GFS2: let spectator mount do read only recovery

Previously, a spectator mount would not even attempt to do
journal recovery for a failed node.  This meant that if all
mounted nodes were spectators, everyone would be stuck after
a node failed, all waiting for recovery to be performed.
This is unnecessary since the failed node had a clean journal.

Instead, allow a spectator mount to do a partial "read only"
recovery, which means it will check if the failed journal is
clean, and if so, report a successful recovery.  If the failed
journal is not clean, it reports that journal recovery failed.
This makes it work the same as a read only mount on a read only
block device.

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

3 files changed, 5 insertions, 2 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index b9422bc8e2fe..e5701c70f6fb 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -498,6 +498,7 @@ enum {
         SDF_NORECOVERY          = 4,
         SDF_DEMOTE              = 5,
         SDF_NOJOURNALID         = 6,
+        SDF_RORECOVERY          = 7, /* read only recovery */
 };
 
 #define GFS2_FSNAME_LEN         256
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index b01573b7ad96..6aacf3f230a2 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1078,7 +1078,7 @@ static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent
 
         if (sdp->sd_args.ar_spectator) {
                 sb->s_flags |= MS_RDONLY;
-                set_bit(SDF_NORECOVERY, &sdp->sd_flags);
+                set_bit(SDF_RORECOVERY, &sdp->sd_flags);
         }
         if (sdp->sd_args.ar_posix_acl)
                 sb->s_flags |= MS_POSIXACL;
diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
index af49e8f432fe..80701d1566a1 100644
--- a/fs/gfs2/recovery.c
+++ b/fs/gfs2/recovery.c
@@ -516,7 +516,9 @@ void gfs2_recover_func(struct work_struct *work)
                 if (error)
                         goto fail_gunlock_ji;
 
-                if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
+                if (test_bit(SDF_RORECOVERY, &sdp->sd_flags)) {
+                        ro = 1;
+                } else if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
                         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
                                 ro = 1;
                 } else {