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, 5 insertions, 19 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 33e5f0a31c21..b7f26a4bb663 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -223,8 +223,6 @@ static int process_one_page(struct btrfs_fs_info *fs_info,
 
 	if (page_ops & PAGE_SET_ORDERED)
 		btrfs_page_clamp_set_ordered(fs_info, page, start, len);
-	if (page_ops & PAGE_SET_ERROR)
-		btrfs_page_clamp_set_error(fs_info, page, start, len);
 	if (page_ops & PAGE_START_WRITEBACK) {
 		btrfs_page_clamp_clear_dirty(fs_info, page, start, len);
 		btrfs_page_clamp_set_writeback(fs_info, page, start, len);
@@ -497,12 +495,10 @@ static void end_page_read(struct page *page, bool uptodate, u64 start, u32 len)
 	ASSERT(page_offset(page) <= start &&
 	       start + len <= page_offset(page) + PAGE_SIZE);
 
-	if (uptodate && btrfs_verify_page(page, start)) {
+	if (uptodate && btrfs_verify_page(page, start))
 		btrfs_page_set_uptodate(fs_info, page, start, len);
-	} else {
+	else
 		btrfs_page_clear_uptodate(fs_info, page, start, len);
-		btrfs_page_set_error(fs_info, page, start, len);
-	}
 
 	if (!btrfs_is_subpage(fs_info, page))
 		unlock_page(page);
@@ -530,7 +526,6 @@ void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
 		len = end + 1 - start;
 
 		btrfs_page_clear_uptodate(fs_info, page, start, len);
-		btrfs_page_set_error(fs_info, page, start, len);
 		ret = err < 0 ? err : -EIO;
 		mapping_set_error(page->mapping, ret);
 	}
@@ -1059,7 +1054,6 @@ static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 	ret = set_page_extent_mapped(page);
 	if (ret < 0) {
 		unlock_extent(tree, start, end, NULL);
-		btrfs_page_set_error(fs_info, page, start, PAGE_SIZE);
 		unlock_page(page);
 		return ret;
 	}
@@ -1263,11 +1257,9 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode,
 		}
 		ret = btrfs_run_delalloc_range(inode, page, delalloc_start,
 				delalloc_end, &page_started, &nr_written, wbc);
-		if (ret) {
-			btrfs_page_set_error(inode->root->fs_info, page,
-					     page_offset(page), PAGE_SIZE);
+		if (ret)
 			return ret;
-		}
+
 		/*
 		 * delalloc_end is already one less than the total length, so
 		 * we don't subtract one from PAGE_SIZE
@@ -1420,7 +1412,6 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 
 		em = btrfs_get_extent(inode, NULL, 0, cur, end - cur + 1);
 		if (IS_ERR(em)) {
-			btrfs_page_set_error(fs_info, page, cur, end - cur + 1);
 			ret = PTR_ERR_OR_ZERO(em);
 			goto out_error;
 		}
@@ -1519,9 +1510,6 @@ static int __extent_writepage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl
 
 	WARN_ON(!PageLocked(page));
 
-	btrfs_page_clear_error(btrfs_sb(inode->i_sb), page,
-			       page_offset(page), PAGE_SIZE);
-
 	pg_offset = offset_in_page(i_size);
 	if (page->index > end_index ||
 	   (page->index == end_index && !pg_offset)) {
@@ -1534,10 +1522,8 @@ static int __extent_writepage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl
 		memzero_page(page, pg_offset, PAGE_SIZE - pg_offset);
 
 	ret = set_page_extent_mapped(page);
-	if (ret < 0) {
-		SetPageError(page);
+	if (ret < 0)
 		goto done;
-	}
 
 	if (!bio_ctrl->extent_locked) {
 		ret = writepage_delalloc(BTRFS_I(inode), page, bio_ctrl->wbc);