btrfs: subpage: introduce helpers for writeback status

Introduces the following functions to handle subpage writeback status:

- btrfs_subpage_set_writeback()
- btrfs_subpage_clear_writeback()
- btrfs_subpage_test_writeback()
  These helpers can only be called when the range is ensured to be
  inside the page.

- btrfs_page_set_writeback()
- btrfs_page_clear_writeback()
- btrfs_page_test_writeback()
  These helpers can handle both regular sector size and subpage without
  problem.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2021-03-25 15:14:38 +08:00 committed by David Sterba
parent d8a5713e89
commit 3470da3b7d
2 changed files with 32 additions and 0 deletions

View File

@ -269,6 +269,33 @@ void btrfs_subpage_clear_dirty(const struct btrfs_fs_info *fs_info,
clear_page_dirty_for_io(page);
}
void btrfs_subpage_set_writeback(const struct btrfs_fs_info *fs_info,
struct page *page, u64 start, u32 len)
{
struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;
u16 tmp = btrfs_subpage_calc_bitmap(fs_info, page, start, len);
unsigned long flags;
spin_lock_irqsave(&subpage->lock, flags);
subpage->writeback_bitmap |= tmp;
set_page_writeback(page);
spin_unlock_irqrestore(&subpage->lock, flags);
}
void btrfs_subpage_clear_writeback(const struct btrfs_fs_info *fs_info,
struct page *page, u64 start, u32 len)
{
struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;
u16 tmp = btrfs_subpage_calc_bitmap(fs_info, page, start, len);
unsigned long flags;
spin_lock_irqsave(&subpage->lock, flags);
subpage->writeback_bitmap &= ~tmp;
if (subpage->writeback_bitmap == 0)
end_page_writeback(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.
@ -290,6 +317,7 @@ bool btrfs_subpage_test_##name(const struct btrfs_fs_info *fs_info, \
IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(uptodate);
IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(error);
IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(dirty);
IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(writeback);
/*
* Note that, in selftests (extent-io-tests), we can have empty fs_info passed
@ -328,3 +356,5 @@ IMPLEMENT_BTRFS_PAGE_OPS(uptodate, SetPageUptodate, ClearPageUptodate,
IMPLEMENT_BTRFS_PAGE_OPS(error, SetPageError, ClearPageError, PageError);
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);

View File

@ -21,6 +21,7 @@ struct btrfs_subpage {
u16 uptodate_bitmap;
u16 error_bitmap;
u16 dirty_bitmap;
u16 writeback_bitmap;
union {
/*
* Structures only used by metadata
@ -89,6 +90,7 @@ bool btrfs_page_test_##name(const struct btrfs_fs_info *fs_info, \
DECLARE_BTRFS_SUBPAGE_OPS(uptodate);
DECLARE_BTRFS_SUBPAGE_OPS(error);
DECLARE_BTRFS_SUBPAGE_OPS(dirty);
DECLARE_BTRFS_SUBPAGE_OPS(writeback);
bool btrfs_subpage_clear_and_test_dirty(const struct btrfs_fs_info *fs_info,
struct page *page, u64 start, u32 len);