[PATCH 4/4] block: memory allocations in bounce_clone_bio must not fail

[Christoph Hellwig <hch@lst.de>]

The caller can't cope with a failure from bounce_clone_bio, so
use __GFP_NOFAIL for the passthrough case.  bio_alloc_bioset already
won't fail due to the use of mempools.

And yes, we need to get rid of this bock layer bouncing code entirely
sooner or later..

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bounce.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/block/bounce.c b/block/bounce.c
index 417faaac36b691..87983a35079c22 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -242,12 +242,11 @@ static struct bio *bounce_clone_bio(struct bio *bio_src)
 	 *    __bio_clone_fast() anyways.
 	 */
 	if (bio_is_passthrough(bio_src))
-		bio = bio_kmalloc(GFP_NOIO, bio_segments(bio_src));
+		bio = bio_kmalloc(GFP_NOIO | __GFP_NOFAIL,
+				  bio_segments(bio_src));
 	else
 		bio = bio_alloc_bioset(GFP_NOIO, bio_segments(bio_src),
 				       &bounce_bio_set);
-	if (!bio)
-		return NULL;
 	bio->bi_bdev		= bio_src->bi_bdev;
 	if (bio_flagged(bio_src, BIO_REMAPPED))
 		bio_set_flag(bio, BIO_REMAPPED);
-- 
2.29.2