dir.c

Go to the documentation of this file.

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dir.c
 *
 * Creates, reads, walks and deletes directory-nodes
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 *  Portions of this code from linux/fs/ext3/dir.c
 *
 *  Copyright (C) 1992, 1993, 1994, 1995
 *  Remy Card ([email protected])
 *  Laboratoire MASI - Institut Blaise pascal
 *  Universite Pierre et Marie Curie (Paris VI)
 *
 *   from
 *
 *   linux/fs/minix/dir.c
 *
 *   Copyright (C) 1991, 1992 Linux Torvalds
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/quotaops.h>
#include <linux/sort.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "blockcheck.h"
#include "dir.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "file.h"
#include "inode.h"
#include "journal.h"
#include "namei.h"
#include "suballoc.h"
#include "super.h"
#include "sysfile.h"
#include "uptodate.h"
#include "ocfs2_trace.h"

#include "buffer_head_io.h"

#define NAMEI_RA_CHUNKS  2
#define NAMEI_RA_BLOCKS  4
#define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
#define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))

static unsigned char ocfs2_filetype_table[] = {
    DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};

static int ocfs2_do_extend_dir(struct super_block *sb,
                   handle_t *handle,
                   struct inode *dir,
                   struct buffer_head *parent_fe_bh,
                   struct ocfs2_alloc_context *data_ac,
                   struct ocfs2_alloc_context *meta_ac,
                   struct buffer_head **new_bh);
static int ocfs2_dir_indexed(struct inode *inode);

/*
 * These are distinct checks because future versions of the file system will
 * want to have a trailing dirent structure independent of indexing.
 */
static int ocfs2_supports_dir_trailer(struct inode *dir)
{
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);

    if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
        return 0;

    return ocfs2_meta_ecc(osb) || ocfs2_dir_indexed(dir);
}

/*
 * "new' here refers to the point at which we're creating a new
 * directory via "mkdir()", but also when we're expanding an inline
 * directory. In either case, we don't yet have the indexing bit set
 * on the directory, so the standard checks will fail in when metaecc
 * is turned off. Only directory-initialization type functions should
 * use this then. Everything else wants ocfs2_supports_dir_trailer()
 */
static int ocfs2_new_dir_wants_trailer(struct inode *dir)
{
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);

    return ocfs2_meta_ecc(osb) ||
        ocfs2_supports_indexed_dirs(osb);
}

static inline unsigned int ocfs2_dir_trailer_blk_off(struct super_block *sb)
{
    return sb->s_blocksize - sizeof(struct ocfs2_dir_block_trailer);
}

#define ocfs2_trailer_from_bh(_bh, _sb) ((struct ocfs2_dir_block_trailer *) ((_bh)->b_data + ocfs2_dir_trailer_blk_off((_sb))))

/* XXX ocfs2_block_dqtrailer() is similar but not quite - can we make
 * them more consistent? */
struct ocfs2_dir_block_trailer *ocfs2_dir_trailer_from_size(int blocksize,
                                void *data)
{
    char *p = data;

    p += blocksize - sizeof(struct ocfs2_dir_block_trailer);
    return (struct ocfs2_dir_block_trailer *)p;
}

/*
 * XXX: This is executed once on every dirent. We should consider optimizing
 * it.
 */
static int ocfs2_skip_dir_trailer(struct inode *dir,
                  struct ocfs2_dir_entry *de,
                  unsigned long offset,
                  unsigned long blklen)
{
    unsigned long toff = blklen - sizeof(struct ocfs2_dir_block_trailer);

    if (!ocfs2_supports_dir_trailer(dir))
        return 0;

    if (offset != toff)
        return 0;

    return 1;
}

static void ocfs2_init_dir_trailer(struct inode *inode,
                   struct buffer_head *bh, u16 rec_len)
{
    struct ocfs2_dir_block_trailer *trailer;

    trailer = ocfs2_trailer_from_bh(bh, inode->i_sb);
    strcpy(trailer->db_signature, OCFS2_DIR_TRAILER_SIGNATURE);
    trailer->db_compat_rec_len =
            cpu_to_le16(sizeof(struct ocfs2_dir_block_trailer));
    trailer->db_parent_dinode = cpu_to_le64(OCFS2_I(inode)->ip_blkno);
    trailer->db_blkno = cpu_to_le64(bh->b_blocknr);
    trailer->db_free_rec_len = cpu_to_le16(rec_len);
}
/*
 * Link an unindexed block with a dir trailer structure into the index free
 * list. This function will modify dirdata_bh, but assumes you've already
 * passed it to the journal.
 */
static int ocfs2_dx_dir_link_trailer(struct inode *dir, handle_t *handle,
                     struct buffer_head *dx_root_bh,
                     struct buffer_head *dirdata_bh)
{
    int ret;
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dir_block_trailer *trailer;

    ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }
    trailer = ocfs2_trailer_from_bh(dirdata_bh, dir->i_sb);
    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;

    trailer->db_free_next = dx_root->dr_free_blk;
    dx_root->dr_free_blk = cpu_to_le64(dirdata_bh->b_blocknr);

    ocfs2_journal_dirty(handle, dx_root_bh);

out:
    return ret;
}

static int ocfs2_free_list_at_root(struct ocfs2_dir_lookup_result *res)
{
    return res->dl_prev_leaf_bh == NULL;
}

void ocfs2_free_dir_lookup_result(struct ocfs2_dir_lookup_result *res)
{
    brelse(res->dl_dx_root_bh);
    brelse(res->dl_leaf_bh);
    brelse(res->dl_dx_leaf_bh);
    brelse(res->dl_prev_leaf_bh);
}

static int ocfs2_dir_indexed(struct inode *inode)
{
    if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INDEXED_DIR_FL)
        return 1;
    return 0;
}

static inline int ocfs2_dx_root_inline(struct ocfs2_dx_root_block *dx_root)
{
    return dx_root->dr_flags & OCFS2_DX_FLAG_INLINE;
}

/*
 * Hashing code adapted from ext3
 */
#define DELTA 0x9E3779B9

static void TEA_transform(__u32 buf[4], __u32 const in[])
{
    __u32   sum = 0;
    __u32   b0 = buf[0], b1 = buf[1];
    __u32   a = in[0], b = in[1], c = in[2], d = in[3];
    int n = 16;

    do {
        sum += DELTA;
        b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
        b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
    } while (--n);

    buf[0] += b0;
    buf[1] += b1;
}

static void str2hashbuf(const char *msg, int len, __u32 *buf, int num)
{
    __u32   pad, val;
    int i;

    pad = (__u32)len | ((__u32)len << 8);
    pad |= pad << 16;

    val = pad;
    if (len > num*4)
        len = num * 4;
    for (i = 0; i < len; i++) {
        if ((i % 4) == 0)
            val = pad;
        val = msg[i] + (val << 8);
        if ((i % 4) == 3) {
            *buf++ = val;
            val = pad;
            num--;
        }
    }
    if (--num >= 0)
        *buf++ = val;
    while (--num >= 0)
        *buf++ = pad;
}

static void ocfs2_dx_dir_name_hash(struct inode *dir, const char *name, int len,
                   struct ocfs2_dx_hinfo *hinfo)
{
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
    const char  *p;
    __u32       in[8], buf[4];

    /*
     * XXX: Is this really necessary, if the index is never looked
     * at by readdir? Is a hash value of '0' a bad idea?
     */
    if ((len == 1 && !strncmp(".", name, 1)) ||
        (len == 2 && !strncmp("..", name, 2))) {
        buf[0] = buf[1] = 0;
        goto out;
    }

#ifdef OCFS2_DEBUG_DX_DIRS
    /*
     * This makes it very easy to debug indexing problems. We
     * should never allow this to be selected without hand editing
     * this file though.
     */
    buf[0] = buf[1] = len;
    goto out;
#endif

    memcpy(buf, osb->osb_dx_seed, sizeof(buf));

    p = name;
    while (len > 0) {
        str2hashbuf(p, len, in, 4);
        TEA_transform(buf, in);
        len -= 16;
        p += 16;
    }

out:
    hinfo->major_hash = buf[0];
    hinfo->minor_hash = buf[1];
}

/*
 * bh passed here can be an inode block or a dir data block, depending
 * on the inode inline data flag.
 */
static int ocfs2_check_dir_entry(struct inode * dir,
                 struct ocfs2_dir_entry * de,
                 struct buffer_head * bh,
                 unsigned long offset)
{
    const char *error_msg = NULL;
    const int rlen = le16_to_cpu(de->rec_len);

    if (unlikely(rlen < OCFS2_DIR_REC_LEN(1)))
        error_msg = "rec_len is smaller than minimal";
    else if (unlikely(rlen % 4 != 0))
        error_msg = "rec_len % 4 != 0";
    else if (unlikely(rlen < OCFS2_DIR_REC_LEN(de->name_len)))
        error_msg = "rec_len is too small for name_len";
    else if (unlikely(
         ((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize))
        error_msg = "directory entry across blocks";

    if (unlikely(error_msg != NULL))
        mlog(ML_ERROR, "bad entry in directory #%llu: %s - "
             "offset=%lu, inode=%llu, rec_len=%d, name_len=%d\n",
             (unsigned long long)OCFS2_I(dir)->ip_blkno, error_msg,
             offset, (unsigned long long)le64_to_cpu(de->inode), rlen,
             de->name_len);

    return error_msg == NULL ? 1 : 0;
}

static inline int ocfs2_match(int len,
                  const char * const name,
                  struct ocfs2_dir_entry *de)
{
    if (len != de->name_len)
        return 0;
    if (!de->inode)
        return 0;
    return !memcmp(name, de->name, len);
}

/*
 * Returns 0 if not found, -1 on failure, and 1 on success
 */
static inline int ocfs2_search_dirblock(struct buffer_head *bh,
                    struct inode *dir,
                    const char *name, int namelen,
                    unsigned long offset,
                    char *first_de,
                    unsigned int bytes,
                    struct ocfs2_dir_entry **res_dir)
{
    struct ocfs2_dir_entry *de;
    char *dlimit, *de_buf;
    int de_len;
    int ret = 0;

    de_buf = first_de;
    dlimit = de_buf + bytes;

    while (de_buf < dlimit) {
        /* this code is executed quadratically often */
        /* do minimal checking `by hand' */

        de = (struct ocfs2_dir_entry *) de_buf;

        if (de_buf + namelen <= dlimit &&
            ocfs2_match(namelen, name, de)) {
            /* found a match - just to be sure, do a full check */
            if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
                ret = -1;
                goto bail;
            }
            *res_dir = de;
            ret = 1;
            goto bail;
        }

        /* prevent looping on a bad block */
        de_len = le16_to_cpu(de->rec_len);
        if (de_len <= 0) {
            ret = -1;
            goto bail;
        }

        de_buf += de_len;
        offset += de_len;
    }

bail:
    trace_ocfs2_search_dirblock(ret);
    return ret;
}

static struct buffer_head *ocfs2_find_entry_id(const char *name,
                           int namelen,
                           struct inode *dir,
                           struct ocfs2_dir_entry **res_dir)
{
    int ret, found;
    struct buffer_head *di_bh = NULL;
    struct ocfs2_dinode *di;
    struct ocfs2_inline_data *data;

    ret = ocfs2_read_inode_block(dir, &di_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    di = (struct ocfs2_dinode *)di_bh->b_data;
    data = &di->id2.i_data;

    found = ocfs2_search_dirblock(di_bh, dir, name, namelen, 0,
                      data->id_data, i_size_read(dir), res_dir);
    if (found == 1)
        return di_bh;

    brelse(di_bh);
out:
    return NULL;
}

static int ocfs2_validate_dir_block(struct super_block *sb,
                    struct buffer_head *bh)
{
    int rc;
    struct ocfs2_dir_block_trailer *trailer =
        ocfs2_trailer_from_bh(bh, sb);


    /*
     * We don't validate dirents here, that's handled
     * in-place when the code walks them.
     */
    trace_ocfs2_validate_dir_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.
     *
     * Note that we are safe to call this even if the directory
     * doesn't have a trailer.  Filesystems without metaecc will do
     * nothing, and filesystems with it will have one.
     */
    rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &trailer->db_check);
    if (rc)
        mlog(ML_ERROR, "Checksum failed for dinode %llu\n",
             (unsigned long long)bh->b_blocknr);

    return rc;
}

/*
 * Validate a directory trailer.
 *
 * We check the trailer here rather than in ocfs2_validate_dir_block()
 * because that function doesn't have the inode to test.
 */
static int ocfs2_check_dir_trailer(struct inode *dir, struct buffer_head *bh)
{
    int rc = 0;
    struct ocfs2_dir_block_trailer *trailer;

    trailer = ocfs2_trailer_from_bh(bh, dir->i_sb);
    if (!OCFS2_IS_VALID_DIR_TRAILER(trailer)) {
        rc = -EINVAL;
        ocfs2_error(dir->i_sb,
                "Invalid dirblock #%llu: "
                "signature = %.*s\n",
                (unsigned long long)bh->b_blocknr, 7,
                trailer->db_signature);
        goto out;
    }
    if (le64_to_cpu(trailer->db_blkno) != bh->b_blocknr) {
        rc = -EINVAL;
        ocfs2_error(dir->i_sb,
                "Directory block #%llu has an invalid "
                "db_blkno of %llu",
                (unsigned long long)bh->b_blocknr,
                (unsigned long long)le64_to_cpu(trailer->db_blkno));
        goto out;
    }
    if (le64_to_cpu(trailer->db_parent_dinode) !=
        OCFS2_I(dir)->ip_blkno) {
        rc = -EINVAL;
        ocfs2_error(dir->i_sb,
                "Directory block #%llu on dinode "
                "#%llu has an invalid parent_dinode "
                "of %llu",
                (unsigned long long)bh->b_blocknr,
                (unsigned long long)OCFS2_I(dir)->ip_blkno,
                (unsigned long long)le64_to_cpu(trailer->db_blkno));
        goto out;
    }
out:
    return rc;
}

/*
 * This function forces all errors to -EIO for consistency with its
 * predecessor, ocfs2_bread().  We haven't audited what returning the
 * real error codes would do to callers.  We log the real codes with
 * mlog_errno() before we squash them.
 */
static int ocfs2_read_dir_block(struct inode *inode, u64 v_block,
                struct buffer_head **bh, int flags)
{
    int rc = 0;
    struct buffer_head *tmp = *bh;

    rc = ocfs2_read_virt_blocks(inode, v_block, 1, &tmp, flags,
                    ocfs2_validate_dir_block);
    if (rc) {
        mlog_errno(rc);
        goto out;
    }

    if (!(flags & OCFS2_BH_READAHEAD) &&
        ocfs2_supports_dir_trailer(inode)) {
        rc = ocfs2_check_dir_trailer(inode, tmp);
        if (rc) {
            if (!*bh)
                brelse(tmp);
            mlog_errno(rc);
            goto out;
        }
    }

    /* If ocfs2_read_virt_blocks() got us a new bh, pass it up. */
    if (!*bh)
        *bh = tmp;

out:
    return rc ? -EIO : 0;
}

/*
 * Read the block at 'phys' which belongs to this directory
 * inode. This function does no virtual->physical block translation -
 * what's passed in is assumed to be a valid directory block.
 */
static int ocfs2_read_dir_block_direct(struct inode *dir, u64 phys,
                       struct buffer_head **bh)
{
    int ret;
    struct buffer_head *tmp = *bh;

    ret = ocfs2_read_block(INODE_CACHE(dir), phys, &tmp,
                   ocfs2_validate_dir_block);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    if (ocfs2_supports_dir_trailer(dir)) {
        ret = ocfs2_check_dir_trailer(dir, tmp);
        if (ret) {
            if (!*bh)
                brelse(tmp);
            mlog_errno(ret);
            goto out;
        }
    }

    if (!ret && !*bh)
        *bh = tmp;
out:
    return ret;
}

static int ocfs2_validate_dx_root(struct super_block *sb,
                  struct buffer_head *bh)
{
    int ret;
    struct ocfs2_dx_root_block *dx_root;

    BUG_ON(!buffer_uptodate(bh));

    dx_root = (struct ocfs2_dx_root_block *) bh->b_data;

    ret = ocfs2_validate_meta_ecc(sb, bh->b_data, &dx_root->dr_check);
    if (ret) {
        mlog(ML_ERROR,
             "Checksum failed for dir index root block %llu\n",
             (unsigned long long)bh->b_blocknr);
        return ret;
    }

    if (!OCFS2_IS_VALID_DX_ROOT(dx_root)) {
        ocfs2_error(sb,
                "Dir Index Root # %llu has bad signature %.*s",
                (unsigned long long)le64_to_cpu(dx_root->dr_blkno),
                7, dx_root->dr_signature);
        return -EINVAL;
    }

    return 0;
}

static int ocfs2_read_dx_root(struct inode *dir, struct ocfs2_dinode *di,
                  struct buffer_head **dx_root_bh)
{
    int ret;
    u64 blkno = le64_to_cpu(di->i_dx_root);
    struct buffer_head *tmp = *dx_root_bh;

    ret = ocfs2_read_block(INODE_CACHE(dir), blkno, &tmp,
                   ocfs2_validate_dx_root);

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

    return ret;
}

static int ocfs2_validate_dx_leaf(struct super_block *sb,
                  struct buffer_head *bh)
{
    int ret;
    struct ocfs2_dx_leaf *dx_leaf = (struct ocfs2_dx_leaf *)bh->b_data;

    BUG_ON(!buffer_uptodate(bh));

    ret = ocfs2_validate_meta_ecc(sb, bh->b_data, &dx_leaf->dl_check);
    if (ret) {
        mlog(ML_ERROR,
             "Checksum failed for dir index leaf block %llu\n",
             (unsigned long long)bh->b_blocknr);
        return ret;
    }

    if (!OCFS2_IS_VALID_DX_LEAF(dx_leaf)) {
        ocfs2_error(sb, "Dir Index Leaf has bad signature %.*s",
                7, dx_leaf->dl_signature);
        return -EROFS;
    }

    return 0;
}

static int ocfs2_read_dx_leaf(struct inode *dir, u64 blkno,
                  struct buffer_head **dx_leaf_bh)
{
    int ret;
    struct buffer_head *tmp = *dx_leaf_bh;

    ret = ocfs2_read_block(INODE_CACHE(dir), blkno, &tmp,
                   ocfs2_validate_dx_leaf);

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

    return ret;
}

/*
 * Read a series of dx_leaf blocks. This expects all buffer_head
 * pointers to be NULL on function entry.
 */
static int ocfs2_read_dx_leaves(struct inode *dir, u64 start, int num,
                struct buffer_head **dx_leaf_bhs)
{
    int ret;

    ret = ocfs2_read_blocks(INODE_CACHE(dir), start, num, dx_leaf_bhs, 0,
                ocfs2_validate_dx_leaf);
    if (ret)
        mlog_errno(ret);

    return ret;
}

static struct buffer_head *ocfs2_find_entry_el(const char *name, int namelen,
                           struct inode *dir,
                           struct ocfs2_dir_entry **res_dir)
{
    struct super_block *sb;
    struct buffer_head *bh_use[NAMEI_RA_SIZE];
    struct buffer_head *bh, *ret = NULL;
    unsigned long start, block, b;
    int ra_max = 0;     /* Number of bh's in the readahead
                   buffer, bh_use[] */
    int ra_ptr = 0;     /* Current index into readahead
                   buffer */
    int num = 0;
    int nblocks, i, err;

    sb = dir->i_sb;

    nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
    start = OCFS2_I(dir)->ip_dir_start_lookup;
    if (start >= nblocks)
        start = 0;
    block = start;

restart:
    do {
        /*
         * We deal with the read-ahead logic here.
         */
        if (ra_ptr >= ra_max) {
            /* Refill the readahead buffer */
            ra_ptr = 0;
            b = block;
            for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
                /*
                 * Terminate if we reach the end of the
                 * directory and must wrap, or if our
                 * search has finished at this block.
                 */
                if (b >= nblocks || (num && block == start)) {
                    bh_use[ra_max] = NULL;
                    break;
                }
                num++;

                bh = NULL;
                err = ocfs2_read_dir_block(dir, b++, &bh,
                               OCFS2_BH_READAHEAD);
                bh_use[ra_max] = bh;
            }
        }
        if ((bh = bh_use[ra_ptr++]) == NULL)
            goto next;
        if (ocfs2_read_dir_block(dir, block, &bh, 0)) {
            /* read error, skip block & hope for the best.
             * ocfs2_read_dir_block() has released the bh. */
            ocfs2_error(dir->i_sb, "reading directory %llu, "
                    "offset %lu\n",
                    (unsigned long long)OCFS2_I(dir)->ip_blkno,
                    block);
            goto next;
        }
        i = ocfs2_search_dirblock(bh, dir, name, namelen,
                      block << sb->s_blocksize_bits,
                      bh->b_data, sb->s_blocksize,
                      res_dir);
        if (i == 1) {
            OCFS2_I(dir)->ip_dir_start_lookup = block;
            ret = bh;
            goto cleanup_and_exit;
        } else {
            brelse(bh);
            if (i < 0)
                goto cleanup_and_exit;
        }
    next:
        if (++block >= nblocks)
            block = 0;
    } while (block != start);

    /*
     * If the directory has grown while we were searching, then
     * search the last part of the directory before giving up.
     */
    block = nblocks;
    nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
    if (block < nblocks) {
        start = 0;
        goto restart;
    }

cleanup_and_exit:
    /* Clean up the read-ahead blocks */
    for (; ra_ptr < ra_max; ra_ptr++)
        brelse(bh_use[ra_ptr]);

    trace_ocfs2_find_entry_el(ret);
    return ret;
}

static int ocfs2_dx_dir_lookup_rec(struct inode *inode,
                   struct ocfs2_extent_list *el,
                   u32 major_hash,
                   u32 *ret_cpos,
                   u64 *ret_phys_blkno,
                   unsigned int *ret_clen)
{
    int ret = 0, i, found;
    struct buffer_head *eb_bh = NULL;
    struct ocfs2_extent_block *eb;
    struct ocfs2_extent_rec *rec = NULL;

    if (el->l_tree_depth) {
        ret = ocfs2_find_leaf(INODE_CACHE(inode), el, major_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 "
                    "btree tree block %llu\n", inode->i_ino,
                    (unsigned long long)eb_bh->b_blocknr);
            ret = -EROFS;
            goto out;
        }
    }

    found = 0;
    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) <= major_hash) {
            found = 1;
            break;
        }
    }

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

    if (ret_phys_blkno)
        *ret_phys_blkno = le64_to_cpu(rec->e_blkno);
    if (ret_cpos)
        *ret_cpos = le32_to_cpu(rec->e_cpos);
    if (ret_clen)
        *ret_clen = le16_to_cpu(rec->e_leaf_clusters);

out:
    brelse(eb_bh);
    return ret;
}

/*
 * Returns the block index, from the start of the cluster which this
 * hash belongs too.
 */
static inline unsigned int __ocfs2_dx_dir_hash_idx(struct ocfs2_super *osb,
                           u32 minor_hash)
{
    return minor_hash & osb->osb_dx_mask;
}

static inline unsigned int ocfs2_dx_dir_hash_idx(struct ocfs2_super *osb,
                      struct ocfs2_dx_hinfo *hinfo)
{
    return __ocfs2_dx_dir_hash_idx(osb, hinfo->minor_hash);
}

static int ocfs2_dx_dir_lookup(struct inode *inode,
                   struct ocfs2_extent_list *el,
                   struct ocfs2_dx_hinfo *hinfo,
                   u32 *ret_cpos,
                   u64 *ret_phys_blkno)
{
    int ret = 0;
    unsigned int cend, uninitialized_var(clen);
    u32 uninitialized_var(cpos);
    u64 uninitialized_var(blkno);
    u32 name_hash = hinfo->major_hash;

    ret = ocfs2_dx_dir_lookup_rec(inode, el, name_hash, &cpos, &blkno,
                      &clen);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    cend = cpos + clen;
    if (name_hash >= cend) {
        /* We want the last cluster */
        blkno += ocfs2_clusters_to_blocks(inode->i_sb, clen - 1);
        cpos += clen - 1;
    } else {
        blkno += ocfs2_clusters_to_blocks(inode->i_sb,
                          name_hash - cpos);
        cpos = name_hash;
    }

    /*
     * We now have the cluster which should hold our entry. To
     * find the exact block from the start of the cluster to
     * search, we take the lower bits of the hash.
     */
    blkno += ocfs2_dx_dir_hash_idx(OCFS2_SB(inode->i_sb), hinfo);

    if (ret_phys_blkno)
        *ret_phys_blkno = blkno;
    if (ret_cpos)
        *ret_cpos = cpos;

out:

    return ret;
}

static int ocfs2_dx_dir_search(const char *name, int namelen,
                   struct inode *dir,
                   struct ocfs2_dx_root_block *dx_root,
                   struct ocfs2_dir_lookup_result *res)
{
    int ret, i, found;
    u64 uninitialized_var(phys);
    struct buffer_head *dx_leaf_bh = NULL;
    struct ocfs2_dx_leaf *dx_leaf;
    struct ocfs2_dx_entry *dx_entry = NULL;
    struct buffer_head *dir_ent_bh = NULL;
    struct ocfs2_dir_entry *dir_ent = NULL;
    struct ocfs2_dx_hinfo *hinfo = &res->dl_hinfo;
    struct ocfs2_extent_list *dr_el;
    struct ocfs2_dx_entry_list *entry_list;

    ocfs2_dx_dir_name_hash(dir, name, namelen, &res->dl_hinfo);

    if (ocfs2_dx_root_inline(dx_root)) {
        entry_list = &dx_root->dr_entries;
        goto search;
    }

    dr_el = &dx_root->dr_list;

    ret = ocfs2_dx_dir_lookup(dir, dr_el, hinfo, NULL, &phys);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    trace_ocfs2_dx_dir_search((unsigned long long)OCFS2_I(dir)->ip_blkno,
                  namelen, name, hinfo->major_hash,
                  hinfo->minor_hash, (unsigned long long)phys);

    ret = ocfs2_read_dx_leaf(dir, phys, &dx_leaf_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    dx_leaf = (struct ocfs2_dx_leaf *) dx_leaf_bh->b_data;

    trace_ocfs2_dx_dir_search_leaf_info(
            le16_to_cpu(dx_leaf->dl_list.de_num_used),
            le16_to_cpu(dx_leaf->dl_list.de_count));

    entry_list = &dx_leaf->dl_list;

search:
    /*
     * Empty leaf is legal, so no need to check for that.
     */
    found = 0;
    for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++) {
        dx_entry = &entry_list->de_entries[i];

        if (hinfo->major_hash != le32_to_cpu(dx_entry->dx_major_hash)
            || hinfo->minor_hash != le32_to_cpu(dx_entry->dx_minor_hash))
            continue;

        /*
         * Search unindexed leaf block now. We're not
         * guaranteed to find anything.
         */
        ret = ocfs2_read_dir_block_direct(dir,
                      le64_to_cpu(dx_entry->dx_dirent_blk),
                      &dir_ent_bh);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        /*
         * XXX: We should check the unindexed block here,
         * before using it.
         */

        found = ocfs2_search_dirblock(dir_ent_bh, dir, name, namelen,
                          0, dir_ent_bh->b_data,
                          dir->i_sb->s_blocksize, &dir_ent);
        if (found == 1)
            break;

        if (found == -1) {
            /* This means we found a bad directory entry. */
            ret = -EIO;
            mlog_errno(ret);
            goto out;
        }

        brelse(dir_ent_bh);
        dir_ent_bh = NULL;
    }

    if (found <= 0) {
        ret = -ENOENT;
        goto out;
    }

    res->dl_leaf_bh = dir_ent_bh;
    res->dl_entry = dir_ent;
    res->dl_dx_leaf_bh = dx_leaf_bh;
    res->dl_dx_entry = dx_entry;

    ret = 0;
out:
    if (ret) {
        brelse(dx_leaf_bh);
        brelse(dir_ent_bh);
    }
    return ret;
}

static int ocfs2_find_entry_dx(const char *name, int namelen,
                   struct inode *dir,
                   struct ocfs2_dir_lookup_result *lookup)
{
    int ret;
    struct buffer_head *di_bh = NULL;
    struct ocfs2_dinode *di;
    struct buffer_head *dx_root_bh = NULL;
    struct ocfs2_dx_root_block *dx_root;

    ret = ocfs2_read_inode_block(dir, &di_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

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

    ret = ocfs2_read_dx_root(dir, di, &dx_root_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }
    dx_root = (struct ocfs2_dx_root_block *) dx_root_bh->b_data;

    ret = ocfs2_dx_dir_search(name, namelen, dir, dx_root, lookup);
    if (ret) {
        if (ret != -ENOENT)
            mlog_errno(ret);
        goto out;
    }

    lookup->dl_dx_root_bh = dx_root_bh;
    dx_root_bh = NULL;
out:
    brelse(di_bh);
    brelse(dx_root_bh);
    return ret;
}

/*
 * Try to find an entry of the provided name within 'dir'.
 *
 * If nothing was found, -ENOENT is returned. Otherwise, zero is
 * returned and the struct 'res' will contain information useful to
 * other directory manipulation functions.
 *
 * Caller can NOT assume anything about the contents of the
 * buffer_heads - they are passed back only so that it can be passed
 * into any one of the manipulation functions (add entry, delete
 * entry, etc). As an example, bh in the extent directory case is a
 * data block, in the inline-data case it actually points to an inode,
 * in the indexed directory case, multiple buffers are involved.
 */
int ocfs2_find_entry(const char *name, int namelen,
             struct inode *dir, struct ocfs2_dir_lookup_result *lookup)
{
    struct buffer_head *bh;
    struct ocfs2_dir_entry *res_dir = NULL;

    if (ocfs2_dir_indexed(dir))
        return ocfs2_find_entry_dx(name, namelen, dir, lookup);

    /*
     * The unindexed dir code only uses part of the lookup
     * structure, so there's no reason to push it down further
     * than this.
     */
    if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
        bh = ocfs2_find_entry_id(name, namelen, dir, &res_dir);
    else
        bh = ocfs2_find_entry_el(name, namelen, dir, &res_dir);

    if (bh == NULL)
        return -ENOENT;

    lookup->dl_leaf_bh = bh;
    lookup->dl_entry = res_dir;
    return 0;
}

/*
 * Update inode number and type of a previously found directory entry.
 */
int ocfs2_update_entry(struct inode *dir, handle_t *handle,
               struct ocfs2_dir_lookup_result *res,
               struct inode *new_entry_inode)
{
    int ret;
    ocfs2_journal_access_func access = ocfs2_journal_access_db;
    struct ocfs2_dir_entry *de = res->dl_entry;
    struct buffer_head *de_bh = res->dl_leaf_bh;

    /*
     * The same code works fine for both inline-data and extent
     * based directories, so no need to split this up.  The only
     * difference is the journal_access function.
     */

    if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
        access = ocfs2_journal_access_di;

    ret = access(handle, INODE_CACHE(dir), de_bh,
             OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    de->inode = cpu_to_le64(OCFS2_I(new_entry_inode)->ip_blkno);
    ocfs2_set_de_type(de, new_entry_inode->i_mode);

    ocfs2_journal_dirty(handle, de_bh);

out:
    return ret;
}

/*
 * __ocfs2_delete_entry deletes a directory entry by merging it with the
 * previous entry
 */
static int __ocfs2_delete_entry(handle_t *handle, struct inode *dir,
                struct ocfs2_dir_entry *de_del,
                struct buffer_head *bh, char *first_de,
                unsigned int bytes)
{
    struct ocfs2_dir_entry *de, *pde;
    int i, status = -ENOENT;
    ocfs2_journal_access_func access = ocfs2_journal_access_db;

    if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
        access = ocfs2_journal_access_di;

    i = 0;
    pde = NULL;
    de = (struct ocfs2_dir_entry *) first_de;
    while (i < bytes) {
        if (!ocfs2_check_dir_entry(dir, de, bh, i)) {
            status = -EIO;
            mlog_errno(status);
            goto bail;
        }
        if (de == de_del)  {
            status = access(handle, INODE_CACHE(dir), bh,
                    OCFS2_JOURNAL_ACCESS_WRITE);
            if (status < 0) {
                status = -EIO;
                mlog_errno(status);
                goto bail;
            }
            if (pde)
                le16_add_cpu(&pde->rec_len,
                        le16_to_cpu(de->rec_len));
            de->inode = 0;
            dir->i_version++;
            ocfs2_journal_dirty(handle, bh);
            goto bail;
        }
        i += le16_to_cpu(de->rec_len);
        pde = de;
        de = (struct ocfs2_dir_entry *)((char *)de + le16_to_cpu(de->rec_len));
    }
bail:
    return status;
}

static unsigned int ocfs2_figure_dirent_hole(struct ocfs2_dir_entry *de)
{
    unsigned int hole;

    if (le64_to_cpu(de->inode) == 0)
        hole = le16_to_cpu(de->rec_len);
    else
        hole = le16_to_cpu(de->rec_len) -
            OCFS2_DIR_REC_LEN(de->name_len);

    return hole;
}

static int ocfs2_find_max_rec_len(struct super_block *sb,
                  struct buffer_head *dirblock_bh)
{
    int size, this_hole, largest_hole = 0;
    char *trailer, *de_buf, *limit, *start = dirblock_bh->b_data;
    struct ocfs2_dir_entry *de;

    trailer = (char *)ocfs2_trailer_from_bh(dirblock_bh, sb);
    size = ocfs2_dir_trailer_blk_off(sb);
    limit = start + size;
    de_buf = start;
    de = (struct ocfs2_dir_entry *)de_buf;
    do {
        if (de_buf != trailer) {
            this_hole = ocfs2_figure_dirent_hole(de);
            if (this_hole > largest_hole)
                largest_hole = this_hole;
        }

        de_buf += le16_to_cpu(de->rec_len);
        de = (struct ocfs2_dir_entry *)de_buf;
    } while (de_buf < limit);

    if (largest_hole >= OCFS2_DIR_MIN_REC_LEN)
        return largest_hole;
    return 0;
}

static void ocfs2_dx_list_remove_entry(struct ocfs2_dx_entry_list *entry_list,
                       int index)
{
    int num_used = le16_to_cpu(entry_list->de_num_used);

    if (num_used == 1 || index == (num_used - 1))
        goto clear;

    memmove(&entry_list->de_entries[index],
        &entry_list->de_entries[index + 1],
        (num_used - index - 1)*sizeof(struct ocfs2_dx_entry));
clear:
    num_used--;
    memset(&entry_list->de_entries[num_used], 0,
           sizeof(struct ocfs2_dx_entry));
    entry_list->de_num_used = cpu_to_le16(num_used);
}

static int ocfs2_delete_entry_dx(handle_t *handle, struct inode *dir,
                 struct ocfs2_dir_lookup_result *lookup)
{
    int ret, index, max_rec_len, add_to_free_list = 0;
    struct buffer_head *dx_root_bh = lookup->dl_dx_root_bh;
    struct buffer_head *leaf_bh = lookup->dl_leaf_bh;
    struct ocfs2_dx_leaf *dx_leaf;
    struct ocfs2_dx_entry *dx_entry = lookup->dl_dx_entry;
    struct ocfs2_dir_block_trailer *trailer;
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dx_entry_list *entry_list;

    /*
     * This function gets a bit messy because we might have to
     * modify the root block, regardless of whether the indexed
     * entries are stored inline.
     */

    /*
     * *Only* set 'entry_list' here, based on where we're looking
     * for the indexed entries. Later, we might still want to
     * journal both blocks, based on free list state.
     */
    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
    if (ocfs2_dx_root_inline(dx_root)) {
        entry_list = &dx_root->dr_entries;
    } else {
        dx_leaf = (struct ocfs2_dx_leaf *) lookup->dl_dx_leaf_bh->b_data;
        entry_list = &dx_leaf->dl_list;
    }

    /* Neither of these are a disk corruption - that should have
     * been caught by lookup, before we got here. */
    BUG_ON(le16_to_cpu(entry_list->de_count) <= 0);
    BUG_ON(le16_to_cpu(entry_list->de_num_used) <= 0);

    index = (char *)dx_entry - (char *)entry_list->de_entries;
    index /= sizeof(*dx_entry);

    if (index >= le16_to_cpu(entry_list->de_num_used)) {
        mlog(ML_ERROR, "Dir %llu: Bad dx_entry ptr idx %d, (%p, %p)\n",
             (unsigned long long)OCFS2_I(dir)->ip_blkno, index,
             entry_list, dx_entry);
        return -EIO;
    }

    /*
     * We know that removal of this dirent will leave enough room
     * for a new one, so add this block to the free list if it
     * isn't already there.
     */
    trailer = ocfs2_trailer_from_bh(leaf_bh, dir->i_sb);
    if (trailer->db_free_rec_len == 0)
        add_to_free_list = 1;

    /*
     * Add the block holding our index into the journal before
     * removing the unindexed entry. If we get an error return
     * from __ocfs2_delete_entry(), then it hasn't removed the
     * entry yet. Likewise, successful return means we *must*
     * remove the indexed entry.
     *
     * We're also careful to journal the root tree block here as
     * the entry count needs to be updated. Also, we might be
     * adding to the start of the free list.
     */
    ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    if (!ocfs2_dx_root_inline(dx_root)) {
        ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir),
                          lookup->dl_dx_leaf_bh,
                          OCFS2_JOURNAL_ACCESS_WRITE);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
    }

    trace_ocfs2_delete_entry_dx((unsigned long long)OCFS2_I(dir)->ip_blkno,
                    index);

    ret = __ocfs2_delete_entry(handle, dir, lookup->dl_entry,
                   leaf_bh, leaf_bh->b_data, leaf_bh->b_size);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    max_rec_len = ocfs2_find_max_rec_len(dir->i_sb, leaf_bh);
    trailer->db_free_rec_len = cpu_to_le16(max_rec_len);
    if (add_to_free_list) {
        trailer->db_free_next = dx_root->dr_free_blk;
        dx_root->dr_free_blk = cpu_to_le64(leaf_bh->b_blocknr);
        ocfs2_journal_dirty(handle, dx_root_bh);
    }

    /* leaf_bh was journal_accessed for us in __ocfs2_delete_entry */
    ocfs2_journal_dirty(handle, leaf_bh);

    le32_add_cpu(&dx_root->dr_num_entries, -1);
    ocfs2_journal_dirty(handle, dx_root_bh);

    ocfs2_dx_list_remove_entry(entry_list, index);

    if (!ocfs2_dx_root_inline(dx_root))
        ocfs2_journal_dirty(handle, lookup->dl_dx_leaf_bh);

out:
    return ret;
}

static inline int ocfs2_delete_entry_id(handle_t *handle,
                    struct inode *dir,
                    struct ocfs2_dir_entry *de_del,
                    struct buffer_head *bh)
{
    int ret;
    struct buffer_head *di_bh = NULL;
    struct ocfs2_dinode *di;
    struct ocfs2_inline_data *data;

    ret = ocfs2_read_inode_block(dir, &di_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    di = (struct ocfs2_dinode *)di_bh->b_data;
    data = &di->id2.i_data;

    ret = __ocfs2_delete_entry(handle, dir, de_del, bh, data->id_data,
                   i_size_read(dir));

    brelse(di_bh);
out:
    return ret;
}

static inline int ocfs2_delete_entry_el(handle_t *handle,
                    struct inode *dir,
                    struct ocfs2_dir_entry *de_del,
                    struct buffer_head *bh)
{
    return __ocfs2_delete_entry(handle, dir, de_del, bh, bh->b_data,
                    bh->b_size);
}

/*
 * Delete a directory entry. Hide the details of directory
 * implementation from the caller.
 */
int ocfs2_delete_entry(handle_t *handle,
               struct inode *dir,
               struct ocfs2_dir_lookup_result *res)
{
    if (ocfs2_dir_indexed(dir))
        return ocfs2_delete_entry_dx(handle, dir, res);

    if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
        return ocfs2_delete_entry_id(handle, dir, res->dl_entry,
                         res->dl_leaf_bh);

    return ocfs2_delete_entry_el(handle, dir, res->dl_entry,
                     res->dl_leaf_bh);
}

/*
 * Check whether 'de' has enough room to hold an entry of
 * 'new_rec_len' bytes.
 */
static inline int ocfs2_dirent_would_fit(struct ocfs2_dir_entry *de,
                     unsigned int new_rec_len)
{
    unsigned int de_really_used;

    /* Check whether this is an empty record with enough space */
    if (le64_to_cpu(de->inode) == 0 &&
        le16_to_cpu(de->rec_len) >= new_rec_len)
        return 1;

    /*
     * Record might have free space at the end which we can
     * use.
     */
    de_really_used = OCFS2_DIR_REC_LEN(de->name_len);
    if (le16_to_cpu(de->rec_len) >= (de_really_used + new_rec_len))
        return 1;

    return 0;
}

static void ocfs2_dx_dir_leaf_insert_tail(struct ocfs2_dx_leaf *dx_leaf,
                      struct ocfs2_dx_entry *dx_new_entry)
{
    int i;

    i = le16_to_cpu(dx_leaf->dl_list.de_num_used);
    dx_leaf->dl_list.de_entries[i] = *dx_new_entry;

    le16_add_cpu(&dx_leaf->dl_list.de_num_used, 1);
}

static void ocfs2_dx_entry_list_insert(struct ocfs2_dx_entry_list *entry_list,
                       struct ocfs2_dx_hinfo *hinfo,
                       u64 dirent_blk)
{
    int i;
    struct ocfs2_dx_entry *dx_entry;

    i = le16_to_cpu(entry_list->de_num_used);
    dx_entry = &entry_list->de_entries[i];

    memset(dx_entry, 0, sizeof(*dx_entry));
    dx_entry->dx_major_hash = cpu_to_le32(hinfo->major_hash);
    dx_entry->dx_minor_hash = cpu_to_le32(hinfo->minor_hash);
    dx_entry->dx_dirent_blk = cpu_to_le64(dirent_blk);

    le16_add_cpu(&entry_list->de_num_used, 1);
}

static int __ocfs2_dx_dir_leaf_insert(struct inode *dir, handle_t *handle,
                      struct ocfs2_dx_hinfo *hinfo,
                      u64 dirent_blk,
                      struct buffer_head *dx_leaf_bh)
{
    int ret;
    struct ocfs2_dx_leaf *dx_leaf;

    ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir), dx_leaf_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    dx_leaf = (struct ocfs2_dx_leaf *)dx_leaf_bh->b_data;
    ocfs2_dx_entry_list_insert(&dx_leaf->dl_list, hinfo, dirent_blk);
    ocfs2_journal_dirty(handle, dx_leaf_bh);

out:
    return ret;
}

static void ocfs2_dx_inline_root_insert(struct inode *dir, handle_t *handle,
                    struct ocfs2_dx_hinfo *hinfo,
                    u64 dirent_blk,
                    struct ocfs2_dx_root_block *dx_root)
{
    ocfs2_dx_entry_list_insert(&dx_root->dr_entries, hinfo, dirent_blk);
}

static int ocfs2_dx_dir_insert(struct inode *dir, handle_t *handle,
                   struct ocfs2_dir_lookup_result *lookup)
{
    int ret = 0;
    struct ocfs2_dx_root_block *dx_root;
    struct buffer_head *dx_root_bh = lookup->dl_dx_root_bh;

    ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    dx_root = (struct ocfs2_dx_root_block *)lookup->dl_dx_root_bh->b_data;
    if (ocfs2_dx_root_inline(dx_root)) {
        ocfs2_dx_inline_root_insert(dir, handle,
                        &lookup->dl_hinfo,
                        lookup->dl_leaf_bh->b_blocknr,
                        dx_root);
    } else {
        ret = __ocfs2_dx_dir_leaf_insert(dir, handle, &lookup->dl_hinfo,
                         lookup->dl_leaf_bh->b_blocknr,
                         lookup->dl_dx_leaf_bh);
        if (ret)
            goto out;
    }

    le32_add_cpu(&dx_root->dr_num_entries, 1);
    ocfs2_journal_dirty(handle, dx_root_bh);

out:
    return ret;
}

static void ocfs2_remove_block_from_free_list(struct inode *dir,
                       handle_t *handle,
                       struct ocfs2_dir_lookup_result *lookup)
{
    struct ocfs2_dir_block_trailer *trailer, *prev;
    struct ocfs2_dx_root_block *dx_root;
    struct buffer_head *bh;

    trailer = ocfs2_trailer_from_bh(lookup->dl_leaf_bh, dir->i_sb);

    if (ocfs2_free_list_at_root(lookup)) {
        bh = lookup->dl_dx_root_bh;
        dx_root = (struct ocfs2_dx_root_block *)bh->b_data;
        dx_root->dr_free_blk = trailer->db_free_next;
    } else {
        bh = lookup->dl_prev_leaf_bh;
        prev = ocfs2_trailer_from_bh(bh, dir->i_sb);
        prev->db_free_next = trailer->db_free_next;
    }

    trailer->db_free_rec_len = cpu_to_le16(0);
    trailer->db_free_next = cpu_to_le64(0);

    ocfs2_journal_dirty(handle, bh);
    ocfs2_journal_dirty(handle, lookup->dl_leaf_bh);
}

/*
 * This expects that a journal write has been reserved on
 * lookup->dl_prev_leaf_bh or lookup->dl_dx_root_bh
 */
static void ocfs2_recalc_free_list(struct inode *dir, handle_t *handle,
                   struct ocfs2_dir_lookup_result *lookup)
{
    int max_rec_len;
    struct ocfs2_dir_block_trailer *trailer;

    /* Walk dl_leaf_bh to figure out what the new free rec_len is. */
    max_rec_len = ocfs2_find_max_rec_len(dir->i_sb, lookup->dl_leaf_bh);
    if (max_rec_len) {
        /*
         * There's still room in this block, so no need to remove it
         * from the free list. In this case, we just want to update
         * the rec len accounting.
         */
        trailer = ocfs2_trailer_from_bh(lookup->dl_leaf_bh, dir->i_sb);
        trailer->db_free_rec_len = cpu_to_le16(max_rec_len);
        ocfs2_journal_dirty(handle, lookup->dl_leaf_bh);
    } else {
        ocfs2_remove_block_from_free_list(dir, handle, lookup);
    }
}

/* we don't always have a dentry for what we want to add, so people
 * like orphan dir can call this instead.
 *
 * The lookup context must have been filled from
 * ocfs2_prepare_dir_for_insert.
 */
int __ocfs2_add_entry(handle_t *handle,
              struct inode *dir,
              const char *name, int namelen,
              struct inode *inode, u64 blkno,
              struct buffer_head *parent_fe_bh,
              struct ocfs2_dir_lookup_result *lookup)
{
    unsigned long offset;
    unsigned short rec_len;
    struct ocfs2_dir_entry *de, *de1;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_fe_bh->b_data;
    struct super_block *sb = dir->i_sb;
    int retval, status;
    unsigned int size = sb->s_blocksize;
    struct buffer_head *insert_bh = lookup->dl_leaf_bh;
    char *data_start = insert_bh->b_data;

    if (!namelen)
        return -EINVAL;

    if (ocfs2_dir_indexed(dir)) {
        struct buffer_head *bh;

        /*
         * An indexed dir may require that we update the free space
         * list. Reserve a write to the previous node in the list so
         * that we don't fail later.
         *
         * XXX: This can be either a dx_root_block, or an unindexed
         * directory tree leaf block.
         */
        if (ocfs2_free_list_at_root(lookup)) {
            bh = lookup->dl_dx_root_bh;
            retval = ocfs2_journal_access_dr(handle,
                         INODE_CACHE(dir), bh,
                         OCFS2_JOURNAL_ACCESS_WRITE);
        } else {
            bh = lookup->dl_prev_leaf_bh;
            retval = ocfs2_journal_access_db(handle,
                         INODE_CACHE(dir), bh,
                         OCFS2_JOURNAL_ACCESS_WRITE);
        }
        if (retval) {
            mlog_errno(retval);
            return retval;
        }
    } else if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
        data_start = di->id2.i_data.id_data;
        size = i_size_read(dir);

        BUG_ON(insert_bh != parent_fe_bh);
    }

    rec_len = OCFS2_DIR_REC_LEN(namelen);
    offset = 0;
    de = (struct ocfs2_dir_entry *) data_start;
    while (1) {
        BUG_ON((char *)de >= (size + data_start));

        /* These checks should've already been passed by the
         * prepare function, but I guess we can leave them
         * here anyway. */
        if (!ocfs2_check_dir_entry(dir, de, insert_bh, offset)) {
            retval = -ENOENT;
            goto bail;
        }
        if (ocfs2_match(namelen, name, de)) {
            retval = -EEXIST;
            goto bail;
        }

        /* We're guaranteed that we should have space, so we
         * can't possibly have hit the trailer...right? */
        mlog_bug_on_msg(ocfs2_skip_dir_trailer(dir, de, offset, size),
                "Hit dir trailer trying to insert %.*s "
                    "(namelen %d) into directory %llu.  "
                "offset is %lu, trailer offset is %d\n",
                namelen, name, namelen,
                (unsigned long long)parent_fe_bh->b_blocknr,
                offset, ocfs2_dir_trailer_blk_off(dir->i_sb));

        if (ocfs2_dirent_would_fit(de, rec_len)) {
            dir->i_mtime = dir->i_ctime = CURRENT_TIME;
            retval = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
            if (retval < 0) {
                mlog_errno(retval);
                goto bail;
            }

            if (insert_bh == parent_fe_bh)
                status = ocfs2_journal_access_di(handle,
                                 INODE_CACHE(dir),
                                 insert_bh,
                                 OCFS2_JOURNAL_ACCESS_WRITE);
            else {
                status = ocfs2_journal_access_db(handle,
                                 INODE_CACHE(dir),
                                 insert_bh,
                          OCFS2_JOURNAL_ACCESS_WRITE);

                if (ocfs2_dir_indexed(dir)) {
                    status = ocfs2_dx_dir_insert(dir,
                                handle,
                                lookup);
                    if (status) {
                        mlog_errno(status);
                        goto bail;
                    }
                }
            }

            /* By now the buffer is marked for journaling */
            offset += le16_to_cpu(de->rec_len);
            if (le64_to_cpu(de->inode)) {
                de1 = (struct ocfs2_dir_entry *)((char *) de +
                    OCFS2_DIR_REC_LEN(de->name_len));
                de1->rec_len =
                    cpu_to_le16(le16_to_cpu(de->rec_len) -
                    OCFS2_DIR_REC_LEN(de->name_len));
                de->rec_len = cpu_to_le16(OCFS2_DIR_REC_LEN(de->name_len));
                de = de1;
            }
            de->file_type = OCFS2_FT_UNKNOWN;
            if (blkno) {
                de->inode = cpu_to_le64(blkno);
                ocfs2_set_de_type(de, inode->i_mode);
            } else
                de->inode = 0;
            de->name_len = namelen;
            memcpy(de->name, name, namelen);

            if (ocfs2_dir_indexed(dir))
                ocfs2_recalc_free_list(dir, handle, lookup);

            dir->i_version++;
            ocfs2_journal_dirty(handle, insert_bh);
            retval = 0;
            goto bail;
        }

        offset += le16_to_cpu(de->rec_len);
        de = (struct ocfs2_dir_entry *) ((char *) de + le16_to_cpu(de->rec_len));
    }

    /* when you think about it, the assert above should prevent us
     * from ever getting here. */
    retval = -ENOSPC;
bail:
    if (retval)
        mlog_errno(retval);

    return retval;
}

static int ocfs2_dir_foreach_blk_id(struct inode *inode,
                    u64 *f_version,
                    loff_t *f_pos, void *priv,
                    filldir_t filldir, int *filldir_err)
{
    int ret, i, filldir_ret;
    unsigned long offset = *f_pos;
    struct buffer_head *di_bh = NULL;
    struct ocfs2_dinode *di;
    struct ocfs2_inline_data *data;
    struct ocfs2_dir_entry *de;

    ret = ocfs2_read_inode_block(inode, &di_bh);
    if (ret) {
        mlog(ML_ERROR, "Unable to read inode block for dir %llu\n",
             (unsigned long long)OCFS2_I(inode)->ip_blkno);
        goto out;
    }

    di = (struct ocfs2_dinode *)di_bh->b_data;
    data = &di->id2.i_data;

    while (*f_pos < i_size_read(inode)) {
revalidate:
        /* If the dir block has changed since the last call to
         * readdir(2), then we might be pointing to an invalid
         * dirent right now.  Scan from the start of the block
         * to make sure. */
        if (*f_version != inode->i_version) {
            for (i = 0; i < i_size_read(inode) && i < offset; ) {
                de = (struct ocfs2_dir_entry *)
                    (data->id_data + i);
                /* It's too expensive to do a full
                 * dirent test each time round this
                 * loop, but we do have to test at
                 * least that it is non-zero.  A
                 * failure will be detected in the
                 * dirent test below. */
                if (le16_to_cpu(de->rec_len) <
                    OCFS2_DIR_REC_LEN(1))
                    break;
                i += le16_to_cpu(de->rec_len);
            }
            *f_pos = offset = i;
            *f_version = inode->i_version;
        }

        de = (struct ocfs2_dir_entry *) (data->id_data + *f_pos);
        if (!ocfs2_check_dir_entry(inode, de, di_bh, *f_pos)) {
            /* On error, skip the f_pos to the end. */
            *f_pos = i_size_read(inode);
            goto out;
        }
        offset += le16_to_cpu(de->rec_len);
        if (le64_to_cpu(de->inode)) {
            /* We might block in the next section
             * if the data destination is
             * currently swapped out.  So, use a
             * version stamp to detect whether or
             * not the directory has been modified
             * during the copy operation.
             */
            u64 version = *f_version;
            unsigned char d_type = DT_UNKNOWN;

            if (de->file_type < OCFS2_FT_MAX)
                d_type = ocfs2_filetype_table[de->file_type];

            filldir_ret = filldir(priv, de->name,
                          de->name_len,
                          *f_pos,
                          le64_to_cpu(de->inode),
                          d_type);
            if (filldir_ret) {
                if (filldir_err)
                    *filldir_err = filldir_ret;
                break;
            }
            if (version != *f_version)
                goto revalidate;
        }
        *f_pos += le16_to_cpu(de->rec_len);
    }

out:
    brelse(di_bh);

    return 0;
}

/*
 * NOTE: This function can be called against unindexed directories,
 * and indexed ones.
 */
static int ocfs2_dir_foreach_blk_el(struct inode *inode,
                    u64 *f_version,
                    loff_t *f_pos, void *priv,
                    filldir_t filldir, int *filldir_err)
{
    int error = 0;
    unsigned long offset, blk, last_ra_blk = 0;
    int i, stored;
    struct buffer_head * bh, * tmp;
    struct ocfs2_dir_entry * de;
    struct super_block * sb = inode->i_sb;
    unsigned int ra_sectors = 16;

    stored = 0;
    bh = NULL;

    offset = (*f_pos) & (sb->s_blocksize - 1);

    while (!error && !stored && *f_pos < i_size_read(inode)) {
        blk = (*f_pos) >> sb->s_blocksize_bits;
        if (ocfs2_read_dir_block(inode, blk, &bh, 0)) {
            /* Skip the corrupt dirblock and keep trying */
            *f_pos += sb->s_blocksize - offset;
            continue;
        }

        /* The idea here is to begin with 8k read-ahead and to stay
         * 4k ahead of our current position.
         *
         * TODO: Use the pagecache for this. We just need to
         * make sure it's cluster-safe... */
        if (!last_ra_blk
            || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) {
            for (i = ra_sectors >> (sb->s_blocksize_bits - 9);
                 i > 0; i--) {
                tmp = NULL;
                if (!ocfs2_read_dir_block(inode, ++blk, &tmp,
                              OCFS2_BH_READAHEAD))
                    brelse(tmp);
            }
            last_ra_blk = blk;
            ra_sectors = 8;
        }

revalidate:
        /* If the dir block has changed since the last call to
         * readdir(2), then we might be pointing to an invalid
         * dirent right now.  Scan from the start of the block
         * to make sure. */
        if (*f_version != inode->i_version) {
            for (i = 0; i < sb->s_blocksize && i < offset; ) {
                de = (struct ocfs2_dir_entry *) (bh->b_data + i);
                /* It's too expensive to do a full
                 * dirent test each time round this
                 * loop, but we do have to test at
                 * least that it is non-zero.  A
                 * failure will be detected in the
                 * dirent test below. */
                if (le16_to_cpu(de->rec_len) <
                    OCFS2_DIR_REC_LEN(1))
                    break;
                i += le16_to_cpu(de->rec_len);
            }
            offset = i;
            *f_pos = ((*f_pos) & ~(sb->s_blocksize - 1))
                | offset;
            *f_version = inode->i_version;
        }

        while (!error && *f_pos < i_size_read(inode)
               && offset < sb->s_blocksize) {
            de = (struct ocfs2_dir_entry *) (bh->b_data + offset);
            if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
                /* On error, skip the f_pos to the
                   next block. */
                *f_pos = ((*f_pos) | (sb->s_blocksize - 1)) + 1;
                brelse(bh);
                goto out;
            }
            offset += le16_to_cpu(de->rec_len);
            if (le64_to_cpu(de->inode)) {
                /* We might block in the next section
                 * if the data destination is
                 * currently swapped out.  So, use a
                 * version stamp to detect whether or
                 * not the directory has been modified
                 * during the copy operation.
                 */
                unsigned long version = *f_version;
                unsigned char d_type = DT_UNKNOWN;

                if (de->file_type < OCFS2_FT_MAX)
                    d_type = ocfs2_filetype_table[de->file_type];
                error = filldir(priv, de->name,
                        de->name_len,
                        *f_pos,
                        le64_to_cpu(de->inode),
                        d_type);
                if (error) {
                    if (filldir_err)
                        *filldir_err = error;
                    break;
                }
                if (version != *f_version)
                    goto revalidate;
                stored ++;
            }
            *f_pos += le16_to_cpu(de->rec_len);
        }
        offset = 0;
        brelse(bh);
        bh = NULL;
    }

    stored = 0;
out:
    return stored;
}

static int ocfs2_dir_foreach_blk(struct inode *inode, u64 *f_version,
                 loff_t *f_pos, void *priv, filldir_t filldir,
                 int *filldir_err)
{
    if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
        return ocfs2_dir_foreach_blk_id(inode, f_version, f_pos, priv,
                        filldir, filldir_err);

    return ocfs2_dir_foreach_blk_el(inode, f_version, f_pos, priv, filldir,
                    filldir_err);
}

/*
 * This is intended to be called from inside other kernel functions,
 * so we fake some arguments.
 */
int ocfs2_dir_foreach(struct inode *inode, loff_t *f_pos, void *priv,
              filldir_t filldir)
{
    int ret = 0, filldir_err = 0;
    u64 version = inode->i_version;

    while (*f_pos < i_size_read(inode)) {
        ret = ocfs2_dir_foreach_blk(inode, &version, f_pos, priv,
                        filldir, &filldir_err);
        if (ret || filldir_err)
            break;
    }

    if (ret > 0)
        ret = -EIO;

    return 0;
}

/*
 * ocfs2_readdir()
 *
 */
int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
    int error = 0;
    struct inode *inode = filp->f_path.dentry->d_inode;
    int lock_level = 0;

    trace_ocfs2_readdir((unsigned long long)OCFS2_I(inode)->ip_blkno);

    error = ocfs2_inode_lock_atime(inode, filp->f_vfsmnt, &lock_level);
    if (lock_level && error >= 0) {
        /* We release EX lock which used to update atime
         * and get PR lock again to reduce contention
         * on commonly accessed directories. */
        ocfs2_inode_unlock(inode, 1);
        lock_level = 0;
        error = ocfs2_inode_lock(inode, NULL, 0);
    }
    if (error < 0) {
        if (error != -ENOENT)
            mlog_errno(error);
        /* we haven't got any yet, so propagate the error. */
        goto bail_nolock;
    }

    error = ocfs2_dir_foreach_blk(inode, &filp->f_version, &filp->f_pos,
                      dirent, filldir, NULL);

    ocfs2_inode_unlock(inode, lock_level);
    if (error)
        mlog_errno(error);

bail_nolock:

    return error;
}

/*
 * NOTE: this should always be called with parent dir i_mutex taken.
 */
int ocfs2_find_files_on_disk(const char *name,
                 int namelen,
                 u64 *blkno,
                 struct inode *inode,
                 struct ocfs2_dir_lookup_result *lookup)
{
    int status = -ENOENT;

    trace_ocfs2_find_files_on_disk(namelen, name, blkno,
                (unsigned long long)OCFS2_I(inode)->ip_blkno);

    status = ocfs2_find_entry(name, namelen, inode, lookup);
    if (status)
        goto leave;

    *blkno = le64_to_cpu(lookup->dl_entry->inode);

    status = 0;
leave:

    return status;
}

/*
 * Convenience function for callers which just want the block number
 * mapped to a name and don't require the full dirent info, etc.
 */
int ocfs2_lookup_ino_from_name(struct inode *dir, const char *name,
                   int namelen, u64 *blkno)
{
    int ret;
    struct ocfs2_dir_lookup_result lookup = { NULL, };

    ret = ocfs2_find_files_on_disk(name, namelen, blkno, dir, &lookup);
    ocfs2_free_dir_lookup_result(&lookup);

    return ret;
}

/* Check for a name within a directory.
 *
 * Return 0 if the name does not exist
 * Return -EEXIST if the directory contains the name
 *
 * Callers should have i_mutex + a cluster lock on dir
 */
int ocfs2_check_dir_for_entry(struct inode *dir,
                  const char *name,
                  int namelen)
{
    int ret;
    struct ocfs2_dir_lookup_result lookup = { NULL, };

    trace_ocfs2_check_dir_for_entry(
        (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name);

    ret = -EEXIST;
    if (ocfs2_find_entry(name, namelen, dir, &lookup) == 0)
        goto bail;

    ret = 0;
bail:
    ocfs2_free_dir_lookup_result(&lookup);

    if (ret)
        mlog_errno(ret);
    return ret;
}

struct ocfs2_empty_dir_priv {
    unsigned seen_dot;
    unsigned seen_dot_dot;
    unsigned seen_other;
    unsigned dx_dir;
};
static int ocfs2_empty_dir_filldir(void *priv, const char *name, int name_len,
                   loff_t pos, u64 ino, unsigned type)
{
    struct ocfs2_empty_dir_priv *p = priv;

    /*
     * Check the positions of "." and ".." records to be sure
     * they're in the correct place.
     *
     * Indexed directories don't need to proceed past the first
     * two entries, so we end the scan after seeing '..'. Despite
     * that, we allow the scan to proceed In the event that we
     * have a corrupted indexed directory (no dot or dot dot
     * entries). This allows us to double check for existing
     * entries which might not have been found in the index.
     */
    if (name_len == 1 && !strncmp(".", name, 1) && pos == 0) {
        p->seen_dot = 1;
        return 0;
    }

    if (name_len == 2 && !strncmp("..", name, 2) &&
        pos == OCFS2_DIR_REC_LEN(1)) {
        p->seen_dot_dot = 1;

        if (p->dx_dir && p->seen_dot)
            return 1;

        return 0;
    }

    p->seen_other = 1;
    return 1;
}

static int ocfs2_empty_dir_dx(struct inode *inode,
                  struct ocfs2_empty_dir_priv *priv)
{
    int ret;
    struct buffer_head *di_bh = NULL;
    struct buffer_head *dx_root_bh = NULL;
    struct ocfs2_dinode *di;
    struct ocfs2_dx_root_block *dx_root;

    priv->dx_dir = 1;

    ret = ocfs2_read_inode_block(inode, &di_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }
    di = (struct ocfs2_dinode *)di_bh->b_data;

    ret = ocfs2_read_dx_root(inode, di, &dx_root_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }
    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;

    if (le32_to_cpu(dx_root->dr_num_entries) != 2)
        priv->seen_other = 1;

out:
    brelse(di_bh);
    brelse(dx_root_bh);
    return ret;
}

/*
 * routine to check that the specified directory is empty (for rmdir)
 *
 * Returns 1 if dir is empty, zero otherwise.
 *
 * XXX: This is a performance problem for unindexed directories.
 */
int ocfs2_empty_dir(struct inode *inode)
{
    int ret;
    loff_t start = 0;
    struct ocfs2_empty_dir_priv priv;

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

    if (ocfs2_dir_indexed(inode)) {
        ret = ocfs2_empty_dir_dx(inode, &priv);
        if (ret)
            mlog_errno(ret);
        /*
         * We still run ocfs2_dir_foreach to get the checks
         * for "." and "..".
         */
    }

    ret = ocfs2_dir_foreach(inode, &start, &priv, ocfs2_empty_dir_filldir);
    if (ret)
        mlog_errno(ret);

    if (!priv.seen_dot || !priv.seen_dot_dot) {
        mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
             (unsigned long long)OCFS2_I(inode)->ip_blkno);
        /*
         * XXX: Is it really safe to allow an unlink to continue?
         */
        return 1;
    }

    return !priv.seen_other;
}

/*
 * Fills "." and ".." dirents in a new directory block. Returns dirent for
 * "..", which might be used during creation of a directory with a trailing
 * header. It is otherwise safe to ignore the return code.
 */
static struct ocfs2_dir_entry *ocfs2_fill_initial_dirents(struct inode *inode,
                              struct inode *parent,
                              char *start,
                              unsigned int size)
{
    struct ocfs2_dir_entry *de = (struct ocfs2_dir_entry *)start;

    de->inode = cpu_to_le64(OCFS2_I(inode)->ip_blkno);
    de->name_len = 1;
    de->rec_len =
        cpu_to_le16(OCFS2_DIR_REC_LEN(de->name_len));
    strcpy(de->name, ".");
    ocfs2_set_de_type(de, S_IFDIR);

    de = (struct ocfs2_dir_entry *) ((char *)de + le16_to_cpu(de->rec_len));
    de->inode = cpu_to_le64(OCFS2_I(parent)->ip_blkno);
    de->rec_len = cpu_to_le16(size - OCFS2_DIR_REC_LEN(1));
    de->name_len = 2;
    strcpy(de->name, "..");
    ocfs2_set_de_type(de, S_IFDIR);

    return de;
}

/*
 * This works together with code in ocfs2_mknod_locked() which sets
 * the inline-data flag and initializes the inline-data section.
 */
static int ocfs2_fill_new_dir_id(struct ocfs2_super *osb,
                 handle_t *handle,
                 struct inode *parent,
                 struct inode *inode,
                 struct buffer_head *di_bh)
{
    int ret;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    struct ocfs2_inline_data *data = &di->id2.i_data;
    unsigned int size = le16_to_cpu(data->id_count);

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

    ocfs2_fill_initial_dirents(inode, parent, data->id_data, size);
    ocfs2_journal_dirty(handle, di_bh);

    i_size_write(inode, size);
    set_nlink(inode, 2);
    inode->i_blocks = ocfs2_inode_sector_count(inode);

    ret = ocfs2_mark_inode_dirty(handle, inode, di_bh);
    if (ret < 0)
        mlog_errno(ret);

out:
    return ret;
}

static int ocfs2_fill_new_dir_el(struct ocfs2_super *osb,
                 handle_t *handle,
                 struct inode *parent,
                 struct inode *inode,
                 struct buffer_head *fe_bh,
                 struct ocfs2_alloc_context *data_ac,
                 struct buffer_head **ret_new_bh)
{
    int status;
    unsigned int size = osb->sb->s_blocksize;
    struct buffer_head *new_bh = NULL;
    struct ocfs2_dir_entry *de;

    if (ocfs2_new_dir_wants_trailer(inode))
        size = ocfs2_dir_trailer_blk_off(parent->i_sb);

    status = ocfs2_do_extend_dir(osb->sb, handle, inode, fe_bh,
                     data_ac, NULL, &new_bh);
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }

    ocfs2_set_new_buffer_uptodate(INODE_CACHE(inode), new_bh);

    status = ocfs2_journal_access_db(handle, INODE_CACHE(inode), new_bh,
                     OCFS2_JOURNAL_ACCESS_CREATE);
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }
    memset(new_bh->b_data, 0, osb->sb->s_blocksize);

    de = ocfs2_fill_initial_dirents(inode, parent, new_bh->b_data, size);
    if (ocfs2_new_dir_wants_trailer(inode)) {
        int size = le16_to_cpu(de->rec_len);

        /*
         * Figure out the size of the hole left over after
         * insertion of '.' and '..'. The trailer wants this
         * information.
         */
        size -= OCFS2_DIR_REC_LEN(2);
        size -= sizeof(struct ocfs2_dir_block_trailer);

        ocfs2_init_dir_trailer(inode, new_bh, size);
    }

    ocfs2_journal_dirty(handle, new_bh);

    i_size_write(inode, inode->i_sb->s_blocksize);
    set_nlink(inode, 2);
    inode->i_blocks = ocfs2_inode_sector_count(inode);
    status = ocfs2_mark_inode_dirty(handle, inode, fe_bh);
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }

    status = 0;
    if (ret_new_bh) {
        *ret_new_bh = new_bh;
        new_bh = NULL;
    }
bail:
    brelse(new_bh);

    return status;
}

static int ocfs2_dx_dir_attach_index(struct ocfs2_super *osb,
                     handle_t *handle, struct inode *dir,
                     struct buffer_head *di_bh,
                     struct buffer_head *dirdata_bh,
                     struct ocfs2_alloc_context *meta_ac,
                     int dx_inline, u32 num_entries,
                     struct buffer_head **ret_dx_root_bh)
{
    int ret;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
    u16 dr_suballoc_bit;
    u64 suballoc_loc, dr_blkno;
    unsigned int num_bits;
    struct buffer_head *dx_root_bh = NULL;
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dir_block_trailer *trailer =
        ocfs2_trailer_from_bh(dirdata_bh, dir->i_sb);

    ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
                   &dr_suballoc_bit, &num_bits, &dr_blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    trace_ocfs2_dx_dir_attach_index(
                (unsigned long long)OCFS2_I(dir)->ip_blkno,
                (unsigned long long)dr_blkno);

    dx_root_bh = sb_getblk(osb->sb, dr_blkno);
    if (dx_root_bh == NULL) {
        ret = -EIO;
        goto out;
    }
    ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), dx_root_bh);

    ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
                      OCFS2_JOURNAL_ACCESS_CREATE);
    if (ret < 0) {
        mlog_errno(ret);
        goto out;
    }

    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
    memset(dx_root, 0, osb->sb->s_blocksize);
    strcpy(dx_root->dr_signature, OCFS2_DX_ROOT_SIGNATURE);
    dx_root->dr_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
    dx_root->dr_suballoc_loc = cpu_to_le64(suballoc_loc);
    dx_root->dr_suballoc_bit = cpu_to_le16(dr_suballoc_bit);
    dx_root->dr_fs_generation = cpu_to_le32(osb->fs_generation);
    dx_root->dr_blkno = cpu_to_le64(dr_blkno);
    dx_root->dr_dir_blkno = cpu_to_le64(OCFS2_I(dir)->ip_blkno);
    dx_root->dr_num_entries = cpu_to_le32(num_entries);
    if (le16_to_cpu(trailer->db_free_rec_len))
        dx_root->dr_free_blk = cpu_to_le64(dirdata_bh->b_blocknr);
    else
        dx_root->dr_free_blk = cpu_to_le64(0);

    if (dx_inline) {
        dx_root->dr_flags |= OCFS2_DX_FLAG_INLINE;
        dx_root->dr_entries.de_count =
            cpu_to_le16(ocfs2_dx_entries_per_root(osb->sb));
    } else {
        dx_root->dr_list.l_count =
            cpu_to_le16(ocfs2_extent_recs_per_dx_root(osb->sb));
    }
    ocfs2_journal_dirty(handle, dx_root_bh);

    ret = ocfs2_journal_access_di(handle, INODE_CACHE(dir), di_bh,
                      OCFS2_JOURNAL_ACCESS_CREATE);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    di->i_dx_root = cpu_to_le64(dr_blkno);

    spin_lock(&OCFS2_I(dir)->ip_lock);
    OCFS2_I(dir)->ip_dyn_features |= OCFS2_INDEXED_DIR_FL;
    di->i_dyn_features = cpu_to_le16(OCFS2_I(dir)->ip_dyn_features);
    spin_unlock(&OCFS2_I(dir)->ip_lock);

    ocfs2_journal_dirty(handle, di_bh);

    *ret_dx_root_bh = dx_root_bh;
    dx_root_bh = NULL;

out:
    brelse(dx_root_bh);
    return ret;
}

static int ocfs2_dx_dir_format_cluster(struct ocfs2_super *osb,
                       handle_t *handle, struct inode *dir,
                       struct buffer_head **dx_leaves,
                       int num_dx_leaves, u64 start_blk)
{
    int ret, i;
    struct ocfs2_dx_leaf *dx_leaf;
    struct buffer_head *bh;

    for (i = 0; i < num_dx_leaves; i++) {
        bh = sb_getblk(osb->sb, start_blk + i);
        if (bh == NULL) {
            ret = -EIO;
            goto out;
        }
        dx_leaves[i] = bh;

        ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), bh);

        ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir), bh,
                          OCFS2_JOURNAL_ACCESS_CREATE);
        if (ret < 0) {
            mlog_errno(ret);
            goto out;
        }

        dx_leaf = (struct ocfs2_dx_leaf *) bh->b_data;

        memset(dx_leaf, 0, osb->sb->s_blocksize);
        strcpy(dx_leaf->dl_signature, OCFS2_DX_LEAF_SIGNATURE);
        dx_leaf->dl_fs_generation = cpu_to_le32(osb->fs_generation);
        dx_leaf->dl_blkno = cpu_to_le64(bh->b_blocknr);
        dx_leaf->dl_list.de_count =
            cpu_to_le16(ocfs2_dx_entries_per_leaf(osb->sb));

        trace_ocfs2_dx_dir_format_cluster(
                (unsigned long long)OCFS2_I(dir)->ip_blkno,
                (unsigned long long)bh->b_blocknr,
                le16_to_cpu(dx_leaf->dl_list.de_count));

        ocfs2_journal_dirty(handle, bh);
    }

    ret = 0;
out:
    return ret;
}

/*
 * Allocates and formats a new cluster for use in an indexed dir
 * leaf. This version will not do the extent insert, so that it can be
 * used by operations which need careful ordering.
 */
static int __ocfs2_dx_dir_new_cluster(struct inode *dir,
                      u32 cpos, handle_t *handle,
                      struct ocfs2_alloc_context *data_ac,
                      struct buffer_head **dx_leaves,
                      int num_dx_leaves, u64 *ret_phys_blkno)
{
    int ret;
    u32 phys, num;
    u64 phys_blkno;
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);

    /*
     * XXX: For create, this should claim cluster for the index
     * *before* the unindexed insert so that we have a better
     * chance of contiguousness as the directory grows in number
     * of entries.
     */
    ret = __ocfs2_claim_clusters(handle, data_ac, 1, 1, &phys, &num);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * Format the new cluster first. That way, we're inserting
     * valid data.
     */
    phys_blkno = ocfs2_clusters_to_blocks(osb->sb, phys);
    ret = ocfs2_dx_dir_format_cluster(osb, handle, dir, dx_leaves,
                      num_dx_leaves, phys_blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    *ret_phys_blkno = phys_blkno;
out:
    return ret;
}

static int ocfs2_dx_dir_new_cluster(struct inode *dir,
                    struct ocfs2_extent_tree *et,
                    u32 cpos, handle_t *handle,
                    struct ocfs2_alloc_context *data_ac,
                    struct ocfs2_alloc_context *meta_ac,
                    struct buffer_head **dx_leaves,
                    int num_dx_leaves)
{
    int ret;
    u64 phys_blkno;

    ret = __ocfs2_dx_dir_new_cluster(dir, cpos, handle, data_ac, dx_leaves,
                     num_dx_leaves, &phys_blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_insert_extent(handle, et, cpos, phys_blkno, 1, 0,
                  meta_ac);
    if (ret)
        mlog_errno(ret);
out:
    return ret;
}

static struct buffer_head **ocfs2_dx_dir_kmalloc_leaves(struct super_block *sb,
                            int *ret_num_leaves)
{
    int num_dx_leaves = ocfs2_clusters_to_blocks(sb, 1);
    struct buffer_head **dx_leaves;

    dx_leaves = kcalloc(num_dx_leaves, sizeof(struct buffer_head *),
                GFP_NOFS);
    if (dx_leaves && ret_num_leaves)
        *ret_num_leaves = num_dx_leaves;

    return dx_leaves;
}

static int ocfs2_fill_new_dir_dx(struct ocfs2_super *osb,
                 handle_t *handle,
                 struct inode *parent,
                 struct inode *inode,
                 struct buffer_head *di_bh,
                 struct ocfs2_alloc_context *data_ac,
                 struct ocfs2_alloc_context *meta_ac)
{
    int ret;
    struct buffer_head *leaf_bh = NULL;
    struct buffer_head *dx_root_bh = NULL;
    struct ocfs2_dx_hinfo hinfo;
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dx_entry_list *entry_list;

    /*
     * Our strategy is to create the directory as though it were
     * unindexed, then add the index block. This works with very
     * little complication since the state of a new directory is a
     * very well known quantity.
     *
     * Essentially, we have two dirents ("." and ".."), in the 1st
     * block which need indexing. These are easily inserted into
     * the index block.
     */

    ret = ocfs2_fill_new_dir_el(osb, handle, parent, inode, di_bh,
                    data_ac, &leaf_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_dx_dir_attach_index(osb, handle, inode, di_bh, leaf_bh,
                    meta_ac, 1, 2, &dx_root_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }
    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
    entry_list = &dx_root->dr_entries;

    /* Buffer has been journaled for us by ocfs2_dx_dir_attach_index */
    ocfs2_dx_dir_name_hash(inode, ".", 1, &hinfo);
    ocfs2_dx_entry_list_insert(entry_list, &hinfo, leaf_bh->b_blocknr);

    ocfs2_dx_dir_name_hash(inode, "..", 2, &hinfo);
    ocfs2_dx_entry_list_insert(entry_list, &hinfo, leaf_bh->b_blocknr);

out:
    brelse(dx_root_bh);
    brelse(leaf_bh);
    return ret;
}

int ocfs2_fill_new_dir(struct ocfs2_super *osb,
               handle_t *handle,
               struct inode *parent,
               struct inode *inode,
               struct buffer_head *fe_bh,
               struct ocfs2_alloc_context *data_ac,
               struct ocfs2_alloc_context *meta_ac)

{
    BUG_ON(!ocfs2_supports_inline_data(osb) && data_ac == NULL);

    if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
        return ocfs2_fill_new_dir_id(osb, handle, parent, inode, fe_bh);

    if (ocfs2_supports_indexed_dirs(osb))
        return ocfs2_fill_new_dir_dx(osb, handle, parent, inode, fe_bh,
                         data_ac, meta_ac);

    return ocfs2_fill_new_dir_el(osb, handle, parent, inode, fe_bh,
                     data_ac, NULL);
}

static int ocfs2_dx_dir_index_block(struct inode *dir,
                    handle_t *handle,
                    struct buffer_head **dx_leaves,
                    int num_dx_leaves,
                    u32 *num_dx_entries,
                    struct buffer_head *dirent_bh)
{
    int ret = 0, namelen, i;
    char *de_buf, *limit;
    struct ocfs2_dir_entry *de;
    struct buffer_head *dx_leaf_bh;
    struct ocfs2_dx_hinfo hinfo;
    u64 dirent_blk = dirent_bh->b_blocknr;

    de_buf = dirent_bh->b_data;
    limit = de_buf + dir->i_sb->s_blocksize;

    while (de_buf < limit) {
        de = (struct ocfs2_dir_entry *)de_buf;

        namelen = de->name_len;
        if (!namelen || !de->inode)
            goto inc;

        ocfs2_dx_dir_name_hash(dir, de->name, namelen, &hinfo);

        i = ocfs2_dx_dir_hash_idx(OCFS2_SB(dir->i_sb), &hinfo);
        dx_leaf_bh = dx_leaves[i];

        ret = __ocfs2_dx_dir_leaf_insert(dir, handle, &hinfo,
                         dirent_blk, dx_leaf_bh);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        *num_dx_entries = *num_dx_entries + 1;

inc:
        de_buf += le16_to_cpu(de->rec_len);
    }

out:
    return ret;
}

/*
 * XXX: This expects dx_root_bh to already be part of the transaction.
 */
static void ocfs2_dx_dir_index_root_block(struct inode *dir,
                     struct buffer_head *dx_root_bh,
                     struct buffer_head *dirent_bh)
{
    char *de_buf, *limit;
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dir_entry *de;
    struct ocfs2_dx_hinfo hinfo;
    u64 dirent_blk = dirent_bh->b_blocknr;

    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;

    de_buf = dirent_bh->b_data;
    limit = de_buf + dir->i_sb->s_blocksize;

    while (de_buf < limit) {
        de = (struct ocfs2_dir_entry *)de_buf;

        if (!de->name_len || !de->inode)
            goto inc;

        ocfs2_dx_dir_name_hash(dir, de->name, de->name_len, &hinfo);

        trace_ocfs2_dx_dir_index_root_block(
                (unsigned long long)dir->i_ino,
                hinfo.major_hash, hinfo.minor_hash,
                de->name_len, de->name,
                le16_to_cpu(dx_root->dr_entries.de_num_used));

        ocfs2_dx_entry_list_insert(&dx_root->dr_entries, &hinfo,
                       dirent_blk);

        le32_add_cpu(&dx_root->dr_num_entries, 1);
inc:
        de_buf += le16_to_cpu(de->rec_len);
    }
}

/*
 * Count the number of inline directory entries in di_bh and compare
 * them against the number of entries we can hold in an inline dx root
 * block.
 */
static int ocfs2_new_dx_should_be_inline(struct inode *dir,
                     struct buffer_head *di_bh)
{
    int dirent_count = 0;
    char *de_buf, *limit;
    struct ocfs2_dir_entry *de;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;

    de_buf = di->id2.i_data.id_data;
    limit = de_buf + i_size_read(dir);

    while (de_buf < limit) {
        de = (struct ocfs2_dir_entry *)de_buf;

        if (de->name_len && de->inode)
            dirent_count++;

        de_buf += le16_to_cpu(de->rec_len);
    }

    /* We are careful to leave room for one extra record. */
    return dirent_count < ocfs2_dx_entries_per_root(dir->i_sb);
}

/*
 * Expand rec_len of the rightmost dirent in a directory block so that it
 * contains the end of our valid space for dirents. We do this during
 * expansion from an inline directory to one with extents. The first dir block
 * in that case is taken from the inline data portion of the inode block.
 *
 * This will also return the largest amount of contiguous space for a dirent
 * in the block. That value is *not* necessarily the last dirent, even after
 * expansion. The directory indexing code wants this value for free space
 * accounting. We do this here since we're already walking the entire dir
 * block.
 *
 * We add the dir trailer if this filesystem wants it.
 */
static unsigned int ocfs2_expand_last_dirent(char *start, unsigned int old_size,
                         struct inode *dir)
{
    struct super_block *sb = dir->i_sb;
    struct ocfs2_dir_entry *de;
    struct ocfs2_dir_entry *prev_de;
    char *de_buf, *limit;
    unsigned int new_size = sb->s_blocksize;
    unsigned int bytes, this_hole;
    unsigned int largest_hole = 0;

    if (ocfs2_new_dir_wants_trailer(dir))
        new_size = ocfs2_dir_trailer_blk_off(sb);

    bytes = new_size - old_size;

    limit = start + old_size;
    de_buf = start;
    de = (struct ocfs2_dir_entry *)de_buf;
    do {
        this_hole = ocfs2_figure_dirent_hole(de);
        if (this_hole > largest_hole)
            largest_hole = this_hole;

        prev_de = de;
        de_buf += le16_to_cpu(de->rec_len);
        de = (struct ocfs2_dir_entry *)de_buf;
    } while (de_buf < limit);

    le16_add_cpu(&prev_de->rec_len, bytes);

    /* We need to double check this after modification of the final
     * dirent. */
    this_hole = ocfs2_figure_dirent_hole(prev_de);
    if (this_hole > largest_hole)
        largest_hole = this_hole;

    if (largest_hole >= OCFS2_DIR_MIN_REC_LEN)
        return largest_hole;
    return 0;
}

/*
 * We allocate enough clusters to fulfill "blocks_wanted", but set
 * i_size to exactly one block. Ocfs2_extend_dir() will handle the
 * rest automatically for us.
 *
 * *first_block_bh is a pointer to the 1st data block allocated to the
 *  directory.
 */
static int ocfs2_expand_inline_dir(struct inode *dir, struct buffer_head *di_bh,
                   unsigned int blocks_wanted,
                   struct ocfs2_dir_lookup_result *lookup,
                   struct buffer_head **first_block_bh)
{
    u32 alloc, dx_alloc, bit_off, len, num_dx_entries = 0;
    struct super_block *sb = dir->i_sb;
    int ret, i, num_dx_leaves = 0, dx_inline = 0,
        credits = ocfs2_inline_to_extents_credits(sb);
    u64 dx_insert_blkno, blkno,
        bytes = blocks_wanted << sb->s_blocksize_bits;
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
    struct ocfs2_inode_info *oi = OCFS2_I(dir);
    struct ocfs2_alloc_context *data_ac = NULL;
    struct ocfs2_alloc_context *meta_ac = NULL;
    struct buffer_head *dirdata_bh = NULL;
    struct buffer_head *dx_root_bh = NULL;
    struct buffer_head **dx_leaves = NULL;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    handle_t *handle;
    struct ocfs2_extent_tree et;
    struct ocfs2_extent_tree dx_et;
    int did_quota = 0, bytes_allocated = 0;

    ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(dir), di_bh);

    alloc = ocfs2_clusters_for_bytes(sb, bytes);
    dx_alloc = 0;

    down_write(&oi->ip_alloc_sem);

    if (ocfs2_supports_indexed_dirs(osb)) {
        credits += ocfs2_add_dir_index_credits(sb);

        dx_inline = ocfs2_new_dx_should_be_inline(dir, di_bh);
        if (!dx_inline) {
            /* Add one more cluster for an index leaf */
            dx_alloc++;
            dx_leaves = ocfs2_dx_dir_kmalloc_leaves(sb,
                                &num_dx_leaves);
            if (!dx_leaves) {
                ret = -ENOMEM;
                mlog_errno(ret);
                goto out;
            }
        }

        /* This gets us the dx_root */
        ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &meta_ac);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
    }

    /*
     * We should never need more than 2 clusters for the unindexed
     * tree - maximum dirent size is far less than one block. In
     * fact, the only time we'd need more than one cluster is if
     * blocksize == clustersize and the dirent won't fit in the
     * extra space that the expansion to a single block gives. As
     * of today, that only happens on 4k/4k file systems.
     */
    BUG_ON(alloc > 2);

    ret = ocfs2_reserve_clusters(osb, alloc + dx_alloc, &data_ac);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    /*
     * Prepare for worst case allocation scenario of two separate
     * extents in the unindexed tree.
     */
    if (alloc == 2)
        credits += OCFS2_SUBALLOC_ALLOC;

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

    ret = dquot_alloc_space_nodirty(dir,
        ocfs2_clusters_to_bytes(osb->sb, alloc + dx_alloc));
    if (ret)
        goto out_commit;
    did_quota = 1;

    if (ocfs2_supports_indexed_dirs(osb) && !dx_inline) {
        /*
         * Allocate our index cluster first, to maximize the
         * possibility that unindexed leaves grow
         * contiguously.
         */
        ret = __ocfs2_dx_dir_new_cluster(dir, 0, handle, data_ac,
                         dx_leaves, num_dx_leaves,
                         &dx_insert_blkno);
        if (ret) {
            mlog_errno(ret);
            goto out_commit;
        }
        bytes_allocated += ocfs2_clusters_to_bytes(dir->i_sb, 1);
    }

    /*
     * Try to claim as many clusters as the bitmap can give though
     * if we only get one now, that's enough to continue. The rest
     * will be claimed after the conversion to extents.
     */
    if (ocfs2_dir_resv_allowed(osb))
        data_ac->ac_resv = &oi->ip_la_data_resv;
    ret = ocfs2_claim_clusters(handle, data_ac, 1, &bit_off, &len);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }
    bytes_allocated += ocfs2_clusters_to_bytes(dir->i_sb, 1);

    /*
     * Operations are carefully ordered so that we set up the new
     * data block first. The conversion from inline data to
     * extents follows.
     */
    blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);
    dirdata_bh = sb_getblk(sb, blkno);
    if (!dirdata_bh) {
        ret = -EIO;
        mlog_errno(ret);
        goto out_commit;
    }

    ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), dirdata_bh);

    ret = ocfs2_journal_access_db(handle, INODE_CACHE(dir), dirdata_bh,
                      OCFS2_JOURNAL_ACCESS_CREATE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    memcpy(dirdata_bh->b_data, di->id2.i_data.id_data, i_size_read(dir));
    memset(dirdata_bh->b_data + i_size_read(dir), 0,
           sb->s_blocksize - i_size_read(dir));
    i = ocfs2_expand_last_dirent(dirdata_bh->b_data, i_size_read(dir), dir);
    if (ocfs2_new_dir_wants_trailer(dir)) {
        /*
         * Prepare the dir trailer up front. It will otherwise look
         * like a valid dirent. Even if inserting the index fails
         * (unlikely), then all we'll have done is given first dir
         * block a small amount of fragmentation.
         */
        ocfs2_init_dir_trailer(dir, dirdata_bh, i);
    }

    ocfs2_journal_dirty(handle, dirdata_bh);

    if (ocfs2_supports_indexed_dirs(osb) && !dx_inline) {
        /*
         * Dx dirs with an external cluster need to do this up
         * front. Inline dx root's get handled later, after
         * we've allocated our root block. We get passed back
         * a total number of items so that dr_num_entries can
         * be correctly set once the dx_root has been
         * allocated.
         */
        ret = ocfs2_dx_dir_index_block(dir, handle, dx_leaves,
                           num_dx_leaves, &num_dx_entries,
                           dirdata_bh);
        if (ret) {
            mlog_errno(ret);
            goto out_commit;
        }
    }

    /*
     * Set extent, i_size, etc on the directory. After this, the
     * inode should contain the same exact dirents as before and
     * be fully accessible from system calls.
     *
     * We let the later dirent insert modify c/mtime - to the user
     * the data hasn't changed.
     */
    ret = ocfs2_journal_access_di(handle, INODE_CACHE(dir), di_bh,
                      OCFS2_JOURNAL_ACCESS_CREATE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    spin_lock(&oi->ip_lock);
    oi->ip_dyn_features &= ~OCFS2_INLINE_DATA_FL;
    di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
    spin_unlock(&oi->ip_lock);

    ocfs2_dinode_new_extent_list(dir, di);

    i_size_write(dir, sb->s_blocksize);
    dir->i_mtime = dir->i_ctime = CURRENT_TIME;

    di->i_size = cpu_to_le64(sb->s_blocksize);
    di->i_ctime = di->i_mtime = cpu_to_le64(dir->i_ctime.tv_sec);
    di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(dir->i_ctime.tv_nsec);

    /*
     * This should never fail as our extent list is empty and all
     * related blocks have been journaled already.
     */
    ret = ocfs2_insert_extent(handle, &et, 0, blkno, len,
                  0, NULL);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    /*
     * Set i_blocks after the extent insert for the most up to
     * date ip_clusters value.
     */
    dir->i_blocks = ocfs2_inode_sector_count(dir);

    ocfs2_journal_dirty(handle, di_bh);

    if (ocfs2_supports_indexed_dirs(osb)) {
        ret = ocfs2_dx_dir_attach_index(osb, handle, dir, di_bh,
                        dirdata_bh, meta_ac, dx_inline,
                        num_dx_entries, &dx_root_bh);
        if (ret) {
            mlog_errno(ret);
            goto out_commit;
        }

        if (dx_inline) {
            ocfs2_dx_dir_index_root_block(dir, dx_root_bh,
                              dirdata_bh);
        } else {
            ocfs2_init_dx_root_extent_tree(&dx_et,
                               INODE_CACHE(dir),
                               dx_root_bh);
            ret = ocfs2_insert_extent(handle, &dx_et, 0,
                          dx_insert_blkno, 1, 0, NULL);
            if (ret)
                mlog_errno(ret);
        }
    }

    /*
     * We asked for two clusters, but only got one in the 1st
     * pass. Claim the 2nd cluster as a separate extent.
     */
    if (alloc > len) {
        ret = ocfs2_claim_clusters(handle, data_ac, 1, &bit_off,
                       &len);
        if (ret) {
            mlog_errno(ret);
            goto out_commit;
        }
        blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);

        ret = ocfs2_insert_extent(handle, &et, 1,
                      blkno, len, 0, NULL);
        if (ret) {
            mlog_errno(ret);
            goto out_commit;
        }
        bytes_allocated += ocfs2_clusters_to_bytes(dir->i_sb, 1);
    }

    *first_block_bh = dirdata_bh;
    dirdata_bh = NULL;
    if (ocfs2_supports_indexed_dirs(osb)) {
        unsigned int off;

        if (!dx_inline) {
            /*
             * We need to return the correct block within the
             * cluster which should hold our entry.
             */
            off = ocfs2_dx_dir_hash_idx(OCFS2_SB(dir->i_sb),
                            &lookup->dl_hinfo);
            get_bh(dx_leaves[off]);
            lookup->dl_dx_leaf_bh = dx_leaves[off];
        }
        lookup->dl_dx_root_bh = dx_root_bh;
        dx_root_bh = NULL;
    }

out_commit:
    if (ret < 0 && did_quota)
        dquot_free_space_nodirty(dir, bytes_allocated);

    ocfs2_commit_trans(osb, handle);

out:
    up_write(&oi->ip_alloc_sem);
    if (data_ac)
        ocfs2_free_alloc_context(data_ac);
    if (meta_ac)
        ocfs2_free_alloc_context(meta_ac);

    if (dx_leaves) {
        for (i = 0; i < num_dx_leaves; i++)
            brelse(dx_leaves[i]);
        kfree(dx_leaves);
    }

    brelse(dirdata_bh);
    brelse(dx_root_bh);

    return ret;
}

/* returns a bh of the 1st new block in the allocation. */
static int ocfs2_do_extend_dir(struct super_block *sb,
                   handle_t *handle,
                   struct inode *dir,
                   struct buffer_head *parent_fe_bh,
                   struct ocfs2_alloc_context *data_ac,
                   struct ocfs2_alloc_context *meta_ac,
                   struct buffer_head **new_bh)
{
    int status;
    int extend, did_quota = 0;
    u64 p_blkno, v_blkno;

    spin_lock(&OCFS2_I(dir)->ip_lock);
    extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters));
    spin_unlock(&OCFS2_I(dir)->ip_lock);

    if (extend) {
        u32 offset = OCFS2_I(dir)->ip_clusters;

        status = dquot_alloc_space_nodirty(dir,
                    ocfs2_clusters_to_bytes(sb, 1));
        if (status)
            goto bail;
        did_quota = 1;

        status = ocfs2_add_inode_data(OCFS2_SB(sb), dir, &offset,
                          1, 0, parent_fe_bh, handle,
                          data_ac, meta_ac, NULL);
        BUG_ON(status == -EAGAIN);
        if (status < 0) {
            mlog_errno(status);
            goto bail;
        }
    }

    v_blkno = ocfs2_blocks_for_bytes(sb, i_size_read(dir));
    status = ocfs2_extent_map_get_blocks(dir, v_blkno, &p_blkno, NULL, NULL);
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }

    *new_bh = sb_getblk(sb, p_blkno);
    if (!*new_bh) {
        status = -EIO;
        mlog_errno(status);
        goto bail;
    }
    status = 0;
bail:
    if (did_quota && status < 0)
        dquot_free_space_nodirty(dir, ocfs2_clusters_to_bytes(sb, 1));
    return status;
}

/*
 * Assumes you already have a cluster lock on the directory.
 *
 * 'blocks_wanted' is only used if we have an inline directory which
 * is to be turned into an extent based one. The size of the dirent to
 * insert might be larger than the space gained by growing to just one
 * block, so we may have to grow the inode by two blocks in that case.
 *
 * If the directory is already indexed, dx_root_bh must be provided.
 */
static int ocfs2_extend_dir(struct ocfs2_super *osb,
                struct inode *dir,
                struct buffer_head *parent_fe_bh,
                unsigned int blocks_wanted,
                struct ocfs2_dir_lookup_result *lookup,
                struct buffer_head **new_de_bh)
{
    int status = 0;
    int credits, num_free_extents, drop_alloc_sem = 0;
    loff_t dir_i_size;
    struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
    struct ocfs2_extent_list *el = &fe->id2.i_list;
    struct ocfs2_alloc_context *data_ac = NULL;
    struct ocfs2_alloc_context *meta_ac = NULL;
    handle_t *handle = NULL;
    struct buffer_head *new_bh = NULL;
    struct ocfs2_dir_entry * de;
    struct super_block *sb = osb->sb;
    struct ocfs2_extent_tree et;
    struct buffer_head *dx_root_bh = lookup->dl_dx_root_bh;

    if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
        /*
         * This would be a code error as an inline directory should
         * never have an index root.
         */
        BUG_ON(dx_root_bh);

        status = ocfs2_expand_inline_dir(dir, parent_fe_bh,
                         blocks_wanted, lookup,
                         &new_bh);
        if (status) {
            mlog_errno(status);
            goto bail;
        }

        /* Expansion from inline to an indexed directory will
         * have given us this. */
        dx_root_bh = lookup->dl_dx_root_bh;

        if (blocks_wanted == 1) {
            /*
             * If the new dirent will fit inside the space
             * created by pushing out to one block, then
             * we can complete the operation
             * here. Otherwise we have to expand i_size
             * and format the 2nd block below.
             */
            BUG_ON(new_bh == NULL);
            goto bail_bh;
        }

        /*
         * Get rid of 'new_bh' - we want to format the 2nd
         * data block and return that instead.
         */
        brelse(new_bh);
        new_bh = NULL;

        down_write(&OCFS2_I(dir)->ip_alloc_sem);
        drop_alloc_sem = 1;
        dir_i_size = i_size_read(dir);
        credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
        goto do_extend;
    }

    down_write(&OCFS2_I(dir)->ip_alloc_sem);
    drop_alloc_sem = 1;
    dir_i_size = i_size_read(dir);
    trace_ocfs2_extend_dir((unsigned long long)OCFS2_I(dir)->ip_blkno,
                   dir_i_size);

    /* dir->i_size is always block aligned. */
    spin_lock(&OCFS2_I(dir)->ip_lock);
    if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) {
        spin_unlock(&OCFS2_I(dir)->ip_lock);
        ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(dir),
                          parent_fe_bh);
        num_free_extents = ocfs2_num_free_extents(osb, &et);
        if (num_free_extents < 0) {
            status = num_free_extents;
            mlog_errno(status);
            goto bail;
        }

        if (!num_free_extents) {
            status = ocfs2_reserve_new_metadata(osb, el, &meta_ac);
            if (status < 0) {
                if (status != -ENOSPC)
                    mlog_errno(status);
                goto bail;
            }
        }

        status = ocfs2_reserve_clusters(osb, 1, &data_ac);
        if (status < 0) {
            if (status != -ENOSPC)
                mlog_errno(status);
            goto bail;
        }

        if (ocfs2_dir_resv_allowed(osb))
            data_ac->ac_resv = &OCFS2_I(dir)->ip_la_data_resv;

        credits = ocfs2_calc_extend_credits(sb, el, 1);
    } else {
        spin_unlock(&OCFS2_I(dir)->ip_lock);
        credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
    }

do_extend:
    if (ocfs2_dir_indexed(dir))
        credits++; /* For attaching the new dirent block to the
                * dx_root */

    handle = ocfs2_start_trans(osb, credits);
    if (IS_ERR(handle)) {
        status = PTR_ERR(handle);
        handle = NULL;
        mlog_errno(status);
        goto bail;
    }

    status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh,
                     data_ac, meta_ac, &new_bh);
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }

    ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), new_bh);

    status = ocfs2_journal_access_db(handle, INODE_CACHE(dir), new_bh,
                     OCFS2_JOURNAL_ACCESS_CREATE);
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }
    memset(new_bh->b_data, 0, sb->s_blocksize);

    de = (struct ocfs2_dir_entry *) new_bh->b_data;
    de->inode = 0;
    if (ocfs2_supports_dir_trailer(dir)) {
        de->rec_len = cpu_to_le16(ocfs2_dir_trailer_blk_off(sb));

        ocfs2_init_dir_trailer(dir, new_bh, le16_to_cpu(de->rec_len));

        if (ocfs2_dir_indexed(dir)) {
            status = ocfs2_dx_dir_link_trailer(dir, handle,
                               dx_root_bh, new_bh);
            if (status) {
                mlog_errno(status);
                goto bail;
            }
        }
    } else {
        de->rec_len = cpu_to_le16(sb->s_blocksize);
    }
    ocfs2_journal_dirty(handle, new_bh);

    dir_i_size += dir->i_sb->s_blocksize;
    i_size_write(dir, dir_i_size);
    dir->i_blocks = ocfs2_inode_sector_count(dir);
    status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }

bail_bh:
    *new_de_bh = new_bh;
    get_bh(*new_de_bh);
bail:
    if (handle)
        ocfs2_commit_trans(osb, handle);
    if (drop_alloc_sem)
        up_write(&OCFS2_I(dir)->ip_alloc_sem);

    if (data_ac)
        ocfs2_free_alloc_context(data_ac);
    if (meta_ac)
        ocfs2_free_alloc_context(meta_ac);

    brelse(new_bh);

    return status;
}

static int ocfs2_find_dir_space_id(struct inode *dir, struct buffer_head *di_bh,
                   const char *name, int namelen,
                   struct buffer_head **ret_de_bh,
                   unsigned int *blocks_wanted)
{
    int ret;
    struct super_block *sb = dir->i_sb;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    struct ocfs2_dir_entry *de, *last_de = NULL;
    char *de_buf, *limit;
    unsigned long offset = 0;
    unsigned int rec_len, new_rec_len, free_space = dir->i_sb->s_blocksize;

    /*
     * This calculates how many free bytes we'd have in block zero, should
     * this function force expansion to an extent tree.
     */
    if (ocfs2_new_dir_wants_trailer(dir))
        free_space = ocfs2_dir_trailer_blk_off(sb) - i_size_read(dir);
    else
        free_space = dir->i_sb->s_blocksize - i_size_read(dir);

    de_buf = di->id2.i_data.id_data;
    limit = de_buf + i_size_read(dir);
    rec_len = OCFS2_DIR_REC_LEN(namelen);

    while (de_buf < limit) {
        de = (struct ocfs2_dir_entry *)de_buf;

        if (!ocfs2_check_dir_entry(dir, de, di_bh, offset)) {
            ret = -ENOENT;
            goto out;
        }
        if (ocfs2_match(namelen, name, de)) {
            ret = -EEXIST;
            goto out;
        }
        /*
         * No need to check for a trailing dirent record here as
         * they're not used for inline dirs.
         */

        if (ocfs2_dirent_would_fit(de, rec_len)) {
            /* Ok, we found a spot. Return this bh and let
             * the caller actually fill it in. */
            *ret_de_bh = di_bh;
            get_bh(*ret_de_bh);
            ret = 0;
            goto out;
        }

        last_de = de;
        de_buf += le16_to_cpu(de->rec_len);
        offset += le16_to_cpu(de->rec_len);
    }

    /*
     * We're going to require expansion of the directory - figure
     * out how many blocks we'll need so that a place for the
     * dirent can be found.
     */
    *blocks_wanted = 1;
    new_rec_len = le16_to_cpu(last_de->rec_len) + free_space;
    if (new_rec_len < (rec_len + OCFS2_DIR_REC_LEN(last_de->name_len)))
        *blocks_wanted = 2;

    ret = -ENOSPC;
out:
    return ret;
}

static int ocfs2_find_dir_space_el(struct inode *dir, const char *name,
                   int namelen, struct buffer_head **ret_de_bh)
{
    unsigned long offset;
    struct buffer_head *bh = NULL;
    unsigned short rec_len;
    struct ocfs2_dir_entry *de;
    struct super_block *sb = dir->i_sb;
    int status;
    int blocksize = dir->i_sb->s_blocksize;

    status = ocfs2_read_dir_block(dir, 0, &bh, 0);
    if (status) {
        mlog_errno(status);
        goto bail;
    }

    rec_len = OCFS2_DIR_REC_LEN(namelen);
    offset = 0;
    de = (struct ocfs2_dir_entry *) bh->b_data;
    while (1) {
        if ((char *)de >= sb->s_blocksize + bh->b_data) {
            brelse(bh);
            bh = NULL;

            if (i_size_read(dir) <= offset) {
                /*
                 * Caller will have to expand this
                 * directory.
                 */
                status = -ENOSPC;
                goto bail;
            }
            status = ocfs2_read_dir_block(dir,
                         offset >> sb->s_blocksize_bits,
                         &bh, 0);
            if (status) {
                mlog_errno(status);
                goto bail;
            }
            /* move to next block */
            de = (struct ocfs2_dir_entry *) bh->b_data;
        }
        if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
            status = -ENOENT;
            goto bail;
        }
        if (ocfs2_match(namelen, name, de)) {
            status = -EEXIST;
            goto bail;
        }

        if (ocfs2_skip_dir_trailer(dir, de, offset % blocksize,
                       blocksize))
            goto next;

        if (ocfs2_dirent_would_fit(de, rec_len)) {
            /* Ok, we found a spot. Return this bh and let
             * the caller actually fill it in. */
            *ret_de_bh = bh;
            get_bh(*ret_de_bh);
            status = 0;
            goto bail;
        }
next:
        offset += le16_to_cpu(de->rec_len);
        de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len));
    }

    status = 0;
bail:
    brelse(bh);
    if (status)
        mlog_errno(status);

    return status;
}

static int dx_leaf_sort_cmp(const void *a, const void *b)
{
    const struct ocfs2_dx_entry *entry1 = a;
    const struct ocfs2_dx_entry *entry2 = b;
    u32 major_hash1 = le32_to_cpu(entry1->dx_major_hash);
    u32 major_hash2 = le32_to_cpu(entry2->dx_major_hash);
    u32 minor_hash1 = le32_to_cpu(entry1->dx_minor_hash);
    u32 minor_hash2 = le32_to_cpu(entry2->dx_minor_hash);

    if (major_hash1 > major_hash2)
        return 1;
    if (major_hash1 < major_hash2)
        return -1;

    /*
     * It is not strictly necessary to sort by minor
     */
    if (minor_hash1 > minor_hash2)
        return 1;
    if (minor_hash1 < minor_hash2)
        return -1;
    return 0;
}

static void dx_leaf_sort_swap(void *a, void *b, int size)
{
    struct ocfs2_dx_entry *entry1 = a;
    struct ocfs2_dx_entry *entry2 = b;
    struct ocfs2_dx_entry tmp;

    BUG_ON(size != sizeof(*entry1));

    tmp = *entry1;
    *entry1 = *entry2;
    *entry2 = tmp;
}

static int ocfs2_dx_leaf_same_major(struct ocfs2_dx_leaf *dx_leaf)
{
    struct ocfs2_dx_entry_list *dl_list = &dx_leaf->dl_list;
    int i, num = le16_to_cpu(dl_list->de_num_used);

    for (i = 0; i < (num - 1); i++) {
        if (le32_to_cpu(dl_list->de_entries[i].dx_major_hash) !=
            le32_to_cpu(dl_list->de_entries[i + 1].dx_major_hash))
            return 0;
    }

    return 1;
}

/*
 * Find the optimal value to split this leaf on. This expects the leaf
 * entries to be in sorted order.
 *
 * leaf_cpos is the cpos of the leaf we're splitting. insert_hash is
 * the hash we want to insert.
 *
 * This function is only concerned with the major hash - that which
 * determines which cluster an item belongs to.
 */
static int ocfs2_dx_dir_find_leaf_split(struct ocfs2_dx_leaf *dx_leaf,
                    u32 leaf_cpos, u32 insert_hash,
                    u32 *split_hash)
{
    struct ocfs2_dx_entry_list *dl_list = &dx_leaf->dl_list;
    int i, num_used = le16_to_cpu(dl_list->de_num_used);
    int allsame;

    /*
     * There's a couple rare, but nasty corner cases we have to
     * check for here. All of them involve a leaf where all value
     * have the same hash, which is what we look for first.
     *
     * Most of the time, all of the above is false, and we simply
     * pick the median value for a split.
     */
    allsame = ocfs2_dx_leaf_same_major(dx_leaf);
    if (allsame) {
        u32 val = le32_to_cpu(dl_list->de_entries[0].dx_major_hash);

        if (val == insert_hash) {
            /*
             * No matter where we would choose to split,
             * the new entry would want to occupy the same
             * block as these. Since there's no space left
             * in their existing block, we know there
             * won't be space after the split.
             */
            return -ENOSPC;
        }

        if (val == leaf_cpos) {
            /*
             * Because val is the same as leaf_cpos (which
             * is the smallest value this leaf can have),
             * yet is not equal to insert_hash, then we
             * know that insert_hash *must* be larger than
             * val (and leaf_cpos). At least cpos+1 in value.
             *
             * We also know then, that there cannot be an
             * adjacent extent (otherwise we'd be looking
             * at it). Choosing this value gives us a
             * chance to get some contiguousness.
             */
            *split_hash = leaf_cpos + 1;
            return 0;
        }

        if (val > insert_hash) {
            /*
             * val can not be the same as insert hash, and
             * also must be larger than leaf_cpos. Also,
             * we know that there can't be a leaf between
             * cpos and val, otherwise the entries with
             * hash 'val' would be there.
             */
            *split_hash = val;
            return 0;
        }

        *split_hash = insert_hash;
        return 0;
    }

    /*
     * Since the records are sorted and the checks above
     * guaranteed that not all records in this block are the same,
     * we simple travel forward, from the median, and pick the 1st
     * record whose value is larger than leaf_cpos.
     */
    for (i = (num_used / 2); i < num_used; i++)
        if (le32_to_cpu(dl_list->de_entries[i].dx_major_hash) >
            leaf_cpos)
            break;

    BUG_ON(i == num_used); /* Should be impossible */
    *split_hash = le32_to_cpu(dl_list->de_entries[i].dx_major_hash);
    return 0;
}

/*
 * Transfer all entries in orig_dx_leaves whose major hash is equal to or
 * larger than split_hash into new_dx_leaves. We use a temporary
 * buffer (tmp_dx_leaf) to make the changes to the original leaf blocks.
 *
 * Since the block offset inside a leaf (cluster) is a constant mask
 * of minor_hash, we can optimize - an item at block offset X within
 * the original cluster, will be at offset X within the new cluster.
 */
static void ocfs2_dx_dir_transfer_leaf(struct inode *dir, u32 split_hash,
                       handle_t *handle,
                       struct ocfs2_dx_leaf *tmp_dx_leaf,
                       struct buffer_head **orig_dx_leaves,
                       struct buffer_head **new_dx_leaves,
                       int num_dx_leaves)
{
    int i, j, num_used;
    u32 major_hash;
    struct ocfs2_dx_leaf *orig_dx_leaf, *new_dx_leaf;
    struct ocfs2_dx_entry_list *orig_list, *new_list, *tmp_list;
    struct ocfs2_dx_entry *dx_entry;

    tmp_list = &tmp_dx_leaf->dl_list;

    for (i = 0; i < num_dx_leaves; i++) {
        orig_dx_leaf = (struct ocfs2_dx_leaf *) orig_dx_leaves[i]->b_data;
        orig_list = &orig_dx_leaf->dl_list;
        new_dx_leaf = (struct ocfs2_dx_leaf *) new_dx_leaves[i]->b_data;
        new_list = &new_dx_leaf->dl_list;

        num_used = le16_to_cpu(orig_list->de_num_used);

        memcpy(tmp_dx_leaf, orig_dx_leaf, dir->i_sb->s_blocksize);
        tmp_list->de_num_used = cpu_to_le16(0);
        memset(&tmp_list->de_entries, 0, sizeof(*dx_entry)*num_used);

        for (j = 0; j < num_used; j++) {
            dx_entry = &orig_list->de_entries[j];
            major_hash = le32_to_cpu(dx_entry->dx_major_hash);
            if (major_hash >= split_hash)
                ocfs2_dx_dir_leaf_insert_tail(new_dx_leaf,
                                  dx_entry);
            else
                ocfs2_dx_dir_leaf_insert_tail(tmp_dx_leaf,
                                  dx_entry);
        }
        memcpy(orig_dx_leaf, tmp_dx_leaf, dir->i_sb->s_blocksize);

        ocfs2_journal_dirty(handle, orig_dx_leaves[i]);
        ocfs2_journal_dirty(handle, new_dx_leaves[i]);
    }
}

static int ocfs2_dx_dir_rebalance_credits(struct ocfs2_super *osb,
                      struct ocfs2_dx_root_block *dx_root)
{
    int credits = ocfs2_clusters_to_blocks(osb->sb, 2);

    credits += ocfs2_calc_extend_credits(osb->sb, &dx_root->dr_list, 1);
    credits += ocfs2_quota_trans_credits(osb->sb);
    return credits;
}

/*
 * Find the median value in dx_leaf_bh and allocate a new leaf to move
 * half our entries into.
 */
static int ocfs2_dx_dir_rebalance(struct ocfs2_super *osb, struct inode *dir,
                  struct buffer_head *dx_root_bh,
                  struct buffer_head *dx_leaf_bh,
                  struct ocfs2_dx_hinfo *hinfo, u32 leaf_cpos,
                  u64 leaf_blkno)
{
    struct ocfs2_dx_leaf *dx_leaf = (struct ocfs2_dx_leaf *)dx_leaf_bh->b_data;
    int credits, ret, i, num_used, did_quota = 0;
    u32 cpos, split_hash, insert_hash = hinfo->major_hash;
    u64 orig_leaves_start;
    int num_dx_leaves;
    struct buffer_head **orig_dx_leaves = NULL;
    struct buffer_head **new_dx_leaves = NULL;
    struct ocfs2_alloc_context *data_ac = NULL, *meta_ac = NULL;
    struct ocfs2_extent_tree et;
    handle_t *handle = NULL;
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dx_leaf *tmp_dx_leaf = NULL;

    trace_ocfs2_dx_dir_rebalance((unsigned long long)OCFS2_I(dir)->ip_blkno,
                     (unsigned long long)leaf_blkno,
                     insert_hash);

    ocfs2_init_dx_root_extent_tree(&et, INODE_CACHE(dir), dx_root_bh);

    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
    /*
     * XXX: This is a rather large limit. We should use a more
     * realistic value.
     */
    if (le32_to_cpu(dx_root->dr_clusters) == UINT_MAX)
        return -ENOSPC;

    num_used = le16_to_cpu(dx_leaf->dl_list.de_num_used);
    if (num_used < le16_to_cpu(dx_leaf->dl_list.de_count)) {
        mlog(ML_ERROR, "DX Dir: %llu, Asked to rebalance empty leaf: "
             "%llu, %d\n", (unsigned long long)OCFS2_I(dir)->ip_blkno,
             (unsigned long long)leaf_blkno, num_used);
        ret = -EIO;
        goto out;
    }

    orig_dx_leaves = ocfs2_dx_dir_kmalloc_leaves(osb->sb, &num_dx_leaves);
    if (!orig_dx_leaves) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    new_dx_leaves = ocfs2_dx_dir_kmalloc_leaves(osb->sb, NULL);
    if (!new_dx_leaves) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_lock_allocators(dir, &et, 1, 0, &data_ac, &meta_ac);
    if (ret) {
        if (ret != -ENOSPC)
            mlog_errno(ret);
        goto out;
    }

    credits = ocfs2_dx_dir_rebalance_credits(osb, dx_root);
    handle = ocfs2_start_trans(osb, credits);
    if (IS_ERR(handle)) {
        ret = PTR_ERR(handle);
        handle = NULL;
        mlog_errno(ret);
        goto out;
    }

    ret = dquot_alloc_space_nodirty(dir,
                       ocfs2_clusters_to_bytes(dir->i_sb, 1));
    if (ret)
        goto out_commit;
    did_quota = 1;

    ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir), dx_leaf_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    /*
     * This block is changing anyway, so we can sort it in place.
     */
    sort(dx_leaf->dl_list.de_entries, num_used,
         sizeof(struct ocfs2_dx_entry), dx_leaf_sort_cmp,
         dx_leaf_sort_swap);

    ocfs2_journal_dirty(handle, dx_leaf_bh);

    ret = ocfs2_dx_dir_find_leaf_split(dx_leaf, leaf_cpos, insert_hash,
                       &split_hash);
    if (ret) {
        mlog_errno(ret);
        goto  out_commit;
    }

    trace_ocfs2_dx_dir_rebalance_split(leaf_cpos, split_hash, insert_hash);

    /*
     * We have to carefully order operations here. There are items
     * which want to be in the new cluster before insert, but in
     * order to put those items in the new cluster, we alter the
     * old cluster. A failure to insert gets nasty.
     *
     * So, start by reserving writes to the old
     * cluster. ocfs2_dx_dir_new_cluster will reserve writes on
     * the new cluster for us, before inserting it. The insert
     * won't happen if there's an error before that. Once the
     * insert is done then, we can transfer from one leaf into the
     * other without fear of hitting any error.
     */

    /*
     * The leaf transfer wants some scratch space so that we don't
     * wind up doing a bunch of expensive memmove().
     */
    tmp_dx_leaf = kmalloc(osb->sb->s_blocksize, GFP_NOFS);
    if (!tmp_dx_leaf) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out_commit;
    }

    orig_leaves_start = ocfs2_block_to_cluster_start(dir->i_sb, leaf_blkno);
    ret = ocfs2_read_dx_leaves(dir, orig_leaves_start, num_dx_leaves,
                   orig_dx_leaves);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    cpos = split_hash;
    ret = ocfs2_dx_dir_new_cluster(dir, &et, cpos, handle,
                       data_ac, meta_ac, new_dx_leaves,
                       num_dx_leaves);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    for (i = 0; i < num_dx_leaves; i++) {
        ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir),
                          orig_dx_leaves[i],
                          OCFS2_JOURNAL_ACCESS_WRITE);
        if (ret) {
            mlog_errno(ret);
            goto out_commit;
        }

        ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir),
                          new_dx_leaves[i],
                          OCFS2_JOURNAL_ACCESS_WRITE);
        if (ret) {
            mlog_errno(ret);
            goto out_commit;
        }
    }

    ocfs2_dx_dir_transfer_leaf(dir, split_hash, handle, tmp_dx_leaf,
                   orig_dx_leaves, new_dx_leaves, num_dx_leaves);

out_commit:
    if (ret < 0 && did_quota)
        dquot_free_space_nodirty(dir,
                ocfs2_clusters_to_bytes(dir->i_sb, 1));

    ocfs2_commit_trans(osb, handle);

out:
    if (orig_dx_leaves || new_dx_leaves) {
        for (i = 0; i < num_dx_leaves; i++) {
            if (orig_dx_leaves)
                brelse(orig_dx_leaves[i]);
            if (new_dx_leaves)
                brelse(new_dx_leaves[i]);
        }
        kfree(orig_dx_leaves);
        kfree(new_dx_leaves);
    }

    if (meta_ac)
        ocfs2_free_alloc_context(meta_ac);
    if (data_ac)
        ocfs2_free_alloc_context(data_ac);

    kfree(tmp_dx_leaf);
    return ret;
}

static int ocfs2_find_dir_space_dx(struct ocfs2_super *osb, struct inode *dir,
                   struct buffer_head *di_bh,
                   struct buffer_head *dx_root_bh,
                   const char *name, int namelen,
                   struct ocfs2_dir_lookup_result *lookup)
{
    int ret, rebalanced = 0;
    struct ocfs2_dx_root_block *dx_root;
    struct buffer_head *dx_leaf_bh = NULL;
    struct ocfs2_dx_leaf *dx_leaf;
    u64 blkno;
    u32 leaf_cpos;

    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;

restart_search:
    ret = ocfs2_dx_dir_lookup(dir, &dx_root->dr_list, &lookup->dl_hinfo,
                  &leaf_cpos, &blkno);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ret = ocfs2_read_dx_leaf(dir, blkno, &dx_leaf_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    dx_leaf = (struct ocfs2_dx_leaf *)dx_leaf_bh->b_data;

    if (le16_to_cpu(dx_leaf->dl_list.de_num_used) >=
        le16_to_cpu(dx_leaf->dl_list.de_count)) {
        if (rebalanced) {
            /*
             * Rebalancing should have provided us with
             * space in an appropriate leaf.
             *
             * XXX: Is this an abnormal condition then?
             * Should we print a message here?
             */
            ret = -ENOSPC;
            goto out;
        }

        ret = ocfs2_dx_dir_rebalance(osb, dir, dx_root_bh, dx_leaf_bh,
                         &lookup->dl_hinfo, leaf_cpos,
                         blkno);
        if (ret) {
            if (ret != -ENOSPC)
                mlog_errno(ret);
            goto out;
        }

        /*
         * Restart the lookup. The rebalance might have
         * changed which block our item fits into. Mark our
         * progress, so we only execute this once.
         */
        brelse(dx_leaf_bh);
        dx_leaf_bh = NULL;
        rebalanced = 1;
        goto restart_search;
    }

    lookup->dl_dx_leaf_bh = dx_leaf_bh;
    dx_leaf_bh = NULL;

out:
    brelse(dx_leaf_bh);
    return ret;
}

static int ocfs2_search_dx_free_list(struct inode *dir,
                     struct buffer_head *dx_root_bh,
                     int namelen,
                     struct ocfs2_dir_lookup_result *lookup)
{
    int ret = -ENOSPC;
    struct buffer_head *leaf_bh = NULL, *prev_leaf_bh = NULL;
    struct ocfs2_dir_block_trailer *db;
    u64 next_block;
    int rec_len = OCFS2_DIR_REC_LEN(namelen);
    struct ocfs2_dx_root_block *dx_root;

    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
    next_block = le64_to_cpu(dx_root->dr_free_blk);

    while (next_block) {
        brelse(prev_leaf_bh);
        prev_leaf_bh = leaf_bh;
        leaf_bh = NULL;

        ret = ocfs2_read_dir_block_direct(dir, next_block, &leaf_bh);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        db = ocfs2_trailer_from_bh(leaf_bh, dir->i_sb);
        if (rec_len <= le16_to_cpu(db->db_free_rec_len)) {
            lookup->dl_leaf_bh = leaf_bh;
            lookup->dl_prev_leaf_bh = prev_leaf_bh;
            leaf_bh = NULL;
            prev_leaf_bh = NULL;
            break;
        }

        next_block = le64_to_cpu(db->db_free_next);
    }

    if (!next_block)
        ret = -ENOSPC;

out:

    brelse(leaf_bh);
    brelse(prev_leaf_bh);
    return ret;
}

static int ocfs2_expand_inline_dx_root(struct inode *dir,
                       struct buffer_head *dx_root_bh)
{
    int ret, num_dx_leaves, i, j, did_quota = 0;
    struct buffer_head **dx_leaves = NULL;
    struct ocfs2_extent_tree et;
    u64 insert_blkno;
    struct ocfs2_alloc_context *data_ac = NULL;
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
    handle_t *handle = NULL;
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dx_entry_list *entry_list;
    struct ocfs2_dx_entry *dx_entry;
    struct ocfs2_dx_leaf *target_leaf;

    ret = ocfs2_reserve_clusters(osb, 1, &data_ac);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    dx_leaves = ocfs2_dx_dir_kmalloc_leaves(osb->sb, &num_dx_leaves);
    if (!dx_leaves) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }

    handle = ocfs2_start_trans(osb, ocfs2_calc_dxi_expand_credits(osb->sb));
    if (IS_ERR(handle)) {
        ret = PTR_ERR(handle);
        mlog_errno(ret);
        goto out;
    }

    ret = dquot_alloc_space_nodirty(dir,
                       ocfs2_clusters_to_bytes(osb->sb, 1));
    if (ret)
        goto out_commit;
    did_quota = 1;

    /*
     * We do this up front, before the allocation, so that a
     * failure to add the dx_root_bh to the journal won't result
     * us losing clusters.
     */
    ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    ret = __ocfs2_dx_dir_new_cluster(dir, 0, handle, data_ac, dx_leaves,
                     num_dx_leaves, &insert_blkno);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    /*
     * Transfer the entries from our dx_root into the appropriate
     * block
     */
    dx_root = (struct ocfs2_dx_root_block *) dx_root_bh->b_data;
    entry_list = &dx_root->dr_entries;

    for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++) {
        dx_entry = &entry_list->de_entries[i];

        j = __ocfs2_dx_dir_hash_idx(osb,
                        le32_to_cpu(dx_entry->dx_minor_hash));
        target_leaf = (struct ocfs2_dx_leaf *)dx_leaves[j]->b_data;

        ocfs2_dx_dir_leaf_insert_tail(target_leaf, dx_entry);

        /* Each leaf has been passed to the journal already
         * via __ocfs2_dx_dir_new_cluster() */
    }

    dx_root->dr_flags &= ~OCFS2_DX_FLAG_INLINE;
    memset(&dx_root->dr_list, 0, osb->sb->s_blocksize -
           offsetof(struct ocfs2_dx_root_block, dr_list));
    dx_root->dr_list.l_count =
        cpu_to_le16(ocfs2_extent_recs_per_dx_root(osb->sb));

    /* This should never fail considering we start with an empty
     * dx_root. */
    ocfs2_init_dx_root_extent_tree(&et, INODE_CACHE(dir), dx_root_bh);
    ret = ocfs2_insert_extent(handle, &et, 0, insert_blkno, 1, 0, NULL);
    if (ret)
        mlog_errno(ret);
    did_quota = 0;

    ocfs2_journal_dirty(handle, dx_root_bh);

out_commit:
    if (ret < 0 && did_quota)
        dquot_free_space_nodirty(dir,
                      ocfs2_clusters_to_bytes(dir->i_sb, 1));

    ocfs2_commit_trans(osb, handle);

out:
    if (data_ac)
        ocfs2_free_alloc_context(data_ac);

    if (dx_leaves) {
        for (i = 0; i < num_dx_leaves; i++)
            brelse(dx_leaves[i]);
        kfree(dx_leaves);
    }
    return ret;
}

static int ocfs2_inline_dx_has_space(struct buffer_head *dx_root_bh)
{
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dx_entry_list *entry_list;

    dx_root = (struct ocfs2_dx_root_block *) dx_root_bh->b_data;
    entry_list = &dx_root->dr_entries;

    if (le16_to_cpu(entry_list->de_num_used) >=
        le16_to_cpu(entry_list->de_count))
        return -ENOSPC;

    return 0;
}

static int ocfs2_prepare_dx_dir_for_insert(struct inode *dir,
                       struct buffer_head *di_bh,
                       const char *name,
                       int namelen,
                       struct ocfs2_dir_lookup_result *lookup)
{
    int ret, free_dx_root = 1;
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
    struct buffer_head *dx_root_bh = NULL;
    struct buffer_head *leaf_bh = NULL;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    struct ocfs2_dx_root_block *dx_root;

    ret = ocfs2_read_dx_root(dir, di, &dx_root_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
    if (le32_to_cpu(dx_root->dr_num_entries) == OCFS2_DX_ENTRIES_MAX) {
        ret = -ENOSPC;
        mlog_errno(ret);
        goto out;
    }

    if (ocfs2_dx_root_inline(dx_root)) {
        ret = ocfs2_inline_dx_has_space(dx_root_bh);

        if (ret == 0)
            goto search_el;

        /*
         * We ran out of room in the root block. Expand it to
         * an extent, then allow ocfs2_find_dir_space_dx to do
         * the rest.
         */
        ret = ocfs2_expand_inline_dx_root(dir, dx_root_bh);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }
    }

    /*
     * Insert preparation for an indexed directory is split into two
     * steps. The call to find_dir_space_dx reserves room in the index for
     * an additional item. If we run out of space there, it's a real error
     * we can't continue on.
     */
    ret = ocfs2_find_dir_space_dx(osb, dir, di_bh, dx_root_bh, name,
                      namelen, lookup);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

search_el:
    /*
     * Next, we need to find space in the unindexed tree. This call
     * searches using the free space linked list. If the unindexed tree
     * lacks sufficient space, we'll expand it below. The expansion code
     * is smart enough to add any new blocks to the free space list.
     */
    ret = ocfs2_search_dx_free_list(dir, dx_root_bh, namelen, lookup);
    if (ret && ret != -ENOSPC) {
        mlog_errno(ret);
        goto out;
    }

    /* Do this up here - ocfs2_extend_dir might need the dx_root */
    lookup->dl_dx_root_bh = dx_root_bh;
    free_dx_root = 0;

    if (ret == -ENOSPC) {
        ret = ocfs2_extend_dir(osb, dir, di_bh, 1, lookup, &leaf_bh);

        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        /*
         * We make the assumption here that new leaf blocks are added
         * to the front of our free list.
         */
        lookup->dl_prev_leaf_bh = NULL;
        lookup->dl_leaf_bh = leaf_bh;
    }

out:
    if (free_dx_root)
        brelse(dx_root_bh);
    return ret;
}

/*
 * Get a directory ready for insert. Any directory allocation required
 * happens here. Success returns zero, and enough context in the dir
 * lookup result that ocfs2_add_entry() will be able complete the task
 * with minimal performance impact.
 */
int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb,
                 struct inode *dir,
                 struct buffer_head *parent_fe_bh,
                 const char *name,
                 int namelen,
                 struct ocfs2_dir_lookup_result *lookup)
{
    int ret;
    unsigned int blocks_wanted = 1;
    struct buffer_head *bh = NULL;

    trace_ocfs2_prepare_dir_for_insert(
        (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen);

    if (!namelen) {
        ret = -EINVAL;
        mlog_errno(ret);
        goto out;
    }

    /*
     * Do this up front to reduce confusion.
     *
     * The directory might start inline, then be turned into an
     * indexed one, in which case we'd need to hash deep inside
     * ocfs2_find_dir_space_id(). Since
     * ocfs2_prepare_dx_dir_for_insert() also needs this hash
     * done, there seems no point in spreading out the calls. We
     * can optimize away the case where the file system doesn't
     * support indexing.
     */
    if (ocfs2_supports_indexed_dirs(osb))
        ocfs2_dx_dir_name_hash(dir, name, namelen, &lookup->dl_hinfo);

    if (ocfs2_dir_indexed(dir)) {
        ret = ocfs2_prepare_dx_dir_for_insert(dir, parent_fe_bh,
                              name, namelen, lookup);
        if (ret)
            mlog_errno(ret);
        goto out;
    }

    if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
        ret = ocfs2_find_dir_space_id(dir, parent_fe_bh, name,
                          namelen, &bh, &blocks_wanted);
    } else
        ret = ocfs2_find_dir_space_el(dir, name, namelen, &bh);

    if (ret && ret != -ENOSPC) {
        mlog_errno(ret);
        goto out;
    }

    if (ret == -ENOSPC) {
        /*
         * We have to expand the directory to add this name.
         */
        BUG_ON(bh);

        ret = ocfs2_extend_dir(osb, dir, parent_fe_bh, blocks_wanted,
                       lookup, &bh);
        if (ret) {
            if (ret != -ENOSPC)
                mlog_errno(ret);
            goto out;
        }

        BUG_ON(!bh);
    }

    lookup->dl_leaf_bh = bh;
    bh = NULL;
out:
    brelse(bh);
    return ret;
}

static int ocfs2_dx_dir_remove_index(struct inode *dir,
                     struct buffer_head *di_bh,
                     struct buffer_head *dx_root_bh)
{
    int ret;
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    struct ocfs2_dx_root_block *dx_root;
    struct inode *dx_alloc_inode = NULL;
    struct buffer_head *dx_alloc_bh = NULL;
    handle_t *handle;
    u64 blk;
    u16 bit;
    u64 bg_blkno;

    dx_root = (struct ocfs2_dx_root_block *) dx_root_bh->b_data;

    dx_alloc_inode = ocfs2_get_system_file_inode(osb,
                    EXTENT_ALLOC_SYSTEM_INODE,
                    le16_to_cpu(dx_root->dr_suballoc_slot));
    if (!dx_alloc_inode) {
        ret = -ENOMEM;
        mlog_errno(ret);
        goto out;
    }
    mutex_lock(&dx_alloc_inode->i_mutex);

    ret = ocfs2_inode_lock(dx_alloc_inode, &dx_alloc_bh, 1);
    if (ret) {
        mlog_errno(ret);
        goto out_mutex;
    }

    handle = ocfs2_start_trans(osb, OCFS2_DX_ROOT_REMOVE_CREDITS);
    if (IS_ERR(handle)) {
        ret = PTR_ERR(handle);
        mlog_errno(ret);
        goto out_unlock;
    }

    ret = ocfs2_journal_access_di(handle, INODE_CACHE(dir), di_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
    if (ret) {
        mlog_errno(ret);
        goto out_commit;
    }

    spin_lock(&OCFS2_I(dir)->ip_lock);
    OCFS2_I(dir)->ip_dyn_features &= ~OCFS2_INDEXED_DIR_FL;
    di->i_dyn_features = cpu_to_le16(OCFS2_I(dir)->ip_dyn_features);
    spin_unlock(&OCFS2_I(dir)->ip_lock);
    di->i_dx_root = cpu_to_le64(0ULL);

    ocfs2_journal_dirty(handle, di_bh);

    blk = le64_to_cpu(dx_root->dr_blkno);
    bit = le16_to_cpu(dx_root->dr_suballoc_bit);
    if (dx_root->dr_suballoc_loc)
        bg_blkno = le64_to_cpu(dx_root->dr_suballoc_loc);
    else
        bg_blkno = ocfs2_which_suballoc_group(blk, bit);
    ret = ocfs2_free_suballoc_bits(handle, dx_alloc_inode, dx_alloc_bh,
                       bit, bg_blkno, 1);
    if (ret)
        mlog_errno(ret);

out_commit:
    ocfs2_commit_trans(osb, handle);

out_unlock:
    ocfs2_inode_unlock(dx_alloc_inode, 1);

out_mutex:
    mutex_unlock(&dx_alloc_inode->i_mutex);
    brelse(dx_alloc_bh);
out:
    iput(dx_alloc_inode);
    return ret;
}

int ocfs2_dx_dir_truncate(struct inode *dir, struct buffer_head *di_bh)
{
    int ret;
    unsigned int uninitialized_var(clen);
    u32 major_hash = UINT_MAX, p_cpos, uninitialized_var(cpos);
    u64 uninitialized_var(blkno);
    struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
    struct buffer_head *dx_root_bh = NULL;
    struct ocfs2_dx_root_block *dx_root;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
    struct ocfs2_cached_dealloc_ctxt dealloc;
    struct ocfs2_extent_tree et;

    ocfs2_init_dealloc_ctxt(&dealloc);

    if (!ocfs2_dir_indexed(dir))
        return 0;

    ret = ocfs2_read_dx_root(dir, di, &dx_root_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }
    dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;

    if (ocfs2_dx_root_inline(dx_root))
        goto remove_index;

    ocfs2_init_dx_root_extent_tree(&et, INODE_CACHE(dir), dx_root_bh);

    /* XXX: What if dr_clusters is too large? */
    while (le32_to_cpu(dx_root->dr_clusters)) {
        ret = ocfs2_dx_dir_lookup_rec(dir, &dx_root->dr_list,
                          major_hash, &cpos, &blkno, &clen);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        p_cpos = ocfs2_blocks_to_clusters(dir->i_sb, blkno);

        ret = ocfs2_remove_btree_range(dir, &et, cpos, p_cpos, clen, 0,
                           &dealloc, 0);
        if (ret) {
            mlog_errno(ret);
            goto out;
        }

        if (cpos == 0)
            break;

        major_hash = cpos - 1;
    }

remove_index:
    ret = ocfs2_dx_dir_remove_index(dir, di_bh, dx_root_bh);
    if (ret) {
        mlog_errno(ret);
        goto out;
    }

    ocfs2_remove_from_cache(INODE_CACHE(dir), dx_root_bh);
out:
    ocfs2_schedule_truncate_log_flush(osb, 1);
    ocfs2_run_deallocs(osb, &dealloc);

    brelse(dx_root_bh);
    return ret;
}