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;