc *loc,
                    struct ocfs2_xattr_value_buf *vb)
{
    int nameval_offset = le16_to_cpu(loc->xl_entry->xe_name_offset);
    int name_size = OCFS2_XATTR_SIZE(loc->xl_entry->xe_name_len);

    /* Value bufs are for value trees */
    BUG_ON(ocfs2_xattr_is_local(loc->xl_entry));
    BUG_ON(namevalue_size_xe(loc->xl_entry) !=
           (name_size + OCFS2_XATTR_ROOT_SIZE));

    loc->xl_ops->xlo_fill_value_buf(loc, vb);
    vb->vb_xv =
        (struct ocfs2_xattr_value_root *)ocfs2_xa_offset_pointer(loc,
                            nameval_offset +
                            name_size);
}

static int ocfs2_xa_block_journal_access(handle_t *handle,
                     struct ocfs2_xa_loc *loc, int type)
{
    struct buffer_head *bh = loc->xl_storage;
    ocfs2_journal_access_func access;

    if (loc->xl_size == (bh->b_size -
                 offsetof(struct ocfs2_xattr_block,
                      xb_attrs.xb_header)))
        access = ocfs2_journal_access_xb;
    else
        access = ocfs2_journal_access_di;
    return access(handle, INODE_CACHE(loc->xl_inode), bh, type);
}

static void ocfs2_xa_block_journal_dirty(handle_t *handle,
                     struct ocfs2_xa_loc *loc)
{
    struct buffer_head *bh = loc->xl_storage;

    ocfs2_journal_dirty(handle, bh);
}

static void *ocfs2_xa_block_offset_pointer(struct ocfs2_xa_loc *loc,
                       int offset)
{
    return (char *)loc->xl_header + offset;
}

static int ocfs2_xa_block_can_reuse(struct ocfs2_xa_loc *loc,
                    struct ocfs2_xattr_info *xi)
{
    /*
     * Block storage is strict.  If the sizes aren't exact, we will
     * remove the old one and reinsert the new.
     */
    return namevalue_size_xe(loc->xl_entry) ==
        namevalue_size_xi(xi);
}

static int ocfs2_xa_block_get_free_start(struct ocfs2_xa_loc *loc)
{
    struct ocfs2_xattr_header *xh = loc->xl_header;
    int i, count = le16_to_cpu(xh->xh_count);
    int offset, free_start = loc->xl_size;

    for (i = 0; i < count; i++) {
        offset = le16_to_cpu(xh->xh_entries[i].xe_name_offset);
        if (offset < free_start)
            free_start = offset;
    }

    return free_start;
}

static int ocfs2_xa_block_check_space(struct ocfs2_xa_loc *loc,
                      struct ocfs2_xattr_info *xi)
{
    int count = le16_to_cpu(loc->xl_header->xh_count);
    int free_start = ocfs2_xa_get_free_start(loc);
    int needed_space = ocfs2_xi_entry_usage(xi);

    /*
     * Block storage will reclaim the original entry before inserting
     * the new value, so we only need the difference.  If the new
     * entry is smaller than the old one, we don't need anything.
     */
    if (loc->xl_entry) {
        /* Don't need space if we're reusing! */
        if (ocfs2_xa_can_reuse_entry(loc, xi))
            needed_space = 0;
        else
            needed_space -= ocfs2_xe_entry_usage(loc->xl_entry);
    }
    if (needed_space < 0)
        needed_space = 0;
    return ocfs2_xa_check_space_helper(needed_space, free_start, count);
}

/*
 * Block storage for xattrs keeps the name+value pairs compacted.  When
 * we remove one, we have to shift any that preceded it towards the end.
 */
static void ocfs2_xa_block_wipe_namevalue(struct ocfs2_xa_loc *loc)
{
    int i, offset;
    int namevalue_offset, first_namevalue_offset, namevalue_size;
    struct ocfs2_xattr_entry *entry = loc->xl_entry;
    struct ocfs2_xattr_header *xh = loc->xl_header;
    int count = le16_to_cpu(xh->xh_count);

    namevalue_offset = le16_to_cpu(entry->xe_name_offset);
    namevalue_size = namevalue_size_xe(entry);
    first_namevalue_offset = ocfs2_xa_get_free_start(loc);

    /* Shift the name+value pairs */
    memmove((char *)xh + first_namevalue_offset + namevalue_size,
        (char *)xh + first_namevalue_offset,
        namevalue_offset - first_namevalue_offset);
    memset((char *)xh + first_namevalue_offset, 0, namevalue_size);

    /* Now tell xh->xh_entries about it */
    for (i = 0; i < count; i++) {
        offset = le16_to_cpu(xh->xh_entries[i].xe_name_offset);
        if (offset <= namevalue_offset)
            le16_add_cpu(&xh->xh_entries[i].xe_name_offset,
                     namevalue_size);
    }

    /*
     * Note that we don't update xh_free_start or xh_name_value_len
     * because they're not used in block-stored xattrs.
     */
}

static void ocfs2_xa_block_add_entry(struct ocfs2_xa_loc *loc, u32 name_hash)
{
    int count = le16_to_cpu(loc->xl_header->xh_count);
    loc->xl_entry = &(loc->xl_header->xh_entries[count]);
    le16_add_cpu(&loc->xl_header->xh_count, 1);
    memset(loc->xl_entry, 0, sizeof(struct ocfs2_xattr_entry));
}

static void ocfs2_xa_block_add_namevalue(struct ocfs2_xa_loc *loc, int size)
{
    int free_start = ocfs2_xa_get_free_start(loc);

    loc->xl_entry->xe_name_offset = cpu_to_le16(free_start - size);
}

static void ocfs2_xa_block_fill_value_buf(struct ocfs2_xa_loc *loc,
                      struct ocfs2_xattr_value_buf *vb)
{
    struct buffer_head *bh = loc->xl_storage;

    if (loc->xl_size == (bh->b_size -
                 offsetof(struct ocfs2_xattr_block,
                      xb_attrs.xb_header)))
        vb->vb_access = ocfs2_journal_access_xb;
    else
        vb->vb_access = ocfs2_journal_access_di;
    vb->vb_bh = bh;
}

/*
 * Operations for xattrs stored in blocks.  This includes inline inode
 * storage and unindexed ocfs2_xattr_blocks.
 */
static const struct ocfs2_xa_loc_operations ocfs2_xa_block_loc_ops = {
    .xlo_journal_access = ocfs2_xa_block_journal_access,
    .xlo_journal_dirty  = ocfs2_xa_block_journal_dirty,
    .xlo_offset_pointer = ocfs2_xa_block_offset_pointer,
    .xlo_check_space    = ocfs2_xa_block_check_space,
    .xlo_can_reuse      = ocfs2_xa_block_can_reuse,
    .xlo_get_free_start = ocfs2_xa_block_get_free_start,
    .xlo_wipe_namevalue = ocfs2_xa_block_wipe_namevalue,
    .xlo_add_entry      = ocfs2_xa_block_add_entry,
    .xlo_add_namevalue  = ocfs2_xa_block_add_namevalue,
    .xlo_fill_value_buf = ocfs2_xa_block_fill_value_buf,
};

static int ocfs2_xa_bucket_journal_access(handle_t *handle,
                      struct ocfs2_xa_loc *loc, int type)
{
    struct ocfs2_xattr_bucket *bucket = loc->xl_storage;

    return ocfs2_xattr_bucket_journal_access(handle, bucket, type);
}

static void ocfs2_xa_bucket_journal_dirty(handle_t *handle,
                      struct ocfs2_xa_loc *loc)
{
    struct ocfs2_xattr_bucket *bucket = loc->xl_storage;

    ocfs2_xattr_bucket_journal_dirty(handle, bucket);
}

static void *ocfs2_xa_bucket_offset_pointer(struct ocfs2_xa_loc *loc,
                        int offset)
{
    struct ocfs2_xattr_bucket *bucket = loc->xl_storage;
    int block, block_offset;

    /* The header is at the front of the bucket */
    block = offset >> loc->xl_inode->i_sb->s_blocksize_bits;
    block_offset = offset % loc->xl_inode->i_sb->s_blocksize;

    return bucket_block(bucket, block) + block_offset;
}

static int ocfs2_xa_bucket_can_reuse(struct ocfs2_xa_loc *loc,
                     struct ocfs2_xattr_info *xi)
{
    return namevalue_size_xe(loc->xl_entry) >=
        namevalue_size_xi(xi);
}

static int ocfs2_xa_bucket_get_free_start(struct ocfs2_xa_loc *loc)
{
    struct ocfs2_xattr_bucket *bucket = loc->xl_storage;
    return le16_to_cpu(bucket_xh(bucket)->xh_free_start);
}

static int ocfs2_bucket_align_free_start(struct super_block *sb,
                     int free_start, int size)
{
    /*
     * We need to make sure that the name+value pair fits within
     * one block.
     */
    if (((free_start - size) >> sb->s_blocksize_bits) !=
        ((free_start - 1) >> sb->s_blocksize_bits))
        free_start -= free_start % sb->s_blocksize;

    return free_start;
}

static int ocfs2_xa_bucket_check_space(struct ocfs2_xa_loc *loc,
                       struct ocfs2_xattr_info *xi)
{
    int rc;
    int count = le16_to_cpu(loc->xl_header->xh_count);
    int free_start = ocfs2_xa_get_free_start(loc);
    int needed_space = ocfs2_xi_entry_usage(xi);
    int size = namevalue_size_xi(xi);
    struct super_block *sb = loc->xl_inode->i_sb;

    /*
     * Bucket storage does not reclaim name+value pairs it cannot
     * reuse.  They live as holes until the bucket fills, and then
     * the bucket is defragmented.  However, the bucket can reclaim
     * the ocfs2_xattr_entry.
     */
    if (loc->xl_entry) {
        /* Don't need space if we're reusing! */
        if (ocfs2_xa_can_reuse_entry(loc, xi))
            needed_space = 0;
        else
            needed_space -= sizeof(struct ocfs2_xattr_entry);
    }
    BUG_ON(needed_space < 0);

    if (free_start < size) {
        if (needed_space)
            return -ENOSPC;
    } else {
        /*
         * First we check if it would fit in the first place.
         * Below, we align the free start to a block.  This may
         * slide us below the minimum gap.  By checking unaligned
         * first, we avoid that error.
         */
        rc = ocfs2_xa_check_space_helper(needed_space, free_start,
                         count);
        if (rc)
            return rc;
        free_start = ocfs2_bucket_align_free_start(sb, free_start,
                               size);
    }
    return ocfs2_xa_check_space_helper(needed_space, free_start, count);
}

static void ocfs2_xa_bucket_wipe_namevalue(struct ocfs2_xa_loc *loc)
{
    le16_add_cpu(&loc->xl_header->xh_name_value_len,
             -namevalue_size_xe(loc->xl_entry));
}

static void ocfs2_xa_bucket_add_entry(struct ocfs2_xa_loc *loc, u32 name_hash)
{
    struct ocfs2_xattr_header *xh = loc->xl_header;
    int count = le16_to_cpu(xh->xh_count);
    int low = 0, high = count - 1, tmp;
    struct ocfs2_xattr_entry *tmp_xe;

    /*
     * We keep buckets sorted by name_hash, so we need to find
     * our insert place.
     */
    while (low <= high && count) {
        tmp = (low + high) / 2;
        tmp_xe = &xh->xh_entries[tmp];

        if (name_hash > le32_to_cpu(tmp_xe->xe_name_hash))
            low = tmp + 1;
        else if (name_hash < le32_to_cpu(tmp_xe->xe_name_hash))
            high = tmp - 1;
        else {
            low = tmp;
            break;
        }
    }

    if (low != count)
        memmove(&xh->xh_entries[low + 1],
            &xh->xh_entries[low],
            ((count - low) * sizeof(struct ocfs2_xattr_entry)));

    le16_add_cpu(&xh->xh_count, 1);
    loc->xl_entry = &xh->xh_entries[low];
    memset(loc->xl_entry, 0, sizeof(struct ocfs2_xattr_entry));
}

static void ocfs2_xa_bucket_add_namevalue(struct ocfs2_xa_loc *loc, int size)
{
    int free_start = ocfs2_xa_get_free_start(loc);
    struct ocfs2_xattr_header *xh = loc->xl_header;
    struct super_block *sb = loc->xl_inode->i_sb;
    int nameval_offset;

    free_start = ocfs2_bucket_align_free_start(sb, free_start, size);
    nameval_offset = free_start - size;
    loc->xl_entry->xe_name_offset = cpu_to_le16(nameval_offset);
    xh->xh_free_start = cpu_to_le16(nameval_offset);
    le16_add_cpu(&xh->xh_name_value_len, size);

}

static void ocfs2_xa_bucket_fill_value_buf(struct ocfs2_xa_loc *loc,
                       struct ocfs2_xattr_value_buf *vb)
{
    struct ocfs2_xattr_bucket *bucket = loc->xl_storage;
    struct super_block *sb = loc->xl_inode->i_sb;
    int nameval_offset = le16_to_cpu(loc->xl_entry->xe_name_offset);
    int size = namevalue_size_xe(loc->xl_entry);
    int block_offset = nameval_offset >> sb->s_blocksize_bits;

    /* Values are not allowed to straddle block boundaries */
    BUG_ON(block_offset !=
           ((nameval_offset + size - 1) >> sb->s_blocksize_bits));
    /* We expect the bucket to be filled in */
    BUG_ON(!bucket->bu_bhs[block_offset]);

    vb->vb_access = ocfs2_journal_access;
    vb->vb_bh = bucket->bu_bhs[block_offset];
}

/* Operations for xattrs stored in buckets. */
static const struct ocfs2_xa_loc_operations ocfs2_xa_bucket_loc_ops = {
    .xlo_journal_access = ocfs2_xa_bucket_journal_access,
    .xlo_journal_dirty  = ocfs2_xa_bucket_journal_dirty,
    .xlo_offset_pointer = ocfs2_xa_bucket_offset_pointer,
    .xlo_check_space    = ocfs2_xa_bucket_check_space,
    .xlo_can_reuse      = ocfs2_xa_bucket_can_reuse,
    .xlo_get_free_start = ocfs2_xa_bucket_get_free_start,
    .xlo_wipe_namevalue = ocfs2_xa_bucket_wipe_namevalue,
    .xlo_add_entry      = ocfs2_xa_bucket_add_entry,
    .xlo_add_namevalue  = ocfs2_xa_bucket_add_namevalue,
    .xlo_fill_value_buf = ocfs2_xa_bucket_fill_value_buf,
};

static unsigned int ocfs2_xa_value_clusters(struct ocfs2_xa_loc *loc)
{
    struct ocfs2_xattr_value_buf vb;

    if (ocfs2_xattr_is_local(loc->xl_entry))
        return 0;

    ocfs2_xa_fill_value_buf(loc, &vb);
    return le32_to_cpu(vb.vb_xv->xr_clusters);
}

static int ocfs2_xa_value_truncate(struct ocfs2_xa_loc *loc, u64 bytes,
                   struct ocfs2_xattr_set_ctxt *ctxt)
{
    int trunc_rc, access_rc;
    struct ocfs2_xattr_value_buf vb;

    ocfs2_xa_fill_value_buf(loc, &vb);
    trunc_rc = ocfs2_xattr_value_truncate(loc->xl_inode, &vb, bytes,
                          ctxt);

    /*
     * The caller of ocfs2_xa_value_truncate() has already called
     * ocfs2_xa_journal_access on the loc.  However, The truncate code
     * calls ocfs2_extend_trans().  This may commit the previous
     * transaction and open a new one.  If this is a bucket, truncate
     * could leave only vb->vb_bh set up for journaling.  Meanwhile,
     * the caller is expecting to dirty the entire bucket.  So we must
     * reset the journal work.  We do this even if truncate has failed,
     * as it could have failed after committing the extend.
     */
    access_rc = ocfs2_xa_journal_access(ctxt->handle, loc,
                        OCFS2_JOURNAL_ACCESS_WRITE);

    /* Errors in truncate take precedence */
    return trunc_rc ? trunc_rc : access_rc;
}

static void ocfs2_xa_remove_entry(struct ocfs2_xa_loc *loc)
{
    int index, count;
    struct ocfs2_xattr_header *xh = loc->xl_header;
    struct ocfs2_xattr_entry *entry = loc->xl_entry;

    ocfs2_xa_wipe_namevalue(loc);
    loc->xl_entry = NULL;

    le16_add_cpu(&xh->xh_count, -1);
    count = le16_to_cpu(xh->xh_count);

    /*
     * Only zero out the entry if there are more remaining.  This is
     * important for an empty bucket, as it keeps track of the
     * bucket's hash value.  It doesn't hurt empty block storage.
     */
    if (count) {
        index = ((char *)entry - (char *)&xh->xh_entries) /
            sizeof(struct ocfs2_xattr_entry);
        memmove(&xh->xh_entries[index], &xh->xh_entries[index + 1],
            (count - index) * sizeof(struct ocfs2_xattr_entry));
        memset(&xh->xh_entries[count], 0,
               sizeof(struct ocfs2_xattr_entry));
    }
}

/*
 * If we have a problem adjusting the size of an external value during
 * ocfs2_xa_prepare_entry() or ocfs2_xa_remove(), we may have an xattr
 * in an intermediate state.  For example, the value may be partially
 * truncated.
 *
 * If the value tree hasn't changed, the extend/truncate went nowhere.
 * We have nothing to do.  The caller can treat it as a straight error.
 *
 * If the value tree got partially truncated, we now have a corrupted
 * extended attribute.  We're going to wipe its entry and leak the
 * clusters.  Better to leak some storage than leave a corrupt entry.
 *
 * If the value tree grew, it obviously didn't grow enough for the
 * new entry.  We're not going to try and reclaim those clusters either.
 * If there was already an external value there (orig_clusters != 0),
 * the new clusters are attached safely and we can just leave the old
 * value in place.  If there was no external value there, we remove
 * the entry.
 *
 * This way, the xattr block we store in the journal will be consistent.
 * If the size change broke because of the journal, no changes will hit
 * disk anyway.
 */
static void ocfs2_xa_cleanup_value_truncate(struct ocfs2_xa_loc *loc,
                        const char *what,
                        unsigned int orig_clusters)
{
    unsigned int new_clusters = ocfs2_xa_value_clusters(loc);
    char *nameval_buf = ocfs2_xa_offset_pointer(loc,
                le16_to_cpu(loc->xl_entry->xe_name_offset));

    if (new_clusters < orig_clusters) {
        mlog(ML_ERROR,
             "Partial truncate while %s xattr %.*s.  Leaking "
             "%u clusters and removing the entry\n",
             what, loc->xl_entry->xe_name_len, nameval_buf,
             orig_clusters - new_clusters);
        ocfs2_xa_remove_entry(loc);
    } else if (!orig_clusters) {
        mlog(ML_ERROR,
             "Unable to allocate an external value for xattr "
             "%.*s safely.  Leaking %u clusters and removing the "
             "entry\n",
             loc->xl_entry->xe_name_len, nameval_buf,
             new_clusters - orig_clusters);
        ocfs2_xa_remove_entry(loc);
    } else if (new_clusters > orig_clusters)
        mlog(ML_ERROR,
             "Unable to grow xattr %.*s safely.  %u new clusters "
             "have been added, but the value will not be "
             "modified\n",
             loc->xl_entry->xe_name_len, nameval_buf,
             new_clusters - orig_clusters);
}

static int ocfs2_xa_remove(struct ocfs2_xa_loc *loc,
               struct ocfs2_xattr_set_ctxt *ctxt)
{
    int rc = 0;
    unsigned int orig_clusters;

    if (!ocfs2_xattr_is_local(loc->xl_entry)) {
        orig_clusters = ocfs2_xa_value_clusters(loc);
        rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
        if (rc) {
            mlog_errno(rc);
            /*
             * Since this is remove, we can return 0 if
             * ocfs2_xa_cleanup_value_truncate() is going to
             * wipe the entry anyway.  So we check the
             * cluster count as well.
             */
            if (orig_clusters != ocfs2_xa_value_clusters(loc))
                rc = 0;
            ocfs2_xa_cleanup_value_truncate(loc, "removing",
                            orig_clusters);
            if (rc)
                goto out;
        }
    }

    ocfs2_xa_remove_entry(loc);

out:
    return rc;
}

static void ocfs2_xa_install_value_root(struct ocfs2_xa_loc *loc)
{
    int name_size = OCFS2_XATTR_SIZE(loc->xl_entry->xe_name_len);
    char *nameval_buf;

    nameval_buf = ocfs2_xa_offset_pointer(loc,
                le16_to_cpu(loc->xl_entry->xe_name_offset));
    memcpy(nameval_buf + name_size, &def_xv, OCFS2_XATTR_ROOT_SIZE);
}

/*
 * Take an existing entry and make it ready for the new value.  This
 * won't allocate space, but it may free space.  It should be ready for
 * ocfs2_xa_prepare_entry() to finish the work.
 */
static int ocfs2_xa_reuse_entry(struct ocfs2_xa_loc *loc,
                struct ocfs2_xattr_info *xi,
                struct ocfs2_xattr_set_ctxt *ctxt)
{
    int rc = 0;
    int name_size = OCFS2_XATTR_SIZE(xi->xi_name_len);
    unsigned int orig_clusters;
    char *nameval_buf;
    int xe_local = ocfs2_xattr_is_local(loc->xl_entry);
    int xi_local = xi->xi_value_len <= OCFS2_XATTR_INLINE_SIZE;

    BUG_ON(OCFS2_XATTR_SIZE(loc->xl_entry->xe_name_len) !=
           name_size);

    nameval_buf = ocfs2_xa_offset_pointer(loc,
                le16_to_cpu(loc->xl_entry->xe_name_offset));
    if (xe_local) {
        memset(nameval_buf + name_size, 0,
               namevalue_size_xe(loc->xl_entry) - name_size);
        if (!xi_local)
            ocfs2_xa_install_value_root(loc);
    } else {
        orig_clusters = ocfs2_xa_value_clusters(loc);
        if (xi_local) {
            rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
            if (rc < 0)
                mlog_errno(rc);
            else
                memset(nameval_buf + name_size, 0,
                       namevalue_size_xe(loc->xl_entry) -
                       name_size);
        } else if (le64_to_cpu(loc->xl_entry->xe_value_size) >
               xi->xi_value_len) {
            rc = ocfs2_xa_value_truncate(loc, xi->xi_value_len,
                             ctxt);
            if (rc < 0)
                mlog_errno(rc);
        }

        if (rc) {
            ocfs2_xa_cleanup_value_truncate(loc, "reusing",
                            orig_clusters);
            goto out;
        }
    }

    loc->xl_entry->xe_value_size = cpu_to_le64(xi->xi_value_len);
    ocfs2_xattr_set_local(loc->xl_entry, xi_local);

out:
    return rc;
}

/*
 * Prepares loc->xl_entry to receive the new xattr.  This includes
 * properly setting up the name+value pair region.  If loc->xl_entry
 * already exists, it will take care of modifying it appropriately.
 *
 * Note that this modifies the data.  You did journal_access already,
 * right?
 */
static int ocfs2_xa_prepare_entry(struct ocfs2_xa_loc *loc,
                  struct ocfs2_xattr_info *xi,
                  u32 name_hash,
                  struct ocfs2_xattr_set_ctxt *ctxt)
{
    int rc = 0;
    unsigned int orig_clusters;
    __le64 orig_value_size = 0;

    rc = ocfs2_xa_check_space(loc, xi);
    if (rc)
        goto out;

    if (loc->xl_entry) {
        if (ocfs2_xa_can_reuse_entry(loc, xi)) {
            orig_value_size = loc->xl_entry->xe_value_size;
            rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
            if (rc)
                goto out;
            goto alloc_value;
        }

        if (!ocfs2_xattr_is_local(loc->xl_entry)) {
            orig_clusters = ocfs2_xa_value_clusters(loc);
            rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
            if (rc) {
                mlog_errno(rc);
                ocfs2_xa_cleanup_value_truncate(loc,
                                "overwriting",
                                orig_clusters);
                goto out;
            }
        }
        ocfs2_xa_wipe_namevalue(loc);
    } else
        ocfs2_xa_add_entry(loc, name_hash);

    /*
     * If we get here, we have a blank entry.  Fill it.  We grow our
     * name+value pair back from the end.
     */
    ocfs2_xa_add_namevalue(loc, xi);
    if (xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE)
        ocfs2_xa_install_value_root(loc);

alloc_value:
    if (xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE) {
        orig_clusters = ocfs2_xa_value_clusters(loc);
        rc = ocfs2_xa_value_truncate(loc, xi->xi_value_len, ctxt);
        if (rc < 0) {
            ctxt->set_abort = 1;
            ocfs2_xa_cleanup_value_truncate(loc, "growing",
                            orig_clusters);
            /*
             * If we were growing an existing value,
             * ocfs2_xa_cleanup_value_truncate() won't remove
             * the entry. We need to restore the original value
             * size.
             */
            if (loc->xl_entry) {
                BUG_ON(!orig_value_size);
                loc->xl_entry->xe_value_size = orig_value_size;
            }
            mlog_errno(rc);
        }
    }

out:
    return rc;
}

/*
 * Store the value portion of the name+value pair.  This will skip
 * values that are stored externally.  Their tree roots were set up
 * by ocfs2_xa_prepare_entry().
 */
static int ocfs2_xa_store_value(struct ocfs2_xa_loc *loc,
                struct ocfs2_xattr_info *xi,
                struct ocfs2_xattr_set_ctxt *ctxt)
{
    int rc = 0;
    int nameval_offset = le16_to_cpu(loc->xl_entry->xe_name_offset);
    int name_size = OCFS2_XATTR_SIZE(xi->xi_name_len);
    char *nameval_buf;
    struct ocfs2_xattr_value_buf vb;

    nameval_buf = ocfs2_xa_offset_pointer(loc, nameval_offset);
    if (xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE) {
        ocfs2_xa_fill_value_buf(loc, &vb);
        rc = __ocfs2_xattr_set_value_outside(loc->xl_inode,
                             ctxt->handle, &vb,
                             xi->xi_value,
                             xi->xi_value_len);
    } else
        memcpy(nameval_buf + name_size, xi->xi_value, xi->xi_value_len);

    return rc;
}

static int ocfs2_xa_set(struct ocfs2_xa_loc *loc,
            struct ocfs2_xattr_info *xi,
            struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;
    u32 name_hash = ocfs2_xattr_name_hash(loc->xl_inode, xi->xi_name,
                          xi->xi_name_len);

    ret = ocfs2_xa_journal_access(ctxt->handle, loc,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * From here on out, everything is going to modify the buffer a
     * little.  Errors are going to leave the xattr header in a
     * sane state.  Thus, even with errors we dirty the sucker.
     */

    /* Don't worry, we are never called with !xi_value and !xl_entry */
    if (!xi->xi_value) {
        ret = ocfs2_xa_remove(loc, ctxt);
        goto out_dirty;
    }

    ret = ocfs2_xa_prepare_entry(loc, xi, name_hash, ctxt);
    if (ret) {
        if (ret != -ENOSPC)
            mlog_errno(ret);
        goto out_dirty;
    }

    ret = ocfs2_xa_store_value(loc, xi, ctxt);
    if (ret)
        mlog_errno(ret);

out_dirty:
    ocfs2_xa_journal_dirty(ctxt->handle, loc);

out:
    return ret;
}

static void ocfs2_init_dinode_xa_loc(struct ocfs2_xa_loc *loc,
                     struct inode *inode,
                     struct buffer_head *bh,
                     struct ocfs2_xattr_entry *entry)
{
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;

    BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_XATTR_FL));

    loc->xl_inode = inode;
    loc->xl_ops = &ocfs2_xa_block_loc_ops;
    loc->xl_storage = bh;
    loc->xl_entry = entry;
    loc->xl_size = le16_to_cpu(di->i_xattr_inline_size);
    loc->xl_header =
        (struct ocfs2_xattr_header *)(bh->b_data + bh->b_size -
                          loc->xl_size);
}

static void ocfs2_init_xattr_block_xa_loc(struct ocfs2_xa_loc *loc,
                      struct inode *inode,
                      struct buffer_head *bh,
                      struct ocfs2_xattr_entry *entry)
{
    struct ocfs2_xattr_block *xb =
        (struct ocfs2_xattr_block *)bh->b_data;

    BUG_ON(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED);

    loc->xl_inode = inode;
    loc->xl_ops = &ocfs2_xa_block_loc_ops;
    loc->xl_storage = bh;
    loc->xl_header = &(xb->xb_attrs.xb_header);
    loc->xl_entry = entry;
    loc->xl_size = bh->b_size - offsetof(struct ocfs2_xattr_block,
                         xb_attrs.xb_header);
}

static void ocfs2_init_xattr_bucket_xa_loc(struct ocfs2_xa_loc *loc,
                       struct ocfs2_xattr_bucket *bucket,
                       struct ocfs2_xattr_entry *entry)
{
    loc->xl_inode = bucket->bu_inode;
    loc->xl_ops = &ocfs2_xa_bucket_loc_ops;
    loc->xl_storage = bucket;
    loc->xl_header = bucket_xh(bucket);
    loc->xl_entry = entry;
    loc->xl_size = OCFS2_XATTR_BUCKET_SIZE;
}

/*
 * In xattr remove, if it is stored outside and refcounted, we may have
 * the chance to split the refcount tree. So need the allocators.
 */
static int ocfs2_lock_xattr_remove_allocators(struct inode *inode,
                    struct ocfs2_xattr_value_root *xv,
                    struct ocfs2_caching_info *ref_ci,
                    struct buffer_head *ref_root_bh,
                    struct ocfs2_alloc_context **meta_ac,
                    int *ref_credits)
{
    int ret, meta_add = 0;
    u32 p_cluster, num_clusters;
    unsigned int ext_flags;

    *ref_credits = 0;
    ret = ocfs2_xattr_get_clusters(inode, 0, &p_cluster,
                       &num_clusters,
                       &xv->xr_list,
                       &ext_flags);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    if (!(ext_flags & OCFS2_EXT_REFCOUNTED))
        goto out;

    ret = ocfs2_refcounted_xattr_delete_need(inode, ref_ci,
                         ref_root_bh, xv,
                         &meta_add, ref_credits);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb),
                        meta_add, meta_ac);
    if (ret)
        mlog_errno(ret);

out:
    return ret;
}

static int ocfs2_remove_value_outside(struct inode*inode,
                      struct ocfs2_xattr_value_buf *vb,
                      struct ocfs2_xattr_header *header,
                      struct ocfs2_caching_info *ref_ci,
                      struct buffer_head *ref_root_bh)
{
    int ret = 0, i, ref_credits;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct ocfs2_xattr_set_ctxt ctxt = { NULL, NULL, };
    void *val;

    ocfs2_init_dealloc_ctxt(&ctxt.dealloc);

    for (i = 0; i < le16_to_cpu(header->xh_count); i++) {
        struct ocfs2_xattr_entry *entry = &header->xh_entries[i];

        if (ocfs2_xattr_is_local(entry))
            continue;

        val = (void *)header +
            le16_to_cpu(entry->xe_name_offset);
        vb->vb_xv = (struct ocfs2_xattr_value_root *)
            (val + OCFS2_XATTR_SIZE(entry->xe_name_len));

        ret = ocfs2_lock_xattr_remove_allocators(inode, vb->vb_xv,
                             ref_ci, ref_root_bh,
                             &ctxt.meta_ac,
                             &ref_credits);

        ctxt.handle = ocfs2_start_trans(osb, ref_credits +
                    ocfs2_remove_extent_credits(osb->sb));
        if (IS_ERR(ctxt.handle)) {
            ret = PTR_ERR(ctxt.handle);
            mlog_errno(ret);
            break;
        }

        ret = ocfs2_xattr_value_truncate(inode, vb, 0, &ctxt);

        ocfs2_commit_trans(osb, ctxt.handle);
        if (ctxt.meta_ac) {
            ocfs2_free_alloc_context(ctxt.meta_ac);
            ctxt.meta_ac = NULL;
        }

        if (ret < 0) {
            mlog_errno(ret);
            break;
        }

    }

    if (ctxt.meta_ac)
        ocfs2_free_alloc_context(ctxt.meta_ac);
    ocfs2_schedule_truncate_log_flush(osb, 1);
    ocfs2_run_deallocs(osb, &ctxt.dealloc);
    return ret;
}

static int ocfs2_xattr_ibody_remove(struct inode *inode,
                    struct buffer_head *di_bh,
                    struct ocfs2_caching_info *ref_ci,
                    struct buffer_head *ref_root_bh)
{

    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    struct ocfs2_xattr_header *header;
    int ret;
    struct ocfs2_xattr_value_buf vb = {
        .vb_bh = di_bh,
        .vb_access = ocfs2_journal_access_di,
    };

    header = (struct ocfs2_xattr_header *)
         ((void *)di + inode->i_sb->s_blocksize -
         le16_to_cpu(di->i_xattr_inline_size));

    ret = ocfs2_remove_value_outside(inode, &vb, header,
                     ref_ci, ref_root_bh);

    return ret;
}

struct ocfs2_rm_xattr_bucket_para {
    struct ocfs2_caching_info *ref_ci;
    struct buffer_head *ref_root_bh;
};

static int ocfs2_xattr_block_remove(struct inode *inode,
                    struct buffer_head *blk_bh,
                    struct ocfs2_caching_info *ref_ci,
                    struct buffer_head *ref_root_bh)
{
    struct ocfs2_xattr_block *xb;
    int ret = 0;
    struct ocfs2_xattr_value_buf vb = {
        .vb_bh = blk_bh,
        .vb_access = ocfs2_journal_access_xb,
    };
    struct ocfs2_rm_xattr_bucket_para args = {
        .ref_ci = ref_ci,
        .ref_root_bh = ref_root_bh,
    };

    xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
    if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
        struct ocfs2_xattr_header *header = &(xb->xb_attrs.xb_header);
        ret = ocfs2_remove_value_outside(inode, &vb, header,
                         ref_ci, ref_root_bh);
    } else
        ret = ocfs2_iterate_xattr_index_block(inode,
                        blk_bh,
                        ocfs2_rm_xattr_cluster,
                        &args);

    return ret;
}

static int ocfs2_xattr_free_block(struct inode *inode,
                  u64 block,
                  struct ocfs2_caching_info *ref_ci,
                  struct buffer_head *ref_root_bh)
{
    struct inode *xb_alloc_inode;
    struct buffer_head *xb_alloc_bh = NULL;
    struct buffer_head *blk_bh = NULL;
    struct ocfs2_xattr_block *xb;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    handle_t *handle;
    int ret = 0;
    u64 blk, bg_blkno;
    u16 bit;

    ret = ocfs2_read_xattr_block(inode, block, &blk_bh);
    if (ret < 0) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xattr_block_remove(inode, blk_bh, ref_ci, ref_root_bh);
    if (ret < 0) {
        mlog_errno(ret);
        goto out;
    }

    xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
    blk = le64_to_cpu(xb->xb_blkno);
    bit = le16_to_cpu(xb->xb_suballoc_bit);
    if (xb->xb_suballoc_loc)
        bg_blkno = le64_to_cpu(xb->xb_suballoc_loc);
    else
        bg_blkno = ocfs2_which_suballoc_group(blk, bit);

    xb_alloc_inode = ocfs2_get_system_file_inode(osb,
                EXTENT_ALLOC_SYSTEM_INODE,
                le16_to_cpu(xb->xb_suballoc_slot));
    if (!xb_alloc_inode) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }
    mutex_lock(&xb_alloc_inode->i_mutex);

    ret = ocfs2_inode_lock(xb_alloc_inode, &xb_alloc_bh, 1);
    if (ret < 0) {
        mlog_errno(ret);
        goto out_mutex;
    }

    handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
    if (IS_ERR(handle)) {
        ret = PTR_ERR(handle);
        mlog_errno(ret);
        goto out_unlock;
    }

    ret = ocfs2_free_suballoc_bits(handle, xb_alloc_inode, xb_alloc_bh,
                       bit, bg_blkno, 1);
    if (ret < 0)
        mlog_errno(ret);

    ocfs2_commit_trans(osb, handle);
out_unlock:
    ocfs2_inode_unlock(xb_alloc_inode, 1);
    brelse(xb_alloc_bh);
out_mutex:
    mutex_unlock(&xb_alloc_inode->i_mutex);
    iput(xb_alloc_inode);
out:
    brelse(blk_bh);
    return ret;
}

/*
 * ocfs2_xattr_remove()
 *
 * Free extended attribute resources associated with this inode.
 */
int ocfs2_xattr_remove(struct inode *inode, struct buffer_head *di_bh)
{
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    struct ocfs2_refcount_tree *ref_tree = NULL;
    struct buffer_head *ref_root_bh = NULL;
    struct ocfs2_caching_info *ref_ci = NULL;
    handle_t *handle;
    int ret;

    if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
        return 0;

    if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
        return 0;

    if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL) {
        ret = ocfs2_lock_refcount_tree(OCFS2_SB(inode->i_sb),
                           le64_to_cpu(di->i_refcount_loc),
                           1, &ref_tree, &ref_root_bh);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
        ref_ci = &ref_tree->rf_ci;

    }

    if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
        ret = ocfs2_xattr_ibody_remove(inode, di_bh,
                           ref_ci, ref_root_bh);
        if (ret < 0) {
            mlog_errno(ret);
            goto out;
        }
    }

    if (di->i_xattr_loc) {
        ret = ocfs2_xattr_free_block(inode,
                         le64_to_cpu(di->i_xattr_loc),
                         ref_ci, ref_root_bh);
        if (ret < 0) {
            mlog_errno(ret);
            goto out;
        }
    }

    handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)),
                   OCFS2_INODE_UPDATE_CREDITS);
    if (IS_ERR(handle)) {
        ret = PTR_ERR(handle);
        mlog_errno(ret);
        goto out;
    }
    ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    di->i_xattr_loc = 0;

    spin_lock(&oi->ip_lock);
    oi->ip_dyn_features &= ~(OCFS2_INLINE_XATTR_FL | OCFS2_HAS_XATTR_FL);
    di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
    spin_unlock(&oi->ip_lock);

    ocfs2_journal_dirty(handle, di_bh);
out_commit:
    ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out:
    if (ref_tree)
        ocfs2_unlock_refcount_tree(OCFS2_SB(inode->i_sb), ref_tree, 1);
    brelse(ref_root_bh);
    return ret;
}

static int ocfs2_xattr_has_space_inline(struct inode *inode,
                    struct ocfs2_dinode *di)
{
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    unsigned int xattrsize = OCFS2_SB(inode->i_sb)->s_xattr_inline_size;
    int free;

    if (xattrsize < OCFS2_MIN_XATTR_INLINE_SIZE)
        return 0;

    if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
        struct ocfs2_inline_data *idata = &di->id2.i_data;
        free = le16_to_cpu(idata->id_count) - le64_to_cpu(di->i_size);
    } else if (ocfs2_inode_is_fast_symlink(inode)) {
        free = ocfs2_fast_symlink_chars(inode->i_sb) -
            le64_to_cpu(di->i_size);
    } else {
        struct ocfs2_extent_list *el = &di->id2.i_list;
        free = (le16_to_cpu(el->l_count) -
            le16_to_cpu(el->l_next_free_rec)) *
            sizeof(struct ocfs2_extent_rec);
    }
    if (free >= xattrsize)
        return 1;

    return 0;
}

/*
 * ocfs2_xattr_ibody_find()
 *
 * Find extended attribute in inode block and
 * fill search info into struct ocfs2_xattr_search.
 */
static int ocfs2_xattr_ibody_find(struct inode *inode,
                  int name_index,
                  const char *name,
                  struct ocfs2_xattr_search *xs)
{
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
    int ret;
    int has_space = 0;

    if (inode->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE)
        return 0;

    if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) {
        down_read(&oi->ip_alloc_sem);
        has_space = ocfs2_xattr_has_space_inline(inode, di);
        up_read(&oi->ip_alloc_sem);
        if (!has_space)
            return 0;
    }

    xs->xattr_bh = xs->inode_bh;
    xs->end = (void *)di + inode->i_sb->s_blocksize;
    if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)
        xs->header = (struct ocfs2_xattr_header *)
            (xs->end - le16_to_cpu(di->i_xattr_inline_size));
    else
        xs->header = (struct ocfs2_xattr_header *)
            (xs->end - OCFS2_SB(inode->i_sb)->s_xattr_inline_size);
    xs->base = (void *)xs->header;
    xs->here = xs->header->xh_entries;

    /* Find the named attribute. */
    if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
        ret = ocfs2_xattr_find_entry(name_index, name, xs);
        if (ret && ret != -ENODATA)
            return ret;
        xs->not_found = ret;
    }

    return 0;
}

static int ocfs2_xattr_ibody_init(struct inode *inode,
                  struct buffer_head *di_bh,
                  struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    unsigned int xattrsize = osb->s_xattr_inline_size;

    if (!ocfs2_xattr_has_space_inline(inode, di)) {
        ret = -ENOSPC;
        goto out;
    }

    ret = ocfs2_journal_access_di(ctxt->handle, INODE_CACHE(inode), di_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * Adjust extent record count or inline data size
     * to reserve space for extended attribute.
     */
    if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
        struct ocfs2_inline_data *idata = &di->id2.i_data;
        le16_add_cpu(&idata->id_count, -xattrsize);
    } else if (!(ocfs2_inode_is_fast_symlink(inode))) {
        struct ocfs2_extent_list *el = &di->id2.i_list;
        le16_add_cpu(&el->l_count, -(xattrsize /
                         sizeof(struct ocfs2_extent_rec)));
    }
    di->i_xattr_inline_size = cpu_to_le16(xattrsize);

    spin_lock(&oi->ip_lock);
    oi->ip_dyn_features |= OCFS2_INLINE_XATTR_FL|OCFS2_HAS_XATTR_FL;
    di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
    spin_unlock(&oi->ip_lock);

    ocfs2_journal_dirty(ctxt->handle, di_bh);

out:
    return ret;
}

/*
 * ocfs2_xattr_ibody_set()
 *
 * Set, replace or remove an extended attribute into inode block.
 *
 */
static int ocfs2_xattr_ibody_set(struct inode *inode,
                 struct ocfs2_xattr_info *xi,
                 struct ocfs2_xattr_search *xs,
                 struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
    struct ocfs2_xa_loc loc;

    if (inode->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE)
        return -ENOSPC;

    down_write(&oi->ip_alloc_sem);
    if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) {
        if (!ocfs2_xattr_has_space_inline(inode, di)) {
            ret = -ENOSPC;
            goto out;
        }
    }

    if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) {
        ret = ocfs2_xattr_ibody_init(inode, xs->inode_bh, ctxt);
        if (ret) {
            if (ret != -ENOSPC)
                mlog_errno(ret);
            goto out;
        }
    }

    ocfs2_init_dinode_xa_loc(&loc, inode, xs->inode_bh,
                 xs->not_found ? NULL : xs->here);
    ret = ocfs2_xa_set(&loc, xi, ctxt);
    if (ret) {
        if (ret != -ENOSPC)
            mlog_errno(ret);
        goto out;
    }
    xs->here = loc.xl_entry;

out:
    up_write(&oi->ip_alloc_sem);

    return ret;
}

/*
 * ocfs2_xattr_block_find()
 *
 * Find extended attribute in external block and
 * fill search info into struct ocfs2_xattr_search.
 */
static int ocfs2_xattr_block_find(struct inode *inode,
                  int name_index,
                  const char *name,
                  struct ocfs2_xattr_search *xs)
{
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
    struct buffer_head *blk_bh = NULL;
    struct ocfs2_xattr_block *xb;
    int ret = 0;

    if (!di->i_xattr_loc)
        return ret;

    ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc),
                     &blk_bh);
    if (ret < 0) {
        mlog_errno(ret);
        return ret;
    }

    xs->xattr_bh = blk_bh;
    xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

    if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
        xs->header = &xb->xb_attrs.xb_header;
        xs->base = (void *)xs->header;
        xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
        xs->here = xs->header->xh_entries;

        ret = ocfs2_xattr_find_entry(name_index, name, xs);
    } else
        ret = ocfs2_xattr_index_block_find(inode, blk_bh,
                           name_index,
                           name, xs);

    if (ret && ret != -ENODATA) {
        xs->xattr_bh = NULL;
        goto cleanup;
    }
    xs->not_found = ret;
    return 0;
cleanup:
    brelse(blk_bh);

    return ret;
}

static int ocfs2_create_xattr_block(struct inode *inode,
                    struct buffer_head *inode_bh,
                    struct ocfs2_xattr_set_ctxt *ctxt,
                    int indexed,
                    struct buffer_head **ret_bh)
{
    int ret;
    u16 suballoc_bit_start;
    u32 num_got;
    u64 suballoc_loc, first_blkno;
    struct ocfs2_dinode *di =  (struct ocfs2_dinode *)inode_bh->b_data;
    struct buffer_head *new_bh = NULL;
    struct ocfs2_xattr_block *xblk;

    ret = ocfs2_journal_access_di(ctxt->handle, INODE_CACHE(inode),
                      inode_bh, OCFS2_JOURNAL_ACCESS_CREATE);
    if (ret < 0) {
        mlog_errno(ret);
        goto end;
    }

    ret = ocfs2_claim_metadata(ctxt->handle, ctxt->meta_ac, 1,
                   &suballoc_loc, &suballoc_bit_start,
                   &num_got, &first_blkno);
    if (ret < 0) {
        mlog_errno(ret);
        goto end;
    }

    new_bh = sb_getblk(inode->i_sb, first_blkno);
    ocfs2_set_new_buffer_uptodate(INODE_CACHE(inode), new_bh);

    ret = ocfs2_journal_access_xb(ctxt->handle, INODE_CACHE(inode),
                      new_bh,
                      OCFS2_JOURNAL_ACCESS_CREATE);
    if (ret < 0) {
        mlog_errno(ret);
        goto end;
    }

    /* Initialize ocfs2_xattr_block */
    xblk = (struct ocfs2_xattr_block *)new_bh->b_data;
    memset(xblk, 0, inode->i_sb->s_blocksize);
    strcpy((void *)xblk, OCFS2_XATTR_BLOCK_SIGNATURE);
    xblk->xb_suballoc_slot = cpu_to_le16(ctxt->meta_ac->ac_alloc_slot);
    xblk->xb_suballoc_loc = cpu_to_le64(suballoc_loc);
    xblk->xb_suballoc_bit = cpu_to_le16(suballoc_bit_start);
    xblk->xb_fs_generation =
        cpu_to_le32(OCFS2_SB(inode->i_sb)->fs_generation);
    xblk->xb_blkno = cpu_to_le64(first_blkno);
    if (indexed) {
        struct ocfs2_xattr_tree_root *xr = &xblk->xb_attrs.xb_root;
        xr->xt_clusters = cpu_to_le32(1);
        xr->xt_last_eb_blk = 0;
        xr->xt_list.l_tree_depth = 0;
        xr->xt_list.l_count = cpu_to_le16(
                    ocfs2_xattr_recs_per_xb(inode->i_sb));
        xr->xt_list.l_next_free_rec = cpu_to_le16(1);
        xblk->xb_flags = cpu_to_le16(OCFS2_XATTR_INDEXED);
    }
    ocfs2_journal_dirty(ctxt->handle, new_bh);

    /* Add it to the inode */
    di->i_xattr_loc = cpu_to_le64(first_blkno);

    spin_lock(&OCFS2_I(inode)->ip_lock);
    OCFS2_I(inode)->ip_dyn_features |= OCFS2_HAS_XATTR_FL;
    di->i_dyn_features = cpu_to_le16(OCFS2_I(inode)->ip_dyn_features);
    spin_unlock(&OCFS2_I(inode)->ip_lock);

    ocfs2_journal_dirty(ctxt->handle, inode_bh);

    *ret_bh = new_bh;
    new_bh = NULL;

end:
    brelse(new_bh);
    return ret;
}

/*
 * ocfs2_xattr_block_set()
 *
 * Set, replace or remove an extended attribute into external block.
 *
 */
static int ocfs2_xattr_block_set(struct inode *inode,
                 struct ocfs2_xattr_info *xi,
                 struct ocfs2_xattr_search *xs,
                 struct ocfs2_xattr_set_ctxt *ctxt)
{
    struct buffer_head *new_bh = NULL;
    struct ocfs2_xattr_block *xblk = NULL;
    int ret;
    struct ocfs2_xa_loc loc;

    if (!xs->xattr_bh) {
        ret = ocfs2_create_xattr_block(inode, xs->inode_bh, ctxt,
                           0, &new_bh);
        if (ret) {
            mlog_errno(ret);
            goto end;
        }

        xs->xattr_bh = new_bh;
        xblk = (struct ocfs2_xattr_block *)xs->xattr_bh->b_data;
        xs->header = &xblk->xb_attrs.xb_header;
        xs->base = (void *)xs->header;
        xs->end = (void *)xblk + inode->i_sb->s_blocksize;
        xs->here = xs->header->xh_entries;
    } else
        xblk = (struct ocfs2_xattr_block *)xs->xattr_bh->b_data;

    if (!(le16_to_cpu(xblk->xb_flags) & OCFS2_XATTR_INDEXED)) {
        ocfs2_init_xattr_block_xa_loc(&loc, inode, xs->xattr_bh,
                          xs->not_found ? NULL : xs->here);

        ret = ocfs2_xa_set(&loc, xi, ctxt);
        if (!ret)
            xs->here = loc.xl_entry;
        else if ((ret != -ENOSPC) || ctxt->set_abort)
            goto end;
        else {
            ret = ocfs2_xattr_create_index_block(inode, xs, ctxt);
            if (ret)
                goto end;
        }
    }

    if (le16_to_cpu(xblk->xb_flags) & OCFS2_XATTR_INDEXED)
        ret = ocfs2_xattr_set_entry_index_block(inode, xi, xs, ctxt);

end:
    return ret;
}

/* Check whether the new xattr can be inserted into the inode. */
static int ocfs2_xattr_can_be_in_inode(struct inode *inode,
                       struct ocfs2_xattr_info *xi,
                       struct ocfs2_xattr_search *xs)
{
    struct ocfs2_xattr_entry *last;
    int free, i;
    size_t min_offs = xs->end - xs->base;

    if (!xs->header)
        return 0;

    last = xs->header->xh_entries;

    for (i = 0; i < le16_to_cpu(xs->header->xh_count); i++) {
        size_t offs = le16_to_cpu(last->xe_name_offset);
        if (offs < min_offs)
            min_offs = offs;
        last += 1;
    }

    free = min_offs - ((void *)last - xs->base) - OCFS2_XATTR_HEADER_GAP;
    if (free < 0)
        return 0;

    BUG_ON(!xs->not_found);

    if (free >= (sizeof(struct ocfs2_xattr_entry) + namevalue_size_xi(xi)))
        return 1;

    return 0;
}

static int ocfs2_calc_xattr_set_need(struct inode *inode,
                     struct ocfs2_dinode *di,
                     struct ocfs2_xattr_info *xi,
                     struct ocfs2_xattr_search *xis,
                     struct ocfs2_xattr_search *xbs,
                     int *clusters_need,
                     int *meta_need,
                     int *credits_need)
{
    int ret = 0, old_in_xb = 0;
    int clusters_add = 0, meta_add = 0, credits = 0;
    struct buffer_head *bh = NULL;
    struct ocfs2_xattr_block *xb = NULL;
    struct ocfs2_xattr_entry *xe = NULL;
    struct ocfs2_xattr_value_root *xv = NULL;
    char *base = NULL;
    int name_offset, name_len = 0;
    u32 new_clusters = ocfs2_clusters_for_bytes(inode->i_sb,
                            xi->xi_value_len);
    u64 value_size;

    /*
     * Calculate the clusters we need to write.
     * No matter whether we replace an old one or add a new one,
     * we need this for writing.
     */
    if (xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE)
        credits += new_clusters *
               ocfs2_clusters_to_blocks(inode->i_sb, 1);

    if (xis->not_found && xbs->not_found) {
        credits += ocfs2_blocks_per_xattr_bucket(inode->i_sb);

        if (xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE) {
            clusters_add += new_clusters;
            credits += ocfs2_calc_extend_credits(inode->i_sb,
                            &def_xv.xv.xr_list,
                            new_clusters);
        }

        goto meta_guess;
    }

    if (!xis->not_found) {
        xe = xis->here;
        name_offset = le16_to_cpu(xe->xe_name_offset);
        name_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
        base = xis->base;
        credits += OCFS2_INODE_UPDATE_CREDITS;
    } else {
        int i, block_off = 0;
        xb = (struct ocfs2_xattr_block *)xbs->xattr_bh->b_data;
        xe = xbs->here;
        name_offset = le16_to_cpu(xe->xe_name_offset);
        name_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
        i = xbs->here - xbs->header->xh_entries;
        old_in_xb = 1;

        if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
            ret = ocfs2_xattr_bucket_get_name_value(inode->i_sb,
                            bucket_xh(xbs->bucket),
                            i, &block_off,
                            &name_offset);
            base = bucket_block(xbs->bucket, block_off);
            credits += ocfs2_blocks_per_xattr_bucket(inode->i_sb);
        } else {
            base = xbs->base;
            credits += OCFS2_XATTR_BLOCK_UPDATE_CREDITS;
        }
    }

    /*
     * delete a xattr doesn't need metadata and cluster allocation.
     * so just calculate the credits and return.
     *
     * The credits for removing the value tree will be extended
     * by ocfs2_remove_extent itself.
     */
    if (!xi->xi_value) {
        if (!ocfs2_xattr_is_local(xe))
            credits += ocfs2_remove_extent_credits(inode->i_sb);

        goto out;
    }

    /* do cluster allocation guess first. */
    value_size = le64_to_cpu(xe->xe_value_size);

    if (old_in_xb) {
        /*
         * In xattr set, we always try to set the xe in inode first,
         * so if it can be inserted into inode successfully, the old
         * one will be removed from the xattr block, and this xattr
         * will be inserted into inode as a new xattr in inode.
         */
        if (ocfs2_xattr_can_be_in_inode(inode, xi, xis)) {
            clusters_add += new_clusters;
            credits += ocfs2_remove_extent_credits(inode->i_sb) +
                    OCFS2_INODE_UPDATE_CREDITS;
            if (!ocfs2_xattr_is_local(xe))
                credits += ocfs2_calc_extend_credits(
                            inode->i_sb,
                            &def_xv.xv.xr_list,
                            new_clusters);
            goto out;
        }
    }

    if (xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE) {
        /* the new values will be stored outside. */
        u32 old_clusters = 0;

        if (!ocfs2_xattr_is_local(xe)) {
            old_clusters =  ocfs2_clusters_for_bytes(inode->i_sb,
                                 value_size);
            xv = (struct ocfs2_xattr_value_root *)
                 (base + name_offset + name_len);
            value_size = OCFS2_XATTR_ROOT_SIZE;
        } else
            xv = &def_xv.xv;

        if (old_clusters >= new_clusters) {
            credits += ocfs2_remove_extent_credits(inode->i_sb);
            goto out;
        } else {
            meta_add += ocfs2_extend_meta_needed(&xv->xr_list);
            clusters_add += new_clusters - old_clusters;
            credits += ocfs2_calc_extend_credits(inode->i_sb,
                                 &xv->xr_list,
                                 new_clusters -
                                 old_clusters);
            if (value_size >= OCFS2_XATTR_ROOT_SIZE)
                goto out;
        }
    } else {
        /*
         * Now the new value will be stored inside. So if the new
         * value is smaller than the size of value root or the old
         * value, we don't need any allocation, otherwise we have
         * to guess metadata allocation.
         */
        if ((ocfs2_xattr_is_local(xe) &&
             (value_size >= xi->xi_value_len)) ||
            (!ocfs2_xattr_is_local(xe) &&
             OCFS2_XATTR_ROOT_SIZE >= xi->xi_value_len))
            goto out;
    }

meta_guess:
    /* calculate metadata allocation. */
    if (di->i_xattr_loc) {
        if (!xbs->xattr_bh) {
            ret = ocfs2_read_xattr_block(inode,
                             le64_to_cpu(di->i_xattr_loc),
                             &bh);
            if (ret) {
                mlog_errno(ret);
                goto out;
            }

            xb = (struct ocfs2_xattr_block *)bh->b_data;
        } else
            xb = (struct ocfs2_xattr_block *)xbs->xattr_bh->b_data;

        /*
         * If there is already an xattr tree, good, we can calculate
         * like other b-trees. Otherwise we may have the chance of
         * create a tree, the credit calculation is borrowed from
         * ocfs2_calc_extend_credits with root_el = NULL. And the
         * new tree will be cluster based, so no meta is needed.
         */
        if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
            struct ocfs2_extent_list *el =
                 &xb->xb_attrs.xb_root.xt_list;
            meta_add += ocfs2_extend_meta_needed(el);
            credits += ocfs2_calc_extend_credits(inode->i_sb,
                                 el, 1);
        } else
            credits += OCFS2_SUBALLOC_ALLOC + 1;

        /*
         * This cluster will be used either for new bucket or for
         * new xattr block.
         * If the cluster size is the same as the bucket size, one
         * more is needed since we may need to extend the bucket
         * also.
         */
        clusters_add += 1;
        credits += ocfs2_blocks_per_xattr_bucket(inode->i_sb);
        if (OCFS2_XATTR_BUCKET_SIZE ==
            OCFS2_SB(inode->i_sb)->s_clustersize) {
            credits += ocfs2_blocks_per_xattr_bucket(inode->i_sb);
            clusters_add += 1;
        }
    } else {
        meta_add += 1;
        credits += OCFS2_XATTR_BLOCK_CREATE_CREDITS;
    }
out:
    if (clusters_need)
        *clusters_need = clusters_add;
    if (meta_need)
        *meta_need = meta_add;
    if (credits_need)
        *credits_need = credits;
    brelse(bh);
    return ret;
}

static int ocfs2_init_xattr_set_ctxt(struct inode *inode,
                     struct ocfs2_dinode *di,
                     struct ocfs2_xattr_info *xi,
                     struct ocfs2_xattr_search *xis,
                     struct ocfs2_xattr_search *xbs,
                     struct ocfs2_xattr_set_ctxt *ctxt,
                     int extra_meta,
                     int *credits)
{
    int clusters_add, meta_add, ret;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

    memset(ctxt, 0, sizeof(struct ocfs2_xattr_set_ctxt));

    ocfs2_init_dealloc_ctxt(&ctxt->dealloc);

    ret = ocfs2_calc_xattr_set_need(inode, di, xi, xis, xbs,
                    &clusters_add, &meta_add, credits);
    if (ret) {
        mlog_errno(ret);
        return ret;
    }

    meta_add += extra_meta;
    trace_ocfs2_init_xattr_set_ctxt(xi->xi_name, meta_add,
                    clusters_add, *credits);

    if (meta_add) {
        ret = ocfs2_reserve_new_metadata_blocks(osb, meta_add,
                            &ctxt->meta_ac);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
    }

    if (clusters_add) {
        ret = ocfs2_reserve_clusters(osb, clusters_add, &ctxt->data_ac);
        if (ret)
            mlog_errno(ret);
    }
out:
    if (ret) {
        if (ctxt->meta_ac) {
            ocfs2_free_alloc_context(ctxt->meta_ac);
            ctxt->meta_ac = NULL;
        }

        /*
         * We cannot have an error and a non null ctxt->data_ac.
         */
    }

    return ret;
}

static int __ocfs2_xattr_set_handle(struct inode *inode,
                    struct ocfs2_dinode *di,
                    struct ocfs2_xattr_info *xi,
                    struct ocfs2_xattr_search *xis,
                    struct ocfs2_xattr_search *xbs,
                    struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret = 0, credits, old_found;

    if (!xi->xi_value) {
        /* Remove existing extended attribute */
        if (!xis->not_found)
            ret = ocfs2_xattr_ibody_set(inode, xi, xis, ctxt);
        else if (!xbs->not_found)
            ret = ocfs2_xattr_block_set(inode, xi, xbs, ctxt);
    } else {
        /* We always try to set extended attribute into inode first*/
        ret = ocfs2_xattr_ibody_set(inode, xi, xis, ctxt);
        if (!ret && !xbs->not_found) {
            /*
             * If succeed and that extended attribute existing in
             * external block, then we will remove it.
             */
            xi->xi_value = NULL;
            xi->xi_value_len = 0;

            old_found = xis->not_found;
            xis->not_found = -ENODATA;
            ret = ocfs2_calc_xattr_set_need(inode,
                            di,
                            xi,
                            xis,
                            xbs,
                            NULL,
                            NULL,
                            &credits);
            xis->not_found = old_found;
            if (ret) {
                mlog_errno(ret);
                goto out;
            }

            ret = ocfs2_extend_trans(ctxt->handle, credits);
            if (ret) {
                mlog_errno(ret);
                goto out;
            }
            ret = ocfs2_xattr_block_set(inode, xi, xbs, ctxt);
        } else if ((ret == -ENOSPC) && !ctxt->set_abort) {
            if (di->i_xattr_loc && !xbs->xattr_bh) {
                ret = ocfs2_xattr_block_find(inode,
                                 xi->xi_name_index,
                                 xi->xi_name, xbs);
                if (ret)
                    goto out;

                old_found = xis->not_found;
                xis->not_found = -ENODATA;
                ret = ocfs2_calc_xattr_set_need(inode,
                                di,
                                xi,
                                xis,
                                xbs,
                                NULL,
                                NULL,
                                &credits);
                xis->not_found = old_found;
                if (ret) {
                    mlog_errno(ret);
                    goto out;
                }

                ret = ocfs2_extend_trans(ctxt->handle, credits);
                if (ret) {
                    mlog_errno(ret);
                    goto out;
                }
            }
            /*
             * If no space in inode, we will set extended attribute
             * into external block.
             */
            ret = ocfs2_xattr_block_set(inode, xi, xbs, ctxt);
            if (ret)
                goto out;
            if (!xis->not_found) {
                /*
                 * If succeed and that extended attribute
                 * existing in inode, we will remove it.
                 */
                xi->xi_value = NULL;
                xi->xi_value_len = 0;
                xbs->not_found = -ENODATA;
                ret = ocfs2_calc_xattr_set_need(inode,
                                di,
                                xi,
                                xis,
                                xbs,
                                NULL,
                                NULL,
                                &credits);
                if (ret) {
                    mlog_errno(ret);
                    goto out;
                }

                ret = ocfs2_extend_trans(ctxt->handle, credits);
                if (ret) {
                    mlog_errno(ret);
                    goto out;
                }
                ret = ocfs2_xattr_ibody_set(inode, xi,
                                xis, ctxt);
            }
        }
    }

    if (!ret) {
        /* Update inode ctime. */
        ret = ocfs2_journal_access_di(ctxt->handle, INODE_CACHE(inode),
                          xis->inode_bh,
                          OCFS2_JOURNAL_ACCESS_WRITE);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        inode->i_ctime = CURRENT_TIME;
        di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
        di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
        ocfs2_journal_dirty(ctxt->handle, xis->inode_bh);
    }
out:
    return ret;
}

/*
 * This function only called duing creating inode
 * for init security/acl xattrs of the new inode.
 * All transanction credits have been reserved in mknod.
 */
int ocfs2_xattr_set_handle(handle_t *handle,
               struct inode *inode,
               struct buffer_head *di_bh,
               int name_index,
               const char *name,
               const void *value,
               size_t value_len,
               int flags,
               struct ocfs2_alloc_context *meta_ac,
               struct ocfs2_alloc_context *data_ac)
{
    struct ocfs2_dinode *di;
    int ret;

    struct ocfs2_xattr_info xi = {
        .xi_name_index = name_index,
        .xi_name = name,
        .xi_name_len = strlen(name),
        .xi_value = value,
        .xi_value_len = value_len,
    };

    struct ocfs2_xattr_search xis = {
        .not_found = -ENODATA,
    };

    struct ocfs2_xattr_search xbs = {
        .not_found = -ENODATA,
    };

    struct ocfs2_xattr_set_ctxt ctxt = {
        .handle = handle,
        .meta_ac = meta_ac,
        .data_ac = data_ac,
    };

    if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
        return -EOPNOTSUPP;

    /*
     * In extreme situation, may need xattr bucket when
     * block size is too small. And we have already reserved
     * the credits for bucket in mknod.
     */
    if (inode->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE) {
        xbs.bucket = ocfs2_xattr_bucket_new(inode);
        if (!xbs.bucket) {
            mlog_errno(-ENOMEM);
            return -ENOMEM;
        }
    }

    xis.inode_bh = xbs.inode_bh = di_bh;
    di = (struct ocfs2_dinode *)di_bh->b_data;

    down_write(&OCFS2_I(inode)->ip_xattr_sem);

    ret = ocfs2_xattr_ibody_find(inode, name_index, name, &xis);
    if (ret)
        goto cleanup;
    if (xis.not_found) {
        ret = ocfs2_xattr_block_find(inode, name_index, name, &xbs);
        if (ret)
            goto cleanup;
    }

    ret = __ocfs2_xattr_set_handle(inode, di, &xi, &xis, &xbs, &ctxt);

cleanup:
    up_write(&OCFS2_I(inode)->ip_xattr_sem);
    brelse(xbs.xattr_bh);
    ocfs2_xattr_bucket_free(xbs.bucket);

    return ret;
}

/*
 * ocfs2_xattr_set()
 *
 * Set, replace or remove an extended attribute for this inode.
 * value is NULL to remove an existing extended attribute, else either
 * create or replace an extended attribute.
 */
int ocfs2_xattr_set(struct inode *inode,
            int name_index,
            const char *name,
            const void *value,
            size_t value_len,
            int flags)
{
    struct buffer_head *di_bh = NULL;
    struct ocfs2_dinode *di;
    int ret, credits, ref_meta = 0, ref_credits = 0;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct inode *tl_inode = osb->osb_tl_inode;
    struct ocfs2_xattr_set_ctxt ctxt = { NULL, NULL, };
    struct ocfs2_refcount_tree *ref_tree = NULL;

    struct ocfs2_xattr_info xi = {
        .xi_name_index = name_index,
        .xi_name = name,
        .xi_name_len = strlen(name),
        .xi_value = value,
        .xi_value_len = value_len,
    };

    struct ocfs2_xattr_search xis = {
        .not_found = -ENODATA,
    };

    struct ocfs2_xattr_search xbs = {
        .not_found = -ENODATA,
    };

    if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
        return -EOPNOTSUPP;

    /*
     * Only xbs will be used on indexed trees.  xis doesn't need a
     * bucket.
     */
    xbs.bucket = ocfs2_xattr_bucket_new(inode);
    if (!xbs.bucket) {
        mlog_errno(-ENOMEM);
        return -ENOMEM;
    }

    ret = ocfs2_inode_lock(inode, &di_bh, 1);
    if (ret < 0) {
        mlog_errno(ret);
        goto cleanup_nolock;
    }
    xis.inode_bh = xbs.inode_bh = di_bh;
    di = (struct ocfs2_dinode *)di_bh->b_data;

    down_write(&OCFS2_I(inode)->ip_xattr_sem);
    /*
     * Scan inode and external block to find the same name
     * extended attribute and collect search information.
     */
    ret = ocfs2_xattr_ibody_find(inode, name_index, name, &xis);
    if (ret)
        goto cleanup;
    if (xis.not_found) {
        ret = ocfs2_xattr_block_find(inode, name_index, name, &xbs);
        if (ret)
            goto cleanup;
    }

    if (xis.not_found && xbs.not_found) {
        ret = -ENODATA;
        if (flags & XATTR_REPLACE)
            goto cleanup;
        ret = 0;
        if (!value)
            goto cleanup;
    } else {
        ret = -EEXIST;
        if (flags & XATTR_CREATE)
            goto cleanup;
    }

    /* Check whether the value is refcounted and do some preparation. */
    if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL &&
        (!xis.not_found || !xbs.not_found)) {
        ret = ocfs2_prepare_refcount_xattr(inode, di, &xi,
                           &xis, &xbs, &ref_tree,
                           &ref_meta, &ref_credits);
        if (ret) {
            mlog_errno(ret);
            goto cleanup;
        }
    }

    mutex_lock(&tl_inode->i_mutex);

    if (ocfs2_truncate_log_needs_flush(osb)) {
        ret = __ocfs2_flush_truncate_log(osb);
        if (ret < 0) {
            mutex_unlock(&tl_inode->i_mutex);
            mlog_errno(ret);
            goto cleanup;
        }
    }
    mutex_unlock(&tl_inode->i_mutex);

    ret = ocfs2_init_xattr_set_ctxt(inode, di, &xi, &xis,
                    &xbs, &ctxt, ref_meta, &credits);
    if (ret) {
        mlog_errno(ret);
        goto cleanup;
    }

    /* we need to update inode's ctime field, so add credit for it. */
    credits += OCFS2_INODE_UPDATE_CREDITS;
    ctxt.handle = ocfs2_start_trans(osb, credits + ref_credits);
    if (IS_ERR(ctxt.handle)) {
        ret = PTR_ERR(ctxt.handle);
        mlog_errno(ret);
        goto cleanup;
    }

    ret = __ocfs2_xattr_set_handle(inode, di, &xi, &xis, &xbs, &ctxt);

    ocfs2_commit_trans(osb, ctxt.handle);

    if (ctxt.data_ac)
        ocfs2_free_alloc_context(ctxt.data_ac);
    if (ctxt.meta_ac)
        ocfs2_free_alloc_context(ctxt.meta_ac);
    if (ocfs2_dealloc_has_cluster(&ctxt.dealloc))
        ocfs2_schedule_truncate_log_flush(osb, 1);
    ocfs2_run_deallocs(osb, &ctxt.dealloc);

cleanup:
    if (ref_tree)
        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
    up_write(&OCFS2_I(inode)->ip_xattr_sem);
    if (!value && !ret) {
        ret = ocfs2_try_remove_refcount_tree(inode, di_bh);
        if (ret)
            mlog_errno(ret);
    }
    ocfs2_inode_unlock(inode, 1);
cleanup_nolock:
    brelse(di_bh);
    brelse(xbs.xattr_bh);
    ocfs2_xattr_bucket_free(xbs.bucket);

    return ret;
}

/*
 * Find the xattr extent rec which may contains name_hash.
 * e_cpos will be the first name hash of the xattr rec.
 * el must be the ocfs2_xattr_header.xb_attrs.xb_root.xt_list.
 */
static int ocfs2_xattr_get_rec(struct inode *inode,
                   u32 name_hash,
                   u64 *p_blkno,
                   u32 *e_cpos,
                   u32 *num_clusters,
                   struct ocfs2_extent_list *el)
{
    int ret = 0, i;
    struct buffer_head *eb_bh = NULL;
    struct ocfs2_extent_block *eb;
    struct ocfs2_extent_rec *rec = NULL;
    u64 e_blkno = 0;

    if (el->l_tree_depth) {
        ret = ocfs2_find_leaf(INODE_CACHE(inode), el, name_hash,
                      &eb_bh);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        eb = (struct ocfs2_extent_block *) eb_bh->b_data;
        el = &eb->h_list;

        if (el->l_tree_depth) {
            ocfs2_error(inode->i_sb,
                    "Inode %lu has non zero tree depth in "
                    "xattr tree block %llu\n", inode->i_ino,
                    (unsigned long long)eb_bh->b_blocknr);
            ret = -EROFS;
            goto out;
        }
    }

    for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
        rec = &el->l_recs[i];

        if (le32_to_cpu(rec->e_cpos) <= name_hash) {
            e_blkno = le64_to_cpu(rec->e_blkno);
            break;
        }
    }

    if (!e_blkno) {
        ocfs2_error(inode->i_sb, "Inode %lu has bad extent "
                "record (%u, %u, 0) in xattr", inode->i_ino,
                le32_to_cpu(rec->e_cpos),
                ocfs2_rec_clusters(el, rec));
        ret = -EROFS;
        goto out;
    }

    *p_blkno = le64_to_cpu(rec->e_blkno);
    *num_clusters = le16_to_cpu(rec->e_leaf_clusters);
    if (e_cpos)
        *e_cpos = le32_to_cpu(rec->e_cpos);
out:
    brelse(eb_bh);
    return ret;
}

typedef int (xattr_bucket_func)(struct inode *inode,
                struct ocfs2_xattr_bucket *bucket,
                void *para);

static int ocfs2_find_xe_in_bucket(struct inode *inode,
                   struct ocfs2_xattr_bucket *bucket,
                   int name_index,
                   const char *name,
                   u32 name_hash,
                   u16 *xe_index,
                   int *found)
{
    int i, ret = 0, cmp = 1, block_off, new_offset;
    struct ocfs2_xattr_header *xh = bucket_xh(bucket);
    size_t name_len = strlen(name);
    struct ocfs2_xattr_entry *xe = NULL;
    char *xe_name;

    /*
     * We don't use binary search in the bucket because there
     * may be multiple entries with the same name hash.
     */
    for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
        xe = &xh->xh_entries[i];

        if (name_hash > le32_to_cpu(xe->xe_name_hash))
            continue;
        else if (name_hash < le32_to_cpu(xe->xe_name_hash))
            break;

        cmp = name_index - ocfs2_xattr_get_type(xe);
        if (!cmp)
            cmp = name_len - xe->xe_name_len;
        if (cmp)
            continue;

        ret = ocfs2_xattr_bucket_get_name_value(inode->i_sb,
                            xh,
                            i,
                            &block_off,
                            &new_offset);
        if (ret) {
            mlog_errno(ret);
            break;
        }


        xe_name = bucket_block(bucket, block_off) + new_offset;
        if (!memcmp(name, xe_name, name_len)) {
            *xe_index = i;
            *found = 1;
            ret = 0;
            break;
        }
    }

    return ret;
}

/*
 * Find the specified xattr entry in a series of buckets.
 * This series start from p_blkno and last for num_clusters.
 * The ocfs2_xattr_header.xh_num_buckets of the first bucket contains
 * the num of the valid buckets.
 *
 * Return the buffer_head this xattr should reside in. And if the xattr's
 * hash is in the gap of 2 buckets, return the lower bucket.
 */
static int ocfs2_xattr_bucket_find(struct inode *inode,
                   int name_index,
                   const char *name,
                   u32 name_hash,
                   u64 p_blkno,
                   u32 first_hash,
                   u32 num_clusters,
                   struct ocfs2_xattr_search *xs)
{
    int ret, found = 0;
    struct ocfs2_xattr_header *xh = NULL;
    struct ocfs2_xattr_entry *xe = NULL;
    u16 index = 0;
    u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
    int low_bucket = 0, bucket, high_bucket;
    struct ocfs2_xattr_bucket *search;
    u32 last_hash;
    u64 blkno, lower_blkno = 0;

    search = ocfs2_xattr_bucket_new(inode);
    if (!search) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_read_xattr_bucket(search, p_blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    xh = bucket_xh(search);
    high_bucket = le16_to_cpu(xh->xh_num_buckets) - 1;
    while (low_bucket <= high_bucket) {
        ocfs2_xattr_bucket_relse(search);

        bucket = (low_bucket + high_bucket) / 2;
        blkno = p_blkno + bucket * blk_per_bucket;
        ret = ocfs2_read_xattr_bucket(search, blkno);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        xh = bucket_xh(search);
        xe = &xh->xh_entries[0];
        if (name_hash < le32_to_cpu(xe->xe_name_hash)) {
            high_bucket = bucket - 1;
            continue;
        }

        /*
         * Check whether the hash of the last entry in our
         * bucket is larger than the search one. for an empty
         * bucket, the last one is also the first one.
         */
        if (xh->xh_count)
            xe = &xh->xh_entries[le16_to_cpu(xh->xh_count) - 1];

        last_hash = le32_to_cpu(xe->xe_name_hash);

        /* record lower_blkno which may be the insert place. */
        lower_blkno = blkno;

        if (name_hash > le32_to_cpu(xe->xe_name_hash)) {
            low_bucket = bucket + 1;
            continue;
        }

        /* the searched xattr should reside in this bucket if exists. */
        ret = ocfs2_find_xe_in_bucket(inode, search,
                          name_index, name, name_hash,
                          &index, &found);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
        break;
    }

    /*
     * Record the bucket we have found.
     * When the xattr's hash value is in the gap of 2 buckets, we will
     * always set it to the previous bucket.
     */
    if (!lower_blkno)
        lower_blkno = p_blkno;

    /* This should be in cache - we just read it during the search */
    ret = ocfs2_read_xattr_bucket(xs->bucket, lower_blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    xs->header = bucket_xh(xs->bucket);
    xs->base = bucket_block(xs->bucket, 0);
    xs->end = xs->base + inode->i_sb->s_blocksize;

    if (found) {
        xs->here = &xs->header->xh_entries[index];
        trace_ocfs2_xattr_bucket_find(OCFS2_I(inode)->ip_blkno,
            name, name_index, name_hash,
            (unsigned long long)bucket_blkno(xs->bucket),
            index);
    } else
        ret = -ENODATA;

out:
    ocfs2_xattr_bucket_free(search);
    return ret;
}

static int ocfs2_xattr_index_block_find(struct inode *inode,
                    struct buffer_head *root_bh,
                    int name_index,
                    const char *name,
                    struct ocfs2_xattr_search *xs)
{
    int ret;
    struct ocfs2_xattr_block *xb =
            (struct ocfs2_xattr_block *)root_bh->b_data;
    struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
    struct ocfs2_extent_list *el = &xb_root->xt_list;
    u64 p_blkno = 0;
    u32 first_hash, num_clusters = 0;
    u32 name_hash = ocfs2_xattr_name_hash(inode, name, strlen(name));

    if (le16_to_cpu(el->l_next_free_rec) == 0)
        return -ENODATA;

    trace_ocfs2_xattr_index_block_find(OCFS2_I(inode)->ip_blkno,
                    name, name_index, name_hash,
                    (unsigned long long)root_bh->b_blocknr,
                    -1);

    ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno, &first_hash,
                  &num_clusters, el);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    BUG_ON(p_blkno == 0 || num_clusters == 0 || first_hash > name_hash);

    trace_ocfs2_xattr_index_block_find_rec(OCFS2_I(inode)->ip_blkno,
                    name, name_index, first_hash,
                    (unsigned long long)p_blkno,
                    num_clusters);

    ret = ocfs2_xattr_bucket_find(inode, name_index, name, name_hash,
                      p_blkno, first_hash, num_clusters, xs);

out:
    return ret;
}

static int ocfs2_iterate_xattr_buckets(struct inode *inode,
                       u64 blkno,
                       u32 clusters,
                       xattr_bucket_func *func,
                       void *para)
{
    int i, ret = 0;
    u32 bpc = ocfs2_xattr_buckets_per_cluster(OCFS2_SB(inode->i_sb));
    u32 num_buckets = clusters * bpc;
    struct ocfs2_xattr_bucket *bucket;

    bucket = ocfs2_xattr_bucket_new(inode);
    if (!bucket) {
        mlog_errno(-ENOMEM);
        return -ENOMEM;
    }

    trace_ocfs2_iterate_xattr_buckets(
        (unsigned long long)OCFS2_I(inode)->ip_blkno,
        (unsigned long long)blkno, clusters);

    for (i = 0; i < num_buckets; i++, blkno += bucket->bu_blocks) {
        ret = ocfs2_read_xattr_bucket(bucket, blkno);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        /*
         * The real bucket num in this series of blocks is stored
         * in the 1st bucket.
         */
        if (i == 0)
            num_buckets = le16_to_cpu(bucket_xh(bucket)->xh_num_buckets);

        trace_ocfs2_iterate_xattr_bucket((unsigned long long)blkno,
             le32_to_cpu(bucket_xh(bucket)->xh_entries[0].xe_name_hash));
        if (func) {
            ret = func(inode, bucket, para);
            if (ret && ret != -ERANGE)
                mlog_errno(ret);
            /* Fall through to bucket_relse() */
        }

        ocfs2_xattr_bucket_relse(bucket);
        if (ret)
            break;
    }

    ocfs2_xattr_bucket_free(bucket);
    return ret;
}

struct ocfs2_xattr_tree_list {
    char *buffer;
    size_t buffer_size;
    size_t result;
};

static int ocfs2_xattr_bucket_get_name_value(struct super_block *sb,
                         struct ocfs2_xattr_header *xh,
                         int index,
                         int *block_off,
                         int *new_offset)
{
    u16 name_offset;

    if (index < 0 || index >= le16_to_cpu(xh->xh_count))
        return -EINVAL;

    name_offset = le16_to_cpu(xh->xh_entries[index].xe_name_offset);

    *block_off = name_offset >> sb->s_blocksize_bits;
    *new_offset = name_offset % sb->s_blocksize;

    return 0;
}

static int ocfs2_list_xattr_bucket(struct inode *inode,
                   struct ocfs2_xattr_bucket *bucket,
                   void *para)
{
    int ret = 0, type;
    struct ocfs2_xattr_tree_list *xl = (struct ocfs2_xattr_tree_list *)para;
    int i, block_off, new_offset;
    const char *prefix, *name;

    for (i = 0 ; i < le16_to_cpu(bucket_xh(bucket)->xh_count); i++) {
        struct ocfs2_xattr_entry *entry = &bucket_xh(bucket)->xh_entries[i];
        type = ocfs2_xattr_get_type(entry);
        prefix = ocfs2_xattr_prefix(type);

        if (prefix) {
            ret = ocfs2_xattr_bucket_get_name_value(inode->i_sb,
                                bucket_xh(bucket),
                                i,
                                &block_off,
                                &new_offset);
            if (ret)
                break;

            name = (const char *)bucket_block(bucket, block_off) +
                new_offset;
            ret = ocfs2_xattr_list_entry(xl->buffer,
                             xl->buffer_size,
                             &xl->result,
                             prefix, name,
                             entry->xe_name_len);
            if (ret)
                break;
        }
    }

    return ret;
}

static int ocfs2_iterate_xattr_index_block(struct inode *inode,
                       struct buffer_head *blk_bh,
                       xattr_tree_rec_func *rec_func,
                       void *para)
{
    struct ocfs2_xattr_block *xb =
            (struct ocfs2_xattr_block *)blk_bh->b_data;
    struct ocfs2_extent_list *el = &xb->xb_attrs.xb_root.xt_list;
    int ret = 0;
    u32 name_hash = UINT_MAX, e_cpos = 0, num_clusters = 0;
    u64 p_blkno = 0;

    if (!el->l_next_free_rec || !rec_func)
        return 0;

    while (name_hash > 0) {
        ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno,
                      &e_cpos, &num_clusters, el);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        ret = rec_func(inode, blk_bh, p_blkno, e_cpos,
                   num_clusters, para);
        if (ret) {
            if (ret != -ERANGE)
                mlog_errno(ret);
            break;
        }

        if (e_cpos == 0)
            break;

        name_hash = e_cpos - 1;
    }

    return ret;

}

static int ocfs2_list_xattr_tree_rec(struct inode *inode,
                     struct buffer_head *root_bh,
                     u64 blkno, u32 cpos, u32 len, void *para)
{
    return ocfs2_iterate_xattr_buckets(inode, blkno, len,
                       ocfs2_list_xattr_bucket, para);
}

static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
                         struct buffer_head *blk_bh,
                         char *buffer,
                         size_t buffer_size)
{
    int ret;
    struct ocfs2_xattr_tree_list xl = {
        .buffer = buffer,
        .buffer_size = buffer_size,
        .result = 0,
    };

    ret = ocfs2_iterate_xattr_index_block(inode, blk_bh,
                          ocfs2_list_xattr_tree_rec, &xl);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = xl.result;
out:
    return ret;
}

static int cmp_xe(const void *a, const void *b)
{
    const struct ocfs2_xattr_entry *l = a, *r = b;
    u32 l_hash = le32_to_cpu(l->xe_name_hash);
    u32 r_hash = le32_to_cpu(r->xe_name_hash);

    if (l_hash > r_hash)
        return 1;
    if (l_hash < r_hash)
        return -1;
    return 0;
}

static void swap_xe(void *a, void *b, int size)
{
    struct ocfs2_xattr_entry *l = a, *r = b, tmp;

    tmp = *l;
    memcpy(l, r, sizeof(struct ocfs2_xattr_entry));
    memcpy(r, &tmp, sizeof(struct ocfs2_xattr_entry));
}

/*
 * When the ocfs2_xattr_block is filled up, new bucket will be created
 * and all the xattr entries will be moved to the new bucket.
 * The header goes at the start of the bucket, and the names+values are
 * filled from the end.  This is why *target starts as the last buffer.
 * Note: we need to sort the entries since they are not saved in order
 * in the ocfs2_xattr_block.
 */
static void ocfs2_cp_xattr_block_to_bucket(struct inode *inode,
                       struct buffer_head *xb_bh,
                       struct ocfs2_xattr_bucket *bucket)
{
    int i, blocksize = inode->i_sb->s_blocksize;
    int blks = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
    u16 offset, size, off_change;
    struct ocfs2_xattr_entry *xe;
    struct ocfs2_xattr_block *xb =
                (struct ocfs2_xattr_block *)xb_bh->b_data;
    struct ocfs2_xattr_header *xb_xh = &xb->xb_attrs.xb_header;
    struct ocfs2_xattr_header *xh = bucket_xh(bucket);
    u16 count = le16_to_cpu(xb_xh->xh_count);
    char *src = xb_bh->b_data;
    char *target = bucket_block(bucket, blks - 1);

    trace_ocfs2_cp_xattr_block_to_bucket_begin(
                (unsigned long long)xb_bh->b_blocknr,
                (unsigned long long)bucket_blkno(bucket));

    for (i = 0; i < blks; i++)
        memset(bucket_block(bucket, i), 0, blocksize);

    /*
     * Since the xe_name_offset is based on ocfs2_xattr_header,
     * there is a offset change corresponding to the change of
     * ocfs2_xattr_header's position.
     */
    off_change = offsetof(struct ocfs2_xattr_block, xb_attrs.xb_header);
    xe = &xb_xh->xh_entries[count - 1];
    offset = le16_to_cpu(xe->xe_name_offset) + off_change;
    size = blocksize - offset;

    /* copy all the names and values. */
    memcpy(target + offset, src + offset, size);

    /* Init new header now. */
    xh->xh_count = xb_xh->xh_count;
    xh->xh_num_buckets = cpu_to_le16(1);
    xh->xh_name_value_len = cpu_to_le16(size);
    xh->xh_free_start = cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE - size);

    /* copy all the entries. */
    target = bucket_block(bucket, 0);
    offset = offsetof(struct ocfs2_xattr_header, xh_entries);
    size = count * sizeof(struct ocfs2_xattr_entry);
    memcpy(target + offset, (char *)xb_xh + offset, size);

    /* Change the xe offset for all the xe because of the move. */
    off_change = OCFS2_XATTR_BUCKET_SIZE - blocksize +
         offsetof(struct ocfs2_xattr_block, xb_attrs.xb_header);
    for (i = 0; i < count; i++)
        le16_add_cpu(&xh->xh_entries[i].xe_name_offset, off_change);

    trace_ocfs2_cp_xattr_block_to_bucket_end(offset, size, off_change);

    sort(target + offset, count, sizeof(struct ocfs2_xattr_entry),
         cmp_xe, swap_xe);
}

/*
 * After we move xattr from block to index btree, we have to
 * update ocfs2_xattr_search to the new xe and base.
 *
 * When the entry is in xattr block, xattr_bh indicates the storage place.
 * While if the entry is in index b-tree, "bucket" indicates the
 * real place of the xattr.
 */
static void ocfs2_xattr_update_xattr_search(struct inode *inode,
                        struct ocfs2_xattr_search *xs,
                        struct buffer_head *old_bh)
{
    char *buf = old_bh->b_data;
    struct ocfs2_xattr_block *old_xb = (struct ocfs2_xattr_block *)buf;
    struct ocfs2_xattr_header *old_xh = &old_xb->xb_attrs.xb_header;
    int i;

    xs->header = bucket_xh(xs->bucket);
    xs->base = bucket_block(xs->bucket, 0);
    xs->end = xs->base + inode->i_sb->s_blocksize;

    if (xs->not_found)
        return;

    i = xs->here - old_xh->xh_entries;
    xs->here = &xs->header->xh_entries[i];
}

static int ocfs2_xattr_create_index_block(struct inode *inode,
                      struct ocfs2_xattr_search *xs,
                      struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;
    u32 bit_off, len;
    u64 blkno;
    handle_t *handle = ctxt->handle;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct buffer_head *xb_bh = xs->xattr_bh;
    struct ocfs2_xattr_block *xb =
            (struct ocfs2_xattr_block *)xb_bh->b_data;
    struct ocfs2_xattr_tree_root *xr;
    u16 xb_flags = le16_to_cpu(xb->xb_flags);

    trace_ocfs2_xattr_create_index_block_begin(
                (unsigned long long)xb_bh->b_blocknr);

    BUG_ON(xb_flags & OCFS2_XATTR_INDEXED);
    BUG_ON(!xs->bucket);

    /*
     * XXX:
     * We can use this lock for now, and maybe move to a dedicated mutex
     * if performance becomes a problem later.
     */
    down_write(&oi->ip_alloc_sem);

    ret = ocfs2_journal_access_xb(handle, INODE_CACHE(inode), xb_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = __ocfs2_claim_clusters(handle, ctxt->data_ac,
                     1, 1, &bit_off, &len);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * The bucket may spread in many blocks, and
     * we will only touch the 1st block and the last block
     * in the whole bucket(one for entry and one for data).
     */
    blkno = ocfs2_clusters_to_blocks(inode->i_sb, bit_off);

    trace_ocfs2_xattr_create_index_block((unsigned long long)blkno);

    ret = ocfs2_init_xattr_bucket(xs->bucket, blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xattr_bucket_journal_access(handle, xs->bucket,
                        OCFS2_JOURNAL_ACCESS_CREATE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ocfs2_cp_xattr_block_to_bucket(inode, xb_bh, xs->bucket);
    ocfs2_xattr_bucket_journal_dirty(handle, xs->bucket);

    ocfs2_xattr_update_xattr_search(inode, xs, xb_bh);

    /* Change from ocfs2_xattr_header to ocfs2_xattr_tree_root */
    memset(&xb->xb_attrs, 0, inode->i_sb->s_blocksize -
           offsetof(struct ocfs2_xattr_block, xb_attrs));

    xr = &xb->xb_attrs.xb_root;
    xr->xt_clusters = cpu_to_le32(1);
    xr->xt_last_eb_blk = 0;
    xr->xt_list.l_tree_depth = 0;
    xr->xt_list.l_count = cpu_to_le16(ocfs2_xattr_recs_per_xb(inode->i_sb));
    xr->xt_list.l_next_free_rec = cpu_to_le16(1);

    xr->xt_list.l_recs[0].e_cpos = 0;
    xr->xt_list.l_recs[0].e_blkno = cpu_to_le64(blkno);
    xr->xt_list.l_recs[0].e_leaf_clusters = cpu_to_le16(1);

    xb->xb_flags = cpu_to_le16(xb_flags | OCFS2_XATTR_INDEXED);

    ocfs2_journal_dirty(handle, xb_bh);

out:
    up_write(&oi->ip_alloc_sem);

    return ret;
}

static int cmp_xe_offset(const void *a, const void *b)
{
    const struct ocfs2_xattr_entry *l = a, *r = b;
    u32 l_name_offset = le16_to_cpu(l->xe_name_offset);
    u32 r_name_offset = le16_to_cpu(r->xe_name_offset);

    if (l_name_offset < r_name_offset)
        return 1;
    if (l_name_offset > r_name_offset)
        return -1;
    return 0;
}

/*
 * defrag a xattr bucket if we find that the bucket has some
 * holes beteen name/value pairs.
 * We will move all the name/value pairs to the end of the bucket
 * so that we can spare some space for insertion.
 */
static int ocfs2_defrag_xattr_bucket(struct inode *inode,
                     handle_t *handle,
                     struct ocfs2_xattr_bucket *bucket)
{
    int ret, i;
    size_t end, offset, len;
    struct ocfs2_xattr_header *xh;
    char *entries, *buf, *bucket_buf = NULL;
    u64 blkno = bucket_blkno(bucket);
    u16 xh_free_start;
    size_t blocksize = inode->i_sb->s_blocksize;
    struct ocfs2_xattr_entry *xe;

    /*
     * In order to make the operation more efficient and generic,
     * we copy all the blocks into a contiguous memory and do the
     * defragment there, so if anything is error, we will not touch
     * the real block.
     */
    bucket_buf = kmalloc(OCFS2_XATTR_BUCKET_SIZE, GFP_NOFS);
    if (!bucket_buf) {
        ret = -EIO;
        goto out;
    }

    buf = bucket_buf;
    for (i = 0; i < bucket->bu_blocks; i++, buf += blocksize)
        memcpy(buf, bucket_block(bucket, i), blocksize);

    ret = ocfs2_xattr_bucket_journal_access(handle, bucket,
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret < 0) {
        mlog_errno(ret);
        goto out;
    }

    xh = (struct ocfs2_xattr_header *)bucket_buf;
    entries = (char *)xh->xh_entries;
    xh_free_start = le16_to_cpu(xh->xh_free_start);

    trace_ocfs2_defrag_xattr_bucket(
         (unsigned long long)blkno, le16_to_cpu(xh->xh_count),
         xh_free_start, le16_to_cpu(xh->xh_name_value_len));

    /*
     * sort all the entries by their offset.
     * the largest will be the first, so that we can
     * move them to the end one by one.
     */
    sort(entries, le16_to_cpu(xh->xh_count),
         sizeof(struct ocfs2_xattr_entry),
         cmp_xe_offset, swap_xe);

    /* Move all name/values to the end of the bucket. */
    xe = xh->xh_entries;
    end = OCFS2_XATTR_BUCKET_SIZE;
    for (i = 0; i < le16_to_cpu(xh->xh_count); i++, xe++) {
        offset = le16_to_cpu(xe->xe_name_offset);
        len = namevalue_size_xe(xe);

        /*
         * We must make sure that the name/value pair
         * exist in the same block. So adjust end to
         * the previous block end if needed.
         */
        if (((end - len) / blocksize !=
            (end - 1) / blocksize))
            end = end - end % blocksize;

        if (end > offset + len) {
            memmove(bucket_buf + end - len,
                bucket_buf + offset, len);
            xe->xe_name_offset = cpu_to_le16(end - len);
        }

        mlog_bug_on_msg(end < offset + len, "Defrag check failed for "
                "bucket %llu\n", (unsigned long long)blkno);

        end -= len;
    }

    mlog_bug_on_msg(xh_free_start > end, "Defrag check failed for "
            "bucket %llu\n", (unsigned long long)blkno);

    if (xh_free_start == end)
        goto out;

    memset(bucket_buf + xh_free_start, 0, end - xh_free_start);
    xh->xh_free_start = cpu_to_le16(end);

    /* sort the entries by their name_hash. */
    sort(entries, le16_to_cpu(xh->xh_count),
         sizeof(struct ocfs2_xattr_entry),
         cmp_xe, swap_xe);

    buf = bucket_buf;
    for (i = 0; i < bucket->bu_blocks; i++, buf += blocksize)
        memcpy(bucket_block(bucket, i), buf, blocksize);
    ocfs2_xattr_bucket_journal_dirty(handle, bucket);

out:
    kfree(bucket_buf);
    return ret;
}

/*
 * prev_blkno points to the start of an existing extent.  new_blkno
 * points to a newly allocated extent.  Because we know each of our
 * clusters contains more than bucket, we can easily split one cluster
 * at a bucket boundary.  So we take the last cluster of the existing
 * extent and split it down the middle.  We move the last half of the
 * buckets in the last cluster of the existing extent over to the new
 * extent.
 *
 * first_bh is the buffer at prev_blkno so we can update the existing
 * extent's bucket count.  header_bh is the bucket were we were hoping
 * to insert our xattr.  If the bucket move places the target in the new
 * extent, we'll update first_bh and header_bh after modifying the old
 * extent.
 *
 * first_hash will be set as the 1st xe's name_hash in the new extent.
 */
static int ocfs2_mv_xattr_bucket_cross_cluster(struct inode *inode,
                           handle_t *handle,
                           struct ocfs2_xattr_bucket *first,
                           struct ocfs2_xattr_bucket *target,
                           u64 new_blkno,
                           u32 num_clusters,
                           u32 *first_hash)
{
    int ret;
    struct super_block *sb = inode->i_sb;
    int blks_per_bucket = ocfs2_blocks_per_xattr_bucket(sb);
    int num_buckets = ocfs2_xattr_buckets_per_cluster(OCFS2_SB(sb));
    int to_move = num_buckets / 2;
    u64 src_blkno;
    u64 last_cluster_blkno = bucket_blkno(first) +
        ((num_clusters - 1) * ocfs2_clusters_to_blocks(sb, 1));

    BUG_ON(le16_to_cpu(bucket_xh(first)->xh_num_buckets) < num_buckets);
    BUG_ON(OCFS2_XATTR_BUCKET_SIZE == OCFS2_SB(sb)->s_clustersize);

    trace_ocfs2_mv_xattr_bucket_cross_cluster(
                (unsigned long long)last_cluster_blkno,
                (unsigned long long)new_blkno);

    ret = ocfs2_mv_xattr_buckets(inode, handle, bucket_blkno(first),
                     last_cluster_blkno, new_blkno,
                     to_move, first_hash);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /* This is the first bucket that got moved */
    src_blkno = last_cluster_blkno + (to_move * blks_per_bucket);

    /*
     * If the target bucket was part of the moved buckets, we need to
     * update first and target.
     */
    if (bucket_blkno(target) >= src_blkno) {
        /* Find the block for the new target bucket */
        src_blkno = new_blkno +
            (bucket_blkno(target) - src_blkno);

        ocfs2_xattr_bucket_relse(first);
        ocfs2_xattr_bucket_relse(target);

        /*
         * These shouldn't fail - the buffers are in the
         * journal from ocfs2_cp_xattr_bucket().
         */
        ret = ocfs2_read_xattr_bucket(first, new_blkno);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
        ret = ocfs2_read_xattr_bucket(target, src_blkno);
        if (ret)
            mlog_errno(ret);

    }

out:
    return ret;
}

/*
 * Find the suitable pos when we divide a bucket into 2.
 * We have to make sure the xattrs with the same hash value exist
 * in the same bucket.
 *
 * If this ocfs2_xattr_header covers more than one hash value, find a
 * place where the hash value changes.  Try to find the most even split.
 * The most common case is that all entries have different hash values,
 * and the first check we make will find a place to split.
 */
static int ocfs2_xattr_find_divide_pos(struct ocfs2_xattr_header *xh)
{
    struct ocfs2_xattr_entry *entries = xh->xh_entries;
    int count = le16_to_cpu(xh->xh_count);
    int delta, middle = count / 2;

    /*
     * We start at the middle.  Each step gets farther away in both
     * directions.  We therefore hit the change in hash value
     * nearest to the middle.  Note that this loop does not execute for
     * count < 2.
     */
    for (delta = 0; delta < middle; delta++) {
        /* Let's check delta earlier than middle */
        if (cmp_xe(&entries[middle - delta - 1],
               &entries[middle - delta]))
            return middle - delta;

        /* For even counts, don't walk off the end */
        if ((middle + delta + 1) == count)
            continue;

        /* Now try delta past middle */
        if (cmp_xe(&entries[middle + delta],
               &entries[middle + delta + 1]))
            return middle + delta + 1;
    }

    /* Every entry had the same hash */
    return count;
}

/*
 * Move some xattrs in old bucket(blk) to new bucket(new_blk).
 * first_hash will record the 1st hash of the new bucket.
 *
 * Normally half of the xattrs will be moved.  But we have to make
 * sure that the xattrs with the same hash value are stored in the
 * same bucket. If all the xattrs in this bucket have the same hash
 * value, the new bucket will be initialized as an empty one and the
 * first_hash will be initialized as (hash_value+1).
 */
static int ocfs2_divide_xattr_bucket(struct inode *inode,
                    handle_t *handle,
                    u64 blk,
                    u64 new_blk,
                    u32 *first_hash,
                    int new_bucket_head)
{
    int ret, i;
    int count, start, len, name_value_len = 0, name_offset = 0;
    struct ocfs2_xattr_bucket *s_bucket = NULL, *t_bucket = NULL;
    struct ocfs2_xattr_header *xh;
    struct ocfs2_xattr_entry *xe;
    int blocksize = inode->i_sb->s_blocksize;

    trace_ocfs2_divide_xattr_bucket_begin((unsigned long long)blk,
                          (unsigned long long)new_blk);

    s_bucket = ocfs2_xattr_bucket_new(inode);
    t_bucket = ocfs2_xattr_bucket_new(inode);
    if (!s_bucket || !t_bucket) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_read_xattr_bucket(s_bucket, blk);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xattr_bucket_journal_access(handle, s_bucket,
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * Even if !new_bucket_head, we're overwriting t_bucket.  Thus,
     * there's no need to read it.
     */
    ret = ocfs2_init_xattr_bucket(t_bucket, new_blk);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * Hey, if we're overwriting t_bucket, what difference does
     * ACCESS_CREATE vs ACCESS_WRITE make?  See the comment in the
     * same part of ocfs2_cp_xattr_bucket().
     */
    ret = ocfs2_xattr_bucket_journal_access(handle, t_bucket,
                        new_bucket_head ?
                        OCFS2_JOURNAL_ACCESS_CREATE :
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    xh = bucket_xh(s_bucket);
    count = le16_to_cpu(xh->xh_count);
    start = ocfs2_xattr_find_divide_pos(xh);

    if (start == count) {
        xe = &xh->xh_entries[start-1];

        /*
         * initialized a new empty bucket here.
         * The hash value is set as one larger than
         * that of the last entry in the previous bucket.
         */
        for (i = 0; i < t_bucket->bu_blocks; i++)
            memset(bucket_block(t_bucket, i), 0, blocksize);

        xh = bucket_xh(t_bucket);
        xh->xh_free_start = cpu_to_le16(blocksize);
        xh->xh_entries[0].xe_name_hash = xe->xe_name_hash;
        le32_add_cpu(&xh->xh_entries[0].xe_name_hash, 1);

        goto set_num_buckets;
    }

    /* copy the whole bucket to the new first. */
    ocfs2_xattr_bucket_copy_data(t_bucket, s_bucket);

    /* update the new bucket. */
    xh = bucket_xh(t_bucket);

    /*
     * Calculate the total name/value len and xh_free_start for
     * the old bucket first.
     */
    name_offset = OCFS2_XATTR_BUCKET_SIZE;
    name_value_len = 0;
    for (i = 0; i < start; i++) {
        xe = &xh->xh_entries[i];
        name_value_len += namevalue_size_xe(xe);
        if (le16_to_cpu(xe->xe_name_offset) < name_offset)
            name_offset = le16_to_cpu(xe->xe_name_offset);
    }

    /*
     * Now begin the modification to the new bucket.
     *
     * In the new bucket, We just move the xattr entry to the beginning
     * and don't touch the name/value. So there will be some holes in the
     * bucket, and they will be removed when ocfs2_defrag_xattr_bucket is
     * called.
     */
    xe = &xh->xh_entries[start];
    len = sizeof(struct ocfs2_xattr_entry) * (count - start);
    trace_ocfs2_divide_xattr_bucket_move(len,
            (int)((char *)xe - (char *)xh),
            (int)((char *)xh->xh_entries - (char *)xh));
    memmove((char *)xh->xh_entries, (char *)xe, len);
    xe = &xh->xh_entries[count - start];
    len = sizeof(struct ocfs2_xattr_entry) * start;
    memset((char *)xe, 0, len);

    le16_add_cpu(&xh->xh_count, -start);
    le16_add_cpu(&xh->xh_name_value_len, -name_value_len);

    /* Calculate xh_free_start for the new bucket. */
    xh->xh_free_start = cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE);
    for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
        xe = &xh->xh_entries[i];
        if (le16_to_cpu(xe->xe_name_offset) <
            le16_to_cpu(xh->xh_free_start))
            xh->xh_free_start = xe->xe_name_offset;
    }

set_num_buckets:
    /* set xh->xh_num_buckets for the new xh. */
    if (new_bucket_head)
        xh->xh_num_buckets = cpu_to_le16(1);
    else
        xh->xh_num_buckets = 0;

    ocfs2_xattr_bucket_journal_dirty(handle, t_bucket);

    /* store the first_hash of the new bucket. */
    if (first_hash)
        *first_hash = le32_to_cpu(xh->xh_entries[0].xe_name_hash);

    /*
     * Now only update the 1st block of the old bucket.  If we
     * just added a new empty bucket, there is no need to modify
     * it.
     */
    if (start == count)
        goto out;

    xh = bucket_xh(s_bucket);
    memset(&xh->xh_entries[start], 0,
           sizeof(struct ocfs2_xattr_entry) * (count - start));
    xh->xh_count = cpu_to_le16(start);
    xh->xh_free_start = cpu_to_le16(name_offset);
    xh->xh_name_value_len = cpu_to_le16(name_value_len);

    ocfs2_xattr_bucket_journal_dirty(handle, s_bucket);

out:
    ocfs2_xattr_bucket_free(s_bucket);
    ocfs2_xattr_bucket_free(t_bucket);

    return ret;
}

/*
 * Copy xattr from one bucket to another bucket.
 *
 * The caller must make sure that the journal transaction
 * has enough space for journaling.
 */
static int ocfs2_cp_xattr_bucket(struct inode *inode,
                 handle_t *handle,
                 u64 s_blkno,
                 u64 t_blkno,
                 int t_is_new)
{
    int ret;
    struct ocfs2_xattr_bucket *s_bucket = NULL, *t_bucket = NULL;

    BUG_ON(s_blkno == t_blkno);

    trace_ocfs2_cp_xattr_bucket((unsigned long long)s_blkno,
                    (unsigned long long)t_blkno,
                    t_is_new);

    s_bucket = ocfs2_xattr_bucket_new(inode);
    t_bucket = ocfs2_xattr_bucket_new(inode);
    if (!s_bucket || !t_bucket) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_read_xattr_bucket(s_bucket, s_blkno);
    if (ret)
        goto out;

    /*
     * Even if !t_is_new, we're overwriting t_bucket.  Thus,
     * there's no need to read it.
     */
    ret = ocfs2_init_xattr_bucket(t_bucket, t_blkno);
    if (ret)
        goto out;

    /*
     * Hey, if we're overwriting t_bucket, what difference does
     * ACCESS_CREATE vs ACCESS_WRITE make?  Well, if we allocated a new
     * cluster to fill, we came here from
     * ocfs2_mv_xattr_buckets(), and it is really new -
     * ACCESS_CREATE is required.  But we also might have moved data
     * out of t_bucket before extending back into it.
     * ocfs2_add_new_xattr_bucket() can do this - its call to
     * ocfs2_add_new_xattr_cluster() may have created a new extent
     * and copied out the end of the old extent.  Then it re-extends
     * the old extent back to create space for new xattrs.  That's
     * how we get here, and the bucket isn't really new.
     */
    ret = ocfs2_xattr_bucket_journal_access(handle, t_bucket,
                        t_is_new ?
                        OCFS2_JOURNAL_ACCESS_CREATE :
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret)
        goto out;

    ocfs2_xattr_bucket_copy_data(t_bucket, s_bucket);
    ocfs2_xattr_bucket_journal_dirty(handle, t_bucket);

out:
    ocfs2_xattr_bucket_free(t_bucket);
    ocfs2_xattr_bucket_free(s_bucket);

    return ret;
}

/*
 * src_blk points to the start of an existing extent.  last_blk points to
 * last cluster in that extent.  to_blk points to a newly allocated
 * extent.  We copy the buckets from the cluster at last_blk to the new
 * extent.  If start_bucket is non-zero, we skip that many buckets before
 * we start copying.  The new extent's xh_num_buckets gets set to the
 * number of buckets we copied.  The old extent's xh_num_buckets shrinks
 * by the same amount.
 */
static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
                  u64 src_blk, u64 last_blk, u64 to_blk,
                  unsigned int start_bucket,
                  u32 *first_hash)
{
    int i, ret, credits;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    int blks_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
    int num_buckets = ocfs2_xattr_buckets_per_cluster(osb);
    struct ocfs2_xattr_bucket *old_first, *new_first;

    trace_ocfs2_mv_xattr_buckets((unsigned long long)last_blk,
                     (unsigned long long)to_blk);

    BUG_ON(start_bucket >= num_buckets);
    if (start_bucket) {
        num_buckets -= start_bucket;
        last_blk += (start_bucket * blks_per_bucket);
    }

    /* The first bucket of the original extent */
    old_first = ocfs2_xattr_bucket_new(inode);
    /* The first bucket of the new extent */
    new_first = ocfs2_xattr_bucket_new(inode);
    if (!old_first || !new_first) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_read_xattr_bucket(old_first, src_blk);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * We need to update the first bucket of the old extent and all
     * the buckets going to the new extent.
     */
    credits = ((num_buckets + 1) * blks_per_bucket);
    ret = ocfs2_extend_trans(handle, credits);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xattr_bucket_journal_access(handle, old_first,
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    for (i = 0; i < num_buckets; i++) {
        ret = ocfs2_cp_xattr_bucket(inode, handle,
                        last_blk + (i * blks_per_bucket),
                        to_blk + (i * blks_per_bucket),
                        1);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
    }

    /*
     * Get the new bucket ready before we dirty anything
     * (This actually shouldn't fail, because we already dirtied
     * it once in ocfs2_cp_xattr_bucket()).
     */
    ret = ocfs2_read_xattr_bucket(new_first, to_blk);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }
    ret = ocfs2_xattr_bucket_journal_access(handle, new_first,
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /* Now update the headers */
    le16_add_cpu(&bucket_xh(old_first)->xh_num_buckets, -num_buckets);
    ocfs2_xattr_bucket_journal_dirty(handle, old_first);

    bucket_xh(new_first)->xh_num_buckets = cpu_to_le16(num_buckets);
    ocfs2_xattr_bucket_journal_dirty(handle, new_first);

    if (first_hash)
        *first_hash = le32_to_cpu(bucket_xh(new_first)->xh_entries[0].xe_name_hash);

out:
    ocfs2_xattr_bucket_free(new_first);
    ocfs2_xattr_bucket_free(old_first);
    return ret;
}

/*
 * Move some xattrs in this cluster to the new cluster.
 * This function should only be called when bucket size == cluster size.
 * Otherwise ocfs2_mv_xattr_bucket_cross_cluster should be used instead.
 */
static int ocfs2_divide_xattr_cluster(struct inode *inode,
                      handle_t *handle,
                      u64 prev_blk,
                      u64 new_blk,
                      u32 *first_hash)
{
    u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
    int ret, credits = 2 * blk_per_bucket;

    BUG_ON(OCFS2_XATTR_BUCKET_SIZE < OCFS2_SB(inode->i_sb)->s_clustersize);

    ret = ocfs2_extend_trans(handle, credits);
    if (ret) {
        mlog_errno(ret);
        return ret;
    }

    /* Move half of the xattr in start_blk to the next bucket. */
    return  ocfs2_divide_xattr_bucket(inode, handle, prev_blk,
                      new_blk, first_hash, 1);
}

/*
 * Move some xattrs from the old cluster to the new one since they are not
 * contiguous in ocfs2 xattr tree.
 *
 * new_blk starts a new separate cluster, and we will move some xattrs from
 * prev_blk to it. v_start will be set as the first name hash value in this
 * new cluster so that it can be used as e_cpos during tree insertion and
 * don't collide with our original b-tree operations. first_bh and header_bh
 * will also be updated since they will be used in ocfs2_extend_xattr_bucket
 * to extend the insert bucket.
 *
 * The problem is how much xattr should we move to the new one and when should
 * we update first_bh and header_bh?
 * 1. If cluster size > bucket size, that means the previous cluster has more
 *    than 1 bucket, so just move half nums of bucket into the new cluster and
 *    update the first_bh and header_bh if the insert bucket has been moved
 *    to the new cluster.
 * 2. If cluster_size == bucket_size:
 *    a) If the previous extent rec has more than one cluster and the insert
 *       place isn't in the last cluster, copy the entire last cluster to the
 *       new one. This time, we don't need to upate the first_bh and header_bh
 *       since they will not be moved into the new cluster.
 *    b) Otherwise, move the bottom half of the xattrs in the last cluster into
 *       the new one. And we set the extend flag to zero if the insert place is
 *       moved into the new allocated cluster since no extend is needed.
 */
static int ocfs2_adjust_xattr_cross_cluster(struct inode *inode,
                        handle_t *handle,
                        struct ocfs2_xattr_bucket *first,
                        struct ocfs2_xattr_bucket *target,
                        u64 new_blk,
                        u32 prev_clusters,
                        u32 *v_start,
                        int *extend)
{
    int ret;

    trace_ocfs2_adjust_xattr_cross_cluster(
            (unsigned long long)bucket_blkno(first),
            (unsigned long long)new_blk, prev_clusters);

    if (ocfs2_xattr_buckets_per_cluster(OCFS2_SB(inode->i_sb)) > 1) {
        ret = ocfs2_mv_xattr_bucket_cross_cluster(inode,
                              handle,
                              first, target,
                              new_blk,
                              prev_clusters,
                              v_start);
        if (ret)
            mlog_errno(ret);
    } else {
        /* The start of the last cluster in the first extent */
        u64 last_blk = bucket_blkno(first) +
            ((prev_clusters - 1) *
             ocfs2_clusters_to_blocks(inode->i_sb, 1));

        if (prev_clusters > 1 && bucket_blkno(target) != last_blk) {
            ret = ocfs2_mv_xattr_buckets(inode, handle,
                             bucket_blkno(first),
                             last_blk, new_blk, 0,
                             v_start);
            if (ret)
                mlog_errno(ret);
        } else {
            ret = ocfs2_divide_xattr_cluster(inode, handle,
                             last_blk, new_blk,
                             v_start);
            if (ret)
                mlog_errno(ret);

            if ((bucket_blkno(target) == last_blk) && extend)
                *extend = 0;
        }
    }

    return ret;
}

/*
 * Add a new cluster for xattr storage.
 *
 * If the new cluster is contiguous with the previous one, it will be
 * appended to the same extent record, and num_clusters will be updated.
 * If not, we will insert a new extent for it and move some xattrs in
 * the last cluster into the new allocated one.
 * We also need to limit the maximum size of a btree leaf, otherwise we'll
 * lose the benefits of hashing because we'll have to search large leaves.
 * So now the maximum size is OCFS2_MAX_XATTR_TREE_LEAF_SIZE(or clustersize,
 * if it's bigger).
 *
 * first_bh is the first block of the previous extent rec and header_bh
 * indicates the bucket we will insert the new xattrs. They will be updated
 * when the header_bh is moved into the new cluster.
 */
static int ocfs2_add_new_xattr_cluster(struct inode *inode,
                       struct buffer_head *root_bh,
                       struct ocfs2_xattr_bucket *first,
                       struct ocfs2_xattr_bucket *target,
                       u32 *num_clusters,
                       u32 prev_cpos,
                       int *extend,
                       struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;
    u16 bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
    u32 prev_clusters = *num_clusters;
    u32 clusters_to_add = 1, bit_off, num_bits, v_start = 0;
    u64 block;
    handle_t *handle = ctxt->handle;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct ocfs2_extent_tree et;

    trace_ocfs2_add_new_xattr_cluster_begin(
        (unsigned long long)OCFS2_I(inode)->ip_blkno,
        (unsigned long long)bucket_blkno(first),
        prev_cpos, prev_clusters);

    ocfs2_init_xattr_tree_extent_tree(&et, INODE_CACHE(inode), root_bh);

    ret = ocfs2_journal_access_xb(handle, INODE_CACHE(inode), root_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret < 0) {
        mlog_errno(ret);
        goto leave;
    }

    ret = __ocfs2_claim_clusters(handle, ctxt->data_ac, 1,
                     clusters_to_add, &bit_off, &num_bits);
    if (ret < 0) {
        if (ret != -ENOSPC)
            mlog_errno(ret);
        goto leave;
    }

    BUG_ON(num_bits > clusters_to_add);

    block = ocfs2_clusters_to_blocks(osb->sb, bit_off);
    trace_ocfs2_add_new_xattr_cluster((unsigned long long)block, num_bits);

    if (bucket_blkno(first) + (prev_clusters * bpc) == block &&
        (prev_clusters + num_bits) << osb->s_clustersize_bits <=
         OCFS2_MAX_XATTR_TREE_LEAF_SIZE) {
        /*
         * If this cluster is contiguous with the old one and
         * adding this new cluster, we don't surpass the limit of
         * OCFS2_MAX_XATTR_TREE_LEAF_SIZE, cool. We will let it be
         * initialized and used like other buckets in the previous
         * cluster.
         * So add it as a contiguous one. The caller will handle
         * its init process.
         */
        v_start = prev_cpos + prev_clusters;
        *num_clusters = prev_clusters + num_bits;
    } else {
        ret = ocfs2_adjust_xattr_cross_cluster(inode,
                               handle,
                               first,
                               target,
                               block,
                               prev_clusters,
                               &v_start,
                               extend);
        if (ret) {
            mlog_errno(ret);
            goto leave;
        }
    }

    trace_ocfs2_add_new_xattr_cluster_insert((unsigned long long)block,
                         v_start, num_bits);
    ret = ocfs2_insert_extent(handle, &et, v_start, block,
                  num_bits, 0, ctxt->meta_ac);
    if (ret < 0) {
        mlog_errno(ret);
        goto leave;
    }

    ocfs2_journal_dirty(handle, root_bh);

leave:
    return ret;
}

/*
 * We are given an extent.  'first' is the bucket at the very front of
 * the extent.  The extent has space for an additional bucket past
 * bucket_xh(first)->xh_num_buckets.  'target_blkno' is the block number
 * of the target bucket.  We wish to shift every bucket past the target
 * down one, filling in that additional space.  When we get back to the
 * target, we split the target between itself and the now-empty bucket
 * at target+1 (aka, target_blkno + blks_per_bucket).
 */
static int ocfs2_extend_xattr_bucket(struct inode *inode,
                     handle_t *handle,
                     struct ocfs2_xattr_bucket *first,
                     u64 target_blk,
                     u32 num_clusters)
{
    int ret, credits;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
    u64 end_blk;
    u16 new_bucket = le16_to_cpu(bucket_xh(first)->xh_num_buckets);

    trace_ocfs2_extend_xattr_bucket((unsigned long long)target_blk,
                    (unsigned long long)bucket_blkno(first),
                    num_clusters, new_bucket);

    /* The extent must have room for an additional bucket */
    BUG_ON(new_bucket >=
           (num_clusters * ocfs2_xattr_buckets_per_cluster(osb)));

    /* end_blk points to the last existing bucket */
    end_blk = bucket_blkno(first) + ((new_bucket - 1) * blk_per_bucket);

    /*
     * end_blk is the start of the last existing bucket.
     * Thus, (end_blk - target_blk) covers the target bucket and
     * every bucket after it up to, but not including, the last
     * existing bucket.  Then we add the last existing bucket, the
     * new bucket, and the first bucket (3 * blk_per_bucket).
     */
    credits = (end_blk - target_blk) + (3 * blk_per_bucket);
    ret = ocfs2_extend_trans(handle, credits);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xattr_bucket_journal_access(handle, first,
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    while (end_blk != target_blk) {
        ret = ocfs2_cp_xattr_bucket(inode, handle, end_blk,
                        end_blk + blk_per_bucket, 0);
        if (ret)
            goto out;
        end_blk -= blk_per_bucket;
    }

    /* Move half of the xattr in target_blkno to the next bucket. */
    ret = ocfs2_divide_xattr_bucket(inode, handle, target_blk,
                    target_blk + blk_per_bucket, NULL, 0);

    le16_add_cpu(&bucket_xh(first)->xh_num_buckets, 1);
    ocfs2_xattr_bucket_journal_dirty(handle, first);

out:
    return ret;
}

/*
 * Add new xattr bucket in an extent record and adjust the buckets
 * accordingly.  xb_bh is the ocfs2_xattr_block, and target is the
 * bucket we want to insert into.
 *
 * In the easy case, we will move all the buckets after target down by
 * one. Half of target's xattrs will be moved to the next bucket.
 *
 * If current cluster is full, we'll allocate a new one.  This may not
 * be contiguous.  The underlying calls will make sure that there is
 * space for the insert, shifting buckets around if necessary.
 * 'target' may be moved by those calls.
 */
static int ocfs2_add_new_xattr_bucket(struct inode *inode,
                      struct buffer_head *xb_bh,
                      struct ocfs2_xattr_bucket *target,
                      struct ocfs2_xattr_set_ctxt *ctxt)
{
    struct ocfs2_xattr_block *xb =
            (struct ocfs2_xattr_block *)xb_bh->b_data;
    struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
    struct ocfs2_extent_list *el = &xb_root->xt_list;
    u32 name_hash =
        le32_to_cpu(bucket_xh(target)->xh_entries[0].xe_name_hash);
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    int ret, num_buckets, extend = 1;
    u64 p_blkno;
    u32 e_cpos, num_clusters;
    /* The bucket at the front of the extent */
    struct ocfs2_xattr_bucket *first;

    trace_ocfs2_add_new_xattr_bucket(
                (unsigned long long)bucket_blkno(target));

    /* The first bucket of the original extent */
    first = ocfs2_xattr_bucket_new(inode);
    if (!first) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno, &e_cpos,
                  &num_clusters, el);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_read_xattr_bucket(first, p_blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    num_buckets = ocfs2_xattr_buckets_per_cluster(osb) * num_clusters;
    if (num_buckets == le16_to_cpu(bucket_xh(first)->xh_num_buckets)) {
        /*
         * This can move first+target if the target bucket moves
         * to the new extent.
         */
        ret = ocfs2_add_new_xattr_cluster(inode,
                          xb_bh,
                          first,
                          target,
                          &num_clusters,
                          e_cpos,
                          &extend,
                          ctxt);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
    }

    if (extend) {
        ret = ocfs2_extend_xattr_bucket(inode,
                        ctxt->handle,
                        first,
                        bucket_blkno(target),
                        num_clusters);
        if (ret)
            mlog_errno(ret);
    }

out:
    ocfs2_xattr_bucket_free(first);

    return ret;
}

static inline char *ocfs2_xattr_bucket_get_val(struct inode *inode,
                    struct ocfs2_xattr_bucket *bucket,
                    int offs)
{
    int block_off = offs >> inode->i_sb->s_blocksize_bits;

    offs = offs % inode->i_sb->s_blocksize;
    return bucket_block(bucket, block_off) + offs;
}

/*
 * Truncate the specified xe_off entry in xattr bucket.
 * bucket is indicated by header_bh and len is the new length.
 * Both the ocfs2_xattr_value_root and the entry will be updated here.
 *
 * Copy the new updated xe and xe_value_root to new_xe and new_xv if needed.
 */
static int ocfs2_xattr_bucket_value_truncate(struct inode *inode,
                         struct ocfs2_xattr_bucket *bucket,
                         int xe_off,
                         int len,
                         struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret, offset;
    u64 value_blk;
    struct ocfs2_xattr_entry *xe;
    struct ocfs2_xattr_header *xh = bucket_xh(bucket);
    size_t blocksize = inode->i_sb->s_blocksize;
    struct ocfs2_xattr_value_buf vb = {
        .vb_access = ocfs2_journal_access,
    };

    xe = &xh->xh_entries[xe_off];

    BUG_ON(!xe || ocfs2_xattr_is_local(xe));

    offset = le16_to_cpu(xe->xe_name_offset) +
         OCFS2_XATTR_SIZE(xe->xe_name_len);

    value_blk = offset / blocksize;

    /* We don't allow ocfs2_xattr_value to be stored in different block. */
    BUG_ON(value_blk != (offset + OCFS2_XATTR_ROOT_SIZE - 1) / blocksize);

    vb.vb_bh = bucket->bu_bhs[value_blk];
    BUG_ON(!vb.vb_bh);

    vb.vb_xv = (struct ocfs2_xattr_value_root *)
        (vb.vb_bh->b_data + offset % blocksize);

    /*
     * From here on out we have to dirty the bucket.  The generic
     * value calls only modify one of the bucket's bhs, but we need
     * to send the bucket at once.  So if they error, they *could* have
     * modified something.  We have to assume they did, and dirty
     * the whole bucket.  This leaves us in a consistent state.
     */
    trace_ocfs2_xattr_bucket_value_truncate(
            (unsigned long long)bucket_blkno(bucket), xe_off, len);
    ret = ocfs2_xattr_value_truncate(inode, &vb, len, ctxt);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xattr_bucket_journal_access(ctxt->handle, bucket,
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    xe->xe_value_size = cpu_to_le64(len);

    ocfs2_xattr_bucket_journal_dirty(ctxt->handle, bucket);

out:
    return ret;
}

static int ocfs2_rm_xattr_cluster(struct inode *inode,
                  struct buffer_head *root_bh,
                  u64 blkno,
                  u32 cpos,
                  u32 len,
                  void *para)
{
    int ret;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct inode *tl_inode = osb->osb_tl_inode;
    handle_t *handle;
    struct ocfs2_xattr_block *xb =
            (struct ocfs2_xattr_block *)root_bh->b_data;
    struct ocfs2_alloc_context *meta_ac = NULL;
    struct ocfs2_cached_dealloc_ctxt dealloc;
    struct ocfs2_extent_tree et;

    ret = ocfs2_iterate_xattr_buckets(inode, blkno, len,
                      ocfs2_delete_xattr_in_bucket, para);
    if (ret) {
        mlog_errno(ret);
        return ret;
    }

    ocfs2_init_xattr_tree_extent_tree(&et, INODE_CACHE(inode), root_bh);

    ocfs2_init_dealloc_ctxt(&dealloc);

    trace_ocfs2_rm_xattr_cluster(
            (unsigned long long)OCFS2_I(inode)->ip_blkno,
            (unsigned long long)blkno, cpos, len);

    ocfs2_remove_xattr_clusters_from_cache(INODE_CACHE(inode), blkno,
                           len);

    ret = ocfs2_lock_allocators(inode, &et, 0, 1, NULL, &meta_ac);
    if (ret) {
        mlog_errno(ret);
        return ret;
    }

    mutex_lock(&tl_inode->i_mutex);

    if (ocfs2_truncate_log_needs_flush(osb)) {
        ret = __ocfs2_flush_truncate_log(osb);
        if (ret < 0) {
            mlog_errno(ret);
            goto out;
        }
    }

    handle = ocfs2_start_trans(osb, ocfs2_remove_extent_credits(osb->sb));
    if (IS_ERR(handle)) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_journal_access_xb(handle, INODE_CACHE(inode), root_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    ret = ocfs2_remove_extent(handle, &et, cpos, len, meta_ac,
                  &dealloc);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    le32_add_cpu(&xb->xb_attrs.xb_root.xt_clusters, -len);
    ocfs2_journal_dirty(handle, root_bh);

    ret = ocfs2_truncate_log_append(osb, handle, blkno, len);
    if (ret)
        mlog_errno(ret);

out_commit:
    ocfs2_commit_trans(osb, handle);
out:
    ocfs2_schedule_truncate_log_flush(osb, 1);

    mutex_unlock(&tl_inode->i_mutex);

    if (meta_ac)
        ocfs2_free_alloc_context(meta_ac);

    ocfs2_run_deallocs(osb, &dealloc);

    return ret;
}

/*
 * check whether the xattr bucket is filled up with the same hash value.
 * If we want to insert the xattr with the same hash, return -ENOSPC.
 * If we want to insert a xattr with different hash value, go ahead
 * and ocfs2_divide_xattr_bucket will handle this.
 */
static int ocfs2_check_xattr_bucket_collision(struct inode *inode,
                          struct ocfs2_xattr_bucket *bucket,
                          const char *name)
{
    struct ocfs2_xattr_header *xh = bucket_xh(bucket);
    u32 name_hash = ocfs2_xattr_name_hash(inode, name, strlen(name));

    if (name_hash != le32_to_cpu(xh->xh_entries[0].xe_name_hash))
        return 0;

    if (xh->xh_entries[le16_to_cpu(xh->xh_count) - 1].xe_name_hash ==
        xh->xh_entries[0].xe_name_hash) {
        mlog(ML_ERROR, "Too much hash collision in xattr bucket %llu, "
             "hash = %u\n",
             (unsigned long long)bucket_blkno(bucket),
             le32_to_cpu(xh->xh_entries[0].xe_name_hash));
        return -ENOSPC;
    }

    return 0;
}

/*
 * Try to set the entry in the current bucket.  If we fail, the caller
 * will handle getting us another bucket.
 */
static int ocfs2_xattr_set_entry_bucket(struct inode *inode,
                    struct ocfs2_xattr_info *xi,
                    struct ocfs2_xattr_search *xs,
                    struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;
    struct ocfs2_xa_loc loc;

    trace_ocfs2_xattr_set_entry_bucket(xi->xi_name);

    ocfs2_init_xattr_bucket_xa_loc(&loc, xs->bucket,
                       xs->not_found ? NULL : xs->here);
    ret = ocfs2_xa_set(&loc, xi, ctxt);
    if (!ret) {
        xs->here = loc.xl_entry;
        goto out;
    }
    if (ret != -ENOSPC) {
        mlog_errno(ret);
        goto out;
    }

    /* Ok, we need space.  Let's try defragmenting the bucket. */
    ret = ocfs2_defrag_xattr_bucket(inode, ctxt->handle,
                    xs->bucket);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xa_set(&loc, xi, ctxt);
    if (!ret) {
        xs->here = loc.xl_entry;
        goto out;
    }
    if (ret != -ENOSPC)
        mlog_errno(ret);


out:
    return ret;
}

static int ocfs2_xattr_set_entry_index_block(struct inode *inode,
                         struct ocfs2_xattr_info *xi,
                         struct ocfs2_xattr_search *xs,
                         struct ocfs2_xattr_set_ctxt *ctxt)
{
    int ret;

    trace_ocfs2_xattr_set_entry_index_block(xi->xi_name);

    ret = ocfs2_xattr_set_entry_bucket(inode, xi, xs, ctxt);
    if (!ret)
        goto out;
    if (ret != -ENOSPC) {
        mlog_errno(ret);
        goto out;
    }

    /* Ack, need more space.  Let's try to get another bucket! */

    /*
     * We do not allow for overlapping ranges between buckets. And
     * the maximum number of collisions we will allow for then is
     * one bucket's worth, so check it here whether we need to
     * add a new bucket for the insert.
     */
    ret = ocfs2_check_xattr_bucket_collision(inode,
                         xs->bucket,
                         xi->xi_name);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_add_new_xattr_bucket(inode,
                     xs->xattr_bh,
                     xs->bucket,
                     ctxt);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * ocfs2_add_new_xattr_bucket() will have updated
     * xs->bucket if it moved, but it will not have updated
     * any of the other search fields.  Thus, we drop it and
     * re-search.  Everything should be cached, so it'll be
     * quick.
     */
    ocfs2_xattr_bucket_relse(xs->bucket);
    ret = ocfs2_xattr_index_block_find(inode, xs->xattr_bh,
                       xi->xi_name_index,
                       xi->xi_name, xs);
    if (ret && ret != -ENODATA)
        goto out;
    xs->not_found = ret;

    /* Ok, we have a new bucket, let's try again */
    ret = ocfs2_xattr_set_entry_bucket(inode, xi, xs, ctxt);
    if (ret && (ret != -ENOSPC))
        mlog_errno(ret);

out:
    return ret;
}

static int ocfs2_delete_xattr_in_bucket(struct inode *inode,
                    struct ocfs2_xattr_bucket *bucket,
                    void *para)
{
    int ret = 0, ref_credits;
    struct ocfs2_xattr_header *xh = bucket_xh(bucket);
    u16 i;
    struct ocfs2_xattr_entry *xe;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct ocfs2_xattr_set_ctxt ctxt = {NULL, NULL,};
    int credits = ocfs2_remove_extent_credits(osb->sb) +
        ocfs2_blocks_per_xattr_bucket(inode->i_sb);
    struct ocfs2_xattr_value_root *xv;
    struct ocfs2_rm_xattr_bucket_para *args =
            (struct ocfs2_rm_xattr_bucket_para *)para;

    ocfs2_init_dealloc_ctxt(&ctxt.dealloc);

    for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
        xe = &xh->xh_entries[i];
        if (ocfs2_xattr_is_local(xe))
            continue;

        ret = ocfs2_get_xattr_tree_value_root(inode->i_sb, bucket,
                              i, &xv, NULL);

        ret = ocfs2_lock_xattr_remove_allocators(inode, xv,
                             args->ref_ci,
                             args->ref_root_bh,
                             &ctxt.meta_ac,
                             &ref_credits);

        ctxt.handle = ocfs2_start_trans(osb, credits + ref_credits);
        if (IS_ERR(ctxt.handle)) {
            ret = PTR_ERR(ctxt.handle);
            mlog_errno(ret);
            break;
        }

        ret = ocfs2_xattr_bucket_value_truncate(inode, bucket,
                            i, 0, &ctxt);

        ocfs2_commit_trans(osb, ctxt.handle);
        if (ctxt.meta_ac) {
            ocfs2_free_alloc_context(ctxt.meta_ac);
            ctxt.meta_ac = NULL;
        }
        if (ret) {
            mlog_errno(ret);
            break;
        }
    }

    if (ctxt.meta_ac)
        ocfs2_free_alloc_context(ctxt.meta_ac);
    ocfs2_schedule_truncate_log_flush(osb, 1);
    ocfs2_run_deallocs(osb, &ctxt.dealloc);
    return ret;
}

/*
 * Whenever we modify a xattr value root in the bucket(e.g, CoW
 * or change the extent record flag), we need to recalculate
 * the metaecc for the whole bucket. So it is done here.
 *
 * Note:
 * We have to give the extra credits for the caller.
 */
static int ocfs2_xattr_bucket_post_refcount(struct inode *inode,
                        handle_t *handle,
                        void *para)
{
    int ret;
    struct ocfs2_xattr_bucket *bucket =
            (struct ocfs2_xattr_bucket *)para;

    ret = ocfs2_xattr_bucket_journal_access(handle, bucket,
                        OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        return ret;
    }

    ocfs2_xattr_bucket_journal_dirty(handle, bucket);

    return 0;
}

/*
 * Special action we need if the xattr value is refcounted.
 *
 * 1. If the xattr is refcounted, lock the tree.
 * 2. CoW the xattr if we are setting the new value and the value
 *    will be stored outside.
 * 3. In other case, decrease_refcount will work for us, so just
 *    lock the refcount tree, calculate the meta and credits is OK.
 *
 * We have to do CoW before ocfs2_init_xattr_set_ctxt since
 * currently CoW is a completed transaction, while this function
 * will also lock the allocators and let us deadlock. So we will
 * CoW the whole xattr value.
 */
static int ocfs2_prepare_refcount_xattr(struct inode *inode,
                    struct ocfs2_dinode *di,
                    struct ocfs2_xattr_info *xi,
                    struct ocfs2_xattr_search *xis,
                    struct ocfs2_xattr_search *xbs,
                    struct ocfs2_refcount_tree **ref_tree,
                    int *meta_add,
                    int *credits)
{
    int ret = 0;
    struct ocfs2_xattr_block *xb;
    struct ocfs2_xattr_entry *xe;
    char *base;
    u32 p_cluster, num_clusters;
    unsigned int ext_flags;
    int name_offset, name_len;
    struct ocfs2_xattr_value_buf vb;
    struct ocfs2_xattr_bucket *bucket = NULL;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct ocfs2_post_refcount refcount;
    struct ocfs2_post_refcount *p = NULL;
    struct buffer_head *ref_root_bh = NULL;

    if (!xis->not_found) {
        xe = xis->here;
        name_offset = le16_to_cpu(xe->xe_name_offset);
        name_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
        base = xis->base;
        vb.vb_bh = xis->inode_bh;
        vb.vb_access = ocfs2_journal_access_di;
    } else {
        int i, block_off = 0;
        xb = (struct ocfs2_xattr_block *)xbs->xattr_bh->b_data;
        xe = xbs->here;
        name_offset = le16_to_cpu(xe->xe_name_offset);
        name_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
        i = xbs->here - xbs->header->xh_entries;

        if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
            ret = ocfs2_xattr_bucket_get_name_value(inode->i_sb,
                            bucket_xh(xbs->bucket),
                            i, &block_off,
                            &name_offset);
            if (ret) {
                mlog_errno(ret);
                goto out;
            }
            base = bucket_block(xbs->bucket, block_off);
            vb.vb_bh = xbs->bucket->bu_bhs[block_off];
            vb.vb_access = ocfs2_journal_access;

            if (ocfs2_meta_ecc(osb)) {
                /*create parameters for ocfs2_post_refcount. */
                bucket = xbs->bucket;
                refcount.credits = bucket->bu_blocks;
                refcount.para = bucket;
                refcount.func =
                    ocfs2_xattr_bucket_post_refcount;
                p = &refcount;
            }
        } else {
            base = xbs->base;
            vb.vb_bh = xbs->xattr_bh;
            vb.vb_access = ocfs2_journal_access_xb;
        }
    }

    if (ocfs2_xattr_is_local(xe))
        goto out;

    vb.vb_xv = (struct ocfs2_xattr_value_root *)
                (base + name_offset + name_len);

    ret = ocfs2_xattr_get_clusters(inode, 0, &p_cluster,
                       &num_clusters, &vb.vb_xv->xr_list,
                       &ext_flags);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * We just need to check the 1st extent record, since we always
     * CoW the whole xattr. So there shouldn't be a xattr with
     * some REFCOUNT extent recs after the 1st one.
     */
    if (!(ext_flags & OCFS2_EXT_REFCOUNTED))
        goto out;

    ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
                       1, ref_tree, &ref_root_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * If we are deleting the xattr or the new size will be stored inside,
     * cool, leave it there, the xattr truncate process will remove them
     * for us(it still needs the refcount tree lock and the meta, credits).
     * And the worse case is that every cluster truncate will split the
     * refcount tree, and make the original extent become 3. So we will need
     * 2 * cluster more extent recs at most.
     */
    if (!xi->xi_value || xi->xi_value_len <= OCFS2_XATTR_INLINE_SIZE) {

        ret = ocfs2_refcounted_xattr_delete_need(inode,
                             &(*ref_tree)->rf_ci,
                             ref_root_bh, vb.vb_xv,
                             meta_add, credits);
        if (ret)
            mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_refcount_cow_xattr(inode, di, &vb,
                       *ref_tree, ref_root_bh, 0,
                       le32_to_cpu(vb.vb_xv->xr_clusters), p);
    if (ret)
        mlog_errno(ret);

out:
    brelse(ref_root_bh);
    return ret;
}

/*
 * Add the REFCOUNTED flags for all the extent rec in ocfs2_xattr_value_root.
 * The physical clusters will be added to refcount tree.
 */
static int ocfs2_xattr_value_attach_refcount(struct inode *inode,
                struct ocfs2_xattr_value_root *xv,
                struct ocfs2_extent_tree *value_et,
                struct ocfs2_caching_info *ref_ci,
                struct buffer_head *ref_root_bh,
                struct ocfs2_cached_dealloc_ctxt *dealloc,
                struct ocfs2_post_refcount *refcount)
{
    int ret = 0;
    u32 clusters = le32_to_cpu(xv->xr_clusters);
    u32 cpos, p_cluster, num_clusters;
    struct ocfs2_extent_list *el = &xv->xr_list;
    unsigned int ext_flags;

    cpos = 0;
    while (cpos < clusters) {
        ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
                           &num_clusters, el, &ext_flags);

        cpos += num_clusters;
        if ((ext_flags & OCFS2_EXT_REFCOUNTED))
            continue;

        BUG_ON(!p_cluster);

        ret = ocfs2_add_refcount_flag(inode, value_et,
                          ref_ci, ref_root_bh,
                          cpos - num_clusters,
                          p_cluster, num_clusters,
                          dealloc, refcount);
        if (ret) {
            mlog_errno(ret);
            break;
        }
    }

    return ret;
}

/*
 * Given a normal ocfs2_xattr_header, refcount all the entries which
 * have value stored outside.
 * Used for xattrs stored in inode and ocfs2_xattr_block.
 */
static int ocfs2_xattr_attach_refcount_normal(struct inode *inode,
                struct ocfs2_xattr_value_buf *vb,
                struct ocfs2_xattr_header *header,
                struct ocfs2_caching_info *ref_ci,
                struct buffer_head *ref_root_bh,
                struct ocfs2_cached_dealloc_ctxt *dealloc)
{

    struct ocfs2_xattr_entry *xe;
    struct ocfs2_xattr_value_root *xv;
    struct ocfs2_extent_tree et;
    int i, ret = 0;

    for (i = 0; i < le16_to_cpu(header->xh_count); i++) {
        xe = &header->xh_entries[i];

        if (ocfs2_xattr_is_local(xe))
            continue;

        xv = (struct ocfs2_xattr_value_root *)((void *)header +
            le16_to_cpu(xe->xe_name_offset) +
            OCFS2_XATTR_SIZE(xe->xe_name_len));

        vb->vb_xv = xv;
        ocfs2_init_xattr_value_extent_tree(&et, INODE_CACHE(inode), vb);

        ret = ocfs2_xattr_value_attach_refcount(inode, xv, &et,
                            ref_ci, ref_root_bh,
                            dealloc, NULL);
        if (ret) {
            mlog_errno(ret);
            break;
        }
    }

    return ret;
}

static int ocfs2_xattr_inline_attach_refcount(struct inode *inode,
                struct buffer_head *fe_bh,
                struct ocfs2_caching_info *ref_ci,
                struct buffer_head *ref_root_bh,
                struct ocfs2_cached_dealloc_ctxt *dealloc)
{
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)fe_bh->b_data;
    struct ocfs2_xattr_header *header = (struct ocfs2_xattr_header *)
                (fe_bh->b_data + inode->i_sb->s_blocksize -
                le16_to_cpu(di->i_xattr_inline_size));
    struct ocfs2_xattr_value_buf vb = {
        .vb_bh = fe_bh,
        .vb_access = ocfs2_journal_access_di,
    };

    return ocfs2_xattr_attach_refcount_normal(inode, &vb, header,
                          ref_ci, ref_root_bh, dealloc);
}

struct ocfs2_xattr_tree_value_refcount_para {
    struct ocfs2_caching_info *ref_ci;
    struct buffer_head *ref_root_bh;
    struct ocfs2_cached_dealloc_ctxt *dealloc;
};

static int ocfs2_get_xattr_tree_value_root(struct super_block *sb,
                       struct ocfs2_xattr_bucket *bucket,
                       int offset,
                       struct ocfs2_xattr_value_root **xv,
                       struct buffer_head **bh)
{
    int ret, block_off, name_offset;
    struct ocfs2_xattr_header *xh = bucket_xh(bucket);
    struct ocfs2_xattr_entry *xe = &xh->xh_entries[offset];
    void *base;

    ret = ocfs2_xattr_bucket_get_name_value(sb,
                        bucket_xh(bucket),
                        offset,
                        &block_off,
                        &name_offset);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    base = bucket_block(bucket, block_off);

    *xv = (struct ocfs2_xattr_value_root *)(base + name_offset +
             OCFS2_XATTR_SIZE(xe->xe_name_len));

    if (bh)
        *bh = bucket->bu_bhs[block_off];
out:
    return ret;
}

/*
 * For a given xattr bucket, refcount all the entries which
 * have value stored outside.
 */
static int ocfs2_xattr_bucket_value_refcount(struct inode *inode,
                         struct ocfs2_xattr_bucket *bucket,
                         void *para)
{
    int i, ret = 0;
    struct ocfs2_extent_tree et;
    struct ocfs2_xattr_tree_value_refcount_para *ref =
            (struct ocfs2_xattr_tree_value_refcount_para *)para;
    struct ocfs2_xattr_header *xh =
            (struct ocfs2_xattr_header *)bucket->bu_bhs[0]->b_data;
    struct ocfs2_xattr_entry *xe;
    struct ocfs2_xattr_value_buf vb = {
        .vb_access = ocfs2_journal_access,
    };
    struct ocfs2_post_refcount refcount = {
        .credits = bucket->bu_blocks,
        .para = bucket,
        .func = ocfs2_xattr_bucket_post_refcount,
    };
    struct ocfs2_post_refcount *p = NULL;

    /* We only need post_refcount if we support metaecc. */
    if (ocfs2_meta_ecc(OCFS2_SB(inode->i_sb)))
        p = &refcount;

    trace_ocfs2_xattr_bucket_value_refcount(
                (unsigned long long)bucket_blkno(bucket),
                le16_to_cpu(xh->xh_count));
    for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
        xe = &xh->xh_entries[i];

        if (ocfs2_xattr_is_local(xe))
            continue;

        ret = ocfs2_get_xattr_tree_value_root(inode->i_sb, bucket, i,
                              &vb.vb_xv, &vb.vb_bh);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        ocfs2_init_xattr_value_extent_tree(&et,
                           INODE_CACHE(inode), &vb);

        ret = ocfs2_xattr_value_attach_refcount(inode, vb.vb_xv,
                            &et, ref->ref_ci,
                            ref->ref_root_bh,
                            ref->dealloc, p);
        if (ret) {
            mlog_errno(ret);
            break;
        }
    }

    return ret;

}

static int ocfs2_refcount_xattr_tree_rec(struct inode *inode,
                     struct buffer_head *root_bh,
                     u64 blkno, u32 cpos, u32 len, void *para)
{
    return ocfs2_iterate_xattr_buckets(inode, blkno, len,
                       ocfs2_xattr_bucket_value_refcount,
                       para);
}

static int ocfs2_xattr_block_attach_refcount(struct inode *inode,
                struct buffer_head *blk_bh,
                struct ocfs2_caching_info *ref_ci,
                struct buffer_head *ref_root_bh,
                struct ocfs2_cached_dealloc_ctxt *dealloc)
{
    int ret = 0;
    struct ocfs2_xattr_block *xb =
                (struct ocfs2_xattr_block *)blk_bh->b_data;

    if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
        struct ocfs2_xattr_header *header = &xb->xb_attrs.xb_header;
        struct ocfs2_xattr_value_buf vb = {
            .vb_bh = blk_bh,
            .vb_access = ocfs2_journal_access_xb,
        };

        ret = ocfs2_xattr_attach_refcount_normal(inode, &vb, header,
                             ref_ci, ref_root_bh,
                             dealloc);
    } else {
        struct ocfs2_xattr_tree_value_refcount_para para = {
            .ref_ci = ref_ci,
            .ref_root_bh = ref_root_bh,
            .dealloc = dealloc,
        };

        ret = ocfs2_iterate_xattr_index_block(inode, blk_bh,
                        ocfs2_refcount_xattr_tree_rec,
                        &para);
    }

    return ret;
}

int ocfs2_xattr_attach_refcount_tree(struct inode *inode,
                     struct buffer_head *fe_bh,
                     struct ocfs2_caching_info *ref_ci,
                     struct buffer_head *ref_root_bh,
                     struct ocfs2_cached_dealloc_ctxt *dealloc)
{
    int ret = 0;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)fe_bh->b_data;
    struct buffer_head *blk_bh = NULL;

    if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
        ret = ocfs2_xattr_inline_attach_refcount(inode, fe_bh,
                             ref_ci, ref_root_bh,
                             dealloc);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
    }

    if (!di->i_xattr_loc)
        goto out;

    ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc),
                     &blk_bh);
    if (ret < 0) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_xattr_block_attach_refcount(inode, blk_bh, ref_ci,
                        ref_root_bh, dealloc);
    if (ret)
        mlog_errno(ret);

    brelse(blk_bh);
out:

    return ret;
}

typedef int (should_xattr_reflinked)(struct ocfs2_xattr_entry *xe);
/*
 * Store the information we need in xattr reflink.
 * old_bh and new_bh are inode bh for the old and new inode.
 */
struct ocfs2_xattr_reflink {
    struct inode *old_inode;
    struct inode *new_inode;
    struct buffer_head *old_bh;
    struct buffer_head *new_bh;
    struct ocfs2_caching_info *ref_ci;
    struct buffer_head *ref_root_bh;
    struct ocfs2_cached_dealloc_ctxt *dealloc;
    should_xattr_reflinked *xattr_reflinked;
};

/*
 * Given a xattr header and xe offset,
 * return the proper xv and the corresponding bh.
 * xattr in inode, block and xattr tree have different implementaions.
 */
typedef int (get_xattr_value_root)(struct super_block *sb,
                   struct buffer_head *bh,
                   struct ocfs2_xattr_header *xh,
                   int offset,
                   struct ocfs2_xattr_value_root **xv,
                   struct buffer_head **ret_bh,
                   void *para);

/*
 * Calculate all the xattr value root metadata stored in this xattr header and
 * credits we need if we create them from the scratch.
 * We use get_xattr_value_root so that all types of xattr container can use it.
 */
static int ocfs2_value_metas_in_xattr_header(struct super_block *sb,
                         struct buffer_head *bh,
                         struct ocfs2_xattr_header *xh,
                         int *metas, int *credits,
                         int *num_recs,
                         get_xattr_value_root *func,
                         void *para)
{
    int i, ret = 0;
    struct ocfs2_xattr_value_root *xv;
    struct ocfs2_xattr_entry *xe;

    for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
        xe = &xh->xh_entries[i];
        if (ocfs2_xattr_is_local(xe))
            continue;

        ret = func(sb, bh, xh, i, &xv, NULL, para);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        *metas += le16_to_cpu(xv->xr_list.l_tree_depth) *
              le16_to_cpu(xv->xr_list.l_next_free_rec);

        *credits += ocfs2_calc_extend_credits(sb,
                        &def_xv.xv.xr_list,
                        le32_to_cpu(xv->xr_clusters));

        /*
         * If the value is a tree with depth > 1, We don't go deep
         * to the extent block, so just calculate a maximum record num.
         */
        if (!xv->xr_list.l_tree_depth)
            *num_recs += le16_to_cpu(xv->xr_list.l_next_free_rec);
        else
            *num_recs += ocfs2_clusters_for_bytes(sb,
                                  XATTR_SIZE_MAX);
    }

    return ret;
}

/* Used by xattr inode and block to return the right xv and buffer_head. */
static int ocfs2_get_xattr_value_root(struct super_block *sb,
                      struct buffer_head *bh,
                      struct ocfs2_xattr_header *xh,
                      int offset,
                      struct ocfs2_xattr_value_root **xv,
                      struct buffer_head **ret_bh,
                      void *para)
{
    struct ocfs2_xattr_entry *xe = &xh->xh_entries[offset];

    *xv = (struct ocfs2_xattr_value_root *)((void *)xh +
        le16_to_cpu(xe->xe_name_offset) +
        OCFS2_XATTR_SIZE(xe->xe_name_len));

    if (ret_bh)
        *ret_bh = bh;

    return 0;
}

/*
 * Lock the meta_ac and caculate how much credits we need for reflink xattrs.
 * It is only used for inline xattr and xattr block.
 */
static int ocfs2_reflink_lock_xattr_allocators(struct ocfs2_super *osb,
                    struct ocfs2_xattr_header *xh,
                    struct buffer_head *ref_root_bh,
                    int *credits,
                    struct ocfs2_alloc_context **meta_ac)
{
    int ret, meta_add = 0, num_recs = 0;
    struct ocfs2_refcount_block *rb =
            (struct ocfs2_refcount_block *)ref_root_bh->b_data;

    *credits = 0;

    ret = ocfs2_value_metas_in_xattr_header(osb->sb, NULL, xh,
                        &meta_add, credits, &num_recs,
                        ocfs2_get_xattr_value_root,
                        NULL);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * We need to add/modify num_recs in refcount tree, so just calculate
     * an approximate number we need for refcount tree change.
     * Sometimes we need to split the tree, and after split,  half recs
     * will be moved to the new block, and a new block can only provide
     * half number of recs. So we multiple new blocks by 2.
     */
    num_recs = num_recs / ocfs2_refcount_recs_per_rb(osb->sb) * 2;
    meta_add += num_recs;
    *credits += num_recs + num_recs * OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
    if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)
        *credits += le16_to_cpu(rb->rf_list.l_tree_depth) *
                le16_to_cpu(rb->rf_list.l_next_free_rec) + 1;
    else
        *credits += 1;

    ret = ocfs2_reserve_new_metadata_blocks(osb, meta_add, meta_ac);
    if (ret)
        mlog_errno(ret);

out:
    return ret;
}

/*
 * Given a xattr header, reflink all the xattrs in this container.
 * It can be used for inode, block and bucket.
 *
 * NOTE:
 * Before we call this function, the caller has memcpy the xattr in
 * old_xh to the new_xh.
 *
 * If args.xattr_reflinked is set, call it to decide whether the xe should
 * be reflinked or not. If not, remove it from the new xattr header.
 */
static int ocfs2_reflink_xattr_header(handle_t *handle,
                      struct ocfs2_xattr_reflink *args,
                      struct buffer_head *old_bh,
                      struct ocfs2_xattr_header *xh,
                      struct buffer_head *new_bh,
                      struct ocfs2_xattr_header *new_xh,
                      struct ocfs2_xattr_value_buf *vb,
                      struct ocfs2_alloc_context *meta_ac,
                      get_xattr_value_root *func,
                      void *para)
{
    int ret = 0, i, j;
    struct super_block *sb = args->old_inode->i_sb;
    struct buffer_head *value_bh;
    struct ocfs2_xattr_entry *xe, *last;
    struct ocfs2_xattr_value_root *xv, *new_xv;
    struct ocfs2_extent_tree data_et;
    u32 clusters, cpos, p_cluster, num_clusters;
    unsigned int ext_flags = 0;

    trace_ocfs2_reflink_xattr_header((unsigned long long)old_bh->b_blocknr,
                     le16_to_cpu(xh->xh_count));

    last = &new_xh->xh_entries[le16_to_cpu(new_xh->xh_count)];
    for (i = 0, j = 0; i < le16_to_cpu(xh->xh_count); i++, j++) {
        xe = &xh->xh_entries[i];

        if (args->xattr_reflinked && !args->xattr_reflinked(xe)) {
            xe = &new_xh->xh_entries[j];

            le16_add_cpu(&new_xh->xh_count, -1);
            if (new_xh->xh_count) {
                memmove(xe, xe + 1,
                    (void *)last - (void *)xe);
                memset(last, 0,
                       sizeof(struct ocfs2_xattr_entry));
            }

            /*
             * We don't want j to increase in the next round since
             * it is already moved ahead.
             */
            j--;
            continue;
        }

        if (ocfs2_xattr_is_local(xe))
            continue;

        ret = func(sb, old_bh, xh, i, &xv, NULL, para);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        ret = func(sb, new_bh, new_xh, j, &new_xv, &value_bh, para);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        /*
         * For the xattr which has l_tree_depth = 0, all the extent
         * recs have already be copied to the new xh with the
         * propriate OCFS2_EXT_REFCOUNTED flag we just need to
         * increase the refount count int the refcount tree.
         *
         * For the xattr which has l_tree_depth > 0, we need
         * to initialize it to the empty default value root,
         * and then insert the extents one by one.
         */
        if (xv->xr_list.l_tree_depth) {
            memcpy(new_xv, &def_xv, sizeof(def_xv));
            vb->vb_xv = new_xv;
            vb->vb_bh = value_bh;
            ocfs2_init_xattr_value_extent_tree(&data_et,
                    INODE_CACHE(args->new_inode), vb);
        }

        clusters = le32_to_cpu(xv->xr_clusters);
        cpos = 0;
        while (cpos < clusters) {
            ret = ocfs2_xattr_get_clusters(args->old_inode,
                               cpos,
                               &p_cluster,
                               &num_clusters,
                               &xv->xr_list,
                               &ext_flags);
            if (ret) {
                mlog_errno(ret);
                goto out;
            }

            BUG_ON(!p_cluster);

            if (xv->xr_list.l_tree_depth) {
                ret = ocfs2_insert_extent(handle,
                        &data_et, cpos,
                        ocfs2_clusters_to_blocks(
                            args->old_inode->i_sb,
                            p_cluster),
                        num_clusters, ext_flags,
                        meta_ac);
                if (ret) {
                    mlog_errno(ret);
                    goto out;
                }
            }

            ret = ocfs2_increase_refcount(handle, args->ref_ci,
                              args->ref_root_bh,
                              p_cluster, num_clusters,
                              meta_ac, args->dealloc);
            if (ret) {
                mlog_errno(ret);
                goto out;
            }

            cpos += num_clusters;
        }
    }

out:
    return ret;
}

static int ocfs2_reflink_xattr_inline(struct ocfs2_xattr_reflink *args)
{
    int ret = 0, credits = 0;
    handle_t *handle;
    struct ocfs2_super *osb = OCFS2_SB(args->old_inode->i_sb);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)args->old_bh->b_data;
    int inline_size = le16_to_cpu(di->i_xattr_inline_size);
    int header_off = osb->sb->s_blocksize - inline_size;
    struct ocfs2_xattr_header *xh = (struct ocfs2_xattr_header *)
                    (args->old_bh->b_data + header_off);
    struct ocfs2_xattr_header *new_xh = (struct ocfs2_xattr_header *)
                    (args->new_bh->b_data + header_off);
    struct ocfs2_alloc_context *meta_ac = NULL;
    struct ocfs2_inode_info *new_oi;
    struct ocfs2_dinode *new_di;
    struct ocfs2_xattr_value_buf vb = {
        .vb_bh = args->new_bh,
        .vb_access = ocfs2_journal_access_di,
    };

    ret = ocfs2_reflink_lock_xattr_allocators(osb, xh, args->ref_root_bh,
                          &credits, &meta_ac);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    handle = ocfs2_start_trans(osb, credits);
    if (IS_ERR(handle)) {
        ret = PTR_ERR(handle);
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_journal_access_di(handle, INODE_CACHE(args->new_inode),
                      args->new_bh, OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    memcpy(args->new_bh->b_data + header_off,
           args->old_bh->b_data + header_off, inline_size);

    new_di = (struct ocfs2_dinode *)args->new_bh->b_data;
    new_di->i_xattr_inline_size = cpu_to_le16(inline_size);

    ret = ocfs2_reflink_xattr_header(handle, args, args->old_bh, xh,
                     args->new_bh, new_xh, &vb, meta_ac,
                     ocfs2_get_xattr_value_root, NULL);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    new_oi = OCFS2_I(args->new_inode);
    spin_lock(&new_oi->ip_lock);
    new_oi->ip_dyn_features |= OCFS2_HAS_XATTR_FL | OCFS2_INLINE_XATTR_FL;
    new_di->i_dyn_features = cpu_to_le16(new_oi->ip_dyn_features);
    spin_unlock(&new_oi->ip_lock);

    ocfs2_journal_dirty(handle, args->new_bh);

out_commit:
    ocfs2_commit_trans(osb, handle);

out:
    if (meta_ac)
        ocfs2_free_alloc_context(meta_ac);
    return ret;
}

static int ocfs2_create_empty_xattr_block(struct inode *inode,
                      struct buffer_head *fe_bh,
                      struct buffer_head **ret_bh,
                      int indexed)
{
    int ret;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct ocfs2_xattr_set_ctxt ctxt;

    memset(&ctxt, 0, sizeof(ctxt));
    ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &ctxt.meta_ac);
    if (ret < 0) {
        mlog_errno(ret);
        return ret;
    }

    ctxt.handle = ocfs2_start_trans(osb, OCFS2_XATTR_BLOCK_CREATE_CREDITS);
    if (IS_ERR(ctxt.handle)) {
        ret = PTR_ERR(ctxt.handle);
        mlog_errno(ret);
        goto out;
    }

    trace_ocfs2_create_empty_xattr_block(
                (unsigned long long)fe_bh->b_blocknr, indexed);
    ret = ocfs2_create_xattr_block(inode, fe_bh, &ctxt, indexed,
                       ret_bh);
    if (ret)
        mlog_errno(ret);

    ocfs2_commit_trans(osb, ctxt.handle);
out:
    ocfs2_free_alloc_context(ctxt.meta_ac);
    return ret;
}

static int ocfs2_reflink_xattr_block(struct ocfs2_xattr_reflink *args,
                     struct buffer_head *blk_bh,
                     struct buffer_head *new_blk_bh)
{
    int ret = 0, credits = 0;
    handle_t *handle;
    struct ocfs2_inode_info *new_oi = OCFS2_I(args->new_inode);
    struct ocfs2_dinode *new_di;
    struct ocfs2_super *osb = OCFS2_SB(args->new_inode->i_sb);
    int header_off = offsetof(struct ocfs2_xattr_block, xb_attrs.xb_header);
    struct ocfs2_xattr_block *xb =
            (struct ocfs2_xattr_block *)blk_bh->b_data;
    struct ocfs2_xattr_header *xh = &xb->xb_attrs.xb_header;
    struct ocfs2_xattr_block *new_xb =
            (struct ocfs2_xattr_block *)new_blk_bh->b_data;
    struct ocfs2_xattr_header *new_xh = &new_xb->xb_attrs.xb_header;
    struct ocfs2_alloc_context *meta_ac;
    struct ocfs2_xattr_value_buf vb = {
        .vb_bh = new_blk_bh,
        .vb_access = ocfs2_journal_access_xb,
    };

    ret = ocfs2_reflink_lock_xattr_allocators(osb, xh, args->ref_root_bh,
                          &credits, &meta_ac);
    if (ret) {
        mlog_errno(ret);
        return ret;
    }

    /* One more credits in case we need to add xattr flags in new inode. */
    handle = ocfs2_start_trans(osb, credits + 1);
    if (IS_ERR(handle)) {
        ret = PTR_ERR(handle);
        mlog_errno(ret);
        goto out;
    }

    if (!(new_oi->ip_dyn_features & OCFS2_HAS_XATTR_FL)) {
        ret = ocfs2_journal_access_di(handle,
                          INODE_CACHE(args->new_inode),
                          args->new_bh,
                          OCFS2_JOURNAL_ACCESS_WRITE);
        if (ret) {
            mlog_errno(ret);
            goto out_commit;
        }
    }

    ret = ocfs2_journal_access_xb(handle, INODE_CACHE(args->new_inode),
                      new_blk_bh, OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    memcpy(new_blk_bh->b_data + header_off, blk_bh->b_data + header_off,
           osb->sb->s_blocksize - header_off);

    ret = ocfs2_reflink_xattr_header(handle, args, blk_bh, xh,
                     new_blk_bh, new_xh, &vb, meta_ac,
                     ocfs2_get_xattr_value_root, NULL);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    ocfs2_journal_dirty(handle, new_blk_bh);

    if (!(new_oi->ip_dyn_features & OCFS2_HAS_XATTR_FL)) {
        new_di = (struct ocfs2_dinode *)args->new_bh->b_data;
        spin_lock(&new_oi->ip_lock);
        new_oi->ip_dyn_features |= OCFS2_HAS_XATTR_FL;
        new_di->i_dyn_features = cpu_to_le16(new_oi->ip_dyn_features);
        spin_unlock(&new_oi->ip_lock);

        ocfs2_journal_dirty(handle, args->new_bh);
    }

out_commit:
    ocfs2_commit_trans(osb, handle);

out:
    ocfs2_free_alloc_context(meta_ac);
    return ret;
}

struct ocfs2_reflink_xattr_tree_args {
    struct ocfs2_xattr_reflink *reflink;
    struct buffer_head *old_blk_bh;
    struct buffer_head *new_blk_bh;
    struct ocfs2_xattr_bucket *old_bucket;
    struct ocfs2_xattr_bucket *new_bucket;
};

/*
 * NOTE:
 * We have to handle the case that both old bucket and new bucket
 * will call this function to get the right ret_bh.
 * So The caller must give us the right bh.
 */
static int ocfs2_get_reflink_xattr_value_root(struct super_block *sb,
                    struct buffer_head *bh,
                    struct ocfs2_xattr_header *xh,
                    int offset,
                    struct ocfs2_xattr_value_root **xv,
                    struct buffer_head **ret_bh,
                    void *para)
{
    struct ocfs2_reflink_xattr_tree_args *args =
            (struct ocfs2_reflink_xattr_tree_args *)para;
    struct ocfs2_xattr_bucket *bucket;

    if (bh == args->old_bucket->bu_bhs[0])
        bucket = args->old_bucket;
    else
        bucket = args->new_bucket;

    return ocfs2_get_xattr_tree_value_root(sb, bucket, offset,
                           xv, ret_bh);
}

struct ocfs2_value_tree_metas {
    int num_metas;
    int credits;
    int num_recs;
};

static int ocfs2_value_tree_metas_in_bucket(struct super_block *sb,
                    struct buffer_head *bh,
                    struct ocfs2_xattr_header *xh,
                    int offset,
                    struct ocfs2_xattr_value_root **xv,
                    struct buffer_head **ret_bh,
                    void *para)
{
    struct ocfs2_xattr_bucket *bucket =
                (struct ocfs2_xattr_bucket *)para;

    return ocfs2_get_xattr_tree_value_root(sb, bucket, offset,
                           xv, ret_bh);
}

static int ocfs2_calc_value_tree_metas(struct inode *inode,
                      struct ocfs2_xattr_bucket *bucket,
                      void *para)
{
    struct ocfs2_value_tree_metas *metas =
            (struct ocfs2_value_tree_metas *)para;
    struct ocfs2_xattr_header *xh =
            (struct ocfs2_xattr_header *)bucket->bu_bhs[0]->b_data;

    /* Add the credits for this bucket first. */
    metas->credits += bucket->bu_blocks;
    return ocfs2_value_metas_in_xattr_header(inode->i_sb, bucket->bu_bhs[0],
                    xh, &metas->num_metas,
                    &metas->credits, &metas->num_recs,
                    ocfs2_value_tree_metas_in_bucket,
                    bucket);
}

/*
 * Given a xattr extent rec starting from blkno and having len clusters,
 * iterate all the buckets calculate how much metadata we need for reflinking
 * all the ocfs2_xattr_value_root and lock the allocators accordingly.
 */
static int ocfs2_lock_reflink_xattr_rec_allocators(
                struct ocfs2_reflink_xattr_tree_args *args,
                struct ocfs2_extent_tree *xt_et,
                u64 blkno, u32 len, int *credits,
                struct ocfs2_alloc_context **meta_ac,
                struct ocfs2_alloc_context **data_ac)
{
    int ret, num_free_extents;
    struct ocfs2_value_tree_metas metas;
    struct ocfs2_super *osb = OCFS2_SB(args->reflink->old_inode->i_sb);
    struct ocfs2_refcount_block *rb;

    memset(&metas, 0, sizeof(metas));

    ret = ocfs2_iterate_xattr_buckets(args->reflink->old_inode, blkno, len,
                      ocfs2_calc_value_tree_metas, &metas);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    *credits = metas.credits;

    /*
     * Calculate we need for refcount tree change.
     *
     * We need to add/modify num_recs in refcount tree, so just calculate
     * an approximate number we need for refcount tree change.
     * Sometimes we need to split the tree, and after split,  half recs
     * will be moved to the new block, and a new block can only provide
     * half number of recs. So we multiple new blocks by 2.
     * In the end, we have to add credits for modifying the already
     * existed refcount block.
     */
    rb = (struct ocfs2_refcount_block *)args->reflink->ref_root_bh->b_data;
    metas.num_recs =
        (metas.num_recs + ocfs2_refcount_recs_per_rb(osb->sb) - 1) /
         ocfs2_refcount_recs_per_rb(osb->sb) * 2;
    metas.num_metas += metas.num_recs;
    *credits += metas.num_recs +
            metas.num_recs * OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
    if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)
        *credits += le16_to_cpu(rb->rf_list.l_tree_depth) *
                le16_to_cpu(rb->rf_list.l_next_free_rec) + 1;
    else
        *credits += 1;

    /* count in the xattr tree change. */
    num_free_extents = ocfs2_num_free_extents(osb, xt_et);
    if (num_free_extents < 0) {
        ret = num_free_extents;
        mlog_errno(ret);
        goto out;
    }

    if (num_free_extents < len)
        metas.num_metas += ocfs2_extend_meta_needed(xt_et->et_root_el);

    *credits += ocfs2_calc_extend_credits(osb->sb,
                          xt_et->et_root_el, len);

    if (metas.num_metas) {
        ret = ocfs2_reserve_new_metadata_blocks(osb, metas.num_metas,
                            meta_ac);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
    }

    if (len) {
        ret = ocfs2_reserve_clusters(osb, len, data_ac);
        if (ret)
            mlog_errno(ret);
    }
out:
    if (ret) {
        if (*meta_ac) {
            ocfs2_free_alloc_context(*meta_ac);
            meta_ac = NULL;
        }
    }

    return ret;
}

static int ocfs2_reflink_xattr_bucket(handle_t *handle,
                u64 blkno, u64 new_blkno, u32 clusters,
                u32 *cpos, int num_buckets,
                struct ocfs2_alloc_context *meta_ac,
                struct ocfs2_alloc_context *data_ac,
                struct ocfs2_reflink_xattr_tree_args *args)
{
    int i, j, ret = 0;
    struct super_block *sb = args->reflink->old_inode->i_sb;
    int bpb = args->old_bucket->bu_blocks;
    struct ocfs2_xattr_value_buf vb = {
        .vb_access = ocfs2_journal_access,
    };

    for (i = 0; i < num_buckets; i++, blkno += bpb, new_blkno += bpb) {
        ret = ocfs2_read_xattr_bucket(args->old_bucket, blkno);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        ret = ocfs2_init_xattr_bucket(args->new_bucket, new_blkno);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        ret = ocfs2_xattr_bucket_journal_access(handle,
                        args->new_bucket,
                        OCFS2_JOURNAL_ACCESS_CREATE);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        for (j = 0; j < bpb; j++)
            memcpy(bucket_block(args->new_bucket, j),
                   bucket_block(args->old_bucket, j),
                   sb->s_blocksize);

        /*
         * Record the start cpos so that we can use it to initialize
         * our xattr tree we also set the xh_num_bucket for the new
         * bucket.
         */
        if (i == 0) {
            *cpos = le32_to_cpu(bucket_xh(args->new_bucket)->
                        xh_entries[0].xe_name_hash);
            bucket_xh(args->new_bucket)->xh_num_buckets =
                cpu_to_le16(num_buckets);
        }

        ocfs2_xattr_bucket_journal_dirty(handle, args->new_bucket);

        ret = ocfs2_reflink_xattr_header(handle, args->reflink,
                    args->old_bucket->bu_bhs[0],
                    bucket_xh(args->old_bucket),
                    args->new_bucket->bu_bhs[0],
                    bucket_xh(args->new_bucket),
                    &vb, meta_ac,
                    ocfs2_get_reflink_xattr_value_root,
                    args);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        /*
         * Re-access and dirty the bucket to calculate metaecc.
         * Because we may extend the transaction in reflink_xattr_header
         * which will let the already accessed block gone.
         */
        ret = ocfs2_xattr_bucket_journal_access(handle,
                        args->new_bucket,
                        OCFS2_JOURNAL_ACCESS_WRITE);
        if (ret) {
            mlog_errno(ret);
            break;
        }

        ocfs2_xattr_bucket_journal_dirty(handle, args->new_bucket);

        ocfs2_xattr_bucket_relse(args->old_bucket);
        ocfs2_xattr_bucket_relse(args->new_bucket);
    }

    ocfs2_xattr_bucket_relse(args->old_bucket);
    ocfs2_xattr_bucket_relse(args->new_bucket);
    return ret;
}

static int ocfs2_reflink_xattr_buckets(handle_t *handle,
                struct inode *inode,
                struct ocfs2_reflink_xattr_tree_args *args,
                struct ocfs2_extent_tree *et,
                struct ocfs2_alloc_context *meta_ac,
                struct ocfs2_alloc_context *data_ac,
                u64 blkno, u32 cpos, u32 len)
{
    int ret, first_inserted = 0;
    u32 p_cluster, num_clusters, reflink_cpos = 0;
    u64 new_blkno;
    unsigned int num_buckets, reflink_buckets;
    unsigned int bpc =
        ocfs2_xattr_buckets_per_cluster(OCFS2_SB(inode->i_sb));

    ret = ocfs2_read_xattr_bucket(args->old_bucket, blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }
    num_buckets = le16_to_cpu(bucket_xh(args->old_bucket)->xh_num_buckets);
    ocfs2_xattr_bucket_relse(args->old_bucket);

    while (len && num_buckets) {
        ret = ocfs2_claim_clusters(handle, data_ac,
                       1, &p_cluster, &num_clusters);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        new_blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);
        reflink_buckets = min(num_buckets, bpc * num_clusters);

        ret = ocfs2_reflink_xattr_bucket(handle, blkno,
                         new_blkno, num_clusters,
                         &reflink_cpos, reflink_buckets,
                         meta_ac, data_ac, args);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        /*
         * For the 1st allocated cluster, we make it use the same cpos
         * so that the xattr tree looks the same as the original one
         * in the most case.
         */
        if (!first_inserted) {
            reflink_cpos = cpos;
            first_inserted = 1;
        }
        ret = ocfs2_insert_extent(handle, et, reflink_cpos, new_blkno,
                      num_clusters, 0, meta_ac);
        if (ret)
            mlog_errno(ret);

        trace_ocfs2_reflink_xattr_buckets((unsigned long long)new_blkno,
                          num_clusters, reflink_cpos);

        len -= num_clusters;
        blkno += ocfs2_clusters_to_blocks(inode->i_sb, num_clusters);
        num_buckets -= reflink_buckets;
    }
out:
    return ret;
}

/*
 * Create the same xattr extent record in the new inode's xattr tree.
 */
static int ocfs2_reflink_xattr_rec(struct inode *inode,
                   struct buffer_head *root_bh,
                   u64 blkno,
                   u32 cpos,
                   u32 len,
                   void *para)
{
    int ret, credits = 0;
    handle_t *handle;
    struct ocfs2_reflink_xattr_tree_args *args =
            (struct ocfs2_reflink_xattr_tree_args *)para;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct ocfs2_alloc_context *meta_ac = NULL;
    struct ocfs2_alloc_context *data_ac = NULL;
    struct ocfs2_extent_tree et;

    trace_ocfs2_reflink_xattr_rec((unsigned long long)blkno, len);

    ocfs2_init_xattr_tree_extent_tree(&et,
                      INODE_CACHE(args->reflink->new_inode),
                      args->new_blk_bh);

    ret = ocfs2_lock_reflink_xattr_rec_allocators(args, &et, blkno,
                              len, &credits,
                              &meta_ac, &data_ac);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    handle = ocfs2_start_trans(osb, credits);
    if (IS_ERR(handle)) {
        ret = PTR_ERR(handle);
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_reflink_xattr_buckets(handle, inode, args, &et,
                      meta_ac, data_ac,
                      blkno, cpos, len);
    if (ret)
        mlog_errno(ret);

    ocfs2_commit_trans(osb, handle);

out:
    if (meta_ac)
        ocfs2_free_alloc_context(meta_ac);
    if (data_ac)
        ocfs2_free_alloc_context(data_ac);
    return ret;
}

/*
 * Create reflinked xattr buckets.
 * We will add bucket one by one, and refcount all the xattrs in the bucket
 * if they are stored outside.
 */
static int ocfs2_reflink_xattr_tree(struct ocfs2_xattr_reflink *args,
                    struct buffer_head *blk_bh,
                    struct buffer_head *new_blk_bh)
{
    int ret;
    struct ocfs2_reflink_xattr_tree_args para;

    memset(&para, 0, sizeof(para));
    para.reflink = args;
    para.old_blk_bh = blk_bh;
    para.new_blk_bh = new_blk_bh;

    para.old_bucket = ocfs2_xattr_bucket_new(args->old_inode);
    if (!para.old_bucket) {
        mlog_errno(-ENOMEM);
        return -ENOMEM;
    }

    para.new_bucket = ocfs2_xattr_bucket_new(args->new_inode);
    if (!para.new_bucket) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_iterate_xattr_index_block(args->old_inode, blk_bh,
                          ocfs2_reflink_xattr_rec,
                          &para);
    if (ret)
        mlog_errno(ret);

out:
    ocfs2_xattr_bucket_free(para.old_bucket);
    ocfs2_xattr_bucket_free(para.new_bucket);
    return ret;
}

static int ocfs2_reflink_xattr_in_block(struct ocfs2_xattr_reflink *args,
                    struct buffer_head *blk_bh)
{
    int ret, indexed = 0;
    struct buffer_head *new_blk_bh = NULL;
    struct ocfs2_xattr_block *xb =
            (struct ocfs2_xattr_block *)blk_bh->b_data;


    if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)
        indexed = 1;

    ret = ocfs2_create_empty_xattr_block(args->new_inode, args->new_bh,
                         &new_blk_bh, indexed);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    if (!indexed)
        ret = ocfs2_reflink_xattr_block(args, blk_bh, new_blk_bh);
    else
        ret = ocfs2_reflink_xattr_tree(args, blk_bh, new_blk_bh);
    if (ret)
        mlog_errno(ret);

out:
    brelse(new_blk_bh);
    return ret;
}

static int ocfs2_reflink_xattr_no_security(struct ocfs2_xattr_entry *xe)
{
    int type = ocfs2_xattr_get_type(xe);

    return type != OCFS2_XATTR_INDEX_SECURITY &&
           type != OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS &&
           type != OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
}

int ocfs2_reflink_xattrs(struct inode *old_inode,
             struct buffer_head *old_bh,
             struct inode *new_inode,
             struct buffer_head *new_bh,
             bool preserve_security)
{
    int ret;
    struct ocfs2_xattr_reflink args;
    struct ocfs2_inode_info *oi = OCFS2_I(old_inode);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)old_bh->b_data;
    struct buffer_head *blk_bh = NULL;
    struct ocfs2_cached_dealloc_ctxt dealloc;
    struct ocfs2_refcount_tree *ref_tree;
    struct buffer_head *ref_root_bh = NULL;

    ret = ocfs2_lock_refcount_tree(OCFS2_SB(old_inode->i_sb),
                       le64_to_cpu(di->i_refcount_loc),
                       1, &ref_tree, &ref_root_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ocfs2_init_dealloc_ctxt(&dealloc);

    args.old_inode = old_inode;
    args.new_inode = new_inode;
    args.old_bh = old_bh;
    args.new_bh = new_bh;
    args.ref_ci = &ref_tree->rf_ci;
    args.ref_root_bh = ref_root_bh;
    args.dealloc = &dealloc;
    if (preserve_security)
        args.xattr_reflinked = NULL;
    else
        args.xattr_reflinked = ocfs2_reflink_xattr_no_security;

    if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
        ret = ocfs2_reflink_xattr_inline(&args);
        if (ret) {
            mlog_errno(ret);
            goto out_unlock;
        }
    }

    if (!di->i_xattr_loc)
        goto out_unlock;

    ret = ocfs2_read_xattr_block(old_inode, le64_to_cpu(di->i_xattr_loc),
                     &blk_bh);
    if (ret < 0) {
        mlog_errno(ret);
        goto out_unlock;
    }

    ret = ocfs2_reflink_xattr_in_block(&args, blk_bh);
    if (ret)
        mlog_errno(ret);

    brelse(blk_bh);

out_unlock:
    ocfs2_unlock_refcount_tree(OCFS2_SB(old_inode->i_sb),
                   ref_tree, 1);
    brelse(ref_root_bh);

    if (ocfs2_dealloc_has_cluster(&dealloc)) {
        ocfs2_schedule_truncate_log_flush(OCFS2_SB(old_inode->i_sb), 1);
        ocfs2_run_deallocs(OCFS2_SB(old_inode->i_sb), &dealloc);
    }

out:
    return ret;
}

/*
 * Initialize security and acl for a already created inode.
 * Used for reflink a non-preserve-security file.
 *
 * It uses common api like ocfs2_xattr_set, so the caller
 * must not hold any lock expect i_mutex.
 */
int ocfs2_init_security_and_acl(struct inode *dir,
                struct inode *inode,
                const struct qstr *qstr)
{
    int ret = 0;
    struct buffer_head *dir_bh = NULL;

    ret = ocfs2_init_security_get(inode, dir, qstr, NULL);
    if (!ret) {
        mlog_errno(ret);
        goto leave;
    }

    ret = ocfs2_inode_lock(dir, &dir_bh, 0);
    if (ret) {
        mlog_errno(ret);
        goto leave;
    }

    ret = ocfs2_init_acl(NULL, inode, dir, NULL, dir_bh, NULL, NULL);
    if (ret)
        mlog_errno(ret);

    ocfs2_inode_unlock(dir, 0);
    brelse(dir_bh);
leave:
    return ret;
}
/*
 * 'security' attributes support
 */
static size_t ocfs2_xattr_security_list(struct dentry *dentry, char *list,
                    size_t list_size, const char *name,
                    size_t name_len, int type)
{
    const size_t prefix_len = XATTR_SECURITY_PREFIX_LEN;
    const size_t total_len = prefix_len + name_len + 1;

    if (list && total_len <= list_size) {
        memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
        memcpy(list + prefix_len, name, name_len);
        list[prefix_len + name_len] = '\0';
    }
    return total_len;
}

static int ocfs2_xattr_security_get(struct dentry *dentry, const char *name,
                    void *buffer, size_t size, int type)
{
    if (strcmp(name, "") == 0)
        return -EINVAL;
    return ocfs2_xattr_get(dentry->d_inode, OCFS2_XATTR_INDEX_SECURITY,
                   name, buffer, size);
}

static int ocfs2_xattr_security_set(struct dentry *dentry, const char *name,
        const void *value, size_t size, int flags, int type)
{
    if (strcmp(name, "") == 0)
        return -EINVAL;

    return ocfs2_xattr_set(dentry->d_inode, OCFS2_XATTR_INDEX_SECURITY,
                   name, value, size, flags);
}

int ocfs2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
             void *fs_info)
{
    const struct xattr *xattr;
    int err = 0;

    for (xattr = xattr_array; xattr->name != NULL; xattr++) {
        err = ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_SECURITY,
                      xattr->name, xattr->value,
                      xattr->value_len, XATTR_CREATE);
        if (err)
            break;
    }
    return err;
}

int ocfs2_init_security_get(struct inode *inode,
                struct inode *dir,
                const struct qstr *qstr,
                struct ocfs2_security_xattr_info *si)
{
    /* check whether ocfs2 support feature xattr */
    if (!ocfs2_supports_xattr(OCFS2_SB(dir->i_sb)))
        return -EOPNOTSUPP;
    if (si)
        return security_old_inode_init_security(inode, dir, qstr,
                            &si->name, &si->value,
                            &si->value_len);

    return security_inode_init_security(inode, dir, qstr,
                        &ocfs2_initxattrs, NULL);
}

int ocfs2_init_security_set(handle_t *handle,
                struct inode *inode,
                struct buffer_head *di_bh,
                struct ocfs2_security_xattr_info *si,
                struct ocfs2_alloc_context *xattr_ac,
                struct ocfs2_alloc_context *data_ac)
{
    return ocfs2_xattr_set_handle(handle, inode, di_bh,
                     OCFS2_XATTR_INDEX_SECURITY,
                     si->name, si->value, si->value_len, 0,
                     xattr_ac, data_ac);
}

const struct xattr_handler ocfs2_xattr_security_handler = {
    .prefix = XATTR_SECURITY_PREFIX,
    .list   = ocfs2_xattr_security_list,
    .get    = ocfs2_xattr_security_get,
    .set    = ocfs2_xattr_security_set,
};

/*
 * 'trusted' attributes support
 */
static size_t ocfs2_xattr_trusted_list(struct dentry *dentry, char *list,
                       size_t list_size, const char *name,
                       size_t name_len, int type)
{
    const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
    const size_t total_len = prefix_len + name_len + 1;

    if (list && total_len <= list_size) {
        memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
        memcpy(list + prefix_len, name, name_len);
        list[prefix_len + name_len] = '\0';
    }
    return total_len;
}

static int ocfs2_xattr_trusted_get(struct dentry *dentry, const char *name,
        void *buffer, size_t size, int type)
{
    if (strcmp(name, "") == 0)
        return -EINVAL;
    return ocfs2_xattr_get(dentry->d_inode, OCFS2_XATTR_INDEX_TRUSTED,
                   name, buffer, size);
}

static int ocfs2_xattr_trusted_set(struct dentry *dentry, const char *name,
        const void *value, size_t size, int flags, int type)
{
    if (strcmp(name, "") == 0)
        return -EINVAL;

    return ocfs2_xattr_set(dentry->d_inode, OCFS2_XATTR_INDEX_TRUSTED,
                   name, value, size, flags);
}

const struct xattr_handler ocfs2_xattr_trusted_handler = {
    .prefix = XATTR_TRUSTED_PREFIX,
    .list   = ocfs2_xattr_trusted_list,
    .get    = ocfs2_xattr_trusted_get,
    .set    = ocfs2_xattr_trusted_set,
};

/*
 * 'user' attributes support
 */
static size_t ocfs2_xattr_user_list(struct dentry *dentry, char *list,
                    size_t list_size, const char *name,
                    size_t name_len, int type)
{
    const size_t prefix_len = XATTR_USER_PREFIX_LEN;
    const size_t total_len = prefix_len + name_len + 1;
    struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);

    if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
        return 0;

    if (list && total_len <= list_size) {
        memcpy(list, XATTR_USER_PREFIX, prefix_len);
        memcpy(list + prefix_len, name, name_len);
        list[prefix_len + name_len] = '\0';
    }
    return total_len;
}

static int ocfs2_xattr_user_get(struct dentry *dentry, const char *name,
        void *buffer, size_t size, int type)
{
    struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);

    if (strcmp(name, "") == 0)
        return -EINVAL;
    if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
        return -EOPNOTSUPP;
    return ocfs2_xattr_get(dentry->d_inode, OCFS2_XATTR_INDEX_USER, name,
                   buffer, size);
}

static int ocfs2_xattr_user_set(struct dentry *dentry, const char *name,
        const void *value, size_t size, int flags, int type)
{
    struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);

    if (strcmp(name, "") == 0)
        return -EINVAL;
    if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
        return -EOPNOTSUPP;

    return ocfs2_xattr_set(dentry->d_inode, OCFS2_XATTR_INDEX_USER,
                   name, value, size, flags);
}

const struct xattr_handler ocfs2_xattr_user_handler = {
    .prefix = XATTR_USER_PREFIX,
    .list   = ocfs2_xattr_user_list,
    .get    = ocfs2_xattr_user_get,
    .set    = ocfs2_xattr_user_set,
};