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 f112a049)
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