Btrfs: Defrag only leaves, and only when the parent node has a single objectid
This allows us to defrag huge directories, but skip the expensive defrag
case in more common usage, where it does not help as much.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 984f474..74fec6b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -16,6 +16,7 @@
* Boston, MA 021110-1307, USA.
*/
+#include <linux/sched.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
@@ -190,7 +191,8 @@
int btrfs_realloc_node(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *parent,
- int cache_only, u64 *last_ret)
+ int start_slot, int cache_only, u64 *last_ret,
+ struct btrfs_key *progress)
{
struct extent_buffer *cur;
struct extent_buffer *tmp;
@@ -199,7 +201,6 @@
u64 last_block = 0;
u64 other;
u32 parent_nritems;
- int start_slot;
int end_slot;
int i;
int err = 0;
@@ -221,15 +222,24 @@
parent_nritems = btrfs_header_nritems(parent);
blocksize = btrfs_level_size(root, parent_level - 1);
-
- start_slot = 0;
end_slot = parent_nritems;
if (parent_nritems == 1)
return 0;
+ if (root != root->fs_info->extent_root) {
+ struct btrfs_key first_key;
+ struct btrfs_key last_key;
+
+ btrfs_node_key_to_cpu(parent, &first_key, 0);
+ btrfs_node_key_to_cpu(parent, &last_key, parent_nritems - 1);
+ if (first_key.objectid != last_key.objectid)
+ return 0;
+ }
+
for (i = start_slot; i < end_slot; i++) {
int close = 1;
+
blocknr = btrfs_node_blockptr(parent, i);
if (last_block == 0)
last_block = blocknr;
@@ -898,7 +908,7 @@
u32 blocksize;
u32 nscan = 0;
- if (level == 0)
+ if (level != 1)
return;
if (!path->nodes[level])
@@ -2370,7 +2380,7 @@
}
/* delete the leaf if it is mostly empty */
- if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
+ if (0 && used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
/* push_leaf_left fixes the path.
* make sure the path still points to our leaf
* for possible call to del_ptr below