With this change and config option, dm-verity errors
will cause uevents to be sent to userspace, notifying
it that an error has occurred and potentially
triggering recovery actions.
Signed-off-by: Geremy Condra <gcondra@xxxxxxxxxx>
Change-Id: If3d9c00770d1a640faa0d42318cce675da40c000
---
drivers/md/Kconfig | 6 ++++++
drivers/md/dm-uevent.c | 40 ++++++++++++++++++++++++++++++++++++++++
drivers/md/dm-uevent.h | 12 ++++++++++--
drivers/md/dm-verity.c | 28 ++++++++++++++++++++++++++++
4 files changed, 84 insertions(+), 2 deletions(-)
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 10f122a..fab9c32 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -390,4 +390,10 @@ config DM_VERITY
If unsure, say N.
+config DM_VERITY_ERROR_NOTIFY
+ tristate "Notify userspace of verity errors through uevents"
+ depends on DM_VERITY && DM_UEVENT
+ ---help---
+ This option instructs dm-verity to send uevents on error.
+
endif # MD
diff --git a/drivers/md/dm-uevent.c b/drivers/md/dm-uevent.c
index 8efe033..17a6662 100644
--- a/drivers/md/dm-uevent.c
+++ b/drivers/md/dm-uevent.c
@@ -36,6 +36,8 @@ static const struct {
} _dm_uevent_type_names[] = {
{DM_UEVENT_PATH_FAILED, KOBJ_CHANGE, "PATH_FAILED"},
{DM_UEVENT_PATH_REINSTATED, KOBJ_CHANGE, "PATH_REINSTATED"},
+ {DM_UEVENT_VERITY_DATA_ERROR, KOBJ_CHANGE, "VERITY_DATA_ERROR"},
+ {DM_UEVENT_VERITY_HASH_ERROR, KOBJ_CHANGE, "VERITY_HASH_ERROR"},
};
static struct kmem_cache *_dm_event_cache;
@@ -202,6 +204,44 @@ void dm_path_uevent(enum dm_uevent_type event_type, struct dm_target *ti,
}
EXPORT_SYMBOL_GPL(dm_path_uevent);
+void dm_send_verity_uevent(enum dm_uevent_type event_type, struct dm_target *ti,
+ unsigned long long block_nr)
+{
+ struct mapped_device *md = dm_table_get_md(ti->table);
+ struct dm_uevent *event = dm_uevent_alloc(md);
+ struct gendisk *disk = dm_disk(md);
+
+ if (!event) {
+ DMERR("%s: dm_uevent_alloc() failed", __func__);
+ return;
+ }
+
+ if (event_type >= ARRAY_SIZE(_dm_uevent_type_names)) {
+ DMERR("%s: Invalid event_type %d", __func__, event_type);
+ goto out;
+ }
+
+ if (add_uevent_var(&event->ku_env, "DM_VERITY_BLOCK_NR=%llu", block_nr)) {
+ DMERR("%s: add_uevent_var() for DM_VERITY_BLOCK failed", __func__);
+ goto out;
+ }
+
+ if (add_uevent_var(&event->ku_env, "DM_ACTION=%s",
+ _dm_uevent_type_names[event_type].name)) {
+ DMERR("%s: add_uevent_var() for DM_ACTION failed", __func__);
+ goto out;
+ }
+
+ if (kobject_uevent_env(&disk_to_dev(disk)->kobj, event_type,
+ event->ku_env.envp)) {
+ DMERR("%s: kobject_uevent_env failed", __func__);
+ }
+
+out:
+ dm_uevent_free(event);
+}
+EXPORT_SYMBOL_GPL(dm_send_verity_uevent);
+
int dm_uevent_init(void)
{
_dm_event_cache = KMEM_CACHE(dm_uevent, 0);
diff --git a/drivers/md/dm-uevent.h b/drivers/md/dm-uevent.h
index 2eccc8b..1c59dba 100644
--- a/drivers/md/dm-uevent.h
+++ b/drivers/md/dm-uevent.h
@@ -24,6 +24,8 @@
enum dm_uevent_type {
DM_UEVENT_PATH_FAILED,
DM_UEVENT_PATH_REINSTATED,
+ DM_UEVENT_VERITY_DATA_ERROR,
+ DM_UEVENT_VERITY_HASH_ERROR,
};
#ifdef CONFIG_DM_UEVENT
@@ -34,7 +36,9 @@ extern void dm_send_uevents(struct list_head *events, struct kobject *kobj);
extern void dm_path_uevent(enum dm_uevent_type event_type,
struct dm_target *ti, const char *path,
unsigned nr_valid_paths);
-
+extern void dm_send_verity_uevent(enum dm_uevent_type event_type,
+ struct dm_target *ti,
+ unsigned long long block_nr);
#else
static inline int dm_uevent_init(void)
@@ -53,7 +57,11 @@ static inline void dm_path_uevent(enum dm_uevent_type event_type,
unsigned nr_valid_paths)
{
}
-
+static inline void dm_send_verity_uevent(enum dm_uevent_type event_type,
+ struct dm_target *ti,
+ unsigned long long block_nr)
+{
+}
#endif /* CONFIG_DM_UEVENT */
#endif /* DM_UEVENT_H */
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 68bf5c3..c9c9ecc 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -20,6 +20,8 @@
#include <linux/device-mapper.h>
#include <crypto/hash.h>
+#include "dm-uevent.h"
+
#define DM_MSG_PREFIX "verity"
#define DM_VERITY_IO_VEC_INLINE 16
@@ -137,6 +139,30 @@ static void dm_bufio_alloc_callback(struct dm_buffer *buf)
}
/*
+ * Trigger userspace data corruption handler.
+ */
+#ifdef CONFIG_DM_VERITY_ERROR_NOTIFY
+static void verity_data_error(struct dm_verity *v, unsigned long long block_nr)
+{
+ dm_send_verity_uevent(DM_UEVENT_VERITY_DATA_ERROR, v->ti, block_nr);
+}
+
+static void verity_hash_error(struct dm_verity *v, unsigned long long block_nr)
+{
+ dm_send_verity_uevent(DM_UEVENT_VERITY_HASH_ERROR, v->ti, block_nr);
+}
+#else
+static inline void verity_data_error(struct dm_verity *v,
+ unsigned long long block_nr)
+{
+}
+static inline void verity_hash_error(struct dm_verity *v,
+ unsigned long long block_nr)
+{
+}
+#endif
+
+/*
* Translate input sector number to the sector number on the target device.
*/
static sector_t verity_map_sector(struct dm_verity *v, sector_t bi_sector)
@@ -255,6 +281,7 @@ static int verity_verify_level(struct dm_verity_io *io, sector_t block,
(unsigned long long)hash_block);
v->hash_failed = 1;
r = -EIO;
+ verity_hash_error(v, (unsigned long long)hash_block);
goto release_ret_r;
} else
aux->hash_verified = 1;
@@ -375,6 +402,7 @@ test_block_hash:
DMERR_LIMIT("data block %llu is corrupted",
(unsigned long long)(io->block + b));
v->hash_failed = 1;
+ verity_data_error(v, (unsigned long long)(io->block + b));
return -EIO;
}
}
--
1.8.3
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
