3.2.97-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
commit 2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058 upstream.
we need to take care of failure exit as well - pages already
in bio should be dropped by analogue of bio_unmap_pages(),
since their refcounts had been bumped only once per reference
in bio.
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
fs/bio.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -976,6 +976,7 @@ static struct bio *__bio_map_user_iov(st
struct bio *bio;
int cur_page = 0;
int ret, offset;
+ struct bio_vec *bvec;
for (i = 0; i < iov_count; i++) {
unsigned long uaddr = (unsigned long)iov[i].iov_base;
@@ -1019,7 +1020,12 @@ static struct bio *__bio_map_user_iov(st
ret = get_user_pages_fast(uaddr, local_nr_pages,
write_to_vm, &pages[cur_page]);
- if (ret < local_nr_pages) {
+ if (unlikely(ret < local_nr_pages)) {
+ for (j = cur_page; j < page_limit; j++) {
+ if (!pages[j])
+ break;
+ put_page(pages[j]);
+ }
ret = -EFAULT;
goto out_unmap;
}
@@ -1074,10 +1080,8 @@ static struct bio *__bio_map_user_iov(st
return bio;
out_unmap:
- for (i = 0; i < nr_pages; i++) {
- if(!pages[i])
- break;
- page_cache_release(pages[i]);
+ bio_for_each_segment_all(bvec, bio, j) {
+ put_page(bvec->bv_page);
}
out:
kfree(pages);