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Commit 897ca6e9 authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

Btrfs: restructure try_release_extent_buffer() 



restructure try_release_extent_buffer() and write a function to release the
extent buffer. It will be used later.

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent bf9022e0

fs/btrfs/extent_io.c

+37 −11
Original line number Diff line number Diff line
@@ -3104,6 +3104,39 @@ static void __free_extent_buffer(struct extent_buffer *eb) 
	kmem_cache_free(extent_buffer_cache, eb);

}



/*

 * Helper for releasing extent buffer page.

 */

static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,

						unsigned long start_idx)

{

	unsigned long index;

	struct page *page;



	if (!eb->first_page)

		return;



	index = num_extent_pages(eb->start, eb->len);

	if (start_idx >= index)

		return;



	do {

		index--;

		page = extent_buffer_page(eb, index);

		if (page)

			page_cache_release(page);

	} while (index != start_idx);

}



/*

 * Helper for releasing the extent buffer.

 */

static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)

{

	btrfs_release_extent_buffer_page(eb, 0);

	__free_extent_buffer(eb);

}



struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,

					  u64 start, unsigned long len,

					  struct page *page0,
@@ -3181,10 +3214,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, 
free_eb:

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

		return exists;

	for (index = 1; index < i; index++)

		page_cache_release(extent_buffer_page(eb, index));

	page_cache_release(extent_buffer_page(eb, 0));

	__free_extent_buffer(eb);

	btrfs_release_extent_buffer(eb);

	return exists;

}
@@ -3838,8 +3868,6 @@ int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page) 
	u64 start = page_offset(page);

	struct extent_buffer *eb;

	int ret = 1;

	unsigned long i;

	unsigned long num_pages;



	spin_lock(&tree->buffer_lock);

	eb = buffer_search(tree, start);
@@ -3854,12 +3882,10 @@ int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page) 
		ret = 0;

		goto out;

	}

	/* at this point we can safely release the extent buffer */

	num_pages = num_extent_pages(eb->start, eb->len);

	for (i = 0; i < num_pages; i++)

		page_cache_release(extent_buffer_page(eb, i));



	rb_erase(&eb->rb_node, &tree->buffer);

	__free_extent_buffer(eb);

	/* at this point we can safely release the extent buffer */

	btrfs_release_extent_buffer(eb);

out:

	spin_unlock(&tree->buffer_lock);

	return ret;