Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs changes from Chris Mason:
 "This is a pretty long stream of bug fixes and performance fixes.

  Qu Wenruo has replaced the btrfs async threads with regular kernel
  workqueues.  We'll keep an eye out for performance differences, but
  it's nice to be using more generic code for this.

  We still have some corruption fixes and other patches coming in for
  the merge window, but this batch is tested and ready to go"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (108 commits)
  Btrfs: fix a crash of clone with inline extents's split
  btrfs: fix uninit variable warning
  Btrfs: take into account total references when doing backref lookup
  Btrfs: part 2, fix incremental send's decision to delay a dir move/rename
  Btrfs: fix incremental send's decision to delay a dir move/rename
  Btrfs: remove unnecessary inode generation lookup in send
  Btrfs: fix race when updating existing ref head
  btrfs: Add trace for btrfs_workqueue alloc/destroy
  Btrfs: less fs tree lock contention when using autodefrag
  Btrfs: return EPERM when deleting a default subvolume
  Btrfs: add missing kfree in btrfs_destroy_workqueue
  Btrfs: cache extent states in defrag code path
  Btrfs: fix deadlock with nested trans handles
  Btrfs: fix possible empty list access when flushing the delalloc inodes
  Btrfs: split the global ordered extents mutex
  Btrfs: don't flush all delalloc inodes when we doesn't get s_umount lock
  Btrfs: reclaim delalloc metadata more aggressively
  Btrfs: remove unnecessary lock in may_commit_transaction()
  Btrfs: remove the unnecessary flush when preparing the pages
  Btrfs: just do dirty page flush for the inode with compression before direct IO
  ...

1 files changed, 8 insertions, 21 deletions

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index f3bff89eecf..31299646024 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -199,44 +199,31 @@ static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
  */
 static struct btrfs_delayed_ref_head *
 find_ref_head(struct rb_root *root, u64 bytenr,
-	      struct btrfs_delayed_ref_head **last, int return_bigger)
+	      int return_bigger)
 {
 	struct rb_node *n;
 	struct btrfs_delayed_ref_head *entry;
-	int cmp = 0;
 
-again:
 	n = root->rb_node;
 	entry = NULL;
 	while (n) {
 		entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
-		if (last)
-			*last = entry;
 
 		if (bytenr < entry->node.bytenr)
-			cmp = -1;
-		else if (bytenr > entry->node.bytenr)
-			cmp = 1;
-		else
-			cmp = 0;
-
-		if (cmp < 0)
 			n = n->rb_left;
-		else if (cmp > 0)
+		else if (bytenr > entry->node.bytenr)
 			n = n->rb_right;
 		else
 			return entry;
 	}
 	if (entry && return_bigger) {
-		if (cmp > 0) {
+		if (bytenr > entry->node.bytenr) {
 			n = rb_next(&entry->href_node);
 			if (!n)
 				n = rb_first(root);
 			entry = rb_entry(n, struct btrfs_delayed_ref_head,
 					 href_node);
-			bytenr = entry->node.bytenr;
-			return_bigger = 0;
-			goto again;
+			return entry;
 		}
 		return entry;
 	}
@@ -415,12 +402,12 @@ btrfs_select_ref_head(struct btrfs_trans_handle *trans)
 
 again:
 	start = delayed_refs->run_delayed_start;
-	head = find_ref_head(&delayed_refs->href_root, start, NULL, 1);
+	head = find_ref_head(&delayed_refs->href_root, start, 1);
 	if (!head && !loop) {
 		delayed_refs->run_delayed_start = 0;
 		start = 0;
 		loop = true;
-		head = find_ref_head(&delayed_refs->href_root, start, NULL, 1);
+		head = find_ref_head(&delayed_refs->href_root, start, 1);
 		if (!head)
 			return NULL;
 	} else if (!head && loop) {
@@ -508,6 +495,7 @@ update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
 	ref = btrfs_delayed_node_to_head(update);
 	BUG_ON(existing_ref->is_data != ref->is_data);
 
+	spin_lock(&existing_ref->lock);
 	if (ref->must_insert_reserved) {
 		/* if the extent was freed and then
 		 * reallocated before the delayed ref
@@ -549,7 +537,6 @@ update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
 	 * only need the lock for this case cause we could be processing it
 	 * currently, for refs we just added we know we're a-ok.
 	 */
-	spin_lock(&existing_ref->lock);
 	existing->ref_mod += update->ref_mod;
 	spin_unlock(&existing_ref->lock);
 }
@@ -898,7 +885,7 @@ btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
 	struct btrfs_delayed_ref_root *delayed_refs;
 
 	delayed_refs = &trans->transaction->delayed_refs;
-	return find_ref_head(&delayed_refs->href_root, bytenr, NULL, 0);
+	return find_ref_head(&delayed_refs->href_root, bytenr, 0);
 }
 
 void btrfs_delayed_ref_exit(void)