btrfstune -s <dev> prints "Seeding flag is currently [un]set", based on
whether or not BTRFS_SUPER_FLAG_SEEDING is enabled for the given device.
Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
---
Documentation/btrfstune.asciidoc | 3 +++
btrfstune.c | 29 +++++++++++++++++++++++++++--
2 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/Documentation/btrfstune.asciidoc b/Documentation/btrfstune.asciidoc
index 27100964..992da95d 100644
--- a/Documentation/btrfstune.asciidoc
+++ b/Documentation/btrfstune.asciidoc
@@ -30,6 +30,9 @@ Enable seeding on a given device. Value 1 will enable seeding, 0 will disable it
A seeding filesystem is forced to be mounted read-only. A new device can be added
to the filesystem and will capture all writes keeping the seeding device intact.
+-s::
+Print whether or not seeding is enabled for a given device.
+
-r::
(since kernel: 3.7)
+
diff --git a/btrfstune.c b/btrfstune.c
index 1e378ba1..603242b7 100644
--- a/btrfstune.c
+++ b/btrfstune.c
@@ -73,6 +73,15 @@ static int update_seeding_flag(struct btrfs_root *root, int set_flag)
return ret;
}
+static void check_seeding_flag(struct btrfs_root *root)
+{
+ struct btrfs_super_block *disk_super = root->fs_info->super_copy;
+ u64 super_flags = btrfs_super_flags(disk_super);
+
+ printf("Seeding flag is currently %sset\n",
+ (super_flags & BTRFS_SUPER_FLAG_SEEDING ? "" : "un"));
+}
+
static int set_super_incompat_flags(struct btrfs_root *root, u64 flags)
{
struct btrfs_trans_handle *trans;
@@ -374,6 +383,7 @@ static void print_usage(void)
{
printf("usage: btrfstune [options] device\n");
printf("\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
+ printf("\t-s \t\tcheck whether seeding is enabled\n");
printf("\t-r \t\tenable extended inode refs\n");
printf("\t-x \t\tenable skinny metadata extent refs\n");
printf("\t-n \t\tenable no-holes feature (more efficient sparse file representation)\n");
@@ -390,6 +400,7 @@ int main(int argc, char *argv[])
int total = 0;
int seeding_flag = 0;
u64 seeding_value = 0;
+ int check_seeding = 0;
int random_fsid = 0;
char *new_fsid_str = NULL;
int ret;
@@ -401,7 +412,7 @@ int main(int argc, char *argv[])
{ "help", no_argument, NULL, GETOPT_VAL_HELP},
{ NULL, 0, NULL, 0 }
};
- int c = getopt_long(argc, argv, "S:rxfuU:n", long_options, NULL);
+ int c = getopt_long(argc, argv, "S:srxfuU:n", long_options, NULL);
if (c < 0)
break;
@@ -410,6 +421,9 @@ int main(int argc, char *argv[])
seeding_flag = 1;
seeding_value = arg_strtou64(optarg);
break;
+ case 's':
+ check_seeding = 1;
+ break;
case 'r':
super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
break;
@@ -448,7 +462,12 @@ int main(int argc, char *argv[])
error("random fsid can't be used with specified fsid");
return 1;
}
- if (!super_flags && !seeding_flag && !(random_fsid || new_fsid_str)) {
+ if (seeding_flag && check_seeding) {
+ error("check seeding can't be used alongside set seeding");
+ return 1;
+ }
+ if (!super_flags && !seeding_flag && !check_seeding &&
+ !(random_fsid || new_fsid_str)) {
error("at least one option should be specified");
print_usage();
return 1;
@@ -512,6 +531,12 @@ int main(int argc, char *argv[])
total++;
}
+ if (check_seeding) {
+ check_seeding_flag(root);
+ success++;
+ total++;
+ }
+
if (super_flags) {
ret = set_super_incompat_flags(root, super_flags);
if (!ret)
--
2.13.7
