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>

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>
Chris Mason
1 parent 18f16f7ba6
Showing 2 changed files with 26 additions and 44 deletions Side-by-side Diff
fs/btrfs/ctree.c
fs/btrfs/tree-defrag.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;
  
@@ -287,10 +264,16 @@
 			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;
 }
@@ -183,7 +183,6 @@
 	if (level == 0) {
 		goto out;
 	}
-
 	if (root->defrag_progress.objectid == 0) {
 		extent_buffer_get(root->node);
 		ret = btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
...	...	@@ -161,34 +161,6 @@
161	161	return 0;
162	162	}
163	163
164		-static int should_defrag_leaf(struct extent_buffer *leaf)
165		-{
166		- struct btrfs_key key;
167		- u32 nritems;
168		-
169		- if (btrfs_buffer_defrag(leaf))
170		- return 1;
171		-
172		- nritems = btrfs_header_nritems(leaf);
173		- if (nritems == 0)
174		- return 0;
175		-
176		- btrfs_item_key_to_cpu(leaf, &key, 0);
177		- if (key.type == BTRFS_DIR_ITEM_KEY)
178		- return 1;
179		-
180		-
181		- btrfs_item_key_to_cpu(leaf, &key, nritems - 1);
182		- if (key.type == BTRFS_DIR_ITEM_KEY)
183		- return 1;
184		- if (nritems > 4) {
185		- btrfs_item_key_to_cpu(leaf, &key, nritems / 2);
186		- if (key.type == BTRFS_DIR_ITEM_KEY)
187		- return 1;
188		- }
189		- return 0;
190		-}
191		-
192	164	int btrfs_realloc_node(struct btrfs_trans_handle *trans,
193	165	struct btrfs_root root, struct extent_buffer parent,
194	166	int start_slot, int cache_only, u64 *last_ret,
...	...	@@ -208,6 +180,10 @@
208	180	int uptodate;
209	181	u32 blocksize;
210	182
	183	+ parent_level = btrfs_header_level(parent);
	184	+ if (cache_only && parent_level != 1)
	185	+ return 0;
	186	+
211	187	if (trans->transaction != root->fs_info->running_transaction) {
212	188	printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
213	189	root->fs_info->running_transaction->transid);
...	...	@@ -218,7 +194,6 @@
218	194	root->fs_info->generation);
219	195	WARN_ON(1);
220	196	}
221		- parent_level = btrfs_header_level(parent);
222	197
223	198	parent_nritems = btrfs_header_nritems(parent);
224	199	blocksize = btrfs_level_size(root, parent_level - 1);
225	200
226	201
227	202
...	...	@@ -227,27 +202,26 @@
227	202	if (parent_nritems == 1)
228	203	return 0;
229	204
230		- if (root != root->fs_info->extent_root) {
231		- struct btrfs_key first_key;
232		- struct btrfs_key last_key;
233		-
234		- btrfs_node_key_to_cpu(parent, &first_key, 0);
235		- btrfs_node_key_to_cpu(parent, &last_key, parent_nritems - 1);
236		- if (first_key.objectid != last_key.objectid)
237		- return 0;
238		- }
239		-
240	205	for (i = start_slot; i < end_slot; i++) {
241	206	int close = 1;
242	207
	208	+ if (!parent->map_token) {
	209	+ map_extent_buffer(parent,
	210	+ btrfs_node_key_ptr_offset(i),
	211	+ sizeof(struct btrfs_key_ptr),
	212	+ &parent->map_token, &parent->kaddr,
	213	+ &parent->map_start, &parent->map_len,
	214	+ KM_USER1);
	215	+ }
243	216	blocknr = btrfs_node_blockptr(parent, i);
244	217	if (last_block == 0)
245	218	last_block = blocknr;
	219	+
246	220	if (i > 0) {
247	221	other = btrfs_node_blockptr(parent, i - 1);
248	222	close = close_blocks(blocknr, other, blocksize);
249	223	}
250		- if (close && i < end_slot - 1) {
	224	+ if (close && i < end_slot - 2) {
251	225	other = btrfs_node_blockptr(parent, i + 1);
252	226	close = close_blocks(blocknr, other, blocksize);
253	227	}
254	228
...	...	@@ -255,15 +229,18 @@
255	229	last_block = blocknr;
256	230	continue;
257	231	}
	232	+ if (parent->map_token) {
	233	+ unmap_extent_buffer(parent, parent->map_token,
	234	+ KM_USER1);
	235	+ parent->map_token = NULL;
	236	+ }
258	237
259	238	cur = btrfs_find_tree_block(root, blocknr, blocksize);
260	239	if (cur)
261	240	uptodate = btrfs_buffer_uptodate(cur);
262	241	else
263	242	uptodate = 0;
264		- if (!cur \|\| !uptodate \|\|
265		- (parent_level != 1 && !btrfs_buffer_defrag(cur)) \|\|
266		- (parent_level == 1 && !should_defrag_leaf(cur))) {
	243	+ if (!cur \|\| !uptodate) {
267	244	if (cache_only) {
268	245	free_extent_buffer(cur);
269	246	continue;
270	247
...	...	@@ -287,10 +264,16 @@
287	264	break;
288	265	}
289	266	search_start = tmp->start;
	267	+ last_block = tmp->start;
290	268	*last_ret = search_start;
291	269	if (parent_level == 1)
292	270	btrfs_clear_buffer_defrag(tmp);
293	271	free_extent_buffer(tmp);
	272	+ }
	273	+ if (parent->map_token) {
	274	+ unmap_extent_buffer(parent, parent->map_token,
	275	+ KM_USER1);
	276	+ parent->map_token = NULL;
294	277	}
295	278	return err;
296	279	}
...	...	@@ -183,7 +183,6 @@
183	183	if (level == 0) {
184	184	goto out;
185	185	}
186		-
187	186	if (root->defrag_progress.objectid == 0) {
188	187	extent_buffer_get(root->node);
189	188	ret = btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);