Lockdep complains about btrfs's async commit: [ 2372.462171] [ BUG: bad unlock balance detected! ] [ 2372.462191] 3.12.0+ #32 Tainted: G W [ 2372.462209] ------------------------------------- [ 2372.462228] ceph-osd/14048 is trying to release lock (sb_internal) at: [ 2372.462275] [<ffffffffa022cb10>] btrfs_commit_transaction_async+0x1b0/0x2a0 [btrfs] [ 2372.462305] but there are no more locks to release! [ 2372.462324] [ 2372.462324] other info that might help us debug this: [ 2372.462349] no locks held by ceph-osd/14048. [ 2372.462367] [ 2372.462367] stack backtrace: [ 2372.462386] CPU: 2 PID: 14048 Comm: ceph-osd Tainted: G W 3.12.0+ #32 [ 2372.462414] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS 080015 11/09/2011 [ 2372.462455] ffffffffa022cb10 ffff88007490fd28 ffffffff816f094a ffff8800378aa320 [ 2372.462491] ffff88007490fd50 ffffffff810adf4c ffff8800378aa320 ffff88009af97650 [ 2372.462526] ffffffffa022cb10 ffff88007490fd88 ffffffff810b01ee ffff8800898c0000 [ 2372.462562] Call Trace: [ 2372.462584] [<ffffffffa022cb10>] ? btrfs_commit_transaction_async+0x1b0/0x2a0 [btrfs] [ 2372.462619] [<ffffffff816f094a>] dump_stack+0x45/0x56 [ 2372.462642] [<ffffffff810adf4c>] print_unlock_imbalance_bug+0xec/0x100 [ 2372.462677] [<ffffffffa022cb10>] ? btrfs_commit_transaction_async+0x1b0/0x2a0 [btrfs] [ 2372.462710] [<ffffffff810b01ee>] lock_release+0x18e/0x210 [ 2372.462742] [<ffffffffa022cb36>] btrfs_commit_transaction_async+0x1d6/0x2a0 [btrfs] [ 2372.462783] [<ffffffffa025a7ce>] btrfs_ioctl_start_sync+0x3e/0xc0 [btrfs] [ 2372.462822] [<ffffffffa025f1d3>] btrfs_ioctl+0x4c3/0x1f70 [btrfs] [ 2372.462849] [<ffffffff812c0321>] ? avc_has_perm+0x121/0x1b0 [ 2372.462873] [<ffffffff812c0224>] ? avc_has_perm+0x24/0x1b0 [ 2372.462897] [<ffffffff8107ecc8>] ? sched_clock_cpu+0xa8/0x100 [ 2372.462922] [<ffffffff8117b145>] do_vfs_ioctl+0x2e5/0x4e0 [ 2372.462946] [<ffffffff812c19e6>] ? file_has_perm+0x86/0xa0 [ 2372.462969] [<ffffffff8117b3c1>] SyS_ioctl+0x81/0xa0 [ 2372.462991] [<ffffffff817045a4>] tracesys+0xdd/0xe2 ==================================================== It's because that we don't do the right thing when checking if it's ok to tell lockdep that we're trying to release the rwsem. If the trans handle's type is TRANS_ATTACH, we won't acquire the freeze rwsem, but as TRANS_ATTACH fits the check (trans < TRANS_JOIN_NOLOCK), we'll release the freeze rwsem, which makes lockdep complains a lot. Reported-by: Ma Jianpeng <majianpeng@xxxxxxxxx> Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx> Signed-off-by: Miao Xie <miaox@xxxxxxxxxxxxxx> --- fs/btrfs/transaction.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 8c81bdc..c094f08 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1453,7 +1453,7 @@ static void do_async_commit(struct work_struct *work) * We've got freeze protection passed with the transaction. * Tell lockdep about it. */ - if (ac->newtrans->type < TRANS_JOIN_NOLOCK) + if (ac->newtrans->type & __TRANS_FREEZABLE) rwsem_acquire_read( &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1], 0, 1, _THIS_IP_); @@ -1494,7 +1494,7 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, * Tell lockdep we've released the freeze rwsem, since the * async commit thread will be the one to unlock it. */ - if (trans->type < TRANS_JOIN_NOLOCK) + if (ac->newtrans->type & __TRANS_FREEZABLE) rwsem_release( &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1], 1, _THIS_IP_); -- 1.8.1.4 _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
