@@ -233,12 +233,12 @@ static int tmem_cleancache_init_fs(size_t pagesize)
 	return xen_tmem_new_pool(uuid_private, 0, pagesize);
 }
 
-static int tmem_cleancache_init_shared_fs(char *uuid, size_t pagesize)
+static int tmem_cleancache_init_shared_fs(uuid_t *uuid, size_t pagesize)
 {
 	struct tmem_pool_uuid shared_uuid;
 
-	shared_uuid.uuid_lo = *(u64 *)uuid;
-	shared_uuid.uuid_hi = *(u64 *)(&uuid[8]);
+	shared_uuid.uuid_lo = *(u64 *)&uuid->b[0];
+	shared_uuid.uuid_hi = *(u64 *)&uuid->b[8];
 	return xen_tmem_new_pool(shared_uuid, TMEM_POOL_SHARED, pagesize);
 }
 

@@ -3952,7 +3952,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		sb->s_qcop = &ext4_qctl_operations;
 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
 #endif
-	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
+	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
 
 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
 	mutex_init(&sbi->s_orphan_lock);

@@ -1937,7 +1937,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_time_gran = 1;
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
-	memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
+	memcpy(&sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
 
 	/* init f2fs-specific super block info */
 	sbi->valid_super_block = valid_super_block;

@@ -203,7 +203,7 @@ static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
 
 	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
 	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
-	memcpy(s->s_uuid, str->sb_uuid, 16);
+	memcpy(&s->s_uuid, str->sb_uuid, 16);
 }
 
 /**

@@ -71,25 +71,14 @@ static ssize_t fsname_show(struct gfs2_sbd *sdp, char *buf)
 	return snprintf(buf, PAGE_SIZE, "%s\n", sdp->sd_fsname);
 }
 
-static int gfs2_uuid_valid(const u8 *uuid)
-{
-	int i;
-
-	for (i = 0; i < 16; i++) {
-		if (uuid[i])
-			return 1;
-	}
-	return 0;
-}
-
 static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
 {
 	struct super_block *s = sdp->sd_vfs;
-	const u8 *uuid = s->s_uuid;
+
 	buf[0] = '\0';
-	if (!gfs2_uuid_valid(uuid))
+	if (uuid_is_null(&s->s_uuid))
 		return 0;
-	return snprintf(buf, PAGE_SIZE, "%pUB\n", uuid);
+	return snprintf(buf, PAGE_SIZE, "%pUB\n", &s->s_uuid);
 }
 
 static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)

@@ -712,14 +701,13 @@ static int gfs2_uevent(struct kset *kset, struct kobject *kobj,
 {
 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
 	struct super_block *s = sdp->sd_vfs;
-	const u8 *uuid = s->s_uuid;
 
 	add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name);
 	add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name);
 	if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags))
 		add_uevent_var(env, "JOURNALID=%d", sdp->sd_lockstruct.ls_jid);
-	if (gfs2_uuid_valid(uuid))
-		add_uevent_var(env, "UUID=%pUB", uuid);
+	if (!uuid_is_null(&s->s_uuid))
+		add_uevent_var(env, "UUID=%pUB", &s->s_uuid);
 	return 0;
 }
 

@@ -2062,7 +2062,7 @@ static int ocfs2_initialize_super(struct super_block *sb,
 	cbits = le32_to_cpu(di->id2.i_super.s_clustersize_bits);
 	bbits = le32_to_cpu(di->id2.i_super.s_blocksize_bits);
 	sb->s_maxbytes = ocfs2_max_file_offset(bbits, cbits);
-	memcpy(sb->s_uuid, di->id2.i_super.s_uuid,
+	memcpy(&sb->s_uuid, di->id2.i_super.s_uuid,
 	       sizeof(di->id2.i_super.s_uuid));
 
 	osb->osb_dx_mask = (1 << (cbits - bbits)) - 1;

@@ -284,7 +284,6 @@ static int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
 			  struct dentry *upper)
 {
 	struct super_block *sb = lower->d_sb;
-	uuid_be *uuid = (uuid_be *) &sb->s_uuid;
 	const struct ovl_fh *fh = NULL;
 	int err;
 

@@ -294,8 +293,8 @@ static int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
 	 * up and a pure upper inode.
 	 */
 	if (sb->s_export_op && sb->s_export_op->fh_to_dentry &&
-	    uuid_be_cmp(*uuid, NULL_UUID_BE)) {
-		fh = ovl_encode_fh(lower, uuid);
+	    !uuid_is_null(&sb->s_uuid)) {
+		fh = ovl_encode_fh(lower, &sb->s_uuid);
 		if (IS_ERR(fh))
 			return PTR_ERR(fh);
 	}

@@ -135,7 +135,7 @@ static struct dentry *ovl_get_origin(struct dentry *dentry,
 	 * Make sure that the stored uuid matches the uuid of the lower
 	 * layer where file handle will be decoded.
 	 */
-	if (uuid_be_cmp(fh->uuid, *(uuid_be *) &mnt->mnt_sb->s_uuid))
+	if (!uuid_equal(&fh->uuid, &mnt->mnt_sb->s_uuid))
 		goto out;
 
 	origin = exportfs_decode_fh(mnt, (struct fid *)fh->fid,

@@ -74,8 +74,7 @@ xfs_uuid_mount(
 	int			hole, i;
 
 	/* Publish UUID in struct super_block */
-	BUILD_BUG_ON(sizeof(mp->m_super->s_uuid) != sizeof(uuid_t));
-	memcpy(&mp->m_super->s_uuid, uuid, sizeof(uuid_t));
+	uuid_copy(&mp->m_super->s_uuid, uuid);
 
 	if (mp->m_flags & XFS_MOUNT_NOUUID)
 		return 0;

@@ -27,7 +27,7 @@ struct cleancache_filekey {
 
 struct cleancache_ops {
 	int (*init_fs)(size_t);
-	int (*init_shared_fs)(char *uuid, size_t);
+	int (*init_shared_fs)(uuid_t *uuid, size_t);
 	int (*get_page)(int, struct cleancache_filekey,
 			pgoff_t, struct page *);
 	void (*put_page)(int, struct cleancache_filekey,

@@ -30,6 +30,7 @@
 #include <linux/percpu-rwsem.h>
 #include <linux/workqueue.h>
 #include <linux/delayed_call.h>
+#include <linux/uuid.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>

@@ -1328,8 +1329,8 @@ struct super_block {
 
 	struct sb_writers	s_writers;
 
-	char s_id[32];				/* Informational name */
-	u8 s_uuid[16];				/* UUID */
+	char			s_id[32];	/* Informational name */
+	uuid_t			s_uuid;		/* UUID */
 
 	void 			*s_fs_info;	/* Filesystem private info */
 	unsigned int		s_max_links;

@@ -130,7 +130,7 @@ void __cleancache_init_shared_fs(struct super_block *sb)
 	int pool_id = CLEANCACHE_NO_BACKEND_SHARED;
 
 	if (cleancache_ops) {
-		pool_id = cleancache_ops->init_shared_fs(sb->s_uuid, PAGE_SIZE);
+		pool_id = cleancache_ops->init_shared_fs(&sb->s_uuid, PAGE_SIZE);
 		if (pool_id < 0)
 			pool_id = CLEANCACHE_NO_POOL;
 	}

@@ -164,7 +164,7 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
 	hmac_misc.mode = inode->i_mode;
 	crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof(hmac_misc));
 	if (evm_hmac_attrs & EVM_ATTR_FSUUID)
-		crypto_shash_update(desc, inode->i_sb->s_uuid,
+		crypto_shash_update(desc, &inode->i_sb->s_uuid.b[0],
 				    sizeof(inode->i_sb->s_uuid));
 	crypto_shash_final(desc, digest);
 }

@@ -244,7 +244,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 	    && rule->fsmagic != inode->i_sb->s_magic)
 		return false;
 	if ((rule->flags & IMA_FSUUID) &&
-	    memcmp(&rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
+	    !uuid_equal(&rule->fsuuid, &inode->i_sb->s_uuid))
 		return false;
 	if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
 		return false;