Hi Mikulas,
On Tue, Oct 29, 2024 at 11:17 AM Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote:
>
> If the user sets panic_on_error and doesn't set panic_on_corruption,
> dm-verity should not panic on data mismatch. But, currently it panics,
> because it treats data mismatch as I/O error.
>
> This commit fixes the logic so that if there is data mismatch and
> panic_on_corruption or restart_on_corruption is not selected, the system
> won't restart or panic.
>
> Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
> Fixes: f811b83879fb ("dm-verity: introduce the options restart_on_error and panic_on_error")
>
> ---
> drivers/md/dm-verity-target.c | 9 ++++++---
> drivers/md/dm-verity.h | 1 +
> 2 files changed, 7 insertions(+), 3 deletions(-)
>
> Index: linux-2.6/drivers/md/dm-verity-target.c
> ===================================================================
> --- linux-2.6.orig/drivers/md/dm-verity-target.c 2024-10-16 16:42:46.000000000 +0200
> +++ linux-2.6/drivers/md/dm-verity-target.c 2024-10-16 17:11:13.000000000 +0200
> @@ -356,9 +356,9 @@ static int verity_verify_level(struct dm
> else if (verity_handle_err(v,
> DM_VERITY_BLOCK_TYPE_METADATA,
> hash_block)) {
> - struct bio *bio =
> - dm_bio_from_per_bio_data(io,
> - v->ti->per_io_data_size);
> + struct bio *bio;
> + io->had_mismatch = true;
> + bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
> dm_audit_log_bio(DM_MSG_PREFIX, "verify-metadata", bio,
> block, 0);
> r = -EIO;
> @@ -482,6 +482,7 @@ static int verity_handle_data_hash_misma
> return -EIO; /* Error correction failed; Just return error */
>
> if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA, blkno)) {
> + io->had_mismatch = true;
> dm_audit_log_bio(DM_MSG_PREFIX, "verify-data", bio, blkno, 0);
> return -EIO;
> }
> @@ -606,6 +607,7 @@ static void verity_finish_io(struct dm_v
>
> if (unlikely(status != BLK_STS_OK) &&
> unlikely(!(bio->bi_opf & REQ_RAHEAD)) &&
> + !io->had_mismatch &&
> !verity_is_system_shutting_down()) {
> if (v->error_mode == DM_VERITY_MODE_PANIC) {
> panic("dm-verity device has I/O error");
> @@ -779,6 +781,7 @@ static int verity_map(struct dm_target *
> io->orig_bi_end_io = bio->bi_end_io;
> io->block = bio->bi_iter.bi_sector >> (v->data_dev_block_bits - SECTOR_SHIFT);
> io->n_blocks = bio->bi_iter.bi_size >> v->data_dev_block_bits;
> + io->had_mismatch = false;
>
> bio->bi_end_io = verity_end_io;
> bio->bi_private = io;
> Index: linux-2.6/drivers/md/dm-verity.h
> ===================================================================
> --- linux-2.6.orig/drivers/md/dm-verity.h 2024-10-16 16:41:30.000000000 +0200
> +++ linux-2.6/drivers/md/dm-verity.h 2024-10-16 17:06:37.000000000 +0200
> @@ -92,6 +92,7 @@ struct dm_verity_io {
> sector_t block;
> unsigned int n_blocks;
> bool in_bh;
> + bool had_mismatch;
This looks correct to me, although I assume wanting to panic only on
I/O errors is probably rare.
Reviewed-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Sami
