[PATCH v6 16/20] dm-crypt: check if adding pages to clone bio fails

[Johannes Thumshirn <johannes.thumshirn@wdc.com>]

Check if adding pages to clone bio fails and if it does retry with
reclaim. This mirrors the behaviour of page allocation in
crypt_alloc_buffer().

This way we can mark bio_add_pages as __must_check.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 drivers/md/dm-crypt.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 8b47b913ee83..0dd231e61757 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1693,7 +1693,10 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned int size)
 
 		len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
 
-		bio_add_page(clone, page, len, 0);
+		if (!bio_add_page(clone, page, len, 0)) {
+			WARN_ONCE(1, "Adding page to bio failed\n");
+			return NULL;
+		}
 
 		remaining_size -= len;
 	}
-- 
2.40.1