[PATCH RFC 07/11] btrfs: make end_bio_extent_*_writepage() to handle split biot properly

[Qu Wenruo <wqu@suse.com>]

There are 3 call sites involved:

- end_bio_extent_writepage()
  For data writeback

- end_bio_subpage_eb_writepage()
  For subpage metadata writeback

- end_bio_extent_buffer_writepage()
  For regular metadata writeback

All those functions share the same modification:

- Remove ASSERT() to non-cloned bios
- Use bio_for_each_segment()
  Which can handle both unsplit bio and split biot properly.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/extent_io.c | 50 ++++++++++++++++++++++----------------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 67965faeef47..91013c1dce25 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2827,31 +2827,31 @@ void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
 static void end_bio_extent_writepage(struct bio *bio)
 {
 	int error = blk_status_to_errno(bio->bi_status);
-	struct bio_vec *bvec;
+	struct bvec_iter iter;
+	struct bio_vec bvec;
 	u64 start;
 	u64 end;
-	struct bvec_iter_all iter_all;
 	bool first_bvec = true;
 
-	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, iter_all) {
-		struct page *page = bvec->bv_page;
+	ASSERT(btrfs_bio(bio)->iter.bi_size);
+	__bio_for_each_segment(bvec, bio, iter, btrfs_bio(bio)->iter) {
+		struct page *page = bvec.bv_page;
 		struct inode *inode = page->mapping->host;
 		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 		const u32 sectorsize = fs_info->sectorsize;
 
 		/* Our read/write should always be sector aligned. */
-		if (!IS_ALIGNED(bvec->bv_offset, sectorsize))
+		if (!IS_ALIGNED(bvec.bv_offset, sectorsize))
 			btrfs_err(fs_info,
 		"partial page write in btrfs with offset %u and length %u",
-				  bvec->bv_offset, bvec->bv_len);
-		else if (!IS_ALIGNED(bvec->bv_len, sectorsize))
+				  bvec.bv_offset, bvec.bv_len);
+		else if (!IS_ALIGNED(bvec.bv_len, sectorsize))
 			btrfs_info(fs_info,
 		"incomplete page write with offset %u and length %u",
-				   bvec->bv_offset, bvec->bv_len);
+				   bvec.bv_offset, bvec.bv_len);
 
-		start = page_offset(page) + bvec->bv_offset;
-		end = start + bvec->bv_len - 1;
+		start = page_offset(page) + bvec.bv_offset;
+		end = start + bvec.bv_len - 1;
 
 		if (first_bvec) {
 			btrfs_record_physical_zoned(inode, start, bio);
@@ -2860,7 +2860,7 @@ static void end_bio_extent_writepage(struct bio *bio)
 
 		end_extent_writepage(page, error, start, end);
 
-		btrfs_page_clear_writeback(fs_info, page, start, bvec->bv_len);
+		btrfs_page_clear_writeback(fs_info, page, start, bvec.bv_len);
 	}
 
 	bio_put(bio);
@@ -4475,20 +4475,20 @@ static struct extent_buffer *find_extent_buffer_nolock(
 static void end_bio_subpage_eb_writepage(struct bio *bio)
 {
 	struct btrfs_fs_info *fs_info;
-	struct bio_vec *bvec;
-	struct bvec_iter_all iter_all;
+	struct bvec_iter iter;
+	struct bio_vec bvec;
 
 	fs_info = btrfs_sb(bio_first_page_all(bio)->mapping->host->i_sb);
 	ASSERT(fs_info->sectorsize < PAGE_SIZE);
 
-	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, iter_all) {
-		struct page *page = bvec->bv_page;
-		u64 bvec_start = page_offset(page) + bvec->bv_offset;
-		u64 bvec_end = bvec_start + bvec->bv_len - 1;
+	ASSERT(btrfs_bio(bio)->iter.bi_size);
+	__bio_for_each_segment(bvec, bio, iter, btrfs_bio(bio)->iter) {
+		struct page *page = bvec.bv_page;
+		u64 bvec_start = page_offset(page) + bvec.bv_offset;
+		u64 bvec_end = bvec_start + bvec.bv_len - 1;
 		u64 cur_bytenr = bvec_start;
 
-		ASSERT(IS_ALIGNED(bvec->bv_len, fs_info->nodesize));
+		ASSERT(IS_ALIGNED(bvec.bv_len, fs_info->nodesize));
 
 		/* Iterate through all extent buffers in the range */
 		while (cur_bytenr <= bvec_end) {
@@ -4531,14 +4531,14 @@ static void end_bio_subpage_eb_writepage(struct bio *bio)
 
 static void end_bio_extent_buffer_writepage(struct bio *bio)
 {
-	struct bio_vec *bvec;
+	struct bvec_iter iter;
+	struct bio_vec bvec;
 	struct extent_buffer *eb;
 	int done;
-	struct bvec_iter_all iter_all;
 
-	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, iter_all) {
-		struct page *page = bvec->bv_page;
+	ASSERT(btrfs_bio(bio)->iter.bi_size);
+	__bio_for_each_segment(bvec, bio, iter, btrfs_bio(bio)->iter) {
+		struct page *page = bvec.bv_page;
 
 		eb = (struct extent_buffer *)page->private;
 		BUG_ON(!eb);
-- 
2.34.0