GFS2: Only run logd and quota when mounted read/write

While investigating a rather strange bit of code in the quota
clean up function, I spotted that the reason for its existence
was that when remounting read only, we were not stopping the
quotad thread, and thus it was possible for it to still have
a reference to some of the quotas in that case.

This patch moves the logd and quota thread start and stop into
the make_fs_rw/ro functions, so that we now stop those threads
when mounted read only.

This means that quotad will always be stopped before we call
the quota clean up function, and we can thus dispose of the
(rather hackish) code that waits for it to give up its
reference on the quotas.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>

1 files changed, 38 insertions, 5 deletions

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 35da5b1..60f60f6 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -369,6 +369,33 @@ int gfs2_jdesc_check(struct gfs2_jdesc *jd)
 	return 0;
 }
 
+static int init_threads(struct gfs2_sbd *sdp)
+{
+	struct task_struct *p;
+	int error = 0;
+
+	p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
+	if (IS_ERR(p)) {
+		error = PTR_ERR(p);
+		fs_err(sdp, "can't start logd thread: %d\n", error);
+		return error;
+	}
+	sdp->sd_logd_process = p;
+
+	p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
+	if (IS_ERR(p)) {
+		error = PTR_ERR(p);
+		fs_err(sdp, "can't start quotad thread: %d\n", error);
+		goto fail;
+	}
+	sdp->sd_quotad_process = p;
+	return 0;
+
+fail:
+	kthread_stop(sdp->sd_logd_process);
+	return error;
+}
+
 /**
  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
  * @sdp: the filesystem
@@ -384,10 +411,14 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	struct gfs2_log_header_host head;
 	int error;
 
-	error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);
+	error = init_threads(sdp);
 	if (error)
 		return error;
 
+	error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);
+	if (error)
+		goto fail_threads;
+
 	j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
 
 	error = gfs2_find_jhead(sdp->sd_jdesc, &head);
@@ -417,7 +448,9 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 fail:
 	t_gh.gh_flags |= GL_NOCACHE;
 	gfs2_glock_dq_uninit(&t_gh);
-
+fail_threads:
+	kthread_stop(sdp->sd_quotad_process);
+	kthread_stop(sdp->sd_logd_process);
 	return error;
 }
 
@@ -800,6 +833,9 @@ static int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 	struct gfs2_holder t_gh;
 	int error;
 
+	kthread_stop(sdp->sd_quotad_process);
+	kthread_stop(sdp->sd_logd_process);
+
 	flush_workqueue(gfs2_delete_workqueue);
 	gfs2_quota_sync(sdp->sd_vfs, 0);
 	gfs2_statfs_sync(sdp->sd_vfs, 0);
@@ -857,9 +893,6 @@ restart:
 	}
 	spin_unlock(&sdp->sd_jindex_spin);
 
-	kthread_stop(sdp->sd_quotad_process);
-	kthread_stop(sdp->sd_logd_process);
-
 	if (!(sb->s_flags & MS_RDONLY)) {
 		error = gfs2_make_fs_ro(sdp);
 		if (error)