From: Naohiro Aota naohiro.aota@wdc.com
commit 4977d121bc9bc5138d4d48b85469123001859573 upstream.
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: 0512a75b98f8 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- block/bio.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/block/bio.c +++ b/block/bio.c @@ -1046,6 +1046,7 @@ static int __bio_iov_append_get_pages(st ssize_t size, left; unsigned len, i; size_t offset; + int ret = 0;
if (WARN_ON_ONCE(!max_append_sectors)) return 0; @@ -1068,15 +1069,17 @@ static int __bio_iov_append_get_pages(st
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; }
/**