[PATCH 5.10 008/105] block: fix bounce_clone_bio for passthrough bios

Greg Kroah-Hartman
2022-07-27T16:50:01Z

From: Christoph Hellwig <hch@lst.de>

commit b90994c6ab623baf9268df9710692f14920ce9d2 upstream.

Now that bio_alloc_bioset does not fall back to kmalloc for a NULL
bio_set, handle that case explicitly and simplify the calling
conventions.

Based on an earlier patch from Chaitanya Kulkarni.

Fixes: 3175199ab0ac ("block: split bio_kmalloc from bio_alloc_bioset")
Reported-by: Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
block/bounce.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

--- a/block/bounce.c
+++ b/block/bounce.c
@@ -214,8 +214,7 @@ static void bounce_end_io_read_isa(struc
__bounce_end_io_read(bio, &isa_page_pool);
}

-static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask,
- struct bio_set *bs)
+static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask)
{
struct bvec_iter iter;
struct bio_vec bv;
@@ -242,8 +241,11 @@ static struct bio *bounce_clone_bio(stru
* asking for trouble and would force extra work on
* __bio_clone_fast() anyways.
*/
-
- bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
+ if (bio_is_passthrough(bio_src))
+ bio = bio_kmalloc(gfp_mask, bio_segments(bio_src));
+ else
+ bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src),
+ &bounce_bio_set);
if (!bio)
return NULL;
bio->bi_disk = bio_src->bi_disk;
@@ -294,7 +296,6 @@ static void __blk_queue_bounce(struct re
unsigned i = 0;
bool bounce = false;
int sectors = 0;
- bool passthrough = bio_is_passthrough(*bio_orig);

bio_for_each_segment(from, *bio_orig, iter) {
if (i++ < BIO_MAX_PAGES)
@@ -305,14 +306,14 @@ static void __blk_queue_bounce(struct re
if (!bounce)
return;

- if (!passthrough && sectors < bio_sectors(*bio_orig)) {
+ if (!bio_is_passthrough(*bio_orig) &&
+ sectors < bio_sectors(*bio_orig)) {
bio = bio_split(*bio_orig, sectors, GFP_NOIO, &bounce_bio_split);
bio_chain(bio, *bio_orig);
submit_bio_noacct(*bio_orig);
*bio_orig = bio;
}
- bio = bounce_clone_bio(*bio_orig, GFP_NOIO, passthrough ? NULL :
- &bounce_bio_set);
+ bio = bounce_clone_bio(*bio_orig, GFP_NOIO);

/*
* Bvec table can't be updated by bio_for_each_segment_all(),