[PATCH] EXT4: Add missing brelse() in ext4_iget()

[Andi Kleen-3]

EXT4: Add missing brelse() in ext4_iget()

One of the invalid error paths in ext4_iget() forgot to brelse() the inode
buffer head. Fix that.

Found during code review.

Signed-off-by: Andi Kleen <ak@...>

---
 fs/ext4/inode.c |    1 +
 1 file changed, 1 insertion(+)

Index: linux-2.6.32-rc6-ak/fs/ext4/inode.c
===================================================================
--- linux-2.6.32-rc6-ak.orig/fs/ext4/inode.c
+++ linux-2.6.32-rc6-ak/fs/ext4/inode.c
@@ -4882,6 +4882,7 @@ struct inode *ext4_iget(struct super_blo
       (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) +
        EXT4_SB(sb)->s_gdb_count)) ||
      (ei->i_file_acl >= ext4_blocks_count(EXT4_SB(sb)->s_es)))) {
+ brelse(bh);
  ext4_error(sb, __func__,
    "bad extended attribute block %llu in inode #%lu",
    ei->i_file_acl, inode->i_ino);
--
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[tytso]

On Sat, Nov 07, 2009 at 11:17:32PM +0100, Andi Kleen wrote:
> EXT4: Add missing brelse() in ext4_iget()
>
> One of the invalid error paths in ext4_iget() forgot to brelse() the inode
> buffer head. Fix that.
>
> Found during code review.
>
> Signed-off-by: Andi Kleen <ak@...>

Hi Andi, my apologies for the delay in responding; crazy travel
schedule.  I've committed a slightly better fix which cleans up the
error handling for ext4_iget(), and drops the net number of lines in
fs/ext4/inode.c by 5, and shrinks the compiled object size as well:

  31495       0      12   31507    7b13 /kbuild/ext4/fs/ext4/inode.o
  31459       0      12   31471    7aef /kbuild/ext4/fs/ext4/inode.o

                                                        - Ted

ext4: plug a buffer_head leak in an error path of ext4_iget()

One of the invalid error paths in ext4_iget() forgot to brelse() the
inode buffer head.  Fix it by adding a brelse() in the common error
return path, which also simplifies function.

Thanks to Andi Kleen <ak@...> reporting the problem.

Signed-off-by: "Theodore Ts'o" <tytso@...>
---
 fs/ext4/inode.c |   11 +++--------
 1 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2c8caa5..554c679 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4781,7 +4781,6 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
  struct ext4_iloc iloc;
  struct ext4_inode *raw_inode;
  struct ext4_inode_info *ei;
- struct buffer_head *bh;
  struct inode *inode;
  long ret;
  int block;
@@ -4793,11 +4792,11 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
  return inode;
 
  ei = EXT4_I(inode);
+ iloc.bh = 0;
 
  ret = __ext4_get_inode_loc(inode, &iloc, 0);
  if (ret < 0)
  goto bad_inode;
- bh = iloc.bh;
  raw_inode = ext4_raw_inode(&iloc);
  inode->i_mode = le16_to_cpu(raw_inode->i_mode);
  inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
@@ -4820,7 +4819,6 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
  if (inode->i_mode == 0 ||
     !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
  /* this inode is deleted */
- brelse(bh);
  ret = -ESTALE;
  goto bad_inode;
  }
@@ -4852,7 +4850,6 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
  ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
  if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
     EXT4_INODE_SIZE(inode->i_sb)) {
- brelse(bh);
  ret = -EIO;
  goto bad_inode;
  }
@@ -4905,10 +4902,8 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
  /* Validate block references which are part of inode */
  ret = ext4_check_inode_blockref(inode);
  }
- if (ret) {
- brelse(bh);
+ if (ret)
  goto bad_inode;
- }
 
  if (S_ISREG(inode->i_mode)) {
  inode->i_op = &ext4_file_inode_operations;
@@ -4936,7 +4931,6 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
  init_special_inode(inode, inode->i_mode,
    new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
  } else {
- brelse(bh);
  ret = -EIO;
  ext4_error(inode->i_sb, __func__,
    "bogus i_mode (%o) for inode=%lu",
@@ -4949,6 +4943,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
  return inode;
 
 bad_inode:
+ brelse(iloc.bh);
  iget_failed(inode);
  return ERR_PTR(ret);
 }
--
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