ocfs2: Fix lockdep warning in reflink.
This patch change mutex_lock to a new subclass and
add a new inode lock subclass for the target inode
which caused this lockdep warning.
=============================================
[ INFO: possible recursive locking detected ]
2.6.35+ #5
---------------------------------------------
reflink/11086 is trying to acquire lock:
(Meta){+++++.}, at: [<ffffffffa06f9d65>] ocfs2_reflink_ioctl+0x898/0x1229 [ocfs2]
but task is already holding lock:
(Meta){+++++.}, at: [<ffffffffa06f9aa0>] ocfs2_reflink_ioctl+0x5d3/0x1229 [ocfs2]
other info that might help us debug this:
6 locks held by reflink/11086:
#0: (&sb->s_type->i_mutex_key#15/1){+.+.+.}, at: [<ffffffff820e09ec>] lookup_create+0x26/0x97
#1: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa06f99a0>] ocfs2_reflink_ioctl+0x4d3/0x1229 [ocfs2]
#2: (Meta){+++++.}, at: [<ffffffffa06f9aa0>] ocfs2_reflink_ioctl+0x5d3/0x1229 [ocfs2]
#3: (&oi->ip_xattr_sem){+.+.+.}, at: [<ffffffffa06f9b58>] ocfs2_reflink_ioctl+0x68b/0x1229 [ocfs2]
#4: (&oi->ip_alloc_sem){+.+.+.}, at: [<ffffffffa06f9b67>] ocfs2_reflink_ioctl+0x69a/0x1229 [ocfs2]
#5: (&sb->s_type->i_mutex_key#15/2){+.+...}, at: [<ffffffffa06f9d4f>] ocfs2_reflink_ioctl+0x882/0x1229 [ocfs2]
stack backtrace:
Pid: 11086, comm: reflink Not tainted 2.6.35+ #5
Call Trace:
[<ffffffff82063dd9>] validate_chain+0x56e/0xd68
[<ffffffff82062275>] ? mark_held_locks+0x49/0x69
[<ffffffff82064d6d>] __lock_acquire+0x79a/0x7f1
[<ffffffff82065a81>] lock_acquire+0xc6/0xed
[<ffffffffa06f9d65>] ? ocfs2_reflink_ioctl+0x898/0x1229 [ocfs2]
[<ffffffffa06c9ade>] __ocfs2_cluster_lock+0x975/0xa0d [ocfs2]
[<ffffffffa06f9d65>] ? ocfs2_reflink_ioctl+0x898/0x1229 [ocfs2]
[<ffffffffa06e107b>] ? ocfs2_wait_for_recovery+0x15/0x8a [ocfs2]
[<ffffffffa06cb6ea>] ocfs2_inode_lock_full_nested+0x1ac/0xdc5 [ocfs2]
[<ffffffffa06f9d65>] ? ocfs2_reflink_ioctl+0x898/0x1229 [ocfs2]
[<ffffffff820623a0>] ? trace_hardirqs_on_caller+0x10b/0x12f
[<ffffffff82060193>] ? debug_mutex_free_waiter+0x4f/0x53
[<ffffffffa06f9d65>] ocfs2_reflink_ioctl+0x898/0x1229 [ocfs2]
[<ffffffffa06ce24a>] ? ocfs2_file_lock_res_init+0x66/0x78 [ocfs2]
[<ffffffff820bb2d2>] ? might_fault+0x40/0x8d
[<ffffffffa06df9f6>] ocfs2_ioctl+0x61a/0x656 [ocfs2]
[<ffffffff820ee5d3>] ? mntput_no_expire+0x1d/0xb0
[<ffffffff820e07b3>] ? path_put+0x2c/0x31
[<ffffffff820e53ac>] vfs_ioctl+0x2a/0x9d
[<ffffffff820e5903>] do_vfs_ioctl+0x45d/0x4ae
[<ffffffff8233a7f6>] ? _raw_spin_unlock+0x26/0x2a
[<ffffffff8200299c>] ? sysret_check+0x27/0x62
[<ffffffff820e59ab>] sys_ioctl+0x57/0x7a
[<ffffffff8200296b>] system_call_fastpath+0x16/0x1b
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 0afeda831..efdd756 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4201,8 +4201,9 @@
goto out;
}
- mutex_lock(&new_inode->i_mutex);
- ret = ocfs2_inode_lock(new_inode, &new_bh, 1);
+ mutex_lock_nested(&new_inode->i_mutex, I_MUTEX_CHILD);
+ ret = ocfs2_inode_lock_nested(new_inode, &new_bh, 1,
+ OI_LS_REFLINK_TARGET);
if (ret) {
mlog_errno(ret);
goto out_unlock;
