| Message ID | 20180830174225.2200-4-josef@toxicpanda.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | My current patch queue | expand |
On Thu, Aug 30, 2018 at 01:41:53PM -0400, Josef Bacik wrote: > From: Josef Bacik <jbacik@fb.com> > > Unify the extent_op handling as well, just add a flag so we don't > actually run the extent op from check_ref_cleanup and instead return a > value so that we can skip cleaning up the ref head. > > Signed-off-by: Josef Bacik <jbacik@fb.com> > --- > fs/btrfs/extent-tree.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 4c9fd35bca07..87c42a2c45b1 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -2443,18 +2443,23 @@ static void unselect_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_ref > } > > static int cleanup_extent_op(struct btrfs_trans_handle *trans, > - struct btrfs_delayed_ref_head *head) > + struct btrfs_delayed_ref_head *head, > + bool run_extent_op) > { > struct btrfs_delayed_extent_op *extent_op = head->extent_op; > int ret; > > if (!extent_op) > return 0; > + > head->extent_op = NULL; > if (head->must_insert_reserved) { > btrfs_free_delayed_extent_op(extent_op); > return 0; > + } else if (!run_extent_op) { > + return 1; > } > + > spin_unlock(&head->lock); > ret = run_delayed_extent_op(trans, head, extent_op); > btrfs_free_delayed_extent_op(extent_op); So if cleanup_extent_op() returns 1, then the head was unlocked, unless run_extent_op was true. That's pretty confusing. Can we make it always unlock in the !must_insert_reserved case? > @@ -2506,7 +2511,7 @@ static int cleanup_ref_head(struct btrfs_trans_handle *trans, > > delayed_refs = &trans->transaction->delayed_refs; > > - ret = cleanup_extent_op(trans, head); > + ret = cleanup_extent_op(trans, head, true); > if (ret < 0) { > unselect_delayed_ref_head(delayed_refs, head); > btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret); > @@ -6977,12 +6982,8 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, > if (!RB_EMPTY_ROOT(&head->ref_tree)) > goto out; > > - if (head->extent_op) { > - if (!head->must_insert_reserved) > - goto out; > - btrfs_free_delayed_extent_op(head->extent_op); > - head->extent_op = NULL; > - } > + if (cleanup_extent_op(trans, head, false)) > + goto out; > > /* > * waiting for the lock here would deadlock. If someone else has it > -- > 2.14.3 >
On Fri, Aug 31, 2018 at 04:00:29PM -0700, Omar Sandoval wrote: > On Thu, Aug 30, 2018 at 01:41:53PM -0400, Josef Bacik wrote: > > From: Josef Bacik <jbacik@fb.com> > > > > Unify the extent_op handling as well, just add a flag so we don't > > actually run the extent op from check_ref_cleanup and instead return a > > value so that we can skip cleaning up the ref head. > > > > Signed-off-by: Josef Bacik <jbacik@fb.com> > > --- > > fs/btrfs/extent-tree.c | 17 +++++++++-------- > > 1 file changed, 9 insertions(+), 8 deletions(-) > > > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > > index 4c9fd35bca07..87c42a2c45b1 100644 > > --- a/fs/btrfs/extent-tree.c > > +++ b/fs/btrfs/extent-tree.c > > @@ -2443,18 +2443,23 @@ static void unselect_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_ref > > } > > > > static int cleanup_extent_op(struct btrfs_trans_handle *trans, > > - struct btrfs_delayed_ref_head *head) > > + struct btrfs_delayed_ref_head *head, > > + bool run_extent_op) > > { > > struct btrfs_delayed_extent_op *extent_op = head->extent_op; > > int ret; > > > > if (!extent_op) > > return 0; > > + > > head->extent_op = NULL; > > if (head->must_insert_reserved) { > > btrfs_free_delayed_extent_op(extent_op); > > return 0; > > + } else if (!run_extent_op) { > > + return 1; > > } > > + > > spin_unlock(&head->lock); > > ret = run_delayed_extent_op(trans, head, extent_op); > > btrfs_free_delayed_extent_op(extent_op); > > So if cleanup_extent_op() returns 1, then the head was unlocked, unless > run_extent_op was true. That's pretty confusing. Can we make it always > unlock in the !must_insert_reserved case? Agreed it's confusing. Possibly cleanup_extent_op can be split to two helpers instead, but the locking semantics should be made more clear.
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 4c9fd35bca07..87c42a2c45b1 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2443,18 +2443,23 @@ static void unselect_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_ref } static int cleanup_extent_op(struct btrfs_trans_handle *trans, - struct btrfs_delayed_ref_head *head) + struct btrfs_delayed_ref_head *head, + bool run_extent_op) { struct btrfs_delayed_extent_op *extent_op = head->extent_op; int ret; if (!extent_op) return 0; + head->extent_op = NULL; if (head->must_insert_reserved) { btrfs_free_delayed_extent_op(extent_op); return 0; + } else if (!run_extent_op) { + return 1; } + spin_unlock(&head->lock); ret = run_delayed_extent_op(trans, head, extent_op); btrfs_free_delayed_extent_op(extent_op); @@ -2506,7 +2511,7 @@ static int cleanup_ref_head(struct btrfs_trans_handle *trans, delayed_refs = &trans->transaction->delayed_refs; - ret = cleanup_extent_op(trans, head); + ret = cleanup_extent_op(trans, head, true); if (ret < 0) { unselect_delayed_ref_head(delayed_refs, head); btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret); @@ -6977,12 +6982,8 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, if (!RB_EMPTY_ROOT(&head->ref_tree)) goto out; - if (head->extent_op) { - if (!head->must_insert_reserved) - goto out; - btrfs_free_delayed_extent_op(head->extent_op); - head->extent_op = NULL; - } + if (cleanup_extent_op(trans, head, false)) + goto out; /* * waiting for the lock here would deadlock. If someone else has it