btrfs: move open coded extent map tree deletion out of inode eviction

Move the loop that removes all the extent maps from the inode's extent
map tree during inode eviction out of inode.c and into extent_map.c, to
btrfs_drop_extent_map_range(). Anything manipulating extent maps or the
extent map tree should be in extent_map.c.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

2 files changed, 28 insertions, 14 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 28c5e0243adc..7376c0aa2bca 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -661,6 +661,29 @@ int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
 }
 
 /*
+ * Drop all extent maps from a tree in the fastest possible way, rescheduling
+ * if needed. This avoids searching the tree, from the root down to the first
+ * extent map, before each deletion.
+ */
+static void drop_all_extent_maps_fast(struct extent_map_tree *tree)
+{
+	write_lock(&tree->lock);
+	while (!RB_EMPTY_ROOT(&tree->map.rb_root)) {
+		struct extent_map *em;
+		struct rb_node *node;
+
+		node = rb_first_cached(&tree->map);
+		em = rb_entry(node, struct extent_map, rb_node);
+		clear_bit(EXTENT_FLAG_PINNED, &em->flags);
+		clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
+		remove_extent_mapping(tree, em);
+		free_extent_map(em);
+		cond_resched_rwlock_write(&tree->lock);
+	}
+	write_unlock(&tree->lock);
+}
+
+/*
  * Drop all extent maps in a given range.
  *
  * @inode:       The target inode.
@@ -685,6 +708,10 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end,
 
 	WARN_ON(end < start);
 	if (end == (u64)-1) {
+		if (start == 0 && !skip_pinned) {
+			drop_all_extent_maps_fast(em_tree);
+			return;
+		}
 		len = (u64)-1;
 		testend = false;
 	}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 491c2b7f48bf..cbf920eba69c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5289,25 +5289,12 @@ static int btrfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentr
 static void evict_inode_truncate_pages(struct inode *inode)
 {
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
-	struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
 	struct rb_node *node;
 
 	ASSERT(inode->i_state & I_FREEING);
 	truncate_inode_pages_final(&inode->i_data);
 
-	write_lock(&map_tree->lock);
-	while (!RB_EMPTY_ROOT(&map_tree->map.rb_root)) {
-		struct extent_map *em;
-
-		node = rb_first_cached(&map_tree->map);
-		em = rb_entry(node, struct extent_map, rb_node);
-		clear_bit(EXTENT_FLAG_PINNED, &em->flags);
-		clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
-		remove_extent_mapping(map_tree, em);
-		free_extent_map(em);
-		cond_resched_rwlock_write(&map_tree->lock);
-	}
-	write_unlock(&map_tree->lock);
+	btrfs_drop_extent_map_range(BTRFS_I(inode), 0, (u64)-1, false);
 
 	/*
 	 * Keep looping until we have no more ranges in the io tree.