btrfs: Add sysfs support for metadata_uuid feature

Since the metadata_uuid is a new incompat feature it requires the
respective sysfs hooks. This patch adds the 'metdata_uuid' feature to
be shown if it supported by the kernel. Additionally it adds
/sys/fs/btrfs/UUID/metadata_uuid attribute which allows one to read
the current metadata_uuid.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Nikolay Borisov 2018-11-19 17:37:45 +02:00 committed by David Sterba
parent 7239ff4b2b
commit 56f20f4009

View File

@ -191,6 +191,7 @@ BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
static struct attribute *btrfs_supported_feature_attrs[] = {
@ -204,6 +205,7 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
BTRFS_FEAT_ATTR_PTR(raid56),
BTRFS_FEAT_ATTR_PTR(skinny_metadata),
BTRFS_FEAT_ATTR_PTR(no_holes),
BTRFS_FEAT_ATTR_PTR(metadata_uuid),
BTRFS_FEAT_ATTR_PTR(free_space_tree),
NULL
};
@ -505,12 +507,24 @@ static ssize_t quota_override_store(struct kobject *kobj,
BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
return snprintf(buf, PAGE_SIZE, "%pU\n",
fs_info->fs_devices->metadata_uuid);
}
BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
static const struct attribute *btrfs_attrs[] = {
BTRFS_ATTR_PTR(, label),
BTRFS_ATTR_PTR(, nodesize),
BTRFS_ATTR_PTR(, sectorsize),
BTRFS_ATTR_PTR(, clone_alignment),
BTRFS_ATTR_PTR(, quota_override),
BTRFS_ATTR_PTR(, metadata_uuid),
NULL,
};