[PATCH 1/5] brd; pass a bvec pointer to brd_do_bvec

Christoph Hellwig
2025-04-21T07:26:56Z

Pass the bvec to brd_do_bvec instead of marshalling the information into
individual arguments.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/block/brd.c | 35 +++++++++++++----------------------
1 file changed, 13 insertions(+), 22 deletions(-)

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 292f127cae0a..c8974bc545fb 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -189,12 +189,10 @@ static void copy_from_brd(void *dst, struct brd_device *brd,
/*
* Process a single bvec of a bio.
*/
-static int brd_do_bvec(struct brd_device *brd, struct page *page,
- unsigned int len, unsigned int off, blk_opf_t opf,
- sector_t sector)
+static int brd_rw_bvec(struct brd_device *brd, struct bio_vec *bv,
+ blk_opf_t opf, sector_t sector)
{
void *mem;
- int err = 0;

if (op_is_write(opf)) {
/*
@@ -202,24 +200,23 @@ static int brd_do_bvec(struct brd_device *brd, struct page *page,
* block or filesystem layers from page reclaim.
*/
gfp_t gfp = opf & REQ_NOWAIT ? GFP_NOWAIT : GFP_NOIO;
+ int err;

- err = copy_to_brd_setup(brd, sector, len, gfp);
+ err = copy_to_brd_setup(brd, sector, bv->bv_len, gfp);
if (err)
- goto out;
+ return err;
}

- mem = kmap_atomic(page);
+ mem = kmap_atomic(bv->bv_page);
if (!op_is_write(opf)) {
- copy_from_brd(mem + off, brd, sector, len);
- flush_dcache_page(page);
+ copy_from_brd(mem + bv->bv_offset, brd, sector, bv->bv_len);
+ flush_dcache_page(bv->bv_page);
} else {
- flush_dcache_page(page);
- copy_to_brd(brd, mem + off, sector, len);
+ flush_dcache_page(bv->bv_page);
+ copy_to_brd(brd, mem + bv->bv_offset, sector, bv->bv_len);
}
kunmap_atomic(mem);
-
-out:
- return err;
+ return 0;
}

static void brd_do_discard(struct brd_device *brd, sector_t sector, u32 size)
@@ -255,15 +252,9 @@ static void brd_submit_bio(struct bio *bio)
}

bio_for_each_segment(bvec, bio, iter) {
- unsigned int len = bvec.bv_len;
int err;

- /* Don't support un-aligned buffer */
- WARN_ON_ONCE((bvec.bv_offset & (SECTOR_SIZE - 1)) ||
- (len & (SECTOR_SIZE - 1)));
-
- err = brd_do_bvec(brd, bvec.bv_page, len, bvec.bv_offset,
- bio->bi_opf, sector);
+ err = brd_rw_bvec(brd, &bvec, bio->bi_opf, sector);
if (err) {
if (err == -ENOMEM && bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
@@ -272,7 +263,7 @@ static void brd_submit_bio(struct bio *bio)
bio_io_error(bio);
return;
}
- sector += len >> SECTOR_SHIFT;
+ sector += bvec.bv_len >> SECTOR_SHIFT;
}

bio_endio(bio);
--
2.47.2