block: advance iov_iter on bio_add_hw_page failure

When the bio's size reaches max_append_sectors, bio_add_hw_page returns
0 then __bio_iov_append_get_pages returns -EINVAL. This is an expected
result of building a small enough bio not to be split in the IO path.
However, iov_iter is not advanced in this case, causing the same pages
are filled for the bio again and again.

Fix the case by properly advancing the iov_iter for already processed
pages.

Fixes: 0512a75b98 ("block: Introduce REQ_OP_ZONE_APPEND")
Cc: stable@vger.kernel.org # 5.8+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Naohiro Aota 2020-10-28 16:25:36 +09:00 committed by Jens Axboe
parent 35bc10b2ea
commit 4977d121bc

View File

@ -1044,6 +1044,7 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
ssize_t size, left;
unsigned len, i;
size_t offset;
int ret = 0;
if (WARN_ON_ONCE(!max_append_sectors))
return 0;
@ -1066,15 +1067,17 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
len = min_t(size_t, PAGE_SIZE - offset, left);
if (bio_add_hw_page(q, bio, page, len, offset,
max_append_sectors, &same_page) != len)
return -EINVAL;
max_append_sectors, &same_page) != len) {
ret = -EINVAL;
break;
}
if (same_page)
put_page(page);
offset = 0;
}
iov_iter_advance(iter, size);
return 0;
iov_iter_advance(iter, size - left);
return ret;
}
/**