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

Qu Wenruo
2021-11-28T05:55:32Z

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