GFS2: Use UUID field in generic superblock

The VFS superblock structure now has a UUID field, so we can use that
in preference to the UUID field in the GFS2 superblock now.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

3 files changed, 17 insertions, 22 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 69a63823f7c5..0a064e91ac70 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -488,7 +488,6 @@ 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 d3c69eb91c74..8ac9ae189b53 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -126,8 +126,10 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
  * changed.
  */
 
-static int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb_host *sb, int silent)
+static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
 {
+        struct gfs2_sb_host *sb = &sdp->sd_sb;
+
         if (sb->sb_magic != GFS2_MAGIC ||
             sb->sb_type != GFS2_METATYPE_SB) {
                 if (!silent)
@@ -157,8 +159,10 @@ static void end_bio_io_page(struct bio *bio, int error)
         unlock_page(page);
 }
 
-static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
+static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
 {
+        struct gfs2_sb_host *sb = &sdp->sd_sb;
+        struct super_block *s = sdp->sd_vfs;
         const struct gfs2_sb *str = buf;
 
         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
@@ -175,7 +179,7 @@ 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);
+        memcpy(s->s_uuid, str->sb_uuid, 16);
 }
 
 /**
@@ -197,7 +201,7 @@ static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
  * Returns: 0 on success or error
  */
 
-static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
+static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
 {
         struct super_block *sb = sdp->sd_vfs;
         struct gfs2_sb *p;
@@ -227,10 +231,10 @@ static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
                 return -EIO;
         }
         p = kmap(page);
-        gfs2_sb_in(&sdp->sd_sb, p);
+        gfs2_sb_in(sdp, p);
         kunmap(page);
         __free_page(page);
-        return 0;
+        return gfs2_check_sb(sdp, silent);
 }
 
 /**
@@ -247,17 +251,13 @@ static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
         unsigned int x;
         int error;
 
-        error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
+        error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
         if (error) {
                 if (!silent)
                         fs_err(sdp, "can't read superblock\n");
                 return error;
         }
 
-        error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
-        if (error)
-                return error;
-
         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
                                GFS2_BASIC_BLOCK_SHIFT;
         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
@@ -340,14 +340,10 @@ static int init_names(struct gfs2_sbd *sdp, int silent)
         /*  Try to autodetect  */
 
         if (!proto[0] || !table[0]) {
-                error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
+                error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
                 if (error)
                         return error;
 
-                error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
-                if (error)
-                        goto out;
-
                 if (!proto[0])
                         proto = sdp->sd_sb.sb_lockproto;
                 if (!table[0])
@@ -364,7 +360,6 @@ static int init_names(struct gfs2_sbd *sdp, int silent)
         while ((table = strchr(table, '/')))
                 *table = '_';
 
-out:
         return error;
 }
 
@@ -1119,8 +1114,7 @@ static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent
         if (sdp->sd_args.ar_statfs_quantum) {
                 sdp->sd_tune.gt_statfs_slow = 0;
                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
-        }
-        else {
+        } else {
                 sdp->sd_tune.gt_statfs_slow = 1;
                 sdp->sd_tune.gt_statfs_quantum = 30;
         }
diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index 748ccb557c18..e20eab37bc80 100644
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -81,7 +81,8 @@ static int gfs2_uuid_valid(const u8 *uuid)
 
 static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
 {
-        const u8 *uuid = sdp->sd_sb.sb_uuid;
+        struct super_block *s = sdp->sd_vfs;
+        const u8 *uuid = s->s_uuid;
         buf[0] = '\0';
         if (!gfs2_uuid_valid(uuid))
                 return 0;
@@ -616,7 +617,8 @@ 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;
+        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);