GFS2: Add online uevent to GFS2

We already have an offline uevent (used when a withdraw occurs)
but no online uevent. This adds an online uevent so that userspace
will be able to detect a successful mount by means other than
not receiving a remove event after the add & recovery (change)
uevents.

It has also been added to the remount path as well - we can't use
a change uevent there as older GFS2 userspace acts on change uevents
according to the state that it thinks the fs is in, so we can't
easily add any new ones.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/ops_fstype.c

@@ -1133,6 +1133,17 @@ void gfs2_lm_unmount(struct gfs2_sbd *sdp)
 		lm->lm_unmount(sdp);
 }
 
+void gfs2_online_uevent(struct gfs2_sbd *sdp)
+{
+	struct super_block *sb = sdp->sd_vfs;
+	char ro[20];
+	char spectator[20];
+	char *envp[] = { ro, spectator, NULL };
+	sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
+	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
+	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
+}
+
 /**
  * fill_super - Read in superblock
  * @sb: The VFS superblock
@@ -1236,7 +1247,7 @@ static int fill_super(struct super_block *sb, void *data, int silent)
 	}
 
 	gfs2_glock_dq_uninit(&mount_gh);
-
+	gfs2_online_uevent(sdp);
 	return 0;
 
 fail_threads:

fs/gfs2/super.c

@@ -1084,6 +1084,7 @@ static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
 	gt->gt_log_flush_secs = args.ar_commit;
 	spin_unlock(&gt->gt_spin);
 
+	gfs2_online_uevent(sdp);
 	return 0;
 }
 

fs/gfs2/super.h

@@ -25,7 +25,7 @@ static inline unsigned int gfs2_jindex_size(struct gfs2_sbd *sdp)
 	return x;
 }
 
-void gfs2_jindex_free(struct gfs2_sbd *sdp);
+extern void gfs2_jindex_free(struct gfs2_sbd *sdp);
 
 extern int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *data);
 
@@ -36,7 +36,7 @@ extern int gfs2_lookup_in_master_dir(struct gfs2_sbd *sdp, char *filename,
 				     struct gfs2_inode **ipp);
 
 extern int gfs2_make_fs_rw(struct gfs2_sbd *sdp);
-
+extern void gfs2_online_uevent(struct gfs2_sbd *sdp);
 extern int gfs2_statfs_init(struct gfs2_sbd *sdp);
 extern void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
 			       s64 dinodes);