1 files changed, 73 insertions, 60 deletions

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index b535285642dc..f25deb9c132c 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -419,28 +419,84 @@ static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
         return container_of(kobj, struct btrfs_fs_info, super_kobj);
 }
 
-void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
+#define NUM_FEATURE_BITS 64
+static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
+static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];
+
+static u64 supported_feature_masks[3] = {
+        [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
+        [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
+        [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
+};
+
+static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
+{
+        int set;
+
+        for (set = 0; set < FEAT_MAX; set++) {
+                int i;
+                struct attribute *attrs[2];
+                struct attribute_group agroup = {
+                        .name = "features",
+                        .attrs = attrs,
+                };
+                u64 features = get_features(fs_info, set);
+                features &= ~supported_feature_masks[set];
+
+                if (!features)
+                        continue;
+
+                attrs[1] = NULL;
+                for (i = 0; i < NUM_FEATURE_BITS; i++) {
+                        struct btrfs_feature_attr *fa;
+
+                        if (!(features & (1ULL << i)))
+                                continue;
+
+                        fa = &btrfs_feature_attrs[set][i];
+                        attrs[0] = &fa->kobj_attr.attr;
+                        if (add) {
+                                int ret;
+                                ret = sysfs_merge_group(&fs_info->super_kobj,
+                                                        &agroup);
+                                if (ret)
+                                        return ret;
+                        } else
+                                sysfs_unmerge_group(&fs_info->super_kobj,
+                                                    &agroup);
+                }
+
+        }
+        return 0;
+}
+
+static void __btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
 {
-        sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
-        kobject_del(fs_info->device_dir_kobj);
-        kobject_put(fs_info->device_dir_kobj);
-        kobject_del(fs_info->space_info_kobj);
-        kobject_put(fs_info->space_info_kobj);
         kobject_del(&fs_info->super_kobj);
         kobject_put(&fs_info->super_kobj);
         wait_for_completion(&fs_info->kobj_unregister);
 }
 
+void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
+{
+        if (fs_info->space_info_kobj) {
+                sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
+                kobject_del(fs_info->space_info_kobj);
+                kobject_put(fs_info->space_info_kobj);
+        }
+        kobject_del(fs_info->device_dir_kobj);
+        kobject_put(fs_info->device_dir_kobj);
+        addrm_unknown_feature_attrs(fs_info, false);
+        sysfs_remove_group(&fs_info->super_kobj, &btrfs_feature_attr_group);
+        __btrfs_sysfs_remove_one(fs_info);
+}
+
 const char * const btrfs_feature_set_names[3] = {
         [FEAT_COMPAT]    = "compat",
         [FEAT_COMPAT_RO] = "compat_ro",
         [FEAT_INCOMPAT]  = "incompat",
 };
 
-#define NUM_FEATURE_BITS 64
-static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
-static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];
-
 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
 {
         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
@@ -510,53 +566,6 @@ static void init_feature_attrs(void)
         }
 }
 
-static u64 supported_feature_masks[3] = {
-        [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
-        [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
-        [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
-};
-
-static int add_unknown_feature_attrs(struct btrfs_fs_info *fs_info)
-{
-        int set;
-
-        for (set = 0; set < FEAT_MAX; set++) {
-                int i, count, ret, index = 0;
-                struct attribute **attrs;
-                struct attribute_group agroup = {
-                        .name = "features",
-                };
-                u64 features = get_features(fs_info, set);
-                features &= ~supported_feature_masks[set];
-
-                count = hweight64(features);
-
-                if (!count)
-                        continue;
-
-                attrs = kcalloc(count + 1, sizeof(void *), GFP_KERNEL);
-
-                for (i = 0; i < NUM_FEATURE_BITS; i++) {
-                        struct btrfs_feature_attr *fa;
-
-                        if (!(features & (1ULL << i)))
-                                continue;
-
-                        fa = &btrfs_feature_attrs[set][i];
-                        attrs[index++] = &fa->kobj_attr.attr;
-                }
-
-                attrs[index] = NULL;
-                agroup.attrs = attrs;
-
-                ret = sysfs_merge_group(&fs_info->super_kobj, &agroup);
-                kfree(attrs);
-                if (ret)
-                        return ret;
-        }
-        return 0;
-}
-
 static int add_device_membership(struct btrfs_fs_info *fs_info)
 {
         int error = 0;
@@ -592,13 +601,17 @@ int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
         fs_info->super_kobj.kset = btrfs_kset;
         error = kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL,
                                      "%pU", fs_info->fsid);
+        if (error)
+                return error;
 
         error = sysfs_create_group(&fs_info->super_kobj,
                                    &btrfs_feature_attr_group);
-        if (error)
-                goto failure;
+        if (error) {
+                __btrfs_sysfs_remove_one(fs_info);
+                return error;
+        }
 
-        error = add_unknown_feature_attrs(fs_info);
+        error = addrm_unknown_feature_attrs(fs_info, true);
         if (error)
                 goto failure;