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
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1af0a96..37bccb1 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -913,7 +913,8 @@
ins_len, int cow);
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);
void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
struct btrfs_path *btrfs_alloc_path(void);
void btrfs_free_path(struct btrfs_path *p);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 67e4aca..bdfe05c 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -353,7 +353,6 @@
if (root->defrag_running)
return 0;
-
trans = btrfs_start_transaction(root, 1);
while (1) {
root->defrag_running = 1;
@@ -361,7 +360,6 @@
nr = trans->blocks_used;
btrfs_end_transaction(trans, root);
mutex_unlock(&info->fs_mutex);
-
btrfs_btree_balance_dirty(info->tree_root, nr);
cond_resched();
diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c
index f86eccf..b02355a 100644
--- a/fs/btrfs/tree-defrag.c
+++ b/fs/btrfs/tree-defrag.c
@@ -76,7 +76,9 @@
if (*level == 1) {
ret = btrfs_realloc_node(trans, root,
path->nodes[*level],
- cache_only, last_ret);
+ path->slots[*level],
+ cache_only, last_ret,
+ &root->defrag_progress);
if (is_extent)
btrfs_extent_post_op(trans, root);
@@ -100,10 +102,6 @@
ret = btrfs_cow_block(trans, root, next, path->nodes[*level],
path->slots[*level], &next);
BUG_ON(ret);
- ret = btrfs_realloc_node(trans, root, next, cache_only,
- last_ret);
- BUG_ON(ret);
-
if (is_extent)
btrfs_extent_post_op(trans, root);
@@ -122,8 +120,8 @@
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level += 1;
- WARN_ON(ret);
- return 0;
+ WARN_ON(ret && ret != -EAGAIN);
+ return ret;
}
static int defrag_walk_up(struct btrfs_trans_handle *trans,
@@ -147,27 +145,6 @@
root->defrag_level = i;
return 0;
} else {
- if (*level > 1 && path->nodes[*level] != root->node &&
- btrfs_buffer_defrag(path->nodes[*level])) {
- struct extent_buffer *next;
- u64 last;
- int ret;
- ret = btrfs_cow_block(trans, root,
- path->nodes[*level],
- path->nodes[*level + 1],
- path->slots[*level + 1],
- &next);
- BUG_ON(ret);
- path->nodes[*level] = next;
- last = next->start;
- ret = btrfs_realloc_node(trans, root, next,
- cache_only, &last);
- BUG_ON(ret);
-
- if (root == root->fs_info->extent_root)
- btrfs_extent_post_op(trans, root);
- }
-
btrfs_clear_buffer_defrag(path->nodes[*level]);
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
@@ -211,9 +188,6 @@
extent_buffer_get(root->node);
ret = btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
BUG_ON(ret);
- ret = btrfs_realloc_node(trans, root, root->node, cache_only,
- &last_ret);
- BUG_ON(ret);
path->nodes[level] = root->node;
path->slots[level] = 0;
if (is_extent)