fs: zms: add a version control

some future contributions could make the deployed ZMS storage incompatible with the current implementation. Add a version holder to handle this if needed. Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
zephyrproject-rtos · Sep 10, 2024 · acdc1b8 · acdc1b8
1 parent 013a303
commit acdc1b8
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Showing 3 changed files with 19 additions and 2 deletions.
diff --git a/subsys/fs/zms/zms.c b/subsys/fs/zms/zms.c
@@ -673,7 +673,7 @@ static int zms_add_empty_ate(struct zms_fs *fs, uint64_t addr)
 	empty_ate.id = ZMS_HEAD_ID;
 	empty_ate.len = 0xffff;
 	empty_ate.offset = 0U;
-	empty_ate.data = 0xffffffff;
+	empty_ate.data = ZMS_DEFAULT_VERSION;
 	rc = zms_get_sector_cycle(fs, addr, &cycle_cnt);
 	if (rc) {
 		if (rc == -ENOENT) {
@@ -989,6 +989,12 @@ static int zms_init(struct zms_fs *fs)
 		    (close_ate.cycle_cnt == empty_ate.cycle_cnt)) {
 			/* closed sector */
 			closed_sectors++;
+			/* Let's check first that we support this ZMS version */
+			if (ZMS_GET_VERSION(empty_ate.data) != ZMS_DEFAULT_VERSION) {
+				LOG_ERR("ZMS Version is not supported");
+				rc = -ENOEXEC;
+				goto end;
+			}
 			zms_sector_advance(fs, &addr);
 			/* addr is pointing to the close ATE */
 			rc = zms_get_sector_header(fs, addr, &empty_ate, &close_ate);
@@ -1033,6 +1039,13 @@ static int zms_init(struct zms_fs *fs)
 				zms_flash_erase_sector(fs, addr);
 			}
 			zms_add_empty_ate(fs, addr);
+		} else {
+			/* empty_ate is valid let's check the version */
+			if (ZMS_GET_VERSION(empty_ate.data) != ZMS_DEFAULT_VERSION) {
+				LOG_ERR("ZMS Version is not supported");
+				rc = -ENOEXEC;
+				goto end;
+			}
 		}
 		rc = zms_get_sector_cycle(fs, addr, &fs->sector_cycle);
 		if (rc) {
@@ -1186,6 +1199,7 @@ static int zms_init(struct zms_fs *fs)
 		rc = zms_add_gc_done_ate(fs);
 	}
 	k_mutex_unlock(&fs->zms_lock);
+
 	return rc;
 }
 

diff --git a/subsys/fs/zms/zms_priv.h b/subsys/fs/zms/zms_priv.h
@@ -22,6 +22,9 @@ extern "C" {
 #define ADDR_OFFS_MASK  GENMASK64(31, 0)
 #define SECTOR_NUM(x)   FIELD_GET(ADDR_SECT_MASK, x)
 
+#define ZMS_VERSION_MASK GENMASK(7, 0)
+#define ZMS_GET_VERSION(x) FIELD_GET(ZMS_VERSION_MASK, x)
+#define ZMS_DEFAULT_VERSION 1
 #define ZMS_BLOCK_SIZE 32
 
 #define ZMS_LOOKUP_CACHE_NO_ADDR GENMASK64(63, 0)

diff --git a/tests/subsys/fs/zms/src/main.c b/tests/subsys/fs/zms/src/main.c
@@ -587,7 +587,7 @@ ZTEST_F(zms, test_zms_gc_corrupt_close_ate)
 	empty_ate.id = 0xFFFFFFFF;
 	empty_ate.offset = 0;
 	empty_ate.len = 0xFFFF;
-	empty_ate.data = 0xffffffff;
+	empty_ate.data = 0x1;
 	empty_ate.cycle_cnt = 1;
 	empty_ate.crc8 = crc8_ccitt(0xff, &empty_ate, offsetof(struct zms_ate, crc8));
 	ate.id = 0x1;