Btrfs: Do delalloc accounting via hooks in the extent_state code

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/extent-tree.c

@@ -2180,7 +2180,6 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
 	unsigned long last_index;
 	unsigned long i;
 	struct page *page;
-	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 	struct file_ra_state *ra;
 
@@ -2220,11 +2219,6 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
 		set_extent_delalloc(io_tree, page_start,
 				    page_end, GFP_NOFS);
 
-		spin_lock(&root->fs_info->delalloc_lock);
-		root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE -
-						 existing_delalloc;
-		spin_unlock(&root->fs_info->delalloc_lock);
-
 		unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 		set_page_dirty(page);
 		unlock_page(page);

fs/btrfs/extent_io.c

@@ -256,6 +256,26 @@ static int merge_state(struct extent_io_tree *tree,
 	return 0;
 }
 
+static void set_state_cb(struct extent_io_tree *tree,
+			 struct extent_state *state,
+			 unsigned long bits)
+{
+	if (tree->ops && tree->ops->set_bit_hook) {
+		tree->ops->set_bit_hook(tree->mapping->host, state->start,
+					state->end, bits);
+	}
+}
+
+static void clear_state_cb(struct extent_io_tree *tree,
+			   struct extent_state *state,
+			   unsigned long bits)
+{
+	if (tree->ops && tree->ops->set_bit_hook) {
+		tree->ops->clear_bit_hook(tree->mapping->host, state->start,
+					  state->end, bits);
+	}
+}
+
 /*
  * insert an extent_state struct into the tree.  'bits' are set on the
  * struct before it is inserted.
@@ -281,6 +301,7 @@ static int insert_state(struct extent_io_tree *tree,
 	state->state |= bits;
 	state->start = start;
 	state->end = end;
+	set_state_cb(tree, state, bits);
 	node = tree_insert(&tree->state, end, &state->rb_node);
 	if (node) {
 		struct extent_state *found;
@@ -349,6 +370,7 @@ static int clear_state_bit(struct extent_io_tree *tree,
 		tree->dirty_bytes -= range;
 	}
 	state->state &= ~bits;
+	clear_state_cb(tree, state, bits);
 	if (wake)
 		wake_up(&state->wq);
 	if (delete || state->state == 0) {
@@ -553,6 +575,7 @@ static void set_state_bits(struct extent_io_tree *tree,
 		tree->dirty_bytes += range;
 	}
 	state->state |= bits;
+	set_state_cb(tree, state, bits);
 }
 
 /*
@@ -975,6 +998,7 @@ u64 find_lock_delalloc_range(struct extent_io_tree *tree,
 			goto search_again;
 		}
 		state->state |= EXTENT_LOCKED;
+		set_state_cb(tree, state, EXTENT_LOCKED);
 		if (!found)
 			*start = state->start;
 		found++;
@@ -1474,6 +1498,7 @@ static int end_bio_extent_readpage(struct bio *bio,
 				state = NULL;
 			}
 			clear->state |= EXTENT_UPTODATE;
+			set_state_cb(tree, clear, EXTENT_UPTODATE);
 			clear_state_bit(tree, clear, EXTENT_LOCKED,
 					1, 0);
 			if (cur == start)

fs/btrfs/extent_io.h

@@ -33,6 +33,10 @@ struct extent_io_ops {
 				    struct extent_state *state);
 	void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
 				      struct extent_state *state);
+	int (*set_bit_hook)(struct inode *inode, u64 start, u64 end,
+			    unsigned long bits);
+	int (*clear_bit_hook)(struct inode *inode, u64 start, u64 end,
+			    unsigned long bits);
 };
 
 struct extent_io_tree {

fs/btrfs/file.c

@@ -323,10 +323,6 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
 		}
 		set_extent_delalloc(io_tree, start_pos, end_of_last_block,
 				 GFP_NOFS);
-		spin_lock(&root->fs_info->delalloc_lock);
-		root->fs_info->delalloc_bytes += (end_of_last_block + 1 -
-					  start_pos) - existing_delalloc;
-		spin_unlock(&root->fs_info->delalloc_lock);
 		btrfs_add_ordered_inode(inode);
 	} else {
 		u64 aligned_end;

fs/btrfs/inode.c

@@ -80,8 +80,6 @@ int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
 	u64 thresh;
 	int ret = 0;
 
-	return 0;
-
 	if (for_del)
 		thresh = total * 90;
 	else
@@ -249,7 +247,6 @@ static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 num_bytes;
 	int ret;
 	mutex_lock(&root->fs_info->fs_mutex);
 	if (btrfs_test_opt(root, NODATACOW) ||
@@ -258,20 +255,34 @@ static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
 	else
 		ret = cow_file_range(inode, start, end);
 
-	spin_lock(&root->fs_info->delalloc_lock);
-	num_bytes = end + 1 - start;
-	if (root->fs_info->delalloc_bytes < num_bytes) {
-		printk("delalloc accounting error total %llu sub %llu\n",
-		       root->fs_info->delalloc_bytes, num_bytes);
-	} else {
-		root->fs_info->delalloc_bytes -= num_bytes;
-	}
-	spin_unlock(&root->fs_info->delalloc_lock);
-
 	mutex_unlock(&root->fs_info->fs_mutex);
 	return ret;
 }
 
+int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
+		       unsigned long bits)
+{
+	if ((bits & EXTENT_DELALLOC)) {
+		struct btrfs_root *root = BTRFS_I(inode)->root;
+		spin_lock(&root->fs_info->delalloc_lock);
+		root->fs_info->delalloc_bytes += end - start + 1;
+		spin_unlock(&root->fs_info->delalloc_lock);
+	}
+	return 0;
+}
+
+int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
+			 unsigned long bits)
+{
+	if ((bits & EXTENT_DELALLOC)) {
+		struct btrfs_root *root = BTRFS_I(inode)->root;
+		spin_lock(&root->fs_info->delalloc_lock);
+		root->fs_info->delalloc_bytes -= end - start + 1;
+		spin_unlock(&root->fs_info->delalloc_lock);
+	}
+	return 0;
+}
+
 int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
 {
 	struct inode *inode = page->mapping->host;
@@ -908,28 +919,17 @@ static int btrfs_cow_one_page(struct inode *inode, struct page *page,
 {
 	char *kaddr;
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
-	struct btrfs_root *root = BTRFS_I(inode)->root;
 	u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 	u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
-	u64 existing_delalloc;
-	u64 delalloc_start;
 	int ret = 0;
 
 	WARN_ON(!PageLocked(page));
 	set_page_extent_mapped(page);
 
 	lock_extent(io_tree, page_start, page_end, GFP_NOFS);
-	delalloc_start = page_start;
-	existing_delalloc = count_range_bits(&BTRFS_I(inode)->io_tree,
-					     &delalloc_start, page_end,
-					     PAGE_CACHE_SIZE, EXTENT_DELALLOC);
 	set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start,
 			    page_end, GFP_NOFS);
 
-	spin_lock(&root->fs_info->delalloc_lock);
-	root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE - existing_delalloc;
-	spin_unlock(&root->fs_info->delalloc_lock);
-
 	if (zero_start != PAGE_CACHE_SIZE) {
 		kaddr = kmap(page);
 		memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
@@ -2456,8 +2456,6 @@ int btrfs_defrag_file(struct file *file) {
 	unsigned long ra_index = 0;
 	u64 page_start;
 	u64 page_end;
-	u64 delalloc_start;
-	u64 existing_delalloc;
 	unsigned long i;
 	int ret;
 
@@ -2491,19 +2489,9 @@ int btrfs_defrag_file(struct file *file) {
 		page_end = page_start + PAGE_CACHE_SIZE - 1;
 
 		lock_extent(io_tree, page_start, page_end, GFP_NOFS);
-		delalloc_start = page_start;
-		existing_delalloc =
-			count_range_bits(&BTRFS_I(inode)->io_tree,
-					 &delalloc_start, page_end,
-					 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
 		set_extent_delalloc(io_tree, page_start,
 				    page_end, GFP_NOFS);
 
-		spin_lock(&root->fs_info->delalloc_lock);
-		root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE -
-						 existing_delalloc;
-		spin_unlock(&root->fs_info->delalloc_lock);
-
 		unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 		set_page_dirty(page);
 		unlock_page(page);