From: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Add bio_add_zone_append_page(), a wrapper around bio_add_hw_page() which
is intended to be used by file systems that directly add pages to a bio
instead of using bio_iov_iter_get_pages().
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
---
block/bio.c | 38 ++++++++++++++++++++++++++++++++++++++
include/linux/bio.h | 2 ++
2 files changed, 40 insertions(+)
diff --git a/block/bio.c b/block/bio.c
index 58d765400226..c8943201c26c 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -853,6 +853,44 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio,
}
EXPORT_SYMBOL(bio_add_pc_page);
+/**
+ * bio_add_zone_append_page - attempt to add page to zone-append bio
+ * @bio: destination bio
+ * @page: page to add
+ * @len: vec entry length
+ * @offset: vec entry offset
+ *
+ * Attempt to add a page to the bio_vec maplist of a bio that will be submitted
+ * for a zone-append request. This can fail for a number of reasons, such as the
+ * bio being full or the target block device is not a zoned block device or
+ * other limitations of the target block device. The target block device must
+ * allow bio's up to PAGE_SIZE, so it is always possible to add a single page
+ * to an empty bio.
+ *
+ * Returns: number of bytes added to the bio, or 0 in case of a failure.
+ */
+int bio_add_zone_append_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset)
+{
+ struct request_queue *q;
+ bool same_page = false;
+
+ if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_ZONE_APPEND))
+ return 0;
+
+ if (WARN_ON_ONCE(!bio->bi_disk))
+ return 0;
+
+ q = bio->bi_disk->queue;
+
+ if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
+ return 0;
+
+ return bio_add_hw_page(q, bio, page, len, offset,
+ queue_max_zone_append_sectors(q), &same_page);
+}
+EXPORT_SYMBOL_GPL(bio_add_zone_append_page);
+
/**
* __bio_try_merge_page - try appending data to an existing bvec.
* @bio: destination bio
diff --git a/include/linux/bio.h b/include/linux/bio.h
index c6d765382926..7ef300cb4e9a 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -442,6 +442,8 @@ void bio_chain(struct bio *, struct bio *);
extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
unsigned int, unsigned int);
+int bio_add_zone_append_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset);
bool __bio_try_merge_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int off, bool *same_page);
void __bio_add_page(struct bio *bio, struct page *page,
--
2.27.0
