dm-verity: do forward error correction on metadata I/O errors
Do forward error correction if metadata I/O fails.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-verity-target.c | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
Index: linux-2.6/drivers/md/dm-verity-target.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-verity-target.c 2025-02-10 16:24:56.000000000 +0100
+++ linux-2.6/drivers/md/dm-verity-target.c 2025-02-17 16:47:37.000000000 +0100
@@ -311,7 +311,7 @@ static int verity_verify_level(struct dm
if (static_branch_unlikely(&use_bh_wq_enabled) && io->in_bh) {
data = dm_bufio_get(v->bufio, hash_block, &buf);
- if (data == NULL) {
+ if (IS_ERR_OR_NULL(data)) {
/*
* In tasklet and the hash was not in the bufio cache.
* Return early and resume execution from a work-queue
@@ -324,8 +324,24 @@ static int verity_verify_level(struct dm
&buf, bio->bi_ioprio);
}
- if (IS_ERR(data))
- return PTR_ERR(data);
+ if (IS_ERR(data)) {
+ if (skip_unverified)
+ return 1;
+ r = PTR_ERR(data);
+ data = dm_bufio_new(v->bufio, hash_block, &buf);
+ if (IS_ERR(data))
+ return r;
+ if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_METADATA,
+ hash_block, data) == 0) {
+ aux = dm_bufio_get_aux_data(buf);
+ aux->hash_verified = 1;
+ goto release_ok;
+ } else {
+ dm_bufio_release(buf);
+ dm_bufio_forget(v->bufio, hash_block);
+ return r;
+ }
+ }
aux = dm_bufio_get_aux_data(buf);
@@ -366,6 +382,7 @@ static int verity_verify_level(struct dm
}
}
+release_ok:
data += offset;
memcpy(want_digest, data, v->digest_size);
r = 0;
@@ -1761,7 +1778,7 @@ static struct target_type verity_target
.name = "verity",
/* Note: the LSMs depend on the singleton and immutable features */
.features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE,
- .version = {1, 10, 0},
+ .version = {1, 11, 0},
.module = THIS_MODULE,
.ctr = verity_ctr,
.dtr = verity_dtr,
