Commit da2c7009 authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

btrfs: teach __process_pages_contig about PAGE_LOCK operation 



Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
[ changes to the helper separated from the following patch ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 873695b3

fs/btrfs/extent_io.c

+42 −6
Original line number Diff line number Diff line
@@ -1554,6 +1554,11 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree, 
	return found;

}



static int __process_pages_contig(struct address_space *mapping,

				  struct page *locked_page,

				  pgoff_t start_index, pgoff_t end_index,

				  unsigned long page_ops, pgoff_t *index_ret);



static noinline void __unlock_for_delalloc(struct inode *inode,

					   struct page *locked_page,

					   u64 start, u64 end)
@@ -1731,17 +1736,24 @@ STATIC u64 find_lock_delalloc_range(struct inode *inode, 
	return found;

}



static void __process_pages_contig(struct address_space *mapping,

static int __process_pages_contig(struct address_space *mapping,

				  struct page *locked_page,

				  pgoff_t start_index, pgoff_t end_index,

				   unsigned long page_ops)

				  unsigned long page_ops, pgoff_t *index_ret)

{

	unsigned long nr_pages = end_index - start_index + 1;

	unsigned long pages_locked = 0;

	pgoff_t index = start_index;

	struct page *pages[16];

	unsigned ret;

	int err = 0;

	int i;



	if (page_ops & PAGE_LOCK) {

		ASSERT(page_ops == PAGE_LOCK);

		ASSERT(index_ret && *index_ret == start_index);

	}



	if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)

		mapping_set_error(mapping, -EIO);
@@ -1749,13 +1761,22 @@ static void __process_pages_contig(struct address_space *mapping, 
		ret = find_get_pages_contig(mapping, index,

				     min_t(unsigned long,

				     nr_pages, ARRAY_SIZE(pages)), pages);

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

		if (ret == 0) {

			/*

			 * Only if we're going to lock these pages,

			 * can we find nothing at @index.

			 */

			ASSERT(page_ops & PAGE_LOCK);

			return ret;

		}



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

			if (page_ops & PAGE_SET_PRIVATE2)

				SetPagePrivate2(pages[i]);



			if (pages[i] == locked_page) {

				put_page(pages[i]);

				pages_locked++;

				continue;

			}

			if (page_ops & PAGE_CLEAR_DIRTY)
@@ -1768,12 +1789,27 @@ static void __process_pages_contig(struct address_space *mapping, 
				end_page_writeback(pages[i]);

			if (page_ops & PAGE_UNLOCK)

				unlock_page(pages[i]);

			if (page_ops & PAGE_LOCK) {

				lock_page(pages[i]);

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

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

					unlock_page(pages[i]);

					put_page(pages[i]);

					err = -EAGAIN;

					goto out;

				}

			}

			put_page(pages[i]);

			pages_locked++;

		}

		nr_pages -= ret;

		index += ret;

		cond_resched();

	}

out:

	if (err && index_ret)

		*index_ret = start_index + pages_locked - 1;

	return err;

}



void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
@@ -1786,7 +1822,7 @@ void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, 


	__process_pages_contig(inode->i_mapping, locked_page,

			       start >> PAGE_SHIFT, end >> PAGE_SHIFT,

			       page_ops);

			       page_ops, NULL);

}



/*

fs/btrfs/extent_io.h

+2 −1
Original line number Diff line number Diff line
@@ -45,13 +45,14 @@ 
#define EXTENT_BUFFER_IN_TREE 10

#define EXTENT_BUFFER_WRITE_ERR 11    /* write IO error */



/* these are flags for extent_clear_unlock_delalloc */

/* these are flags for __process_pages_contig */

#define PAGE_UNLOCK		(1 << 0)

#define PAGE_CLEAR_DIRTY	(1 << 1)

#define PAGE_SET_WRITEBACK	(1 << 2)

#define PAGE_END_WRITEBACK	(1 << 3)

#define PAGE_SET_PRIVATE2	(1 << 4)

#define PAGE_SET_ERROR		(1 << 5)

#define PAGE_LOCK		(1 << 6)



/*

 * page->private values.  Every page that is controlled by the extent