gfs2: use workqueue instead of slow-work

Workqueue can now handle high concurrency.  Convert gfs to use
workqueue instead of slow-work.

* Steven pointed out that recovery path might be run from allocation
  path and thus requires forward progress guarantee without memory
  allocation.  Create and use gfs_recovery_wq with rescuer.  Please
  note that forward progress wasn't guaranteed with slow-work.

* Updated to use non-reentrant workqueue.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index 37f5393e68e6..6b60316ae327 100644
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -25,6 +25,7 @@
 #include "quota.h"
 #include "util.h"
 #include "glops.h"
+#include "recovery.h"
 
 struct gfs2_attr {
         struct attribute attr;
@@ -352,7 +353,7 @@ static ssize_t recover_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
                 if (jd->jd_jid != jid)
                         continue;
-                rv = slow_work_enqueue(&jd->jd_work);
+                rv = gfs2_recover_journal(jd, false);
                 break;
         }
 out: