From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:39004 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727178AbeHaMEA (ORCPT ); Fri, 31 Aug 2018 08:04:00 -0400 Subject: Re: [PATCH 01/35] btrfs: add btrfs_delete_ref_head helper To: Josef Bacik , linux-btrfs@vger.kernel.org References: <20180830174225.2200-1-josef@toxicpanda.com> <20180830174225.2200-2-josef@toxicpanda.com> From: Nikolay Borisov Message-ID: Date: Fri, 31 Aug 2018 10:57:45 +0300 MIME-Version: 1.0 In-Reply-To: <20180830174225.2200-2-josef@toxicpanda.com> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 30.08.2018 20:41, Josef Bacik wrote: > From: Josef Bacik > > We do this dance in cleanup_ref_head and check_ref_cleanup, unify it > into a helper and cleanup the calling functions. > > Signed-off-by: Josef Bacik > --- > fs/btrfs/delayed-ref.c | 14 ++++++++++++++ > fs/btrfs/delayed-ref.h | 3 ++- > fs/btrfs/extent-tree.c | 24 ++++-------------------- > 3 files changed, 20 insertions(+), 21 deletions(-) > > diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c > index 62ff545ba1f7..3a9e4ac21794 100644 > --- a/fs/btrfs/delayed-ref.c > +++ b/fs/btrfs/delayed-ref.c > @@ -393,6 +393,20 @@ btrfs_select_ref_head(struct btrfs_trans_handle *trans) > return head; > } > > +void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs, > + struct btrfs_delayed_ref_head *head) > +{ > + lockdep_assert_held(&delayed_refs->lock); > + lockdep_assert_held(&head->lock); > + > + rb_erase(&head->href_node, &delayed_refs->href_root); > + RB_CLEAR_NODE(&head->href_node); > + atomic_dec(&delayed_refs->num_entries); > + delayed_refs->num_heads--; > + if (head->processing == 0) > + delayed_refs->num_heads_ready--; > +} > + > /* > * Helper to insert the ref_node to the tail or merge with tail. > * > diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h > index d9f2a4ebd5db..7769177b489e 100644 > --- a/fs/btrfs/delayed-ref.h > +++ b/fs/btrfs/delayed-ref.h > @@ -261,7 +261,8 @@ static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head) > { > mutex_unlock(&head->mutex); > } > - > +void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs, > + struct btrfs_delayed_ref_head *head); > > struct btrfs_delayed_ref_head * > btrfs_select_ref_head(struct btrfs_trans_handle *trans); > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index f77226d8020a..6799950fa057 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -2492,12 +2492,9 @@ static int cleanup_ref_head(struct btrfs_trans_handle *trans, > spin_unlock(&delayed_refs->lock); > return 1; > } > - delayed_refs->num_heads--; > - rb_erase(&head->href_node, &delayed_refs->href_root); > - RB_CLEAR_NODE(&head->href_node); > - spin_unlock(&head->lock); > + btrfs_delete_ref_head(delayed_refs, head); > spin_unlock(&delayed_refs->lock); > - atomic_dec(&delayed_refs->num_entries); > + spin_unlock(&head->lock); > Again, the feedback of reversed lock-order is not addressed: https://www.spinics.net/lists/linux-btrfs/msg80482.html > trace_run_delayed_ref_head(fs_info, head, 0); > > @@ -6984,22 +6981,9 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, > if (!mutex_trylock(&head->mutex)) > goto out; > > - /* > - * at this point we have a head with no other entries. Go > - * ahead and process it. > - */ > - rb_erase(&head->href_node, &delayed_refs->href_root); > - RB_CLEAR_NODE(&head->href_node); > - atomic_dec(&delayed_refs->num_entries); > - > - /* > - * we don't take a ref on the node because we're removing it from the > - * tree, so we just steal the ref the tree was holding. > - */ > - delayed_refs->num_heads--; > - if (head->processing == 0) > - delayed_refs->num_heads_ready--; > + btrfs_delete_ref_head(delayed_refs, head); > head->processing = 0; > + > spin_unlock(&head->lock); > spin_unlock(&delayed_refs->lock); > >