[Ocfs2-devel] [PATCH] ocfs2: mknod: fix recursive locking hung

[Junxiao Bi]

Here another recursive lock caught and it caused the cluster hung.

 #0 [ffff88008e3935a8] __schedule at ffffffff816e4722
 #1 [ffff88008e393600] schedule at ffffffff816e4dee
 #2 [ffff88008e393620] schedule_timeout at ffffffff816e7cd5
 #3 [ffff88008e3936c0] wait_for_completion at ffffffff816e631f
 #4 [ffff88008e393740] __ocfs2_cluster_lock at ffffffffa05a9111 [ocfs2]
 #5 [ffff88008e393890] ocfs2_inode_lock_full_nested at ffffffffa05aec14 [ocfs2]
 #6 [ffff88008e393910] ocfs2_inode_lock_tracker at ffffffffa05af02f [ocfs2]
 #7 [ffff88008e393970] ocfs2_iop_get_acl at ffffffffa0620c92 [ocfs2]
 #8 [ffff88008e3939d0] get_acl at ffffffff8126ae79
 #9 [ffff88008e3939f0] posix_acl_create at ffffffff8126b27a
 #10 [ffff88008e393a20] ocfs2_mknod at ffffffffa05cedcc [ocfs2]
 #11 [ffff88008e393b60] ocfs2_create at ffffffffa05cfb13 [ocfs2]
 #12 [ffff88008e393bd0] vfs_create at ffffffff81217338
 #13 [ffff88008e393c10] lookup_open at ffffffff81217a85
 #14 [ffff88008e393ca0] do_last at ffffffff8121ac6d
 #15 [ffff88008e393d30] path_openat at ffffffff8121b112
 #16 [ffff88008e393df0] do_filp_open at ffffffff8121b53a
 #17 [ffff88008e393ed0] do_sys_open at ffffffff81209a5a
 #18 [ffff88008e393f40] sys_open at ffffffff81209bae
 #19 [ffff88008e393f50] system_call_fastpath at ffffffff816e902e

inode lock is got by ocfs2_mknod() before call into posix_acl_create().

Signed-off-by: Junxiao Bi <junxiao.bi at oracle.com>
Cc: <stable at vger.kernel.org>
---
 fs/ocfs2/namei.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 3b0a10d9b36f..f0ee52e600ff 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -260,6 +260,8 @@ static int ocfs2_mknod(struct inode *dir,
 	sigset_t oldset;
 	int did_block_signals = 0;
 	struct ocfs2_dentry_lock *dl = NULL;
+	int locked;
+	struct ocfs2_lock_holder oh;
 
 	trace_ocfs2_mknod(dir, dentry, dentry->d_name.len, dentry->d_name.name,
 			  (unsigned long long)OCFS2_I(dir)->ip_blkno,
@@ -274,11 +276,11 @@ static int ocfs2_mknod(struct inode *dir,
 	/* get our super block */
 	osb = OCFS2_SB(dir->i_sb);
 
-	status = ocfs2_inode_lock(dir, &parent_fe_bh, 1);
-	if (status < 0) {
-		if (status != -ENOENT)
-			mlog_errno(status);
-		return status;
+	locked = ocfs2_inode_lock_tracker(dir, &parent_fe_bh, 1, &oh);
+	if (locked < 0) {
+		if (locked != -ENOENT)
+			mlog_errno(locked);
+		return locked;
 	}
 
 	if (S_ISDIR(mode) && (dir->i_nlink >= ocfs2_link_max(osb))) {
@@ -462,7 +464,7 @@ static int ocfs2_mknod(struct inode *dir,
 	if (handle)
 		ocfs2_commit_trans(osb, handle);
 
-	ocfs2_inode_unlock(dir, 1);
+	ocfs2_inode_unlock_tracker(dir, 1, &oh, locked);
 	if (did_block_signals)
 		ocfs2_unblock_signals(&oldset);
 
-- 
1.7.9.5