From: Eric Sandeen <sandeen@xxxxxxxxxx> Return -ENOENT from ext[34]_link if we've raced with unlink and i_nlink is 0. Doing otherwise has the potential to corrupt the orphan inode list, because we'd wind up with an inode with a non-zero link count on the list, and it will never get properly cleaned up & removed from the orphan list before it is freed. [akpm@xxxxxxxx: build fix] Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> Cc: <linux-ext4@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ext3/namei.c | 6 ++++++ fs/ext4/namei.c | 6 ++++++ 2 files changed, 12 insertions(+) diff -puN fs/ext3/namei.c~return-enoent-from-ext3_link-when-racing-with-unlink fs/ext3/namei.c --- a/fs/ext3/namei.c~return-enoent-from-ext3_link-when-racing-with-unlink +++ a/fs/ext3/namei.c @@ -2191,6 +2191,12 @@ static int ext3_link (struct dentry * ol if (inode->i_nlink >= EXT3_LINK_MAX) return -EMLINK; + /* + * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing + * otherwise has the potential to corrupt the orphan inode list. + */ + if (inode->i_nlink == 0) + return -ENOENT; retry: handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) + diff -puN fs/ext4/namei.c~return-enoent-from-ext3_link-when-racing-with-unlink fs/ext4/namei.c --- a/fs/ext4/namei.c~return-enoent-from-ext3_link-when-racing-with-unlink +++ a/fs/ext4/namei.c @@ -2189,6 +2189,12 @@ static int ext4_link (struct dentry * ol if (inode->i_nlink >= EXT4_LINK_MAX) return -EMLINK; + /* + * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing + * otherwise has the potential to corrupt the orphan inode list. + */ + if (inode->i_nlink == 0) + return -ENOENT; retry: handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + _ - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
