Btrfs: unlock nodes earlier when inserting items in a btree

In ctree.c:setup_items_for_insert(), we can unlock all nodes in our
path before we process the leaf (shift items and data, adjust data
offsets, etc). This allows for better btree concurrency, as we're
often holding a write lock on at least the node at level 1.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 263145b27155..bd0ae3ec76ff 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -4738,6 +4738,12 @@ void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path,
         int slot;
         struct btrfs_map_token token;
 
+        if (path->slots[0] == 0) {
+                btrfs_cpu_key_to_disk(&disk_key, cpu_key);
+                fixup_low_keys(root, path, &disk_key, 1);
+        }
+        btrfs_unlock_up_safe(path, 1);
+
         btrfs_init_map_token(&token);
 
         leaf = path->nodes[0];
@@ -4798,12 +4804,6 @@ void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path,
         }
 
         btrfs_set_header_nritems(leaf, nritems + nr);
-
-        if (slot == 0) {
-                btrfs_cpu_key_to_disk(&disk_key, cpu_key);
-                fixup_low_keys(root, path, &disk_key, 1);
-        }
-        btrfs_unlock_up_safe(path, 1);
         btrfs_mark_buffer_dirty(leaf);
 
         if (btrfs_leaf_free_space(root, leaf) < 0) {