start-handle-later-in-ext4-rename

   1 ext4: start handle at least possible moment when renaming files
   2
   3 In ext4_rename(), don't start the journal handle until the the
   4 directory entries have been successfully looked up.
   5
   6 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
   7 ---
   8  fs/ext4/namei.c | 23 +++++++++++++----------
   9  1 file changed, 13 insertions(+), 10 deletions(-)
  10
  11 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
  12 index ab2f6dc..f57980c 100644
  13 --- a/fs/ext4/namei.c
  14 +++ b/fs/ext4/namei.c
  15 @@ -2965,7 +2965,7 @@ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
  16  static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
  17                        struct inode *new_dir, struct dentry *new_dentry)
  18  {
  19 -       handle_t *handle;
  20 +       handle_t *handle = NULL;
  21         struct inode *old_inode, *new_inode;
  22         struct buffer_head *old_bh, *new_bh, *dir_bh;
  23         struct ext4_dir_entry_2 *old_de, *new_de;
  24 @@ -2982,14 +2982,6 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
  25          * in separate transaction */
  26         if (new_dentry->d_inode)
  27                 dquot_initialize(new_dentry->d_inode);
  28 -       handle = ext4_journal_start(old_dir, EXT4_HT_DIR,
  29 -               (2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
  30 -                EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
  31 -       if (IS_ERR(handle))
  32 -               return PTR_ERR(handle);
  33 -
  34 -       if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
  35 -               ext4_handle_sync(handle);
  36
  37         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de, NULL);
  38         /*
  39 @@ -3012,6 +3004,16 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
  40                         new_bh = NULL;
  41                 }
  42         }
  43 +
  44 +       handle = ext4_journal_start(old_dir, EXT4_HT_DIR,
  45 +               (2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
  46 +                EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
  47 +       if (IS_ERR(handle))
  48 +               return PTR_ERR(handle);
  49 +
  50 +       if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
  51 +               ext4_handle_sync(handle);
  52 +
  53         if (S_ISDIR(old_inode->i_mode)) {
  54                 if (new_inode) {
  55                         retval = -ENOTEMPTY;
  56 @@ -3151,7 +3153,8 @@ end_rename:
  57         brelse(dir_bh);
  58         brelse(old_bh);
  59         brelse(new_bh);
  60 -       ext4_journal_stop(handle);
  61 +       if (handle)
  62 +               ext4_journal_stop(handle);
  63         if (retval == 0 && force_da_alloc)
  64                 ext4_alloc_da_blocks(old_inode);
  65         return retval;