@@ -271,6 +271,12 @@ struct btrfs_super_block {
(BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
#define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR 0ULL
+#define BTRFS_FEATURE_KERNEL_SUPP \
+ BTRFS_FEATURE_KERNEL_RMDIR_SUBVOL
+
+#define BTRFS_FEATURE_KERNEL_SAFE_SET 0ULL
+#define BTRFS_FEATURE_KERNEL_SAFE_CLEAR 0ULL
+
/*
* A leaf is full of items. offset and size tell us where to find
* the item in the leaf (relative to the start of the data area)
@@ -30,20 +30,24 @@ static u64 get_features(struct btrfs_fs_info *fs_info,
return btrfs_super_compat_flags(disk_super);
else if (set == FEAT_COMPAT_RO)
return btrfs_super_compat_ro_flags(disk_super);
- else
+ else if (set == FEAT_INCOMPAT)
return btrfs_super_incompat_flags(disk_super);
+ else
+ return BTRFS_FEATURE_KERNEL_SUPP;
}
static void set_features(struct btrfs_fs_info *fs_info,
enum btrfs_feature_set set, u64 features)
{
struct btrfs_super_block *disk_super = fs_info->super_copy;
+
if (set == FEAT_COMPAT)
btrfs_set_super_compat_flags(disk_super, features);
else if (set == FEAT_COMPAT_RO)
btrfs_set_super_compat_ro_flags(disk_super, features);
- else
+ else if (set == FEAT_INCOMPAT)
btrfs_set_super_incompat_flags(disk_super, features);
+ /* Nothing for FEAT_KERNEL for now */
}
static int can_modify_feature(struct btrfs_feature_attr *fa)
@@ -63,6 +67,10 @@ static int can_modify_feature(struct btrfs_feature_attr *fa)
set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
break;
+ case FEAT_KERNEL:
+ set = BTRFS_FEATURE_KERNEL_SAFE_SET;
+ clear = BTRFS_FEATURE_KERNEL_SAFE_CLEAR;
+ break;
default:
pr_warn("btrfs: sysfs: unknown feature set %d\n",
fa->feature_set);
@@ -110,6 +118,10 @@ static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
if (sb_rdonly(fs_info->sb))
return -EROFS;
+ /* FEAT_KERNEL features cannot be changed at runtime */
+ if (fa->feature_set == FEAT_KERNEL)
+ return -EINVAL;
+
ret = kstrtoul(skip_spaces(buf), 0, &val);
if (ret)
return ret;
@@ -174,7 +186,10 @@ static umode_t btrfs_feature_visible(struct kobject *kobj,
fa = attr_to_btrfs_feature_attr(attr);
features = get_features(fs_info, fa->feature_set);
- if (can_modify_feature(fa))
+ /* Do not show FEAT_KERNEL features in /sys/fs/UUID/features */
+ if (fa->feature_set == FEAT_KERNEL)
+ mode = 0;
+ else if (can_modify_feature(fa))
mode |= S_IWUSR;
else if (!(features & fa->feature_bit))
mode = 0;
@@ -194,6 +209,7 @@ 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_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
+BTRFS_FEAT_ATTR_KERNEL(rmdir_subvol, RMDIR_SUBVOL);
static struct attribute *btrfs_supported_feature_attrs[] = {
BTRFS_FEAT_ATTR_PTR(mixed_backref),
@@ -207,6 +223,7 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
BTRFS_FEAT_ATTR_PTR(skinny_metadata),
BTRFS_FEAT_ATTR_PTR(no_holes),
BTRFS_FEAT_ATTR_PTR(free_space_tree),
+ BTRFS_FEAT_ATTR_PTR(rmdir_subvol),
NULL
};
@@ -515,10 +532,11 @@ static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
#define NUM_FEATURE_BITS 64
#define BTRFS_FEATURE_NAME_MAX 13
-static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
-static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
+/* These are for features related to feature bit and FEAT_KERNEL is excluded */
+static char btrfs_unknown_feature_names[FEAT_MAX-1][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
+static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX-1][NUM_FEATURE_BITS];
-static const u64 supported_feature_masks[FEAT_MAX] = {
+static const u64 supported_feature_masks[FEAT_MAX-1] = {
[FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP,
[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
[FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP,
@@ -528,7 +546,7 @@ static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
{
int set;
- for (set = 0; set < FEAT_MAX; set++) {
+ for (set = 0; set < FEAT_MAX-1; set++) {
int i;
struct attribute *attrs[2];
struct attribute_group agroup = {
@@ -610,7 +628,7 @@ void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL);
}
-const char * const btrfs_feature_set_names[FEAT_MAX] = {
+const char * const btrfs_feature_set_names[FEAT_MAX-1] = {
[FEAT_COMPAT] = "compat",
[FEAT_COMPAT_RO] = "compat_ro",
[FEAT_INCOMPAT] = "incompat",
@@ -666,7 +684,7 @@ static void init_feature_attrs(void)
fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
}
- for (set = 0; set < FEAT_MAX; set++) {
+ for (set = 0; set < FEAT_MAX-1; set++) {
for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
char *name = btrfs_unknown_feature_names[set][i];
fa = &btrfs_feature_attrs[set][i];
@@ -12,6 +12,7 @@ enum btrfs_feature_set {
FEAT_COMPAT,
FEAT_COMPAT_RO,
FEAT_INCOMPAT,
+ FEAT_KERNEL, /* Kernel feature indepenedent of feature bits */
FEAT_MAX
};
@@ -57,6 +58,8 @@ static struct btrfs_feature_attr btrfs_attr_features_##_name = { \
BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
+#define BTRFS_FEAT_ATTR_KERNEL(name, feature) \
+ BTRFS_FEAT_ATTR(name, FEAT_KERNEL, BTRFS_FEATURE_KERNEL, feature)
/* convert from attribute */
static inline struct btrfs_feature_attr *
@@ -77,7 +80,7 @@ attr_to_btrfs_feature_attr(struct attribute *attr)
}
char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags);
-extern const char * const btrfs_feature_set_names[FEAT_MAX];
+extern const char * const btrfs_feature_set_names[FEAT_MAX-1];
extern struct kobj_type space_info_ktype;
extern struct kobj_type btrfs_raid_ktype;
int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices,
@@ -270,6 +270,8 @@ struct btrfs_ioctl_fs_info_args {
#define BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA (1ULL << 8)
#define BTRFS_FEATURE_INCOMPAT_NO_HOLES (1ULL << 9)
+#define BTRFS_FEATURE_KERNEL_RMDIR_SUBVOL (1ULL << 0)
+
struct btrfs_ioctl_feature_flags {
__u64 compat_flags;
__u64 compat_ro_flags;
Deletion of a subvolume by rmdir(2) has become allowed by the 'commit cd2decf640b1 ("btrfs: Allow rmdir(2) to delete an empty subvolume")'. It is a kind of new feature and this commits add new sysfs entry /sys/fs/btrfs/features/rmdir_subvol to indicate the feature. Since the behavior is independent of feature bits of superblock, new type FEAT_KERNEL is added to struct btrfs_feature_set. Features of FEAT_KERNEL is supposed to be visible only in /sys/fs/features and not in /sys/fs/UUID/features. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> --- fs/btrfs/ctree.h | 6 ++++++ fs/btrfs/sysfs.c | 36 +++++++++++++++++++++++++++--------- fs/btrfs/sysfs.h | 5 ++++- include/uapi/linux/btrfs.h | 2 ++ 4 files changed, 39 insertions(+), 10 deletions(-)