Commit 76c0021d authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

Btrfs: use helper to simplify lock/unlock pages 



Since we have a helper to set page bits, let lock_delalloc_pages and
__unlock_for_delalloc use it.

Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent da2c7009

fs/btrfs/extent_io.c

+10 −64
Original line number Diff line number Diff line
@@ -1563,29 +1563,15 @@ static noinline void __unlock_for_delalloc(struct inode *inode, 
					   struct page *locked_page,

					   u64 start, u64 end)

{

	int ret;

	struct page *pages[16];

	unsigned long index = start >> PAGE_SHIFT;

	unsigned long end_index = end >> PAGE_SHIFT;

	unsigned long nr_pages = end_index - index + 1;

	int i;



	ASSERT(locked_page);

	if (index == locked_page->index && end_index == index)

		return;



	while (nr_pages > 0) {

		ret = find_get_pages_contig(inode->i_mapping, index,

				     min_t(unsigned long, nr_pages,

				     ARRAY_SIZE(pages)), pages);

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

			if (pages[i] != locked_page)

				unlock_page(pages[i]);

			put_page(pages[i]);

		}

		nr_pages -= ret;

		index += ret;

		cond_resched();

	}

	__process_pages_contig(inode->i_mapping, locked_page, index, end_index,

			       PAGE_UNLOCK, NULL);

}



static noinline int lock_delalloc_pages(struct inode *inode,
@@ -1594,59 +1580,19 @@ static noinline int lock_delalloc_pages(struct inode *inode, 
					u64 delalloc_end)

{

	unsigned long index = delalloc_start >> PAGE_SHIFT;

	unsigned long start_index = index;

	unsigned long index_ret = index;

	unsigned long end_index = delalloc_end >> PAGE_SHIFT;

	unsigned long pages_locked = 0;

	struct page *pages[16];

	unsigned long nrpages;

	int ret;

	int i;



	/* the caller is responsible for locking the start index */

	ASSERT(locked_page);

	if (index == locked_page->index && index == end_index)

		return 0;



	/* skip the page at the start index */

	nrpages = end_index - index + 1;

	while (nrpages > 0) {

		ret = find_get_pages_contig(inode->i_mapping, index,

				     min_t(unsigned long,

				     nrpages, ARRAY_SIZE(pages)), pages);

		if (ret == 0) {

			ret = -EAGAIN;

			goto done;

		}

		/* now we have an array of pages, lock them all */

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

			/*

			 * the caller is taking responsibility for

			 * locked_page

			 */

			if (pages[i] != locked_page) {

				lock_page(pages[i]);

				if (!PageDirty(pages[i]) ||

				    pages[i]->mapping != inode->i_mapping) {

					ret = -EAGAIN;

					unlock_page(pages[i]);

					put_page(pages[i]);

					goto done;

				}

			}

			put_page(pages[i]);

			pages_locked++;

		}

		nrpages -= ret;

		index += ret;

		cond_resched();

	}

	ret = 0;

done:

	if (ret && pages_locked) {

		__unlock_for_delalloc(inode, locked_page,

			      delalloc_start,

			      ((u64)(start_index + pages_locked - 1)) <<

			      PAGE_SHIFT);

	}

	ret = __process_pages_contig(inode->i_mapping, locked_page, index,

				     end_index, PAGE_LOCK, &index_ret);

	if (ret == -EAGAIN)

		__unlock_for_delalloc(inode, locked_page, delalloc_start,

				      (u64)index_ret << PAGE_SHIFT);

	return ret;

}