From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 23 Sep 2017 16:16:06 -0400
Subject: [PATCH] don't rely upon subsequent bio_add_pc_page() calls failing
Git-commit: e2e115d18b76467274d8f818f8828ba168f9c80b
Patch-mainline: v4.15-rc1
References: bsc#1104967,FATE#325924
... they might actually succeed in some cases (when we are at the
queue-imposed segments limit, the next page is not mergable with
the last one we'd got in, but the first page covered by the next
iovec *is* mergable). Make sure that once it's failed, we are
done with that bio.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
block/bio.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 5dbc5e90d716..fe40948d62af 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1380,10 +1380,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
if (n > bytes)
n = bytes;
- /*
- * sorry...
- */
- if (bio_add_pc_page(q, bio, pages[j], n, offs) < n)
+ if (!bio_add_pc_page(q, bio, pages[j], n, offs))
break;
/*
@@ -1405,6 +1402,9 @@ struct bio *bio_map_user_iov(struct request_queue *q,
while (j < npages)
put_page(pages[j++]);
kvfree(pages);
+ /* couldn't stuff something into bio? */
+ if (bytes)
+ break;
}
bio_set_flag(bio, BIO_USER_MAPPED);
--
2.16.4