btrfs: stop setting PageError in the data I/O path

PageError is not used by the VFS/MM and deprecated because it uses up a
page bit and has no coherent rules.  Instead read errors are usually
propagated by not setting or clearing the uptodate bit, and write errors
are propagated through the address_space.  Btrfs now only sets the flag
and never clears it for data pages, so just remove all places setting it,
and the subpage error bit.

Note that the error propagation for superblock writes that work on the
block device mapping still uses PageError for now, but that will be
addressed in a separate series.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 0 insertions, 35 deletions

diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c
index 74bc43040531..1b999c6e4193 100644
--- a/fs/btrfs/subpage.c
+++ b/fs/btrfs/subpage.c
@@ -100,9 +100,6 @@ void btrfs_init_subpage_info(struct btrfs_subpage_info *subpage_info, u32 sector
 	subpage_info->uptodate_offset = cur;
 	cur += nr_bits;
 
-	subpage_info->error_offset = cur;
-	cur += nr_bits;
-
 	subpage_info->dirty_offset = cur;
 	cur += nr_bits;
 
@@ -416,35 +413,6 @@ void btrfs_subpage_clear_uptodate(const struct btrfs_fs_info *fs_info,
 	spin_unlock_irqrestore(&subpage->lock, flags);
 }
 
-void btrfs_subpage_set_error(const struct btrfs_fs_info *fs_info,
-		struct page *page, u64 start, u32 len)
-{
-	struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;
-	unsigned int start_bit = subpage_calc_start_bit(fs_info, page,
-							error, start, len);
-	unsigned long flags;
-
-	spin_lock_irqsave(&subpage->lock, flags);
-	bitmap_set(subpage->bitmaps, start_bit, len >> fs_info->sectorsize_bits);
-	SetPageError(page);
-	spin_unlock_irqrestore(&subpage->lock, flags);
-}
-
-void btrfs_subpage_clear_error(const struct btrfs_fs_info *fs_info,
-		struct page *page, u64 start, u32 len)
-{
-	struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;
-	unsigned int start_bit = subpage_calc_start_bit(fs_info, page,
-							error, start, len);
-	unsigned long flags;
-
-	spin_lock_irqsave(&subpage->lock, flags);
-	bitmap_clear(subpage->bitmaps, start_bit, len >> fs_info->sectorsize_bits);
-	if (subpage_test_bitmap_all_zero(fs_info, subpage, error))
-		ClearPageError(page);
-	spin_unlock_irqrestore(&subpage->lock, flags);
-}
-
 void btrfs_subpage_set_dirty(const struct btrfs_fs_info *fs_info,
 		struct page *page, u64 start, u32 len)
 {
@@ -606,7 +574,6 @@ bool btrfs_subpage_test_##name(const struct btrfs_fs_info *fs_info,	\
 	return ret;							\
 }
 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);
@@ -674,7 +641,6 @@ bool btrfs_page_clamp_test_##name(const struct btrfs_fs_info *fs_info,	\
 }
 IMPLEMENT_BTRFS_PAGE_OPS(uptodate, SetPageUptodate, ClearPageUptodate,
 			 PageUptodate);
-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,
@@ -769,7 +735,6 @@ void __cold btrfs_subpage_dump_bitmap(const struct btrfs_fs_info *fs_info,
 
 	spin_lock_irqsave(&subpage->lock, flags);
 	GET_SUBPAGE_BITMAP(subpage, subpage_info, uptodate, &uptodate_bitmap);
-	GET_SUBPAGE_BITMAP(subpage, subpage_info, error, &error_bitmap);
 	GET_SUBPAGE_BITMAP(subpage, subpage_info, dirty, &dirty_bitmap);
 	GET_SUBPAGE_BITMAP(subpage, subpage_info, writeback, &writeback_bitmap);
 	GET_SUBPAGE_BITMAP(subpage, subpage_info, ordered, &ordered_bitmap);