On 4.01.19 г. 1:22 ч., David Disseldorp wrote:
> 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>
btrfs inspect-internal dump-super already supports showing seeding, why
do we need btrfstune support for that as well? Also the way you've
phrased is a bit misleading, since checking the superflag doesn't mean
seeding for a particular _device_ is enabled but that the filesystem
itself is set as seeding.
> ---
> 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)
>
