This patch introduces the options restart_on_error and panic_on_error on
dm-verity.
Previously, restarting on error was handled by the patch
e6a3531dd542cb127c8de32ab1e54a48ae19962b, but Google engineers wanted to
have a special option for it.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-verity-target.c | 83 +++++++++++++++++++++++++++++++++++++++++-
drivers/md/dm-verity.h | 1
2 files changed, 83 insertions(+), 1 deletion(-)
Index: linux-2.6/drivers/md/dm-verity-target.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-verity-target.c 2024-10-02 12:40:18.000000000 +0200
+++ linux-2.6/drivers/md/dm-verity-target.c 2024-10-02 16:02:07.000000000 +0200
@@ -36,11 +36,13 @@
#define DM_VERITY_OPT_LOGGING "ignore_corruption"
#define DM_VERITY_OPT_RESTART "restart_on_corruption"
#define DM_VERITY_OPT_PANIC "panic_on_corruption"
+#define DM_VERITY_OPT_ERROR_RESTART "restart_on_error"
+#define DM_VERITY_OPT_ERROR_PANIC "panic_on_error"
#define DM_VERITY_OPT_IGN_ZEROES "ignore_zero_blocks"
#define DM_VERITY_OPT_AT_MOST_ONCE "check_at_most_once"
#define DM_VERITY_OPT_TASKLET_VERIFY "try_verify_in_tasklet"
-#define DM_VERITY_OPTS_MAX (4 + DM_VERITY_OPTS_FEC + \
+#define DM_VERITY_OPTS_MAX (5 + DM_VERITY_OPTS_FEC + \
DM_VERITY_ROOT_HASH_VERIFICATION_OPTS)
static unsigned int dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE;
@@ -583,6 +585,11 @@ static inline bool verity_is_system_shut
|| system_state == SYSTEM_RESTART;
}
+static void restart_io_error(struct work_struct *w)
+{
+ kernel_restart("dm-verity device has I/O error");
+}
+
/*
* End one "io" structure with a given error.
*/
@@ -597,6 +604,23 @@ static void verity_finish_io(struct dm_v
if (!static_branch_unlikely(&use_bh_wq_enabled) || !io->in_bh)
verity_fec_finish_io(io);
+ if (unlikely(status != BLK_STS_OK) &&
+ unlikely(!(bio->bi_opf & REQ_RAHEAD)) &&
+ !verity_is_system_shutting_down()) {
+ if (v->error_mode == DM_VERITY_MODE_PANIC) {
+ panic("dm-verity device has I/O error");
+ }
+ if (v->error_mode == DM_VERITY_MODE_RESTART) {
+ static DECLARE_WORK(restart_work, restart_io_error);
+ queue_work(v->verify_wq, &restart_work);
+ /*
+ * We deliberately don't call bio_endio here, because
+ * the machine will be restarted anyway.
+ */
+ return;
+ }
+ }
+
bio_endio(bio);
}
@@ -805,6 +829,8 @@ static void verity_status(struct dm_targ
DMEMIT("%02x", v->salt[x]);
if (v->mode != DM_VERITY_MODE_EIO)
args++;
+ if (v->error_mode != DM_VERITY_MODE_EIO)
+ args++;
if (verity_fec_is_enabled(v))
args += DM_VERITY_OPTS_FEC;
if (v->zero_digest)
@@ -834,6 +860,19 @@ static void verity_status(struct dm_targ
BUG();
}
}
+ if (v->error_mode != DM_VERITY_MODE_EIO) {
+ DMEMIT(" ");
+ switch (v->error_mode) {
+ case DM_VERITY_MODE_RESTART:
+ DMEMIT(DM_VERITY_OPT_ERROR_RESTART);
+ break;
+ case DM_VERITY_MODE_PANIC:
+ DMEMIT(DM_VERITY_OPT_ERROR_PANIC);
+ break;
+ default:
+ BUG();
+ }
+ }
if (v->zero_digest)
DMEMIT(" " DM_VERITY_OPT_IGN_ZEROES);
if (v->validated_blocks)
@@ -886,6 +925,19 @@ static void verity_status(struct dm_targ
DMEMIT("invalid");
}
}
+ if (v->error_mode != DM_VERITY_MODE_EIO) {
+ DMEMIT(",verity_error_mode=");
+ switch (v->error_mode) {
+ case DM_VERITY_MODE_RESTART:
+ DMEMIT(DM_VERITY_OPT_ERROR_RESTART);
+ break;
+ case DM_VERITY_MODE_PANIC:
+ DMEMIT(DM_VERITY_OPT_ERROR_PANIC);
+ break;
+ default:
+ DMEMIT("invalid");
+ }
+ }
DMEMIT(";");
break;
}
@@ -1088,6 +1140,25 @@ static int verity_parse_verity_mode(stru
return 0;
}
+static inline bool verity_is_verity_error_mode(const char *arg_name)
+{
+ return (!strcasecmp(arg_name, DM_VERITY_OPT_ERROR_RESTART) ||
+ !strcasecmp(arg_name, DM_VERITY_OPT_ERROR_PANIC));
+}
+
+static int verity_parse_verity_error_mode(struct dm_verity *v, const char *arg_name)
+{
+ if (v->error_mode)
+ return -EINVAL;
+
+ if (!strcasecmp(arg_name, DM_VERITY_OPT_ERROR_RESTART))
+ v->error_mode = DM_VERITY_MODE_RESTART;
+ else if (!strcasecmp(arg_name, DM_VERITY_OPT_ERROR_PANIC))
+ v->error_mode = DM_VERITY_MODE_PANIC;
+
+ return 0;
+}
+
static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
struct dm_verity_sig_opts *verify_args,
bool only_modifier_opts)
@@ -1119,6 +1190,16 @@ static int verity_parse_opt_args(struct
if (r) {
ti->error = "Conflicting error handling parameters";
return r;
+ }
+ continue;
+
+ } else if (verity_is_verity_error_mode(arg_name)) {
+ if (only_modifier_opts)
+ continue;
+ r = verity_parse_verity_error_mode(v, arg_name);
+ if (r) {
+ ti->error = "Conflicting error handling parameters";
+ return r;
}
continue;
Index: linux-2.6/drivers/md/dm-verity.h
===================================================================
--- linux-2.6.orig/drivers/md/dm-verity.h 2024-10-02 12:39:50.000000000 +0200
+++ linux-2.6/drivers/md/dm-verity.h 2024-10-02 13:38:28.000000000 +0200
@@ -64,6 +64,7 @@ struct dm_verity {
unsigned int digest_size; /* digest size for the current hash algorithm */
unsigned int hash_reqsize; /* the size of temporary space for crypto */
enum verity_mode mode; /* mode for handling verification errors */
+ enum verity_mode error_mode;/* mode for handling I/O errors */
unsigned int corrupted_errs;/* Number of errors for corrupted blocks */
struct workqueue_struct *verify_wq;
