Extend mkfs options to specify optional or potentially backwards
incompatible features.
Signed-off-by: David Sterba <dsterba@xxxxxxx>
---
man/mkfs.btrfs.8.in | 9 ++++
mkfs.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 123 insertions(+), 10 deletions(-)
diff --git a/man/mkfs.btrfs.8.in b/man/mkfs.btrfs.8.in
index a3f1503..548e754 100644
--- a/man/mkfs.btrfs.8.in
+++ b/man/mkfs.btrfs.8.in
@@ -15,6 +15,7 @@ mkfs.btrfs \- create a btrfs filesystem
[ \fB\-s\fP\fI sectorsize\fP ]
[ \fB\-r\fP\fI rootdir\fP ]
[ \fB\-K\fP ]
+[ \fB\-O\fP\fI feature1,feature2,...\fP ]
[ \fB\-h\fP ]
[ \fB\-V\fP ]
\fI device\fP [ \fIdevice ...\fP ]
@@ -77,6 +78,14 @@ Specify a directory to copy into the newly created fs.
\fB\-K\fR, \fB\-\-nodiscard \fR
Do not perform whole device TRIM operation by default.
.TP
+\fB\-O\fR, \fB\-\-features \fIfeature1,feature2,...\fR
+A list of filesystem features turned on at mkfs time. Not all features are
+supported by old kernels.
+
+To see all run
+
+\fBmkfs.btrfs -O list-all\fR
+.TP
\fB\-V\fR, \fB\-\-version\fR
Print the \fBmkfs.btrfs\fP version and exit.
.SH UNIT
diff --git a/mkfs.c b/mkfs.c
index 7ff60e5..79a5779 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -336,6 +336,7 @@ static void print_usage(void)
fprintf(stderr, "\t -s --sectorsize min block allocation\n");
fprintf(stderr, "\t -r --rootdir the source directory\n");
fprintf(stderr, "\t -K --nodiscard do not perform whole device TRIM\n");
+ fprintf(stderr, "\t -O --features comma separated list of filesystem features\n");
fprintf(stderr, "\t -V --version print the mkfs.btrfs version and exit\n");
fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
exit(1);
@@ -397,6 +398,7 @@ static struct option long_options[] = {
{ "version", 0, NULL, 'V' },
{ "rootdir", 1, NULL, 'r' },
{ "nodiscard", 0, NULL, 'K' },
+ { "features", 0, NULL, 'O' },
{ 0, 0, 0, 0}
};
@@ -1253,6 +1255,87 @@ static int is_ssd(const char *file)
return !atoi((const char *)&rotational);
}
+#define BTRFS_FEATURE_LIST_ALL (1ULL << 63)
+
+static const struct btrfs_fs_feature {
+ const char *name;
+ u64 flag;
+ const char *desc;
+} mkfs_features[] = {
+ { "mixed-bg", BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS,
+ "mixed data and metadata block groups" },
+ { "extref", BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF,
+ "increased hardlink limit per file to 65536" },
+ { "raid56", BTRFS_FEATURE_INCOMPAT_RAID56,
+ "raid56 extended format" },
+ { "skinny-metadata", BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA,
+ "reduced-size metadata extent refs" },
+ /* Keep this one last */
+ { "list-all", BTRFS_FEATURE_LIST_ALL, NULL }
+};
+
+static void list_all_fs_features(void)
+{
+ int i;
+
+ fprintf(stderr, "Filesystem features available at mkfs time:\n");
+ for (i = 0; i < ARRAY_SIZE(mkfs_features) - 1; i++) {
+ fprintf(stderr, "%-20s- %s (0x%llx)\n",
+ mkfs_features[i].name,
+ mkfs_features[i].desc,
+ mkfs_features[i].flag);
+ }
+}
+
+static int parse_one_fs_feature(const char *name, u64 *flags)
+{
+ int i;
+ int found = 0;
+
+ for (i = 0; i < ARRAY_SIZE(mkfs_features); i++) {
+ if (!strcmp(mkfs_features[i].name, name)) {
+ *flags |= mkfs_features[i].flag;
+ found = 1;
+ }
+ }
+
+ return !found;
+}
+
+static void process_fs_features(u64 flags)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(mkfs_features); i++) {
+ if (flags & mkfs_features[i].flag) {
+ fprintf(stderr,
+ "Turning ON incompat feature '%s': %s\n",
+ mkfs_features[i].name,
+ mkfs_features[i].desc);
+ }
+ }
+}
+
+
+/*
+ * Return NULL if all features were parsed fine, otherwise return the name of
+ * the first unparsed.
+ */
+static char* parse_fs_features(char *namelist, u64 *flags)
+{
+ char *this_char;
+ char *save_ptr = NULL; /* Satisfy static checkers */
+
+ for (this_char = strtok_r(namelist, ",", &save_ptr);
+ this_char != NULL;
+ this_char = strtok_r(NULL, ",", &save_ptr)) {
+ if (parse_one_fs_feature(this_char, flags))
+ return this_char;
+ }
+
+ return NULL;
+}
+
int main(int ac, char **av)
{
char *file;
@@ -1293,10 +1376,11 @@ int main(int ac, char **av)
int dev_cnt = 0;
int saved_optind;
char estr[100];
+ u64 features = 0;
while(1) {
int c;
- c = getopt_long(ac, av, "A:b:fl:n:s:m:d:L:r:VMK",
+ c = getopt_long(ac, av, "A:b:fl:n:s:m:d:L:O:r:VMK",
long_options, &option_index);
if (c < 0)
break;
@@ -1326,6 +1410,25 @@ int main(int ac, char **av)
case 'M':
mixed = 1;
break;
+ case 'O': {
+ char *orig = strdup(optarg);
+ char *tmp = orig;
+
+ tmp = parse_fs_features(tmp, &features);
+ if (tmp) {
+ fprintf(stderr,
+ "Unrecognized filesystem feature '%s'\n",
+ tmp);
+ free(orig);
+ exit(1);
+ }
+ free(orig);
+ if (features & BTRFS_FEATURE_LIST_ALL) {
+ list_all_fs_features();
+ exit(0);
+ }
+ break;
+ }
case 's':
sectorsize = parse_size(optarg);
break;
@@ -1521,21 +1624,22 @@ raid_groups:
super = root->fs_info->super_copy;
flags = btrfs_super_incompat_flags(super);
+ /*
+ * FS features that can be set by other means than -O
+ * just set the bit here
+ */
if (mixed)
- flags |= BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS;
-
- btrfs_set_super_incompat_flags(super, flags);
+ features |= BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS;
if ((data_profile | metadata_profile) &
(BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
- struct btrfs_super_block *super = root->fs_info->super_copy;
- u64 flags = btrfs_super_incompat_flags(super);
-
- flags |= BTRFS_FEATURE_INCOMPAT_RAID56;
- btrfs_set_super_incompat_flags(super, flags);
- printf("Setting RAID5/6 feature flag\n");
+ features |= BTRFS_FEATURE_INCOMPAT_RAID56;
}
+ process_fs_features(features);
+ flags |= features;
+ btrfs_set_super_incompat_flags(super, flags);
+
printf("fs created label %s on %s\n\tnodesize %u leafsize %u "
"sectorsize %u size %s\n",
label, first_file, nodesize, leafsize, sectorsize,
--
1.8.2
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