don't rely upon subsequent bio_add_pc_page() calls failing

... 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>
This commit is contained in:
Al Viro 2017-09-23 16:16:06 -04:00
parent 629e42bcc3
commit e2e115d18b

View File

@ -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);