btrfs: sysfs: introduce helper for syncing bits with sysfs files

The files under /sys/fs/UUID/features get out of sync with the actual
incompat bits set for the filesystem if they change after mount. We're
going to sync them and need a helper to do that.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2016-01-21 18:50:40 +01:00
parent 3b5bb73bd8
commit 444e751698
2 changed files with 33 additions and 0 deletions

View File

@ -782,6 +782,36 @@ int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
return error;
}
/*
* Change per-fs features in /sys/fs/btrfs/UUID/features to match current
* values in superblock. Call after any changes to incompat/compat_ro flags
*/
void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
u64 bit, enum btrfs_feature_set set)
{
struct btrfs_fs_devices *fs_devs;
struct kobject *fsid_kobj;
u64 features;
int ret;
if (!fs_info)
return;
features = get_features(fs_info, set);
ASSERT(bit & supported_feature_masks[set]);
fs_devs = fs_info->fs_devices;
fsid_kobj = &fs_devs->fsid_kobj;
/*
* FIXME: this is too heavy to update just one value, ideally we'd like
* to use sysfs_update_group but some refactoring is needed first.
*/
sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
}
static int btrfs_init_debugfs(void)
{
#ifdef CONFIG_DEBUG_FS

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@ -90,4 +90,7 @@ int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs,
struct kobject *parent);
int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs);
void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs);
void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
u64 bit, enum btrfs_feature_set set);
#endif /* _BTRFS_SYSFS_H_ */