inode.c

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/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * inode.c
 *
 * vfs' aops, fops, dops and iops
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * 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/highmem.h>
#include <linux/pagemap.h>
#include <linux/quotaops.h>

#include <asm/byteorder.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

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

#include "buffer_head_io.h"

struct ocfs2_find_inode_args
{
    u64     fi_blkno;
    unsigned long   fi_ino;
    unsigned int    fi_flags;
    unsigned int    fi_sysfile_type;
};

static struct lock_class_key ocfs2_sysfile_lock_key[NUM_SYSTEM_INODES];

static int ocfs2_read_locked_inode(struct inode *inode,
                   struct ocfs2_find_inode_args *args);
static int ocfs2_init_locked_inode(struct inode *inode, void *opaque);
static int ocfs2_find_actor(struct inode *inode, void *opaque);
static int ocfs2_truncate_for_delete(struct ocfs2_super *osb,
                    struct inode *inode,
                    struct buffer_head *fe_bh);

void ocfs2_set_inode_flags(struct inode *inode)
{
    unsigned int flags = OCFS2_I(inode)->ip_attr;

    inode->i_flags &= ~(S_IMMUTABLE |
        S_SYNC | S_APPEND | S_NOATIME | S_DIRSYNC);

    if (flags & OCFS2_IMMUTABLE_FL)
        inode->i_flags |= S_IMMUTABLE;

    if (flags & OCFS2_SYNC_FL)
        inode->i_flags |= S_SYNC;
    if (flags & OCFS2_APPEND_FL)
        inode->i_flags |= S_APPEND;
    if (flags & OCFS2_NOATIME_FL)
        inode->i_flags |= S_NOATIME;
    if (flags & OCFS2_DIRSYNC_FL)
        inode->i_flags |= S_DIRSYNC;
}

/* Propagate flags from i_flags to OCFS2_I(inode)->ip_attr */
void ocfs2_get_inode_flags(struct ocfs2_inode_info *oi)
{
    unsigned int flags = oi->vfs_inode.i_flags;

    oi->ip_attr &= ~(OCFS2_SYNC_FL|OCFS2_APPEND_FL|
            OCFS2_IMMUTABLE_FL|OCFS2_NOATIME_FL|OCFS2_DIRSYNC_FL);
    if (flags & S_SYNC)
        oi->ip_attr |= OCFS2_SYNC_FL;
    if (flags & S_APPEND)
        oi->ip_attr |= OCFS2_APPEND_FL;
    if (flags & S_IMMUTABLE)
        oi->ip_attr |= OCFS2_IMMUTABLE_FL;
    if (flags & S_NOATIME)
        oi->ip_attr |= OCFS2_NOATIME_FL;
    if (flags & S_DIRSYNC)
        oi->ip_attr |= OCFS2_DIRSYNC_FL;
}

struct inode *ocfs2_ilookup(struct super_block *sb, u64 blkno)
{
    struct ocfs2_find_inode_args args;

    args.fi_blkno = blkno;
    args.fi_flags = 0;
    args.fi_ino = ino_from_blkno(sb, blkno);
    args.fi_sysfile_type = 0;

    return ilookup5(sb, blkno, ocfs2_find_actor, &args);
}
struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno, unsigned flags,
             int sysfile_type)
{
    struct inode *inode = NULL;
    struct super_block *sb = osb->sb;
    struct ocfs2_find_inode_args args;

    trace_ocfs2_iget_begin((unsigned long long)blkno, flags,
                   sysfile_type);

    /* Ok. By now we've either got the offsets passed to us by the
     * caller, or we just pulled them off the bh. Lets do some
     * sanity checks to make sure they're OK. */
    if (blkno == 0) {
        inode = ERR_PTR(-EINVAL);
        mlog_errno(PTR_ERR(inode));
        goto bail;
    }

    args.fi_blkno = blkno;
    args.fi_flags = flags;
    args.fi_ino = ino_from_blkno(sb, blkno);
    args.fi_sysfile_type = sysfile_type;

    inode = iget5_locked(sb, args.fi_ino, ocfs2_find_actor,
                 ocfs2_init_locked_inode, &args);
    /* inode was *not* in the inode cache. 2.6.x requires
     * us to do our own read_inode call and unlock it
     * afterwards. */
    if (inode == NULL) {
        inode = ERR_PTR(-ENOMEM);
        mlog_errno(PTR_ERR(inode));
        goto bail;
    }
    trace_ocfs2_iget5_locked(inode->i_state);
    if (inode->i_state & I_NEW) {
        ocfs2_read_locked_inode(inode, &args);
        unlock_new_inode(inode);
    }
    if (is_bad_inode(inode)) {
        iput(inode);
        inode = ERR_PTR(-ESTALE);
        goto bail;
    }

bail:
    if (!IS_ERR(inode)) {
        trace_ocfs2_iget_end(inode, 
            (unsigned long long)OCFS2_I(inode)->ip_blkno);
    }

    return inode;
}


/*
 * here's how inodes get read from disk:
 * iget5_locked -> find_actor -> OCFS2_FIND_ACTOR
 * found? : return the in-memory inode
 * not found? : get_new_inode -> OCFS2_INIT_LOCKED_INODE
 */

static int ocfs2_find_actor(struct inode *inode, void *opaque)
{
    struct ocfs2_find_inode_args *args = NULL;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    int ret = 0;

    args = opaque;

    mlog_bug_on_msg(!inode, "No inode in find actor!\n");

    trace_ocfs2_find_actor(inode, inode->i_ino, opaque, args->fi_blkno);

    if (oi->ip_blkno != args->fi_blkno)
        goto bail;

    ret = 1;
bail:
    return ret;
}

/*
 * initialize the new inode, but don't do anything that would cause
 * us to sleep.
 * return 0 on success, 1 on failure
 */
static int ocfs2_init_locked_inode(struct inode *inode, void *opaque)
{
    struct ocfs2_find_inode_args *args = opaque;
    static struct lock_class_key ocfs2_quota_ip_alloc_sem_key,
                     ocfs2_file_ip_alloc_sem_key;

    inode->i_ino = args->fi_ino;
    OCFS2_I(inode)->ip_blkno = args->fi_blkno;
    if (args->fi_sysfile_type != 0)
        lockdep_set_class(&inode->i_mutex,
            &ocfs2_sysfile_lock_key[args->fi_sysfile_type]);
    if (args->fi_sysfile_type == USER_QUOTA_SYSTEM_INODE ||
        args->fi_sysfile_type == GROUP_QUOTA_SYSTEM_INODE ||
        args->fi_sysfile_type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
        args->fi_sysfile_type == LOCAL_GROUP_QUOTA_SYSTEM_INODE)
        lockdep_set_class(&OCFS2_I(inode)->ip_alloc_sem,
                  &ocfs2_quota_ip_alloc_sem_key);
    else
        lockdep_set_class(&OCFS2_I(inode)->ip_alloc_sem,
                  &ocfs2_file_ip_alloc_sem_key);

    return 0;
}

void ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
              int create_ino)
{
    struct super_block *sb;
    struct ocfs2_super *osb;
    int use_plocks = 1;

    sb = inode->i_sb;
    osb = OCFS2_SB(sb);

    if ((osb->s_mount_opt & OCFS2_MOUNT_LOCALFLOCKS) ||
        ocfs2_mount_local(osb) || !ocfs2_stack_supports_plocks())
        use_plocks = 0;

    /*
     * These have all been checked by ocfs2_read_inode_block() or set
     * by ocfs2_mknod_locked(), so a failure is a code bug.
     */
    BUG_ON(!OCFS2_IS_VALID_DINODE(fe));  /* This means that read_inode
                        cannot create a superblock
                        inode today.  change if
                        that is needed. */
    BUG_ON(!(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)));
    BUG_ON(le32_to_cpu(fe->i_fs_generation) != osb->fs_generation);


    OCFS2_I(inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
    OCFS2_I(inode)->ip_attr = le32_to_cpu(fe->i_attr);
    OCFS2_I(inode)->ip_dyn_features = le16_to_cpu(fe->i_dyn_features);

    inode->i_version = 1;
    inode->i_generation = le32_to_cpu(fe->i_generation);
    inode->i_rdev = huge_decode_dev(le64_to_cpu(fe->id1.dev1.i_rdev));
    inode->i_mode = le16_to_cpu(fe->i_mode);
    inode->i_uid = le32_to_cpu(fe->i_uid);
    inode->i_gid = le32_to_cpu(fe->i_gid);

    /* Fast symlinks will have i_size but no allocated clusters. */
    if (S_ISLNK(inode->i_mode) && !fe->i_clusters) {
        inode->i_blocks = 0;
        inode->i_mapping->a_ops = &ocfs2_fast_symlink_aops;
    } else {
        inode->i_blocks = ocfs2_inode_sector_count(inode);
        inode->i_mapping->a_ops = &ocfs2_aops;
    }
    inode->i_atime.tv_sec = le64_to_cpu(fe->i_atime);
    inode->i_atime.tv_nsec = le32_to_cpu(fe->i_atime_nsec);
    inode->i_mtime.tv_sec = le64_to_cpu(fe->i_mtime);
    inode->i_mtime.tv_nsec = le32_to_cpu(fe->i_mtime_nsec);
    inode->i_ctime.tv_sec = le64_to_cpu(fe->i_ctime);
    inode->i_ctime.tv_nsec = le32_to_cpu(fe->i_ctime_nsec);

    if (OCFS2_I(inode)->ip_blkno != le64_to_cpu(fe->i_blkno))
        mlog(ML_ERROR,
             "ip_blkno %llu != i_blkno %llu!\n",
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
             (unsigned long long)le64_to_cpu(fe->i_blkno));

    set_nlink(inode, ocfs2_read_links_count(fe));

    trace_ocfs2_populate_inode(OCFS2_I(inode)->ip_blkno,
                   le32_to_cpu(fe->i_flags));
    if (fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) {
        OCFS2_I(inode)->ip_flags |= OCFS2_INODE_SYSTEM_FILE;
        inode->i_flags |= S_NOQUOTA;
    }
  
    if (fe->i_flags & cpu_to_le32(OCFS2_LOCAL_ALLOC_FL)) {
        OCFS2_I(inode)->ip_flags |= OCFS2_INODE_BITMAP;
    } else if (fe->i_flags & cpu_to_le32(OCFS2_BITMAP_FL)) {
        OCFS2_I(inode)->ip_flags |= OCFS2_INODE_BITMAP;
    } else if (fe->i_flags & cpu_to_le32(OCFS2_QUOTA_FL)) {
        inode->i_flags |= S_NOQUOTA;
    } else if (fe->i_flags & cpu_to_le32(OCFS2_SUPER_BLOCK_FL)) {
        /* we can't actually hit this as read_inode can't
         * handle superblocks today ;-) */
        BUG();
    }

    switch (inode->i_mode & S_IFMT) {
        case S_IFREG:
            if (use_plocks)
                inode->i_fop = &ocfs2_fops;
            else
                inode->i_fop = &ocfs2_fops_no_plocks;
            inode->i_op = &ocfs2_file_iops;
            i_size_write(inode, le64_to_cpu(fe->i_size));
            break;
        case S_IFDIR:
            inode->i_op = &ocfs2_dir_iops;
            if (use_plocks)
                inode->i_fop = &ocfs2_dops;
            else
                inode->i_fop = &ocfs2_dops_no_plocks;
            i_size_write(inode, le64_to_cpu(fe->i_size));
            OCFS2_I(inode)->ip_dir_lock_gen = 1;
            break;
        case S_IFLNK:
            inode->i_op = &ocfs2_symlink_inode_operations;
            i_size_write(inode, le64_to_cpu(fe->i_size));
            break;
        default:
            inode->i_op = &ocfs2_special_file_iops;
            init_special_inode(inode, inode->i_mode,
                       inode->i_rdev);
            break;
    }

    if (create_ino) {
        inode->i_ino = ino_from_blkno(inode->i_sb,
                   le64_to_cpu(fe->i_blkno));

        /*
         * If we ever want to create system files from kernel,
         * the generation argument to
         * ocfs2_inode_lock_res_init() will have to change.
         */
        BUG_ON(le32_to_cpu(fe->i_flags) & OCFS2_SYSTEM_FL);

        ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_inode_lockres,
                      OCFS2_LOCK_TYPE_META, 0, inode);

        ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_open_lockres,
                      OCFS2_LOCK_TYPE_OPEN, 0, inode);
    }

    ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_rw_lockres,
                  OCFS2_LOCK_TYPE_RW, inode->i_generation,
                  inode);

    ocfs2_set_inode_flags(inode);

    OCFS2_I(inode)->ip_last_used_slot = 0;
    OCFS2_I(inode)->ip_last_used_group = 0;

    if (S_ISDIR(inode->i_mode))
        ocfs2_resv_set_type(&OCFS2_I(inode)->ip_la_data_resv,
                    OCFS2_RESV_FLAG_DIR);
}

static int ocfs2_read_locked_inode(struct inode *inode,
                   struct ocfs2_find_inode_args *args)
{
    struct super_block *sb;
    struct ocfs2_super *osb;
    struct ocfs2_dinode *fe;
    struct buffer_head *bh = NULL;
    int status, can_lock;
    u32 generation = 0;

    status = -EINVAL;
    if (inode == NULL || inode->i_sb == NULL) {
        mlog(ML_ERROR, "bad inode\n");
        return status;
    }
    sb = inode->i_sb;
    osb = OCFS2_SB(sb);

    if (!args) {
        mlog(ML_ERROR, "bad inode args\n");
        make_bad_inode(inode);
        return status;
    }

    /*
     * To improve performance of cold-cache inode stats, we take
     * the cluster lock here if possible.
     *
     * Generally, OCFS2 never trusts the contents of an inode
     * unless it's holding a cluster lock, so taking it here isn't
     * a correctness issue as much as it is a performance
     * improvement.
     *
     * There are three times when taking the lock is not a good idea:
     *
     * 1) During startup, before we have initialized the DLM.
     *
     * 2) If we are reading certain system files which never get
     *    cluster locks (local alloc, truncate log).
     *
     * 3) If the process doing the iget() is responsible for
     *    orphan dir recovery. We're holding the orphan dir lock and
     *    can get into a deadlock with another process on another
     *    node in ->delete_inode().
     *
     * #1 and #2 can be simply solved by never taking the lock
     * here for system files (which are the only type we read
     * during mount). It's a heavier approach, but our main
     * concern is user-accessible files anyway.
     *
     * #3 works itself out because we'll eventually take the
     * cluster lock before trusting anything anyway.
     */
    can_lock = !(args->fi_flags & OCFS2_FI_FLAG_SYSFILE)
        && !(args->fi_flags & OCFS2_FI_FLAG_ORPHAN_RECOVERY)
        && !ocfs2_mount_local(osb);

    trace_ocfs2_read_locked_inode(
        (unsigned long long)OCFS2_I(inode)->ip_blkno, can_lock);

    /*
     * To maintain backwards compatibility with older versions of
     * ocfs2-tools, we still store the generation value for system
     * files. The only ones that actually matter to userspace are
     * the journals, but it's easier and inexpensive to just flag
     * all system files similarly.
     */
    if (args->fi_flags & OCFS2_FI_FLAG_SYSFILE)
        generation = osb->fs_generation;

    ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_inode_lockres,
                  OCFS2_LOCK_TYPE_META,
                  generation, inode);

    ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_open_lockres,
                  OCFS2_LOCK_TYPE_OPEN,
                  0, inode);

    if (can_lock) {
        status = ocfs2_open_lock(inode);
        if (status) {
            make_bad_inode(inode);
            mlog_errno(status);
            return status;
        }
        status = ocfs2_inode_lock(inode, NULL, 0);
        if (status) {
            make_bad_inode(inode);
            mlog_errno(status);
            return status;
        }
    }

    if (args->fi_flags & OCFS2_FI_FLAG_ORPHAN_RECOVERY) {
        status = ocfs2_try_open_lock(inode, 0);
        if (status) {
            make_bad_inode(inode);
            return status;
        }
    }

    if (can_lock) {
        status = ocfs2_read_inode_block_full(inode, &bh,
                             OCFS2_BH_IGNORE_CACHE);
    } else {
        status = ocfs2_read_blocks_sync(osb, args->fi_blkno, 1, &bh);
        /*
         * If buffer is in jbd, then its checksum may not have been
         * computed as yet.
         */
        if (!status && !buffer_jbd(bh))
            status = ocfs2_validate_inode_block(osb->sb, bh);
    }
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }

    status = -EINVAL;
    fe = (struct ocfs2_dinode *) bh->b_data;

    /*
     * This is a code bug. Right now the caller needs to
     * understand whether it is asking for a system file inode or
     * not so the proper lock names can be built.
     */
    mlog_bug_on_msg(!!(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) !=
            !!(args->fi_flags & OCFS2_FI_FLAG_SYSFILE),
            "Inode %llu: system file state is ambigous\n",
            (unsigned long long)args->fi_blkno);

    if (S_ISCHR(le16_to_cpu(fe->i_mode)) ||
        S_ISBLK(le16_to_cpu(fe->i_mode)))
        inode->i_rdev = huge_decode_dev(le64_to_cpu(fe->id1.dev1.i_rdev));

    ocfs2_populate_inode(inode, fe, 0);

    BUG_ON(args->fi_blkno != le64_to_cpu(fe->i_blkno));

    status = 0;

bail:
    if (can_lock)
        ocfs2_inode_unlock(inode, 0);

    if (status < 0)
        make_bad_inode(inode);

    if (args && bh)
        brelse(bh);

    return status;
}

void ocfs2_sync_blockdev(struct super_block *sb)
{
    sync_blockdev(sb->s_bdev);
}

static int ocfs2_truncate_for_delete(struct ocfs2_super *osb,
                     struct inode *inode,
                     struct buffer_head *fe_bh)
{
    int status = 0;
    struct ocfs2_dinode *fe;
    handle_t *handle = NULL;

    fe = (struct ocfs2_dinode *) fe_bh->b_data;

    /*
     * This check will also skip truncate of inodes with inline
     * data and fast symlinks.
     */
    if (fe->i_clusters) {
        if (ocfs2_should_order_data(inode))
            ocfs2_begin_ordered_truncate(inode, 0);

        handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
        if (IS_ERR(handle)) {
            status = PTR_ERR(handle);
            handle = NULL;
            mlog_errno(status);
            goto out;
        }

        status = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
                         fe_bh,
                         OCFS2_JOURNAL_ACCESS_WRITE);
        if (status < 0) {
            mlog_errno(status);
            goto out;
        }

        i_size_write(inode, 0);

        status = ocfs2_mark_inode_dirty(handle, inode, fe_bh);
        if (status < 0) {
            mlog_errno(status);
            goto out;
        }

        ocfs2_commit_trans(osb, handle);
        handle = NULL;

        status = ocfs2_commit_truncate(osb, inode, fe_bh);
        if (status < 0) {
            mlog_errno(status);
            goto out;
        }
    }

out:
    if (handle)
        ocfs2_commit_trans(osb, handle);
    return status;
}

static int ocfs2_remove_inode(struct inode *inode,
                  struct buffer_head *di_bh,
                  struct inode *orphan_dir_inode,
                  struct buffer_head *orphan_dir_bh)
{
    int status;
    struct inode *inode_alloc_inode = NULL;
    struct buffer_head *inode_alloc_bh = NULL;
    handle_t *handle;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;

    inode_alloc_inode =
        ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
                        le16_to_cpu(di->i_suballoc_slot));
    if (!inode_alloc_inode) {
        status = -EEXIST;
        mlog_errno(status);
        goto bail;
    }

    mutex_lock(&inode_alloc_inode->i_mutex);
    status = ocfs2_inode_lock(inode_alloc_inode, &inode_alloc_bh, 1);
    if (status < 0) {
        mutex_unlock(&inode_alloc_inode->i_mutex);

        mlog_errno(status);
        goto bail;
    }

    handle = ocfs2_start_trans(osb, OCFS2_DELETE_INODE_CREDITS +
                   ocfs2_quota_trans_credits(inode->i_sb));
    if (IS_ERR(handle)) {
        status = PTR_ERR(handle);
        mlog_errno(status);
        goto bail_unlock;
    }

    if (!(OCFS2_I(inode)->ip_flags & OCFS2_INODE_SKIP_ORPHAN_DIR)) {
        status = ocfs2_orphan_del(osb, handle, orphan_dir_inode, inode,
                      orphan_dir_bh);
        if (status < 0) {
            mlog_errno(status);
            goto bail_commit;
        }
    }

    /* set the inodes dtime */
    status = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
                     OCFS2_JOURNAL_ACCESS_WRITE);
    if (status < 0) {
        mlog_errno(status);
        goto bail_commit;
    }

    di->i_dtime = cpu_to_le64(CURRENT_TIME.tv_sec);
    di->i_flags &= cpu_to_le32(~(OCFS2_VALID_FL | OCFS2_ORPHANED_FL));
    ocfs2_journal_dirty(handle, di_bh);

    ocfs2_remove_from_cache(INODE_CACHE(inode), di_bh);
    dquot_free_inode(inode);

    status = ocfs2_free_dinode(handle, inode_alloc_inode,
                   inode_alloc_bh, di);
    if (status < 0)
        mlog_errno(status);

bail_commit:
    ocfs2_commit_trans(osb, handle);
bail_unlock:
    ocfs2_inode_unlock(inode_alloc_inode, 1);
    mutex_unlock(&inode_alloc_inode->i_mutex);
    brelse(inode_alloc_bh);
bail:
    iput(inode_alloc_inode);

    return status;
}

/*
 * Serialize with orphan dir recovery. If the process doing
 * recovery on this orphan dir does an iget() with the dir
 * i_mutex held, we'll deadlock here. Instead we detect this
 * and exit early - recovery will wipe this inode for us.
 */
static int ocfs2_check_orphan_recovery_state(struct ocfs2_super *osb,
                         int slot)
{
    int ret = 0;

    spin_lock(&osb->osb_lock);
    if (ocfs2_node_map_test_bit(osb, &osb->osb_recovering_orphan_dirs, slot)) {
        ret = -EDEADLK;
        goto out;
    }
    /* This signals to the orphan recovery process that it should
     * wait for us to handle the wipe. */
    osb->osb_orphan_wipes[slot]++;
out:
    spin_unlock(&osb->osb_lock);
    trace_ocfs2_check_orphan_recovery_state(slot, ret);
    return ret;
}

static void ocfs2_signal_wipe_completion(struct ocfs2_super *osb,
                     int slot)
{
    spin_lock(&osb->osb_lock);
    osb->osb_orphan_wipes[slot]--;
    spin_unlock(&osb->osb_lock);

    wake_up(&osb->osb_wipe_event);
}

static int ocfs2_wipe_inode(struct inode *inode,
                struct buffer_head *di_bh)
{
    int status, orphaned_slot = -1;
    struct inode *orphan_dir_inode = NULL;
    struct buffer_head *orphan_dir_bh = NULL;
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
    struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;

    if (!(OCFS2_I(inode)->ip_flags & OCFS2_INODE_SKIP_ORPHAN_DIR)) {
        orphaned_slot = le16_to_cpu(di->i_orphaned_slot);

        status = ocfs2_check_orphan_recovery_state(osb, orphaned_slot);
        if (status)
            return status;

        orphan_dir_inode = ocfs2_get_system_file_inode(osb,
                                   ORPHAN_DIR_SYSTEM_INODE,
                                   orphaned_slot);
        if (!orphan_dir_inode) {
            status = -EEXIST;
            mlog_errno(status);
            goto bail;
        }

        /* Lock the orphan dir. The lock will be held for the entire
         * delete_inode operation. We do this now to avoid races with
         * recovery completion on other nodes. */
        mutex_lock(&orphan_dir_inode->i_mutex);
        status = ocfs2_inode_lock(orphan_dir_inode, &orphan_dir_bh, 1);
        if (status < 0) {
            mutex_unlock(&orphan_dir_inode->i_mutex);

            mlog_errno(status);
            goto bail;
        }
    }

    /* we do this while holding the orphan dir lock because we
     * don't want recovery being run from another node to try an
     * inode delete underneath us -- this will result in two nodes
     * truncating the same file! */
    status = ocfs2_truncate_for_delete(osb, inode, di_bh);
    if (status < 0) {
        mlog_errno(status);
        goto bail_unlock_dir;
    }

    /* Remove any dir index tree */
    if (S_ISDIR(inode->i_mode)) {
        status = ocfs2_dx_dir_truncate(inode, di_bh);
        if (status) {
            mlog_errno(status);
            goto bail_unlock_dir;
        }
    }

    /*Free extended attribute resources associated with this inode.*/
    status = ocfs2_xattr_remove(inode, di_bh);
    if (status < 0) {
        mlog_errno(status);
        goto bail_unlock_dir;
    }

    status = ocfs2_remove_refcount_tree(inode, di_bh);
    if (status < 0) {
        mlog_errno(status);
        goto bail_unlock_dir;
    }

    status = ocfs2_remove_inode(inode, di_bh, orphan_dir_inode,
                    orphan_dir_bh);
    if (status < 0)
        mlog_errno(status);

bail_unlock_dir:
    if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SKIP_ORPHAN_DIR)
        return status;

    ocfs2_inode_unlock(orphan_dir_inode, 1);
    mutex_unlock(&orphan_dir_inode->i_mutex);
    brelse(orphan_dir_bh);
bail:
    iput(orphan_dir_inode);
    ocfs2_signal_wipe_completion(osb, orphaned_slot);

    return status;
}

/* There is a series of simple checks that should be done before a
 * trylock is even considered. Encapsulate those in this function. */
static int ocfs2_inode_is_valid_to_delete(struct inode *inode)
{
    int ret = 0;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

    trace_ocfs2_inode_is_valid_to_delete(current, osb->dc_task,
                         (unsigned long long)oi->ip_blkno,
                         oi->ip_flags);

    /* We shouldn't be getting here for the root directory
     * inode.. */
    if (inode == osb->root_inode) {
        mlog(ML_ERROR, "Skipping delete of root inode.\n");
        goto bail;
    }

    /* If we're coming from downconvert_thread we can't go into our own
     * voting [hello, deadlock city!], so unforuntately we just
     * have to skip deleting this guy. That's OK though because
     * the node who's doing the actual deleting should handle it
     * anyway. */
    if (current == osb->dc_task)
        goto bail;

    spin_lock(&oi->ip_lock);
    /* OCFS2 *never* deletes system files. This should technically
     * never get here as system file inodes should always have a
     * positive link count. */
    if (oi->ip_flags & OCFS2_INODE_SYSTEM_FILE) {
        mlog(ML_ERROR, "Skipping delete of system file %llu\n",
             (unsigned long long)oi->ip_blkno);
        goto bail_unlock;
    }

    /* If we have allowd wipe of this inode for another node, it
     * will be marked here so we can safely skip it. Recovery will
     * cleanup any inodes we might inadvertently skip here. */
    if (oi->ip_flags & OCFS2_INODE_SKIP_DELETE)
        goto bail_unlock;

    ret = 1;
bail_unlock:
    spin_unlock(&oi->ip_lock);
bail:
    return ret;
}

/* Query the cluster to determine whether we should wipe an inode from
 * disk or not.
 *
 * Requires the inode to have the cluster lock. */
static int ocfs2_query_inode_wipe(struct inode *inode,
                  struct buffer_head *di_bh,
                  int *wipe)
{
    int status = 0, reason = 0;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    struct ocfs2_dinode *di;

    *wipe = 0;

    trace_ocfs2_query_inode_wipe_begin((unsigned long long)oi->ip_blkno,
                       inode->i_nlink);

    /* While we were waiting for the cluster lock in
     * ocfs2_delete_inode, another node might have asked to delete
     * the inode. Recheck our flags to catch this. */
    if (!ocfs2_inode_is_valid_to_delete(inode)) {
        reason = 1;
        goto bail;
    }

    /* Now that we have an up to date inode, we can double check
     * the link count. */
    if (inode->i_nlink)
        goto bail;

    /* Do some basic inode verification... */
    di = (struct ocfs2_dinode *) di_bh->b_data;
    if (!(di->i_flags & cpu_to_le32(OCFS2_ORPHANED_FL)) &&
        !(oi->ip_flags & OCFS2_INODE_SKIP_ORPHAN_DIR)) {
        /*
         * Inodes in the orphan dir must have ORPHANED_FL.  The only
         * inodes that come back out of the orphan dir are reflink
         * targets. A reflink target may be moved out of the orphan
         * dir between the time we scan the directory and the time we
         * process it. This would lead to HAS_REFCOUNT_FL being set but
         * ORPHANED_FL not.
         */
        if (di->i_dyn_features & cpu_to_le16(OCFS2_HAS_REFCOUNT_FL)) {
            reason = 2;
            goto bail;
        }

        /* for lack of a better error? */
        status = -EEXIST;
        mlog(ML_ERROR,
             "Inode %llu (on-disk %llu) not orphaned! "
             "Disk flags  0x%x, inode flags 0x%x\n",
             (unsigned long long)oi->ip_blkno,
             (unsigned long long)le64_to_cpu(di->i_blkno),
             le32_to_cpu(di->i_flags), oi->ip_flags);
        goto bail;
    }

    /* has someone already deleted us?! baaad... */
    if (di->i_dtime) {
        status = -EEXIST;
        mlog_errno(status);
        goto bail;
    }

    /*
     * This is how ocfs2 determines whether an inode is still live
     * within the cluster. Every node takes a shared read lock on
     * the inode open lock in ocfs2_read_locked_inode(). When we
     * get to ->delete_inode(), each node tries to convert it's
     * lock to an exclusive. Trylocks are serialized by the inode
     * meta data lock. If the upconvert succeeds, we know the inode
     * is no longer live and can be deleted.
     *
     * Though we call this with the meta data lock held, the
     * trylock keeps us from ABBA deadlock.
     */
    status = ocfs2_try_open_lock(inode, 1);
    if (status == -EAGAIN) {
        status = 0;
        reason = 3;
        goto bail;
    }
    if (status < 0) {
        mlog_errno(status);
        goto bail;
    }

    *wipe = 1;
    trace_ocfs2_query_inode_wipe_succ(le16_to_cpu(di->i_orphaned_slot));

bail:
    trace_ocfs2_query_inode_wipe_end(status, reason);
    return status;
}

/* Support function for ocfs2_delete_inode. Will help us keep the
 * inode data in a consistent state for clear_inode. Always truncates
 * pages, optionally sync's them first. */
static void ocfs2_cleanup_delete_inode(struct inode *inode,
                       int sync_data)
{
    trace_ocfs2_cleanup_delete_inode(
        (unsigned long long)OCFS2_I(inode)->ip_blkno, sync_data);
    if (sync_data)
        filemap_write_and_wait(inode->i_mapping);
    truncate_inode_pages(&inode->i_data, 0);
}

static void ocfs2_delete_inode(struct inode *inode)
{
    int wipe, status;
    sigset_t oldset;
    struct buffer_head *di_bh = NULL;

    trace_ocfs2_delete_inode(inode->i_ino,
                 (unsigned long long)OCFS2_I(inode)->ip_blkno,
                 is_bad_inode(inode));

    /* When we fail in read_inode() we mark inode as bad. The second test
     * catches the case when inode allocation fails before allocating
     * a block for inode. */
    if (is_bad_inode(inode) || !OCFS2_I(inode)->ip_blkno)
        goto bail;

    dquot_initialize(inode);

    if (!ocfs2_inode_is_valid_to_delete(inode)) {
        /* It's probably not necessary to truncate_inode_pages
         * here but we do it for safety anyway (it will most
         * likely be a no-op anyway) */
        ocfs2_cleanup_delete_inode(inode, 0);
        goto bail;
    }

    /* We want to block signals in delete_inode as the lock and
     * messaging paths may return us -ERESTARTSYS. Which would
     * cause us to exit early, resulting in inodes being orphaned
     * forever. */
    ocfs2_block_signals(&oldset);

    /*
     * Synchronize us against ocfs2_get_dentry. We take this in
     * shared mode so that all nodes can still concurrently
     * process deletes.
     */
    status = ocfs2_nfs_sync_lock(OCFS2_SB(inode->i_sb), 0);
    if (status < 0) {
        mlog(ML_ERROR, "getting nfs sync lock(PR) failed %d\n", status);
        ocfs2_cleanup_delete_inode(inode, 0);
        goto bail_unblock;
    }
    /* Lock down the inode. This gives us an up to date view of
     * it's metadata (for verification), and allows us to
     * serialize delete_inode on multiple nodes.
     *
     * Even though we might be doing a truncate, we don't take the
     * allocation lock here as it won't be needed - nobody will
     * have the file open.
     */
    status = ocfs2_inode_lock(inode, &di_bh, 1);
    if (status < 0) {
        if (status != -ENOENT)
            mlog_errno(status);
        ocfs2_cleanup_delete_inode(inode, 0);
        goto bail_unlock_nfs_sync;
    }

    /* Query the cluster. This will be the final decision made
     * before we go ahead and wipe the inode. */
    status = ocfs2_query_inode_wipe(inode, di_bh, &wipe);
    if (!wipe || status < 0) {
        /* Error and remote inode busy both mean we won't be
         * removing the inode, so they take almost the same
         * path. */
        if (status < 0)
            mlog_errno(status);

        /* Someone in the cluster has disallowed a wipe of
         * this inode, or it was never completely
         * orphaned. Write out the pages and exit now. */
        ocfs2_cleanup_delete_inode(inode, 1);
        goto bail_unlock_inode;
    }

    ocfs2_cleanup_delete_inode(inode, 0);

    status = ocfs2_wipe_inode(inode, di_bh);
    if (status < 0) {
        if (status != -EDEADLK)
            mlog_errno(status);
        goto bail_unlock_inode;
    }

    /*
     * Mark the inode as successfully deleted.
     *
     * This is important for ocfs2_clear_inode() as it will check
     * this flag and skip any checkpointing work
     *
     * ocfs2_stuff_meta_lvb() also uses this flag to invalidate
     * the LVB for other nodes.
     */
    OCFS2_I(inode)->ip_flags |= OCFS2_INODE_DELETED;

bail_unlock_inode:
    ocfs2_inode_unlock(inode, 1);
    brelse(di_bh);

bail_unlock_nfs_sync:
    ocfs2_nfs_sync_unlock(OCFS2_SB(inode->i_sb), 0);

bail_unblock:
    ocfs2_unblock_signals(&oldset);
bail:
    return;
}

static void ocfs2_clear_inode(struct inode *inode)
{
    int status;
    struct ocfs2_inode_info *oi = OCFS2_I(inode);

    clear_inode(inode);
    trace_ocfs2_clear_inode((unsigned long long)oi->ip_blkno,
                inode->i_nlink);

    mlog_bug_on_msg(OCFS2_SB(inode->i_sb) == NULL,
            "Inode=%lu\n", inode->i_ino);

    dquot_drop(inode);

    /* To preven remote deletes we hold open lock before, now it
     * is time to unlock PR and EX open locks. */
    ocfs2_open_unlock(inode);

    /* Do these before all the other work so that we don't bounce
     * the downconvert thread while waiting to destroy the locks. */
    ocfs2_mark_lockres_freeing(&oi->ip_rw_lockres);
    ocfs2_mark_lockres_freeing(&oi->ip_inode_lockres);
    ocfs2_mark_lockres_freeing(&oi->ip_open_lockres);

    ocfs2_resv_discard(&OCFS2_SB(inode->i_sb)->osb_la_resmap,
               &oi->ip_la_data_resv);
    ocfs2_resv_init_once(&oi->ip_la_data_resv);

    /* We very well may get a clear_inode before all an inodes
     * metadata has hit disk. Of course, we can't drop any cluster
     * locks until the journal has finished with it. The only
     * exception here are successfully wiped inodes - their
     * metadata can now be considered to be part of the system
     * inodes from which it came. */
    if (!(OCFS2_I(inode)->ip_flags & OCFS2_INODE_DELETED))
        ocfs2_checkpoint_inode(inode);

    mlog_bug_on_msg(!list_empty(&oi->ip_io_markers),
            "Clear inode of %llu, inode has io markers\n",
            (unsigned long long)oi->ip_blkno);

    ocfs2_extent_map_trunc(inode, 0);

    status = ocfs2_drop_inode_locks(inode);
    if (status < 0)
        mlog_errno(status);

    ocfs2_lock_res_free(&oi->ip_rw_lockres);
    ocfs2_lock_res_free(&oi->ip_inode_lockres);
    ocfs2_lock_res_free(&oi->ip_open_lockres);

    ocfs2_metadata_cache_exit(INODE_CACHE(inode));

    mlog_bug_on_msg(INODE_CACHE(inode)->ci_num_cached,
            "Clear inode of %llu, inode has %u cache items\n",
            (unsigned long long)oi->ip_blkno,
            INODE_CACHE(inode)->ci_num_cached);

    mlog_bug_on_msg(!(INODE_CACHE(inode)->ci_flags & OCFS2_CACHE_FL_INLINE),
            "Clear inode of %llu, inode has a bad flag\n",
            (unsigned long long)oi->ip_blkno);

    mlog_bug_on_msg(spin_is_locked(&oi->ip_lock),
            "Clear inode of %llu, inode is locked\n",
            (unsigned long long)oi->ip_blkno);

    mlog_bug_on_msg(!mutex_trylock(&oi->ip_io_mutex),
            "Clear inode of %llu, io_mutex is locked\n",
            (unsigned long long)oi->ip_blkno);
    mutex_unlock(&oi->ip_io_mutex);

    /*
     * down_trylock() returns 0, down_write_trylock() returns 1
     * kernel 1, world 0
     */
    mlog_bug_on_msg(!down_write_trylock(&oi->ip_alloc_sem),
            "Clear inode of %llu, alloc_sem is locked\n",
            (unsigned long long)oi->ip_blkno);
    up_write(&oi->ip_alloc_sem);

    mlog_bug_on_msg(oi->ip_open_count,
            "Clear inode of %llu has open count %d\n",
            (unsigned long long)oi->ip_blkno, oi->ip_open_count);

    /* Clear all other flags. */
    oi->ip_flags = 0;
    oi->ip_dir_start_lookup = 0;
    oi->ip_blkno = 0ULL;

    /*
     * ip_jinode is used to track txns against this inode. We ensure that
     * the journal is flushed before journal shutdown. Thus it is safe to
     * have inodes get cleaned up after journal shutdown.
     */
    jbd2_journal_release_jbd_inode(OCFS2_SB(inode->i_sb)->journal->j_journal,
                       &oi->ip_jinode);
}

void ocfs2_evict_inode(struct inode *inode)
{
    if (!inode->i_nlink ||
        (OCFS2_I(inode)->ip_flags & OCFS2_INODE_MAYBE_ORPHANED)) {
        ocfs2_delete_inode(inode);
    } else {
        truncate_inode_pages(&inode->i_data, 0);
    }
    ocfs2_clear_inode(inode);
}

/* Called under inode_lock, with no more references on the
 * struct inode, so it's safe here to check the flags field
 * and to manipulate i_nlink without any other locks. */
int ocfs2_drop_inode(struct inode *inode)
{
    struct ocfs2_inode_info *oi = OCFS2_I(inode);
    int res;

    trace_ocfs2_drop_inode((unsigned long long)oi->ip_blkno,
                inode->i_nlink, oi->ip_flags);

    if (oi->ip_flags & OCFS2_INODE_MAYBE_ORPHANED)
        res = 1;
    else
        res = generic_drop_inode(inode);

    return res;
}

/*
 * This is called from our getattr.
 */
int ocfs2_inode_revalidate(struct dentry *dentry)
{
    struct inode *inode = dentry->d_inode;
    int status = 0;

    trace_ocfs2_inode_revalidate(inode,
        inode ? (unsigned long long)OCFS2_I(inode)->ip_blkno : 0ULL,
        inode ? (unsigned long long)OCFS2_I(inode)->ip_flags : 0);

    if (!inode) {
        status = -ENOENT;
        goto bail;
    }

    spin_lock(&OCFS2_I(inode)->ip_lock);
    if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_DELETED) {
        spin_unlock(&OCFS2_I(inode)->ip_lock);
        status = -ENOENT;
        goto bail;
    }
    spin_unlock(&OCFS2_I(inode)->ip_lock);

    /* Let ocfs2_inode_lock do the work of updating our struct
     * inode for us. */
    status = ocfs2_inode_lock(inode, NULL, 0);
    if (status < 0) {
        if (status != -ENOENT)
            mlog_errno(status);
        goto bail;
    }
    ocfs2_inode_unlock(inode, 0);
bail:
    return status;
}

/*
 * Updates a disk inode from a
 * struct inode.
 * Only takes ip_lock.
 */
int ocfs2_mark_inode_dirty(handle_t *handle,
               struct inode *inode,
               struct buffer_head *bh)
{
    int status;
    struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;

    trace_ocfs2_mark_inode_dirty((unsigned long long)OCFS2_I(inode)->ip_blkno);

    status = ocfs2_journal_access_di(handle, INODE_CACHE(inode), bh,
                     OCFS2_JOURNAL_ACCESS_WRITE);
    if (status < 0) {
        mlog_errno(status);
        goto leave;
    }

    spin_lock(&OCFS2_I(inode)->ip_lock);
    fe->i_clusters = cpu_to_le32(OCFS2_I(inode)->ip_clusters);
    ocfs2_get_inode_flags(OCFS2_I(inode));
    fe->i_attr = cpu_to_le32(OCFS2_I(inode)->ip_attr);
    fe->i_dyn_features = cpu_to_le16(OCFS2_I(inode)->ip_dyn_features);
    spin_unlock(&OCFS2_I(inode)->ip_lock);

    fe->i_size = cpu_to_le64(i_size_read(inode));
    ocfs2_set_links_count(fe, inode->i_nlink);
    fe->i_uid = cpu_to_le32(inode->i_uid);
    fe->i_gid = cpu_to_le32(inode->i_gid);
    fe->i_mode = cpu_to_le16(inode->i_mode);
    fe->i_atime = cpu_to_le64(inode->i_atime.tv_sec);
    fe->i_atime_nsec = cpu_to_le32(inode->i_atime.tv_nsec);
    fe->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
    fe->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
    fe->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
    fe->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);

    ocfs2_journal_dirty(handle, bh);
leave:
    return status;
}

/*
 *
 * Updates a struct inode from a disk inode.
 * does no i/o, only takes ip_lock.
 */
void ocfs2_refresh_inode(struct inode *inode,
             struct ocfs2_dinode *fe)
{
    spin_lock(&OCFS2_I(inode)->ip_lock);

    OCFS2_I(inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
    OCFS2_I(inode)->ip_attr = le32_to_cpu(fe->i_attr);
    OCFS2_I(inode)->ip_dyn_features = le16_to_cpu(fe->i_dyn_features);
    ocfs2_set_inode_flags(inode);
    i_size_write(inode, le64_to_cpu(fe->i_size));
    set_nlink(inode, ocfs2_read_links_count(fe));
    inode->i_uid = le32_to_cpu(fe->i_uid);
    inode->i_gid = le32_to_cpu(fe->i_gid);
    inode->i_mode = le16_to_cpu(fe->i_mode);
    if (S_ISLNK(inode->i_mode) && le32_to_cpu(fe->i_clusters) == 0)
        inode->i_blocks = 0;
    else
        inode->i_blocks = ocfs2_inode_sector_count(inode);
    inode->i_atime.tv_sec = le64_to_cpu(fe->i_atime);
    inode->i_atime.tv_nsec = le32_to_cpu(fe->i_atime_nsec);
    inode->i_mtime.tv_sec = le64_to_cpu(fe->i_mtime);
    inode->i_mtime.tv_nsec = le32_to_cpu(fe->i_mtime_nsec);
    inode->i_ctime.tv_sec = le64_to_cpu(fe->i_ctime);
    inode->i_ctime.tv_nsec = le32_to_cpu(fe->i_ctime_nsec);

    spin_unlock(&OCFS2_I(inode)->ip_lock);
}

int ocfs2_validate_inode_block(struct super_block *sb,
                   struct buffer_head *bh)
{
    int rc;
    struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;

    trace_ocfs2_validate_inode_block((unsigned long long)bh->b_blocknr);

    BUG_ON(!buffer_uptodate(bh));

    /*
     * If the ecc fails, we return the error but otherwise
     * leave the filesystem running.  We know any error is
     * local to this block.
     */
    rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &di->i_check);
    if (rc) {
        mlog(ML_ERROR, "Checksum failed for dinode %llu\n",
             (unsigned long long)bh->b_blocknr);
        goto bail;
    }

    /*
     * Errors after here are fatal.
     */

    rc = -EINVAL;

    if (!OCFS2_IS_VALID_DINODE(di)) {
        ocfs2_error(sb, "Invalid dinode #%llu: signature = %.*s\n",
                (unsigned long long)bh->b_blocknr, 7,
                di->i_signature);
        goto bail;
    }

    if (le64_to_cpu(di->i_blkno) != bh->b_blocknr) {
        ocfs2_error(sb, "Invalid dinode #%llu: i_blkno is %llu\n",
                (unsigned long long)bh->b_blocknr,
                (unsigned long long)le64_to_cpu(di->i_blkno));
        goto bail;
    }

    if (!(di->i_flags & cpu_to_le32(OCFS2_VALID_FL))) {
        ocfs2_error(sb,
                "Invalid dinode #%llu: OCFS2_VALID_FL not set\n",
                (unsigned long long)bh->b_blocknr);
        goto bail;
    }

    if (le32_to_cpu(di->i_fs_generation) !=
        OCFS2_SB(sb)->fs_generation) {
        ocfs2_error(sb,
                "Invalid dinode #%llu: fs_generation is %u\n",
                (unsigned long long)bh->b_blocknr,
                le32_to_cpu(di->i_fs_generation));
        goto bail;
    }

    rc = 0;

bail:
    return rc;
}

int ocfs2_read_inode_block_full(struct inode *inode, struct buffer_head **bh,
                int flags)
{
    int rc;
    struct buffer_head *tmp = *bh;

    rc = ocfs2_read_blocks(INODE_CACHE(inode), OCFS2_I(inode)->ip_blkno,
                   1, &tmp, flags, ocfs2_validate_inode_block);

    /* If ocfs2_read_blocks() got us a new bh, pass it up. */
    if (!rc && !*bh)
        *bh = tmp;

    return rc;
}

int ocfs2_read_inode_block(struct inode *inode, struct buffer_head **bh)
{
    return ocfs2_read_inode_block_full(inode, bh, 0);
}


static u64 ocfs2_inode_cache_owner(struct ocfs2_caching_info *ci)
{
    struct ocfs2_inode_info *oi = cache_info_to_inode(ci);

    return oi->ip_blkno;
}

static struct super_block *ocfs2_inode_cache_get_super(struct ocfs2_caching_info *ci)
{
    struct ocfs2_inode_info *oi = cache_info_to_inode(ci);

    return oi->vfs_inode.i_sb;
}

static void ocfs2_inode_cache_lock(struct ocfs2_caching_info *ci)
{
    struct ocfs2_inode_info *oi = cache_info_to_inode(ci);

    spin_lock(&oi->ip_lock);
}

static void ocfs2_inode_cache_unlock(struct ocfs2_caching_info *ci)
{
    struct ocfs2_inode_info *oi = cache_info_to_inode(ci);

    spin_unlock(&oi->ip_lock);
}

static void ocfs2_inode_cache_io_lock(struct ocfs2_caching_info *ci)
{
    struct ocfs2_inode_info *oi = cache_info_to_inode(ci);

    mutex_lock(&oi->ip_io_mutex);
}

static void ocfs2_inode_cache_io_unlock(struct ocfs2_caching_info *ci)
{
    struct ocfs2_inode_info *oi = cache_info_to_inode(ci);

    mutex_unlock(&oi->ip_io_mutex);
}

const struct ocfs2_caching_operations ocfs2_inode_caching_ops = {
    .co_owner       = ocfs2_inode_cache_owner,
    .co_get_super       = ocfs2_inode_cache_get_super,
    .co_cache_lock      = ocfs2_inode_cache_lock,
    .co_cache_unlock    = ocfs2_inode_cache_unlock,
    .co_io_lock     = ocfs2_inode_cache_io_lock,
    .co_io_unlock       = ocfs2_inode_cache_io_unlock,
};