fs: Add a minimal littlefs blocksize

Prevents littlefs from failing when block size is too small to work

Signed-off-by: Camille BAUD <[email protected]>

Author: VynDragon

subsys/fs/littlefs_fs.c

@@ -30,6 +30,8 @@
 
 /* Used on devices that have no explicit erase */
 #define LITTLEFS_DEFAULT_BLOCK_SIZE     4096
+/* Rounded up from minimal block size for littlefs working */
+#define LITTLEFS_MINIMUM_BLOCK_SIZE     128
 
 /* note: one of the next options have to be enabled, at least */
 BUILD_ASSERT(IS_ENABLED(CONFIG_FS_LITTLEFS_BLK_DEV) ||
@@ -786,6 +788,10 @@ static int littlefs_init_cfg(struct fs_littlefs *fs, int flags)
 		return -EINVAL;
 	}
 
+	if (block_size < LITTLEFS_MINIMUM_BLOCK_SIZE) {
+		block_size = LITTLEFS_MINIMUM_BLOCK_SIZE;
+	}
+
 	int32_t block_cycles = lcp->block_cycles;
 
 	if (block_cycles == 0) {