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@linux.intel.com> reporting the problem.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2c8caa5..554c679 100644 (file)
--- 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);
 }