Sage Weil
2012-Sep-10 03:52 UTC
Re: [PATCH] Btrfs: move the sb_end_intwrite until after the throttle logic
On Wed, 5 Sep 2012, Josef Bacik wrote:> Sage reported the following lockdep backtrace > > ====================================> [ BUG: bad unlock balance detected! ] > 3.6.0-rc2-ceph-00171-gc7ed62d #1 Not tainted > ------------------------------------- > btrfs-cleaner/7607 is trying to release lock (sb_internal) at: > [<ffffffffa00422ae>] btrfs_commit_transaction+0xa6e/0xb20 [btrfs] > but there are no more locks to release! > > other info that might help us debug this: > 1 lock held by btrfs-cleaner/7607: > #0: (&fs_info->cleaner_mutex){+.+...}, at: [<ffffffffa003b405>] cleaner_kthread+0x95/0x120 [btrfs] > > stack backtrace: > Pid: 7607, comm: btrfs-cleaner Not tainted 3.6.0-rc2-ceph-00171-gc7ed62d #1 > Call Trace: > [<ffffffffa00422ae>] ? btrfs_commit_transaction+0xa6e/0xb20 [btrfs] > [<ffffffff810afa9e>] print_unlock_inbalance_bug+0xfe/0x110 > [<ffffffff810b289e>] lock_release_non_nested+0x1ee/0x310 > [<ffffffff81172f9b>] ? kmem_cache_free+0x7b/0x160 > [<ffffffffa004106c>] ? put_transaction+0x8c/0x130 [btrfs] > [<ffffffffa00422ae>] ? btrfs_commit_transaction+0xa6e/0xb20 [btrfs] > [<ffffffff810b2a95>] lock_release+0xd5/0x220 > [<ffffffff81173071>] ? kmem_cache_free+0x151/0x160 > [<ffffffff8117d9ed>] __sb_end_write+0x7d/0x90 > [<ffffffffa00422ae>] btrfs_commit_transaction+0xa6e/0xb20 [btrfs] > [<ffffffff81079850>] ? __init_waitqueue_head+0x60/0x60 > [<ffffffff81634c6b>] ? _raw_spin_unlock+0x2b/0x40 > [<ffffffffa0042758>] __btrfs_end_transaction+0x368/0x3c0 [btrfs] > [<ffffffffa0042808>] btrfs_end_transaction_throttle+0x18/0x20 [btrfs] > [<ffffffffa00318f0>] btrfs_drop_snapshot+0x410/0x600 [btrfs] > [<ffffffff8132babd>] ? do_raw_spin_unlock+0x5d/0xb0 > [<ffffffffa00430ef>] btrfs_clean_old_snapshots+0xaf/0x150 [btrfs] > [<ffffffffa003b405>] ? cleaner_kthread+0x95/0x120 [btrfs] > [<ffffffffa003b419>] cleaner_kthread+0xa9/0x120 [btrfs] > [<ffffffffa003b370>] ? btrfs_destroy_delayed_refs.isra.102+0x220/0x220 [btrfs] > [<ffffffff810791ee>] kthread+0xae/0xc0 > [<ffffffff810b379d>] ? trace_hardirqs_on+0xd/0x10 > [<ffffffff8163e744>] kernel_thread_helper+0x4/0x10 > [<ffffffff81635430>] ? retint_restore_args+0x13/0x13 > [<ffffffff81079140>] ? flush_kthread_work+0x1a0/0x1a0 > [<ffffffff8163e740>] ? gs_change+0x13/0x13 > > This is because the throttle stuff can commit the transaction, which expects to > be the one stopping the intwrite stuff, but we''ve already done it in the > __btrfs_end_transaction. Moving the sb_end_intewrite after this logic makes the > lockdep go away. Thanks, > > Signed-off-by: Josef Bacik <jbacik@fusionio.com>This appears to have done the trick (at least so far). I''m running it on top of -rc5 and the 3 patches I posted on Aug 30th. Tested-by: Sage Weil <sage@inktank.com> Thanks! sage> --- > 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 a86fc72..0163afa 100644 > --- a/fs/btrfs/transaction.c > +++ b/fs/btrfs/transaction.c > @@ -551,8 +551,6 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, > btrfs_trans_release_metadata(trans, root); > trans->block_rsv = NULL; > > - sb_end_intwrite(root->fs_info->sb); > - > if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) && > should_end_transaction(trans, root)) { > trans->transaction->blocked = 1; > @@ -573,6 +571,8 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, > } > } > > + sb_end_intwrite(root->fs_info->sb); > + > WARN_ON(cur_trans != info->running_transaction); > WARN_ON(atomic_read(&cur_trans->num_writers) < 1); > atomic_dec(&cur_trans->num_writers); > -- > 1.7.11.4 > >-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html