3 files changed, 39 insertions, 0 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 3f29bd224ba1..980a0864ca6c 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -470,6 +470,7 @@ struct gfs2_sb_host {
 
         char sb_lockproto[GFS2_LOCKNAME_LEN];
         char sb_locktable[GFS2_LOCKNAME_LEN];
+        u8 sb_uuid[16];
 };
 
 /*
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e502b379a4da..804ca7273a49 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -234,6 +234,7 @@ static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
 
         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
+        memcpy(sb->sb_uuid, str->sb_uuid, 16);
 }
 
 /**
diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index a78997ea5037..4d284d14980b 100644
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -36,6 +36,30 @@ 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)
+{
+        const u8 *uuid = sdp->sd_sb.sb_uuid;
+        buf[0] = '\0';
+        if (!gfs2_uuid_valid(uuid))
+                return 0;
+        return snprintf(buf, PAGE_SIZE, "%02X%02X%02X%02X-%02X%02X-"
+                        "%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X\n",
+                        uuid[0], uuid[1], uuid[2], uuid[3], uuid[4], uuid[5],
+                        uuid[6], uuid[7], uuid[8], uuid[9], uuid[10], uuid[11],
+                        uuid[12], uuid[13], uuid[14], uuid[15]);
+}
+
 static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
 {
         unsigned int count;
@@ -158,6 +182,7 @@ static struct gfs2_attr gfs2_attr_##name = __ATTR(name, mode, show, store)
 
 GFS2_ATTR(id,                  0444, id_show,       NULL);
 GFS2_ATTR(fsname,              0444, fsname_show,   NULL);
+GFS2_ATTR(uuid,                0444, uuid_show,     NULL);
 GFS2_ATTR(freeze,              0644, freeze_show,   freeze_store);
 GFS2_ATTR(withdraw,            0644, withdraw_show, withdraw_store);
 GFS2_ATTR(statfs_sync,         0200, NULL,          statfs_sync_store);
@@ -168,6 +193,7 @@ GFS2_ATTR(quota_refresh_group, 0200, NULL,          quota_refresh_group_store);
 static struct attribute *gfs2_attrs[] = {
         &gfs2_attr_id.attr,
         &gfs2_attr_fsname.attr,
+        &gfs2_attr_uuid.attr,
         &gfs2_attr_freeze.attr,
         &gfs2_attr_withdraw.attr,
         &gfs2_attr_statfs_sync.attr,
@@ -598,12 +624,23 @@ void gfs2_sys_fs_del(struct gfs2_sbd *sdp)
         kobject_put(&sdp->sd_kobj);
 }
 
+
 static int gfs2_uevent(struct kset *kset, struct kobject *kobj,
                        struct kobj_uevent_env *env)
 {
         struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
+        const u8 *uuid = sdp->sd_sb.sb_uuid;
+
         add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name);
         add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name);
+        if (gfs2_uuid_valid(uuid)) {
+                add_uevent_var(env, "UUID=%02X%02X%02X%02X-%02X%02X-%02X%02X-"
+                               "%02X%02X-%02X%02X%02X%02X%02X%02X",
+                               uuid[0], uuid[1], uuid[2], uuid[3], uuid[4],
+                               uuid[5], uuid[6], uuid[7], uuid[8], uuid[9],
+                               uuid[10], uuid[11], uuid[12], uuid[13],
+                               uuid[14], uuid[15]);
+        }
         return 0;
 }