[PATCH 7/8] btrfs: add a helper to iterate through a btrfs_bio with sector sized chunks

Christoph Hellwig
2022-05-22T11:48:27Z

From: Qu Wenruo <wqu@suse.com>

Add a helper that works similar to __bio_for_each_segment, but instead of
iterating over PAGE_SIZE chunks it iterates over each sector.

Signed-off-by: Qu Wenruo <wqu@suse.com>
[hch: split from a larger patch, and iterate over the offset instead of
the offset bits]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/btrfs/volumes.h | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 12b2af9260e92..6f784d4f54664 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -391,6 +391,18 @@ static inline void btrfs_bio_free_csum(struct btrfs_bio *bbio)
}
}

+/*
+ * Iterate through a btrfs_bio (@bbio) on a per-sector basis.
+ */
+#define btrfs_bio_for_each_sector(fs_info, bvl, bbio, iter, bio_offset) \
+ for ((iter) = (bbio)->iter, (bio_offset) = 0; \
+ (iter).bi_size && \
+ (((bvl) = bio_iter_iovec((&(bbio)->bio), (iter))), 1); \
+ (bio_offset) += fs_info->sectorsize, \
+ bio_advance_iter_single(&(bbio)->bio, &(iter), \
+ (fs_info)->sectorsize))
+
+
struct btrfs_io_stripe {
struct btrfs_device *dev;
u64 physical;
--
2.30.2