littlefs: translate error code when mount fails

When lfs mount fails and there is no formatting requested, the return
code must be translated to errno before being passed to the application
layer.

Additionally, only log a warning that the FS will be formatted, when the
system is not read-only.

Fixes #56378

Signed-off-by: Manuel Arguelles <[email protected]>

Author: manuargue

subsys/fs/littlefs_fs.c

@@ -855,8 +855,8 @@ static int littlefs_mount(struct fs_mount_t *mountp)
 	ret = lfs_mount(&fs->lfs, &fs->cfg);
 	if (ret < 0 &&
 	    (mountp->flags & FS_MOUNT_FLAG_NO_FORMAT) == 0) {
-		LOG_WRN("can't mount (LFS %d); formatting", ret);
 		if ((mountp->flags & FS_MOUNT_FLAG_READ_ONLY) == 0) {
+			LOG_WRN("can't mount (LFS %d); formatting", ret);
 			ret = lfs_format(&fs->lfs, &fs->cfg);
 			if (ret < 0) {
 				LOG_ERR("format failed (LFS %d)", ret);
@@ -875,6 +875,9 @@ static int littlefs_mount(struct fs_mount_t *mountp)
 			ret = lfs_to_errno(ret);
 			goto out;
 		}
+	} else {
+		ret = lfs_to_errno(ret);
+		goto out;
 	}
 
 	LOG_INF("%s mounted", mountp->mnt_point);

tests/subsys/fs/common/test_fs_mkfs.c

@@ -26,7 +26,7 @@ void test_fs_mkfs_simple(void)
 	ret = fs_mount(fs_mkfs_mp);
 
 	if (fs_mkfs_mp->type == FS_LITTLEFS) {
-		zassert_equal(ret, -EILSEQ, "Expected EILSEQ got %d", ret);
+		zassert_equal(ret, -EFAULT, "Expected EFAULT got %d", ret);
 	} else if (fs_mkfs_mp->type == FS_FATFS) {
 		zassert_equal(ret, -ENODEV, "Expected ENODEV got %d", ret);
 	}