diff options
| -rw-r--r-- | fs/btrfs/sysfs.c | 44 | ||||
| -rw-r--r-- | fs/btrfs/sysfs.h | 43 |
2 files changed, 87 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 5b326cd60a4a..9e217b581903 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -26,20 +26,64 @@ #include "ctree.h" #include "disk-io.h" #include "transaction.h" +#include "sysfs.h" + +static ssize_t btrfs_feature_attr_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "0\n"); +} + +BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); +BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); +BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); +BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO); +BTRFS_FEAT_ATTR_INCOMPAT(compress_lzov2, COMPRESS_LZOv2); +BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA); +BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF); +BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56); +BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA); + +static struct attribute *btrfs_supported_feature_attrs[] = { + BTRFS_FEAT_ATTR_PTR(mixed_backref), + BTRFS_FEAT_ATTR_PTR(default_subvol), + BTRFS_FEAT_ATTR_PTR(mixed_groups), + BTRFS_FEAT_ATTR_PTR(compress_lzo), + BTRFS_FEAT_ATTR_PTR(compress_lzov2), + BTRFS_FEAT_ATTR_PTR(big_metadata), + BTRFS_FEAT_ATTR_PTR(extended_iref), + BTRFS_FEAT_ATTR_PTR(raid56), + BTRFS_FEAT_ATTR_PTR(skinny_metadata), + NULL +}; + +static const struct attribute_group btrfs_feature_attr_group = { + .name = "features", + .attrs = btrfs_supported_feature_attrs, +}; /* /sys/fs/btrfs/ entry */ static struct kset *btrfs_kset; int btrfs_init_sysfs(void) { + int ret; btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); if (!btrfs_kset) return -ENOMEM; + + ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); + if (ret) { + kset_unregister(btrfs_kset); + return ret; + } + return 0; } void btrfs_exit_sysfs(void) { + sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); kset_unregister(btrfs_kset); } 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_ */ |