Commit 09be207d authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Fix failure cleanups when allocating extent buffers fail 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 0da5468f

fs/btrfs/extent_map.c

+30 −26
Original line number Diff line number Diff line
@@ -2106,25 +2106,17 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 


	spin_lock(&tree->lru_lock);

	eb = find_lru(tree, start, len);

	spin_unlock(&tree->lru_lock);

	if (eb) {

		goto lru_add;

		return eb;

	}

	spin_unlock(&tree->lru_lock);



	if (eb) {

		memset(eb, 0, sizeof(*eb));

	} else {

	eb = kmem_cache_zalloc(extent_buffer_cache, mask);

	}

	INIT_LIST_HEAD(&eb->lru);

	eb->start = start;

	eb->len = len;

	atomic_set(&eb->refs, 1);



	spin_lock(&tree->lru_lock);

lru_add:

	add_lru(tree, eb);

	spin_unlock(&tree->lru_lock);

	return eb;

}
@@ -2151,7 +2143,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 
		return NULL;



	if (eb->flags & EXTENT_BUFFER_FILLED)

		return eb;

		goto lru_add;



	if (page0) {

		eb->first_page = page0;
@@ -2169,11 +2161,6 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 
		p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);

		if (!p) {

			WARN_ON(1);

			/* make sure the free only frees the pages we've

			 * grabbed a reference on

			 */

			eb->len = i << PAGE_CACHE_SHIFT;

			eb->start &= ~((u64)PAGE_CACHE_SIZE - 1);

			goto fail;

		}

		set_page_extent_mapped(p);
@@ -2192,9 +2179,20 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 
	if (uptodate)

		eb->flags |= EXTENT_UPTODATE;

	eb->flags |= EXTENT_BUFFER_FILLED;



lru_add:

	spin_lock(&tree->lru_lock);

	add_lru(tree, eb);

	spin_unlock(&tree->lru_lock);

	return eb;



fail:

	free_extent_buffer(eb);

	if (!atomic_dec_and_test(&eb->refs))

		return NULL;

	for (index = 0; index < i; index++) {

		page_cache_release(extent_buffer_page(eb, index));

	}

	__free_extent_buffer(eb);

	return NULL;

}

EXPORT_SYMBOL(alloc_extent_buffer);
@@ -2204,7 +2202,8 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 
					  gfp_t mask)

{

	unsigned long num_pages = num_extent_pages(start, len);

	unsigned long i; unsigned long index = start >> PAGE_CACHE_SHIFT;

	unsigned long i;

	unsigned long index = start >> PAGE_CACHE_SHIFT;

	struct extent_buffer *eb;

	struct page *p;

	struct address_space *mapping = tree->mapping;
@@ -2215,16 +2214,11 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 
		return NULL;



	if (eb->flags & EXTENT_BUFFER_FILLED)

		return eb;

		goto lru_add;



	for (i = 0; i < num_pages; i++, index++) {

		p = find_lock_page(mapping, index);

		if (!p) {

			/* make sure the free only frees the pages we've

			 * grabbed a reference on

			 */

			eb->len = i << PAGE_CACHE_SHIFT;

			eb->start &= ~((u64)PAGE_CACHE_SIZE - 1);

			goto fail;

		}

		set_page_extent_mapped(p);
@@ -2245,9 +2239,19 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 
	if (uptodate)

		eb->flags |= EXTENT_UPTODATE;

	eb->flags |= EXTENT_BUFFER_FILLED;



lru_add:

	spin_lock(&tree->lru_lock);

	add_lru(tree, eb);

	spin_unlock(&tree->lru_lock);

	return eb;

fail:

	free_extent_buffer(eb);

	if (!atomic_dec_and_test(&eb->refs))

		return NULL;

	for (index = 0; index < i; index++) {

		page_cache_release(extent_buffer_page(eb, index));

	}

	__free_extent_buffer(eb);

	return NULL;

}

EXPORT_SYMBOL(find_extent_buffer);