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

Pull btrfs fixes from Chris Mason:
 "This is a small pull with btrfs fixes.  The biggest of the bunch is
  another fix for the new backref walking code.

  We're still hammering out one btrfs dio vs buffered reads problem, but
  that one will have to wait for the next rc."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: delay iput with async extents
  Btrfs: add a missing spin_lock
  Btrfs: don't assume to be on the correct extent in add_all_parents
  Btrfs: introduce btrfs_next_old_item

4 files changed, 62 insertions, 46 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 8f7d1237b7a..7301cdb4b2c 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -179,61 +179,74 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id,
 
 static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
 				struct ulist *parents, int level,
-				struct btrfs_key *key, u64 time_seq,
+				struct btrfs_key *key_for_search, u64 time_seq,
 				u64 wanted_disk_byte,
 				const u64 *extent_item_pos)
 {
-	int ret;
-	int slot = path->slots[level];
-	struct extent_buffer *eb = path->nodes[level];
+	int ret = 0;
+	int slot;
+	struct extent_buffer *eb;
+	struct btrfs_key key;
 	struct btrfs_file_extent_item *fi;
 	struct extent_inode_elem *eie = NULL;
 	u64 disk_byte;
-	u64 wanted_objectid = key->objectid;
 
-add_parent:
-	if (level == 0 && extent_item_pos) {
-		fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
-		ret = check_extent_in_eb(key, eb, fi, *extent_item_pos, &eie);
+	if (level != 0) {
+		eb = path->nodes[level];
+		ret = ulist_add(parents, eb->start, 0, GFP_NOFS);
 		if (ret < 0)
 			return ret;
-	}
-	ret = ulist_add(parents, eb->start, (unsigned long)eie, GFP_NOFS);
-	if (ret < 0)
-		return ret;
-
-	if (level != 0)
 		return 0;
+	}
 
 	/*
-	 * if the current leaf is full with EXTENT_DATA items, we must
-	 * check the next one if that holds a reference as well.
-	 * ref->count cannot be used to skip this check.
-	 * repeat this until we don't find any additional EXTENT_DATA items.
+	 * We normally enter this function with the path already pointing to
+	 * the first item to check. But sometimes, we may enter it with
+	 * slot==nritems. In that case, go to the next leaf before we continue.
 	 */
-	while (1) {
-		eie = NULL;
+	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0]))
 		ret = btrfs_next_old_leaf(root, path, time_seq);
-		if (ret < 0)
-			return ret;
-		if (ret)
-			return 0;
 
+	while (!ret) {
 		eb = path->nodes[0];
-		for (slot = 0; slot < btrfs_header_nritems(eb); ++slot) {
-			btrfs_item_key_to_cpu(eb, key, slot);
-			if (key->objectid != wanted_objectid ||
-			    key->type != BTRFS_EXTENT_DATA_KEY)
-				return 0;
-			fi = btrfs_item_ptr(eb, slot,
-						struct btrfs_file_extent_item);
-			disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
-			if (disk_byte == wanted_disk_byte)
-				goto add_parent;
+		slot = path->slots[0];
+
+		btrfs_item_key_to_cpu(eb, &key, slot);
+
+		if (key.objectid != key_for_search->objectid ||
+		    key.type != BTRFS_EXTENT_DATA_KEY)
+			break;
+
+		fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
+		disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
+
+		if (disk_byte == wanted_disk_byte) {
+			eie = NULL;
+			if (extent_item_pos) {
+				ret = check_extent_in_eb(&key, eb, fi,
+						*extent_item_pos,
+						&eie);
+				if (ret < 0)
+					break;
+			}
+			if (!ret) {
+				ret = ulist_add(parents, eb->start,
+						(unsigned long)eie, GFP_NOFS);
+				if (ret < 0)
+					break;
+				if (!extent_item_pos) {
+					ret = btrfs_next_old_leaf(root, path,
+							time_seq);
+					continue;
+				}
+			}
 		}
+		ret = btrfs_next_old_item(root, path, time_seq);
 	}
 
-	return 0;
+	if (ret > 0)
+		ret = 0;
+	return ret;
 }
 
 /*
@@ -250,7 +263,6 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 	struct btrfs_path *path;
 	struct btrfs_root *root;
 	struct btrfs_key root_key;
-	struct btrfs_key key = {0};
 	struct extent_buffer *eb;
 	int ret = 0;
 	int root_level;
@@ -295,11 +307,9 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 		goto out;
 	}
 
-	if (level == 0)
-		btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
-
-	ret = add_all_parents(root, path, parents, level, &key, time_seq,
-				ref->wanted_disk_byte, extent_item_pos);
+	ret = add_all_parents(root, path, parents, level, &ref->key_for_search,
+				time_seq, ref->wanted_disk_byte,
+				extent_item_pos);
 out:
 	btrfs_free_path(path);
 	return ret;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8b73b2d4deb..fa5c45b3907 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2755,13 +2755,18 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 			u64 time_seq);
-static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
+static inline int btrfs_next_old_item(struct btrfs_root *root,
+				      struct btrfs_path *p, u64 time_seq)
 {
 	++p->slots[0];
 	if (p->slots[0] >= btrfs_header_nritems(p->nodes[0]))
-		return btrfs_next_leaf(root, p);
+		return btrfs_next_old_leaf(root, p, time_seq);
 	return 0;
 }
+static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
+{
+	return btrfs_next_old_item(root, p, 0);
+}
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);
 int __must_check btrfs_drop_snapshot(struct btrfs_root *root,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e1890b1d307..7b845ff4af9 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3426,6 +3426,7 @@ int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 				mutex_unlock(&head->mutex);
 				btrfs_put_delayed_ref(ref);
 
+				spin_lock(&delayed_refs->lock);
 				continue;
 			}
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a4f02501da4..d8bb0dbc494 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -987,7 +987,7 @@ static noinline void async_cow_start(struct btrfs_work *work)
 			    async_cow->start, async_cow->end, async_cow,
 			    &num_added);
 	if (num_added == 0) {
-		iput(async_cow->inode);
+		btrfs_add_delayed_iput(async_cow->inode);
 		async_cow->inode = NULL;
 	}
 }
@@ -1023,7 +1023,7 @@ static noinline void async_cow_free(struct btrfs_work *work)
 	struct async_cow *async_cow;
 	async_cow = container_of(work, struct async_cow, work);
 	if (async_cow->inode)
-		iput(async_cow->inode);
+		btrfs_add_delayed_iput(async_cow->inode);
 	kfree(async_cow);
 }