[RFC PATCH 1/7] block: share more code for bio addition helpers
From: Leon Romanovsky
Date: Sun Oct 27 2024 - 10:29:51 EST
From: Christoph Hellwig <hch@xxxxxx>
__bio_iov_iter_get_pages currently open codes adding pages to the bio,
which duplicates a lot of code from bio_add_page and
bio_add_zone_append_page. Add bio_add_page_int and
bio_add_zone_append_page_int helpers that pass down the same_page
output argument so that __bio_iov_iter_get_pages can reuse the main
add bio to page helpers.
Note that I'd normally call these helpers __bio_add_page and
__bio_add_zone_append_page, but the former is already taken for an
exported API.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
block/bio.c | 114 +++++++++++++++++++++++-----------------------------
1 file changed, 51 insertions(+), 63 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index ac4d77c88932..2d3bc8bfb071 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1064,6 +1064,19 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio,
}
EXPORT_SYMBOL(bio_add_pc_page);
+static int bio_add_zone_append_page_int(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset, bool *same_page)
+{
+ struct block_device *bdev = bio->bi_bdev;
+
+ if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_ZONE_APPEND))
+ return 0;
+ if (WARN_ON_ONCE(!bdev_is_zoned(bdev)))
+ return 0;
+ return bio_add_hw_page(bdev_get_queue(bdev), bio, page, len, offset,
+ bdev_max_zone_append_sectors(bdev), same_page);
+}
+
/**
* bio_add_zone_append_page - attempt to add page to zone-append bio
* @bio: destination bio
@@ -1083,17 +1096,9 @@ EXPORT_SYMBOL(bio_add_pc_page);
int bio_add_zone_append_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset)
{
- struct request_queue *q = bdev_get_queue(bio->bi_bdev);
bool same_page = false;
- if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_ZONE_APPEND))
- return 0;
-
- if (WARN_ON_ONCE(!bdev_is_zoned(bio->bi_bdev)))
- return 0;
-
- return bio_add_hw_page(q, bio, page, len, offset,
- queue_max_zone_append_sectors(q), &same_page);
+ return bio_add_zone_append_page_int(bio, page, len, offset, &same_page);
}
EXPORT_SYMBOL_GPL(bio_add_zone_append_page);
@@ -1119,20 +1124,9 @@ void __bio_add_page(struct bio *bio, struct page *page,
}
EXPORT_SYMBOL_GPL(__bio_add_page);
-/**
- * bio_add_page - attempt to add page(s) to bio
- * @bio: destination bio
- * @page: start page to add
- * @len: vec entry length, may cross pages
- * @offset: vec entry offset relative to @page, may cross pages
- *
- * Attempt to add page(s) to the bio_vec maplist. This will only fail
- * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio.
- */
-int bio_add_page(struct bio *bio, struct page *page,
- unsigned int len, unsigned int offset)
+static int bio_add_page_int(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset, bool *same_page)
{
- bool same_page = false;
if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
return 0;
@@ -1141,7 +1135,7 @@ int bio_add_page(struct bio *bio, struct page *page,
if (bio->bi_vcnt > 0 &&
bvec_try_merge_page(&bio->bi_io_vec[bio->bi_vcnt - 1],
- page, len, offset, &same_page)) {
+ page, len, offset, same_page)) {
bio->bi_iter.bi_size += len;
return len;
}
@@ -1151,6 +1145,24 @@ int bio_add_page(struct bio *bio, struct page *page,
__bio_add_page(bio, page, len, offset);
return len;
}
+
+/**
+ * bio_add_page - attempt to add page(s) to bio
+ * @bio: destination bio
+ * @page: start page to add
+ * @len: vec entry length, may cross pages
+ * @offset: vec entry offset relative to @page, may cross pages
+ *
+ * Attempt to add page(s) to the bio_vec maplist. Will only fail if the
+ * bio is full, or it is incorrectly used on a cloned bio.
+ */
+int bio_add_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset)
+{
+ bool same_page = false;
+
+ return bio_add_page_int(bio, page, len, offset, &same_page);
+}
EXPORT_SYMBOL(bio_add_page);
void bio_add_folio_nofail(struct bio *bio, struct folio *folio, size_t len,
@@ -1224,41 +1236,6 @@ void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter)
bio_set_flag(bio, BIO_CLONED);
}
-static int bio_iov_add_folio(struct bio *bio, struct folio *folio, size_t len,
- size_t offset)
-{
- bool same_page = false;
-
- if (WARN_ON_ONCE(bio->bi_iter.bi_size > UINT_MAX - len))
- return -EIO;
-
- if (bio->bi_vcnt > 0 &&
- bvec_try_merge_page(&bio->bi_io_vec[bio->bi_vcnt - 1],
- folio_page(folio, 0), len, offset,
- &same_page)) {
- bio->bi_iter.bi_size += len;
- if (same_page && bio_flagged(bio, BIO_PAGE_PINNED))
- unpin_user_folio(folio, 1);
- return 0;
- }
- bio_add_folio_nofail(bio, folio, len, offset);
- return 0;
-}
-
-static int bio_iov_add_zone_append_folio(struct bio *bio, struct folio *folio,
- size_t len, size_t offset)
-{
- struct request_queue *q = bdev_get_queue(bio->bi_bdev);
- bool same_page = false;
-
- if (bio_add_hw_folio(q, bio, folio, len, offset,
- queue_max_zone_append_sectors(q), &same_page) != len)
- return -EINVAL;
- if (same_page && bio_flagged(bio, BIO_PAGE_PINNED))
- unpin_user_folio(folio, 1);
- return 0;
-}
-
static unsigned int get_contig_folio_len(unsigned int *num_pages,
struct page **pages, unsigned int i,
struct folio *folio, size_t left,
@@ -1353,6 +1330,8 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
for (left = size, i = 0; left > 0; left -= len, i += num_pages) {
struct page *page = pages[i];
struct folio *folio = page_folio(page);
+ struct page *first_page = folio_page(folio, 0);
+ bool same_page = false;
folio_offset = ((size_t)folio_page_idx(folio, page) <<
PAGE_SHIFT) + offset;
@@ -1366,12 +1345,21 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
folio, left, offset);
if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
- ret = bio_iov_add_zone_append_folio(bio, folio, len,
- folio_offset);
- if (ret)
+ if (bio_add_zone_append_page_int(bio, first_page, len,
+ folio_offset, &same_page) != len) {
+ ret = -EINVAL;
+ break;
+ }
+ } else {
+ if (bio_add_page_int(bio, folio_page(folio, 0), len,
+ folio_offset, &same_page) != len) {
+ ret = -EINVAL;
break;
- } else
- bio_iov_add_folio(bio, folio, len, folio_offset);
+ }
+ }
+
+ if (same_page && bio_flagged(bio, BIO_PAGE_PINNED))
+ unpin_user_folio(folio, 1);
offset = 0;
}
--
2.46.2