[PATCH 2/2] btrfs: allocate dummy ordereded_sums objects for nocsum I/O on zoned file systems

[Christoph Hellwig <hch@lst.de>]

Zoned file systems now need the ordereded_sums structure to record the
actual write location returned by zone append, so allocate dummy
structures without the csum array for them when the I/O doesn't use
checksums, and free them when completing the ordered_extent.

Fixes: 5a1b7f2b6306 ("btrfs: optimize the logical to physical mapping for zoned writes")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/btrfs/bio.c       |  4 ++++
 fs/btrfs/file-item.c | 12 ++++++++++--
 fs/btrfs/zoned.c     | 11 ++++++++++-
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/bio.c b/fs/btrfs/bio.c
index 627d06fbb4c425..2482739be49163 100644
--- a/fs/btrfs/bio.c
+++ b/fs/btrfs/bio.c
@@ -668,6 +668,10 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
 			ret = btrfs_bio_csum(bbio);
 			if (ret)
 				goto fail_put_bio;
+		} else if (use_append) {
+			ret = btrfs_csum_one_bio(bbio);
+			if (ret)
+				goto fail_put_bio;
 		}
 	}
 
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 5e6603e76e5ac0..1308c369b1ebd8 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -751,8 +751,16 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
 	sums->logical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
 	index = 0;
 
-	shash->tfm = fs_info->csum_shash;
+	/*
+	 * If we are called for a nodatasum inode, this means we are on a zoned
+	 * file system.  In this case a ordered_csum structure needs to be
+	 * allocated to track the logical address actually written, but it does
+	 * notactually carry any checksums.
+	 */
+	if (btrfs_inode_is_nodatasum(inode))
+		goto done;
 
+	shash->tfm = fs_info->csum_shash;
 	bio_for_each_segment(bvec, bio, iter) {
 		if (!ordered) {
 			ordered = btrfs_lookup_ordered_extent(inode, offset);
@@ -817,7 +825,7 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
 
 	}
 	this_sum_bytes = 0;
-
+done:
 	/*
 	 * The ->sums assignment is for zoned writes, where a bio never spans
 	 * ordered extents and is only done unconditionally because that's cheaper
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index bbde4ddd475492..1f5497b9b2695c 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1717,7 +1717,7 @@ void btrfs_finish_ordered_zoned(struct btrfs_ordered_extent *ordered)
 		if (!btrfs_zoned_split_ordered(ordered, logical, len)) {
 			set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
 			btrfs_err(fs_info, "failed to split ordered extent\n");
-			return;
+			goto out;
 		}
 		logical = sum->logical;
 		len = sum->len;
@@ -1725,6 +1725,15 @@ void btrfs_finish_ordered_zoned(struct btrfs_ordered_extent *ordered)
 
 	if (ordered->disk_bytenr != logical)
 		btrfs_rewrite_logical_zoned(ordered, logical);
+
+out:
+	if (btrfs_inode_is_nodatasum(BTRFS_I(ordered->inode))) {
+		while ((sum = list_first_entry_or_null(&ordered->list,
+						       typeof(*sum), list))) {
+			list_del(&sum->list);
+			kfree(sum);
+		}
+	}
 }
 
 bool btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
-- 
2.39.2