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, 1 insertions, 2 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index b5d7363b22da..dd8f2e63d15a 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -12,7 +12,6 @@
 
 #include <linux/fs.h>
 #include <linux/workqueue.h>
-#include <linux/slow-work.h>
 #include <linux/dlm.h>
 #include <linux/buffer_head.h>
 
@@ -383,7 +382,7 @@ struct gfs2_journal_extent {
 struct gfs2_jdesc {
         struct list_head jd_list;
         struct list_head extent_list;
-        struct slow_work jd_work;
+        struct work_struct jd_work;
         struct inode *jd_inode;
         unsigned long jd_flags;
 #define JDF_RECOVERY 1