btrfs: split out the mount option validation code into its own helper

We're going to need to validate mount options after they're all parsed
with the new mount API, split this code out into its own helper so we
can use it when we swap over to the new mount API.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor adjustments in the messages ]
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/super.c

@@ -236,6 +236,41 @@ static bool check_ro_option(struct btrfs_fs_info *fs_info, unsigned long opt,
 	return false;
 }
 
+static bool check_options(struct btrfs_fs_info *info, unsigned long flags)
+{
+	bool ret = true;
+
+	if (!(flags & SB_RDONLY) &&
+	    (check_ro_option(info, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
+	     check_ro_option(info, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
+	     check_ro_option(info, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums")))
+		ret = false;
+
+	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
+	    !btrfs_test_opt(info, FREE_SPACE_TREE) &&
+	    !btrfs_test_opt(info, CLEAR_CACHE)) {
+		btrfs_err(info, "cannot disable free-space-tree");
+		ret = false;
+	}
+	if (btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE) &&
+	     !btrfs_test_opt(info, FREE_SPACE_TREE)) {
+		btrfs_err(info, "cannot disable free-space-tree with block-group-tree feature");
+		ret = false;
+	}
+
+	if (btrfs_check_mountopts_zoned(info))
+		ret = false;
+
+	if (!test_bit(BTRFS_FS_STATE_REMOUNTING, &info->fs_state)) {
+		if (btrfs_test_opt(info, SPACE_CACHE))
+			btrfs_info(info, "disk space caching is enabled");
+		if (btrfs_test_opt(info, FREE_SPACE_TREE))
+			btrfs_info(info, "using free-space-tree");
+	}
+
+	return ret;
+}
+
 static int parse_rescue_options(struct btrfs_fs_info *info, const char *options)
 {
 	char *opts;
@@ -314,7 +349,6 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 	int saved_compress_level;
 	bool saved_compress_force;
 	int no_compress = 0;
-	const bool remounting = test_bit(BTRFS_FS_STATE_REMOUNTING, &info->fs_state);
 
 	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
 		btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
@@ -333,7 +367,7 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 	 * against new flags
 	 */
 	if (!options)
-		goto check;
+		goto out;
 
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
@@ -777,35 +811,9 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 			break;
 		}
 	}
-check:
-	/* We're read-only, don't have to check. */
-	if (new_flags & SB_RDONLY)
-		goto out;
-
-	if (check_ro_option(info, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
-	    check_ro_option(info, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
-	    check_ro_option(info, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums"))
-		ret = -EINVAL;
 out:
-	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
-	    !btrfs_test_opt(info, FREE_SPACE_TREE) &&
-	    !btrfs_test_opt(info, CLEAR_CACHE)) {
-		btrfs_err(info, "cannot disable free space tree");
+	if (!ret && !check_options(info, new_flags))
 		ret = -EINVAL;
-	}
-	if (btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE) &&
-	     !btrfs_test_opt(info, FREE_SPACE_TREE)) {
-		btrfs_err(info, "cannot disable free space tree with block-group-tree feature");
-		ret = -EINVAL;
-	}
-	if (!ret)
-		ret = btrfs_check_mountopts_zoned(info);
-	if (!ret && !remounting) {
-		if (btrfs_test_opt(info, SPACE_CACHE))
-			btrfs_info(info, "disk space caching is enabled");
-		if (btrfs_test_opt(info, FREE_SPACE_TREE))
-			btrfs_info(info, "using free space tree");
-	}
 	return ret;
 }