[PATCH] Fix missing ret assignment in __bio_map_user() error path

If get_user_pages() returns less pages than what we asked for, we jump
to out_unmap which will return ERR_PTR(ret).  But ret can contain a
positive number just smaller than local_nr_pages, so be sure to set it
to -EFAULT always.

Problem found and diagnosed by Damien Le Moal <damien@sdl.hitachi.co.jp>

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 098c12b2d60a..6a0b9ad8f8c9 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -654,9 +654,10 @@ static struct bio *__bio_map_user_iov(request_queue_t *q,
                                      write_to_vm, 0, &pages[cur_page], NULL);
                 up_read(&current->mm->mmap_sem);
 
-                if (ret < local_nr_pages)
+                if (ret < local_nr_pages) {
+                        ret = -EFAULT;
                         goto out_unmap;
-
+                }
 
                 offset = uaddr & ~PAGE_MASK;
                 for (j = cur_page; j < page_limit; j++) {