btrfs-progs: mkfs: make -R|--runtime-features option deprecated

The option -R|--runtime-features was introduced to support features that
don't result in a full incompat flag change, thus things like
free-space-tree and quota features are put here.

But to end users, such separation of features is not helpful and can be
sometimes confusing.

Thus we're already migrating those runtime features into -O|--features
option under experimental builds.

I believe this is the proper time to move those runtime features into
-O|--features option, and mark the -R|--runtime-features option
deprecated.

For now we still keep the old option as for compatibility purposes.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Documentation/mkfs.btrfs.rst

@@ -161,18 +161,6 @@ OPTIONS
 
                 $ mkfs.btrfs -O list-all
 
--R|--runtime-features <feature1>[,<feature2>...]
-        A list of features that be can enabled at mkfs time, otherwise would have
-        to be turned on on a mounted filesystem.
-        To disable a feature, prefix it with *^*.
-
-        See section *RUNTIME FEATURES* for more details.  To see all available
-        runtime features that **mkfs.btrfs** supports run:
-
-        .. code-block:: bash
-
-                $ mkfs.btrfs -R list-all
-
 -f|--force
         Forcibly overwrite the block devices when an existing filesystem is detected.
         By default, **mkfs.btrfs** will utilize *libblkid* to check for any known
@@ -199,6 +187,11 @@ OPTIONS
 -l|--leafsize <size>
         Removed in 6.0, used to be alias for *--nodesize*.
 
+-R|--runtime-features <feature1>[,<feature2>...]
+        Removed in 6.3, was used to specify features not affecting on-disk format.
+        Now all such features are merged into `-O|--features` option. The option
+        -R will stay for backward compatibility.
+
 SIZE UNITS
 ----------
 
@@ -279,15 +272,6 @@ zoned
         see *ZONED MODE* in :doc:`btrfs(5)<btrfs-man5>`, the mode is automatically selected when
         a zoned device is detected
 
-
-RUNTIME FEATURES
-----------------
-
-Features that are typically enabled on a mounted filesystem, e.g. by a mount
-option or by an ioctl. Some of them can be enabled early, at mkfs time.  This
-applies to features that need to be enabled once and then the status is
-permanent, this does not replace mount options.
-
 quota
         (kernel support since 3.4)
 

common/fsfeatures.c

@@ -99,7 +99,6 @@ static const struct btrfs_feature mkfs_features[] = {
 		VERSION_NULL(default),
 		.desc		= "mixed data and metadata block groups"
 	},
-#if EXPERIMENTAL
 	{
 		.name		= "quota",
 		.runtime_flag	= BTRFS_FEATURE_RUNTIME_QUOTA,
@@ -109,7 +108,6 @@ static const struct btrfs_feature mkfs_features[] = {
 		VERSION_NULL(default),
 		.desc		= "quota support (qgroups)"
 	},
-#endif
 	{
 		.name		= "extref",
 		.incompat_flag	= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF,
@@ -143,7 +141,6 @@ static const struct btrfs_feature mkfs_features[] = {
 		VERSION_TO_STRING2(default, 5,15),
 		.desc		= "no explicit hole extents for files"
 	},
-#if EXPERIMENTAL
 	{
 		.name		= "free-space-tree",
 		.compat_ro_flag	= BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |
@@ -154,7 +151,6 @@ static const struct btrfs_feature mkfs_features[] = {
 		VERSION_TO_STRING2(default, 5,15),
 		.desc		= "free space tree (space_cache=v2)"
 	},
-#endif
 	{
 		.name		= "raid1c34",
 		.incompat_flag	= BTRFS_FEATURE_INCOMPAT_RAID1C34,
@@ -185,8 +181,6 @@ static const struct btrfs_feature mkfs_features[] = {
 		VERSION_NULL(default),
 		.desc		= "block group tree to reduce mount time"
 	},
-#endif
-#if EXPERIMENTAL
 	{
 		.name		= "extent-tree-v2",
 		.incompat_flag	= BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2,

mkfs/main.c

@@ -424,7 +424,6 @@ static const char * const mkfs_usage[] = {
 	OPTLINE("-n|--nodesize SIZE", "size of btree nodes"),
 	OPTLINE("-s|--sectorsize SIZE", "data block size (may not be mountable by current kernel)"),
 	OPTLINE("-O|--features LIST", "comma separated list of filesystem features (use '-O list-all' to list features)"),
-	OPTLINE("-R|--runtime-features LIST", "comma separated list of runtime features (use '-R list-all' to list runtime features)"),
 	OPTLINE("-L|--label LABEL", "set the filesystem label"),
 	OPTLINE("-U|--uuid UUID", "specify the filesystem UUID (must be unique)"),
 	"Creation:",
@@ -440,6 +439,7 @@ static const char * const mkfs_usage[] = {
 	OPTLINE("--help", "print this help and exit"),
 	"Deprecated:",
 	OPTLINE("-l|--leafsize SIZE", "removed in 6.0, use --nodesize"),
+	OPTLINE("-R|--runtime-features LIST", "removed in 6.3, use -O|--features"),
 	NULL
 };
 
@@ -1140,6 +1140,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 				char *orig = strdup(optarg);
 				char *tmp = orig;
 
+				warning("runtime features are deprecated, use -O|--features instead");
 				tmp = btrfs_parse_runtime_features(tmp,
 						&features);
 				if (tmp) {