[PATCH v9 5/9] block: Make bio_iov_iter_get_pages() respect bio_required_sector_alignment()
From: Satya Tangirala <hidden>
Date: 2021-06-04 21:10:36
Also in:
linux-block, linux-f2fs-devel, linux-fscrypt, linux-xfs, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Previously, bio_iov_iter_get_pages() wasn't used with bios that could have an encryption context. However, direct I/O support using blk-crypto introduces this possibility, so this function must now respect bio_required_sector_alignment() (otherwise, xfstests like generic/465 with ext4 will fail). Signed-off-by: Satya Tangirala <redacted> --- block/bio.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/block/bio.c b/block/bio.c
index 32f75f31bb5c..99c510f706e2 100644
--- a/block/bio.c
+++ b/block/bio.c@@ -1099,7 +1099,8 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter) * The function tries, but does not guarantee, to pin as many pages as * fit into the bio, or are requested in @iter, whatever is smaller. If * MM encounters an error pinning the requested pages, it stops. Error - * is returned only if 0 pages could be pinned. + * is returned only if 0 pages could be pinned. It also ensures that the number + * of sectors added to the bio is aligned to bio_required_sector_alignment(). * * It's intended for direct IO, so doesn't do PSI tracking, the caller is * responsible for setting BIO_WORKINGSET if necessary.
@@ -1107,6 +1108,7 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter) int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { int ret = 0; + unsigned int aligned_sectors; if (iov_iter_is_bvec(iter)) { if (bio_op(bio) == REQ_OP_ZONE_APPEND)
@@ -1121,6 +1123,15 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) ret = __bio_iov_iter_get_pages(bio, iter); } while (!ret && iov_iter_count(iter) && !bio_full(bio, 0)); + /* + * Ensure that number of sectors in bio is aligned to + * bio_required_sector_align() + */ + aligned_sectors = round_down(bio_sectors(bio), + bio_required_sector_alignment(bio)); + iov_iter_revert(iter, (bio_sectors(bio) - aligned_sectors) << SECTOR_SHIFT); + bio_truncate(bio, aligned_sectors << SECTOR_SHIFT); + /* don't account direct I/O as memory stall */ bio_clear_flag(bio, BIO_WORKINGSET); return bio->bi_vcnt ? 0 : ret;
--
2.32.0.rc1.229.g3e70b5a671-goog