[Ocfs2-devel] [PATCH 1/2] ocfs2: fix BUG when iput after ocfs2_mknod fails

[Joseph Qi]

Commit b1529a41f777 tried to reclaim the claimed inode if
__ocfs2_mknod_locked() fails later. But this introduce a race, the freed
bit may be reused immediately by another thread, which will update
dinode, e.g. i_generation. Then iput this inode will lead to BUG:
  inode->i_generation != le32_to_cpu(fe->i_generation)

We could make this inode as bad, but we did want to do operations like
wipe in some cases. Since the claimed inode bit can only affect that an
dinode is missing and will return back after fsck, it seems not a big
problem. So just leave it as is by revert the reclaim logic.

Fixes: b1529a41f777 ("ocfs2: should reclaim the inode if '__ocfs2_mknod_locked' returns an error")
Reported-by: Yan Wang <wangyan122 at huawei.com>
Signed-off-by: Joseph Qi <joseph.qi at linux.alibaba.com>
---
 fs/ocfs2/namei.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 961d1cf54388..1a97e167b219 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -632,18 +632,9 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
 		return status;
 	}
 
-	status = __ocfs2_mknod_locked(dir, inode, dev, new_fe_bh,
+	return __ocfs2_mknod_locked(dir, inode, dev, new_fe_bh,
 				    parent_fe_bh, handle, inode_ac,
 				    fe_blkno, suballoc_loc, suballoc_bit);
-	if (status < 0) {
-		u64 bg_blkno = ocfs2_which_suballoc_group(fe_blkno, suballoc_bit);
-		int tmp = ocfs2_free_suballoc_bits(handle, inode_ac->ac_inode,
-				inode_ac->ac_bh, suballoc_bit, bg_blkno, 1);
-		if (tmp)
-			mlog_errno(tmp);
-	}
-
-	return status;
 }
 
 static int ocfs2_mkdir(struct user_namespace *mnt_userns,
-- 
2.24.4