#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
+#include "sysfs.h"
+
+static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
+
+static u64 get_features(struct btrfs_fs_info *fs_info,
+ enum btrfs_feature_set set)
+{
+ struct btrfs_super_block *disk_super = fs_info->super_copy;
+ if (set == FEAT_COMPAT)
+ return btrfs_super_compat_flags(disk_super);
+ else if (set == FEAT_COMPAT_RO)
+ return btrfs_super_compat_ro_flags(disk_super);
+ else
+ return btrfs_super_incompat_flags(disk_super);
+}
+
+static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ int val = 0;
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ if (fs_info) {
+ struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
+ u64 features = get_features(fs_info, fa->feature_set);
+ if (features & fa->feature_bit)
+ val = 1;
+ }
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
+static umode_t btrfs_feature_visible(struct kobject *kobj,
+ struct attribute *attr, int unused)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ umode_t mode = attr->mode;
+
+ if (fs_info) {
+ struct btrfs_feature_attr *fa;
+ u64 features;
+
+ fa = attr_to_btrfs_feature_attr(attr);
+ features = get_features(fs_info, fa->feature_set);
+
+ if (!(features & fa->feature_bit))
+ mode = 0;
+ }
+
+ return mode;
+}
+
+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",
+ .is_visible = btrfs_feature_visible,
+ .attrs = btrfs_supported_feature_attrs,
+};
+
+static void btrfs_release_super_kobj(struct kobject *kobj)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ complete(&fs_info->kobj_unregister);
+}
+
+static struct kobj_type btrfs_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = btrfs_release_super_kobj,
+};
+
+static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
+{
+ if (kobj->ktype != &btrfs_ktype)
+ return NULL;
+ return container_of(kobj, struct btrfs_fs_info, super_kobj);
+}
+
+void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
+{
+ kobject_del(&fs_info->super_kobj);
+ kobject_put(&fs_info->super_kobj);
+ wait_for_completion(&fs_info->kobj_unregister);
+}
/* /sys/fs/btrfs/ entry */
static struct kset *btrfs_kset;
+int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
+{
+ int error;
+
+ init_completion(&fs_info->kobj_unregister);
+ fs_info->super_kobj.kset = btrfs_kset;
+ error = kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL,
+ "%pU", fs_info->fsid);
+
+ error = sysfs_create_group(&fs_info->super_kobj,
+ &btrfs_feature_attr_group);
+ if (error)
+ btrfs_sysfs_remove_one(fs_info);
+ return error;
+}
+
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);
}