fs: zms: Add flag to wipe partition on mount failure

include/zephyr/fs/zms.h

@@ -92,6 +92,7 @@ typedef uint32_t zms_id_t;
  * @brief Mount a ZMS file system onto the device specified in `fs`.
  *
  * @param fs Pointer to the file system.
+ * @param wipe_on_failure If true, the partition will be wiped if mounting fails the first time.
  *
  * @retval 0 on success.
  * @retval -ENOTSUP if the detected file system is not ZMS.
@@ -100,7 +101,7 @@ typedef uint32_t zms_id_t;
  * @retval -ENXIO if there is a device error.
  * @retval -EIO if there is a memory read/write error.
  */
-int zms_mount(struct zms_fs *fs);
+int zms_mount(struct zms_fs *fs, bool wipe_on_failure);
 
 /**
  * @brief Clear the ZMS file system from device. The ZMS file system must be re-mounted after this

subsys/fs/zms/zms.c

@@ -21,6 +21,7 @@ LOG_MODULE_REGISTER(fs_zms, CONFIG_ZMS_LOG_LEVEL);
 
 static int zms_prev_ate(struct zms_fs *fs, uint64_t *addr, struct zms_ate *ate);
 static int zms_ate_valid(struct zms_fs *fs, const struct zms_ate *entry);
+static int zms_add_empty_ate(struct zms_fs *fs, uint64_t addr);
 static int zms_get_sector_cycle(struct zms_fs *fs, uint64_t addr, uint8_t *cycle_cnt);
 static int zms_get_sector_header(struct zms_fs *fs, uint64_t addr, struct zms_ate *empty_ate,
 				 struct zms_ate *close_ate);
@@ -598,6 +599,26 @@ static int zms_flash_write_entry(struct zms_fs *fs, zms_id_t id, const void *dat
 	return 0;
 }
 
+/* zms_wipe_partition erases the whole partition used by ZMS */
+static int zms_wipe_partition(struct zms_fs *fs)
+{
+	int rc;
+	uint64_t addr;
+
+	for (uint32_t i = 0; i < fs->sector_count; i++) {
+		addr = (uint64_t)i << ADDR_SECT_SHIFT;
+		rc = zms_flash_erase_sector(fs, addr);
+		if (rc) {
+			return rc;
+		}
+		rc = zms_add_empty_ate(fs, addr);
+		if (rc) {
+			return rc;
+		}
+	}
+	return 0;
+}
+
 /* end of flash routines */
 
 /* Search for the last valid ATE written in a sector and also update data write address
@@ -1128,7 +1149,6 @@ static int zms_gc(struct zms_fs *fs)
 int zms_clear(struct zms_fs *fs)
 {
 	int rc;
-	uint64_t addr;
 
 	if (!fs) {
 		LOG_ERR("Invalid fs");
@@ -1141,25 +1161,15 @@ int zms_clear(struct zms_fs *fs)
 	}
 
 	k_mutex_lock(&fs->zms_lock, K_FOREVER);
-	for (uint32_t i = 0; i < fs->sector_count; i++) {
-		addr = (uint64_t)i << ADDR_SECT_SHIFT;
-		rc = zms_flash_erase_sector(fs, addr);
-		if (rc) {
-			goto end;
-		}
-		rc = zms_add_empty_ate(fs, addr);
-		if (rc) {
-			goto end;
-		}
-	}
+
+	rc = zms_wipe_partition(fs);
 
 	/* zms needs to be reinitialized after clearing */
 	fs->ready = false;
 
-end:
 	k_mutex_unlock(&fs->zms_lock);
 
-	return 0;
+	return rc;
 }
 
 static int zms_init(struct zms_fs *fs)
@@ -1459,7 +1469,7 @@ static int zms_init(struct zms_fs *fs)
 	return rc;
 }
 
-int zms_mount(struct zms_fs *fs)
+int zms_mount(struct zms_fs *fs, bool wipe_on_failure)
 {
 	int rc;
 	struct flash_pages_info info;
@@ -1519,6 +1529,13 @@ int zms_mount(struct zms_fs *fs)
 
 	rc = zms_init(fs);
 
+	if (rc && wipe_on_failure) {
+		/* wipe partition and try once more */
+		LOG_WRN("ZMS init failed (%d), wiping partition", rc);
+		zms_wipe_partition(fs);
+		rc = zms_init(fs);
+	}
+
 	if (rc) {
 		return rc;
 	}

subsys/settings/Kconfig

@@ -92,6 +92,13 @@ config SETTINGS_ZMS_LL_CACHE_SIZE
 	help
 	  Number of entries in Settings ZMS linked list cache.
 
+config SETTINGS_ZMS_WIPE_ON_MOUNT_FAILURE
+	bool "ZMS wipe on mount failure"
+	default n
+	help
+	  Enable wiping of ZMS storage on mount failure to recover from
+	  corrupted data.
+
 endif # SETTINGS_ZMS
 
 config SETTINGS_FCB

subsys/settings/src/settings_zms.c

@@ -680,13 +680,14 @@ static int settings_zms_get_last_hash_ids(struct settings_zms *cf)
 static int settings_zms_backend_init(struct settings_zms *cf)
 {
 	int rc;
+	bool wipe_on_failure = IS_ENABLED(CONFIG_SETTINGS_ZMS_WIPE_ON_MOUNT_FAILURE);
 
 	cf->cf_zms.flash_device = cf->flash_dev;
 	if (cf->cf_zms.flash_device == NULL) {
 		return -ENODEV;
 	}
 
-	rc = zms_mount(&cf->cf_zms);
+	rc = zms_mount(&cf->cf_zms, wipe_on_failure);
 	if (rc) {
 		return rc;
 	}