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authorDave Chinner <dchinner@redhat.com>2013-09-30 09:37:03 +1000
committerBen Myers <bpm@sgi.com>2013-10-04 13:55:33 -0500
commit89c6c89af2ef41cb127c9694ef7783e585e96337 (patch)
tree7d1bbcf898660e9f98822ef0d4ce84a5a105b50c /fs
parent997def25e4b9cee3b01609e18a52f926bca8bd2b (diff)
downloadlinux-89c6c89af2ef41cb127c9694ef7783e585e96337.tar.gz
xfs: lockdep needs to know about 3 dquot-deep nesting
Michael Semon reported that xfs/299 generated this lockdep warning: ============================================= [ INFO: possible recursive locking detected ] 3.12.0-rc2+ #2 Not tainted --------------------------------------------- touch/21072 is trying to acquire lock: (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64 but task is already holding lock: (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&xfs_dquot_other_class); lock(&xfs_dquot_other_class); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by touch/21072: #0: (sb_writers#10){++++.+}, at: [<c11185b6>] mnt_want_write+0x1e/0x3e #1: (&type->i_mutex_dir_key#4){+.+.+.}, at: [<c11078ee>] do_last+0x245/0xe40 #2: (sb_internal#2){++++.+}, at: [<c122c9e0>] xfs_trans_alloc+0x1f/0x35 #3: (&(&ip->i_lock)->mr_lock/1){+.+...}, at: [<c126cd1b>] xfs_ilock+0x100/0x1f1 #4: (&(&ip->i_lock)->mr_lock){++++-.}, at: [<c126cf52>] xfs_ilock_nowait+0x105/0x22f #5: (&dqp->q_qlock){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64 #6: (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64 The lockdep annotation for dquot lock nesting only understands locking for user and "other" dquots, not user, group and quota dquots. Fix the annotations to match the locking heirarchy we now have. Reported-by: Michael L. Semon <mlsemon35@gmail.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com> (cherry picked from commit f112a049712a5c07de25d511c3c6587a2b1a015e)
Diffstat (limited to 'fs')
-rw-r--r--fs/xfs/xfs_dquot.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index 71520e6e5d65..1ee776d477c3 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -64,7 +64,8 @@ int xfs_dqerror_mod = 33;
struct kmem_zone *xfs_qm_dqtrxzone;
static struct kmem_zone *xfs_qm_dqzone;
-static struct lock_class_key xfs_dquot_other_class;
+static struct lock_class_key xfs_dquot_group_class;
+static struct lock_class_key xfs_dquot_project_class;
/*
* This is called to free all the memory associated with a dquot
@@ -703,8 +704,20 @@ xfs_qm_dqread(
* Make sure group quotas have a different lock class than user
* quotas.
*/
- if (!(type & XFS_DQ_USER))
- lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
+ switch (type) {
+ case XFS_DQ_USER:
+ /* uses the default lock class */
+ break;
+ case XFS_DQ_GROUP:
+ lockdep_set_class(&dqp->q_qlock, &xfs_dquot_group_class);
+ break;
+ case XFS_DQ_PROJ:
+ lockdep_set_class(&dqp->q_qlock, &xfs_dquot_project_class);
+ break;
+ default:
+ ASSERT(0);
+ break;
+ }
XFS_STATS_INC(xs_qm_dquot);