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| author |   Jeff Mahoney <jeffm@suse.com> | 2013-11-01 13:06:57 -0400 |
|---|---|---|
| committer |   Chris Mason <clm@fb.com> | 2014-01-28 13:19:25 -0800 |
| commit | 079b72bca30dbc74c86c7c7825b8c34eb86ce3ee (patch) | |
| tree | ede5269ab3f4dbde076d9d7e5a3042c1966b1743 /fs/btrfs/sysfs.h | |
| parent | kobject: export kobj_sysfs_ops (diff) | |
| download | wireguard-linux-079b72bca30dbc74c86c7c7825b8c34eb86ce3ee.tar.xz wireguard-linux-079b72bca30dbc74c86c7c7825b8c34eb86ce3ee.zip | |
btrfs: publish supported featured in sysfs
This patch adds the ability to publish supported features to sysfs under
/sys/fs/btrfs/features.
The files are module-wide and export which features the kernel supports.
The content, for now, is just "0\n".
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/sysfs.h')
| -rw-r--r-- | fs/btrfs/sysfs.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.h b/fs/btrfs/sysfs.h new file mode 100644 index 000000000000..863e031ed1c1 --- /dev/null +++ b/fs/btrfs/sysfs.h @@ -0,0 +1,43 @@ +#ifndef _BTRFS_SYSFS_H_ +#define _BTRFS_SYSFS_H_ + +enum btrfs_feature_set { + FEAT_COMPAT, + FEAT_COMPAT_RO, + FEAT_INCOMPAT, + FEAT_MAX +}; + +#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \ +{ \ + .attr = { .name = __stringify(_name), .mode = _mode }, \ + .show = _show, \ + .store = _store, \ +} + +struct btrfs_feature_attr { + struct kobj_attribute kobj_attr; + enum btrfs_feature_set feature_set; + u64 feature_bit; +}; + +#define BTRFS_FEAT_ATTR(_name, _feature_set, _prefix, _feature_bit) \ +static struct btrfs_feature_attr btrfs_attr_##_name = { \ + .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO, \ + btrfs_feature_attr_show, NULL), \ + .feature_set = _feature_set, \ + .feature_bit = _prefix ##_## _feature_bit, \ +} +#define BTRFS_FEAT_ATTR_PTR(_name) (&btrfs_attr_##_name.kobj_attr.attr) + +#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \ + BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature) +#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \ + BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT, feature) +#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \ + BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature) + +/* convert from attribute */ +#define to_btrfs_feature_attr(a) \ + container_of(a, struct btrfs_feature_attr, kobj_attr) +#endif /* _BTRFS_SYSFS_H_ */ |