Commit 6f17400b authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: introduce helpers for subpage ordered status 



This patch introduces the following functions to handle btrfs subpage
ordered (Private2) status:

- btrfs_subpage_set_ordered()
- btrfs_subpage_clear_ordered()
- btrfs_subpage_test_ordered()
  These helpers can only be called when the range is ensured to be
  inside the page.

- btrfs_page_set_ordered()
- btrfs_page_clear_ordered()
- btrfs_page_test_ordered()
  These helpers can handle both regular sector size and subpage without
  problem.

These functions are here to coordinate btrfs_invalidatepage() with
btrfs_writepage_endio_finish_ordered(), to make sure only one of those
functions can finish the ordered extent.

Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64]
Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64]
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 1e1de387

fs/btrfs/subpage.c

+29 −0
Original line number Diff line number Diff line
@@ -429,6 +429,32 @@ void btrfs_subpage_clear_writeback(const struct btrfs_fs_info *fs_info, 
	spin_unlock_irqrestore(&subpage->lock, flags);

}



void btrfs_subpage_set_ordered(const struct btrfs_fs_info *fs_info,

		struct page *page, u64 start, u32 len)

{

	struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;

	const u16 tmp = btrfs_subpage_calc_bitmap(fs_info, page, start, len);

	unsigned long flags;



	spin_lock_irqsave(&subpage->lock, flags);

	subpage->ordered_bitmap |= tmp;

	SetPageOrdered(page);

	spin_unlock_irqrestore(&subpage->lock, flags);

}



void btrfs_subpage_clear_ordered(const struct btrfs_fs_info *fs_info,

		struct page *page, u64 start, u32 len)

{

	struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;

	const u16 tmp = btrfs_subpage_calc_bitmap(fs_info, page, start, len);

	unsigned long flags;



	spin_lock_irqsave(&subpage->lock, flags);

	subpage->ordered_bitmap &= ~tmp;

	if (subpage->ordered_bitmap == 0)

		ClearPageOrdered(page);

	spin_unlock_irqrestore(&subpage->lock, flags);

}

/*

 * Unlike set/clear which is dependent on each page status, for test all bits

 * are tested in the same way.
@@ -451,6 +477,7 @@ IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(uptodate); 
IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(error);

IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(dirty);

IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(writeback);

IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(ordered);



/*

 * Note that, in selftests (extent-io-tests), we can have empty fs_info passed
@@ -519,3 +546,5 @@ IMPLEMENT_BTRFS_PAGE_OPS(dirty, set_page_dirty, clear_page_dirty_for_io, 
			 PageDirty);

IMPLEMENT_BTRFS_PAGE_OPS(writeback, set_page_writeback, end_page_writeback,

			 PageWriteback);

IMPLEMENT_BTRFS_PAGE_OPS(ordered, SetPageOrdered, ClearPageOrdered,

			 PageOrdered);

fs/btrfs/subpage.h

+4 −0
Original line number Diff line number Diff line
@@ -34,6 +34,9 @@ struct btrfs_subpage { 
		struct {

			atomic_t readers;

			atomic_t writers;



			/* Tracke pending ordered extent in this sector */

			u16 ordered_bitmap;

		};

	};

};
@@ -111,6 +114,7 @@ DECLARE_BTRFS_SUBPAGE_OPS(uptodate); 
DECLARE_BTRFS_SUBPAGE_OPS(error);

DECLARE_BTRFS_SUBPAGE_OPS(dirty);

DECLARE_BTRFS_SUBPAGE_OPS(writeback);

DECLARE_BTRFS_SUBPAGE_OPS(ordered);



bool btrfs_subpage_clear_and_test_dirty(const struct btrfs_fs_info *fs_info,

		struct page *page, u64 start, u32 len);