From 56f20f4009d3c0b2e6165d9136fed40028c8225d Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Mon, 19 Nov 2018 17:37:45 +0200 Subject: [PATCH] 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 Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/sysfs.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 3717c864ba23..5a5930e3d32b 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -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, }; -- 2.30.2