Btrfs: Tune the automatic defrag code
1) Forced defrag wasn't working properly (btrfsctl -d) because some
cache only checks were incorrect.
2) Defrag only the leaves unless in forced defrag mode.
3) Don't use complex logic to figure out if a leaf is needs defrag
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 3eb5a9f..516b902 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -161,34 +161,6 @@
return 0;
}
-static int should_defrag_leaf(struct extent_buffer *leaf)
-{
- struct btrfs_key key;
- u32 nritems;
-
- if (btrfs_buffer_defrag(leaf))
- return 1;
-
- nritems = btrfs_header_nritems(leaf);
- if (nritems == 0)
- return 0;
-
- btrfs_item_key_to_cpu(leaf, &key, 0);
- if (key.type == BTRFS_DIR_ITEM_KEY)
- return 1;
-
-
- btrfs_item_key_to_cpu(leaf, &key, nritems - 1);
- if (key.type == BTRFS_DIR_ITEM_KEY)
- return 1;
- if (nritems > 4) {
- btrfs_item_key_to_cpu(leaf, &key, nritems / 2);
- if (key.type == BTRFS_DIR_ITEM_KEY)
- return 1;
- }
- return 0;
-}
-
int btrfs_realloc_node(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *parent,
int start_slot, int cache_only, u64 *last_ret,
@@ -208,6 +180,10 @@
int uptodate;
u32 blocksize;
+ parent_level = btrfs_header_level(parent);
+ if (cache_only && parent_level != 1)
+ return 0;
+
if (trans->transaction != root->fs_info->running_transaction) {
printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
root->fs_info->running_transaction->transid);
@@ -218,7 +194,6 @@
root->fs_info->generation);
WARN_ON(1);
}
- parent_level = btrfs_header_level(parent);
parent_nritems = btrfs_header_nritems(parent);
blocksize = btrfs_level_size(root, parent_level - 1);
@@ -227,27 +202,26 @@
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;
+ if (!parent->map_token) {
+ map_extent_buffer(parent,
+ btrfs_node_key_ptr_offset(i),
+ sizeof(struct btrfs_key_ptr),
+ &parent->map_token, &parent->kaddr,
+ &parent->map_start, &parent->map_len,
+ KM_USER1);
+ }
blocknr = btrfs_node_blockptr(parent, i);
if (last_block == 0)
last_block = blocknr;
+
if (i > 0) {
other = btrfs_node_blockptr(parent, i - 1);
close = close_blocks(blocknr, other, blocksize);
}
- if (close && i < end_slot - 1) {
+ if (close && i < end_slot - 2) {
other = btrfs_node_blockptr(parent, i + 1);
close = close_blocks(blocknr, other, blocksize);
}
@@ -255,15 +229,18 @@
last_block = blocknr;
continue;
}
+ if (parent->map_token) {
+ unmap_extent_buffer(parent, parent->map_token,
+ KM_USER1);
+ parent->map_token = NULL;
+ }
cur = btrfs_find_tree_block(root, blocknr, blocksize);
if (cur)
uptodate = btrfs_buffer_uptodate(cur);
else
uptodate = 0;
- if (!cur || !uptodate ||
- (parent_level != 1 && !btrfs_buffer_defrag(cur)) ||
- (parent_level == 1 && !should_defrag_leaf(cur))) {
+ if (!cur || !uptodate) {
if (cache_only) {
free_extent_buffer(cur);
continue;
@@ -287,11 +264,17 @@
break;
}
search_start = tmp->start;
+ last_block = tmp->start;
*last_ret = search_start;
if (parent_level == 1)
btrfs_clear_buffer_defrag(tmp);
free_extent_buffer(tmp);
}
+ if (parent->map_token) {
+ unmap_extent_buffer(parent, parent->map_token,
+ KM_USER1);
+ parent->map_token = NULL;
+ }
return err;
}
