utils: add support for getting/changing file system, features

index f41a72a..ca096e0 100644
@@ -515,6 +515,47 @@ static int cmd_label(int argc, char **argv)
 		return get_label(argv[1]);
 }
 
+static const char * const cmd_features_usage[] = {
+	"btrfs filesystem features [<device>|<mountpoint>] [[-f] <features>]",
+	"Get or change the list of features currently enabled by a filesystem",
+	"With one argument, get the currently enabled features of filesystem",
+	"on <device> or <mountpoint>.", "",
+	"If <features> is passed, add new features to the file system.",
+	"The format of new features can be a comma separated list of names or",
+	"or a comma-separated list of specifiers of the following format: A",
+	"prefix of compat, compat_ro, or incompat and a decimal number, ",
+	"separated by a colon: (e.g. compat:10)", "",
+	"Features to be enabled will be confirmed against the supported",
+	"features of the kernel (if mounted) or the progs (if unmounted). This",
+	"behavior can be overridden when operating on unmounted",
+	"filesystems by using the -f (force) flag.", "",
+	"A list of features supported by the progs can be found in the manual.",
+	NULL
+};
+
+static int cmd_features(int argc, char **argv)
+{
+	if (check_argc_min(argc, 2) || check_argc_max(argc, 4))
+		usage(cmd_features_usage);
+
+	if (argc > 2) {
+		char *features = argv[2];
+		int force = 0;
+		if (argc > 3) {
+			if (!strcmp(argv[3], "-f"))
+				force = 1;
+			else if (!strcmp(argv[2], "-f")) {
+				force = 1;
+				features = argv[3];
+			} else
+				usage(cmd_features_usage);
+		}
+
+		return parse_and_set_features(argv[1], features, force);
+	} else
+		return get_features(argv[1]);
+}
+
 const struct cmd_group filesystem_cmd_group = {
 	filesystem_cmd_group_usage, NULL, {
 		{ "df", cmd_df, cmd_df_usage, NULL, 0 },

@@ -524,6 +565,7 @@ const struct cmd_group filesystem_cmd_group = {
 		{ "balance", cmd_balance, NULL, &balance_cmd_group, 1 },
 		{ "resize", cmd_resize, cmd_resize_usage, NULL, 0 },
 		{ "label", cmd_label, cmd_label_usage, NULL, 0 },
+		{ "features", cmd_features, cmd_features_usage, NULL, 0 },
 		{ 0, 0, 0, 0, 0 },
 	}
 };

index abe6dd4..44483d1 100644
@@ -172,6 +172,12 @@ struct btrfs_ioctl_fs_info_args {
 	__u64 reserved[124];			/* pad to 1k */
 };
 
+struct btrfs_ioctl_feature_flags {
+	__u64 compat_flags;
+	__u64 compat_ro_flags;
+	__u64 incompat_flags;
+};
+
 /* balance control ioctl modes */
 #define BTRFS_BALANCE_CTL_PAUSE		1
 #define BTRFS_BALANCE_CTL_CANCEL	2

@@ -537,6 +543,12 @@ struct btrfs_ioctl_clone_range_args {
 				      struct btrfs_ioctl_get_dev_stats)
 #define BTRFS_IOC_DEV_REPLACE _IOWR(BTRFS_IOCTL_MAGIC, 53, \
 				    struct btrfs_ioctl_dev_replace_args)
+#define BTRFS_IOC_GET_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 54, \
+				    struct btrfs_ioctl_feature_flags)
+#define BTRFS_IOC_ADD_FEATURES _IOW(BTRFS_IOCTL_MAGIC, 55, \
+				    struct btrfs_ioctl_feature_flags)
+#define BTRFS_IOC_GET_SUPPORTED_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 56, \
+				    struct btrfs_ioctl_feature_flags[2])
 
 #ifdef __cplusplus
 }

490 lines not on this page · raw message

index 3c17e14..ca86025 100644
@@ -55,6 +55,16 @@ int get_fs_info(char *path, struct btrfs_ioctl_fs_info_args *fi_args,
 		struct btrfs_ioctl_dev_info_args **di_ret);
 int get_label(const char *btrfs_dev);
 int set_label(const char *btrfs_dev, const char *label);
+int get_features(const char *btrfs_dev);
+int parse_features(const char *features,
+		   struct btrfs_ioctl_feature_flags *set_flags,
+		   struct btrfs_ioctl_feature_flags *clear_flags);
+int set_features(const char *btrfs_dev,
+		 const struct btrfs_ioctl_feature_flags *flags,
+		 const struct btrfs_ioctl_feature_flags *clear_flags,
+		 int force);
+int parse_and_set_features(const char *btrfs_dev, const char *features,
+			   int force);
 
 char *__strncpy__null(char *dest, const char *src, size_t n);
 int is_block_device(const char *file);