NFS: Add an nfsiod workqueue
NFS post-rpciod cleanups often involve tasks that cannot be safely
performed within the rpciod context (due to deadlock concerns). We
therefore add a dedicated NFS workqueue that can perform tasks like
cleaning up state after an interrupted NFSv4 open() call, or calling
put_nfs_open_context() after an asynchronous read or write call.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index a499fb5..36cb999 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1219,6 +1219,36 @@
kmem_cache_destroy(nfs_inode_cachep);
}
+struct workqueue_struct *nfsiod_workqueue;
+
+/*
+ * start up the nfsiod workqueue
+ */
+static int nfsiod_start(void)
+{
+ struct workqueue_struct *wq;
+ dprintk("RPC: creating workqueue nfsiod\n");
+ wq = create_singlethread_workqueue("nfsiod");
+ if (wq == NULL)
+ return -ENOMEM;
+ nfsiod_workqueue = wq;
+ return 0;
+}
+
+/*
+ * Destroy the nfsiod workqueue
+ */
+static void nfsiod_stop(void)
+{
+ struct workqueue_struct *wq;
+
+ wq = nfsiod_workqueue;
+ if (wq == NULL)
+ return;
+ nfsiod_workqueue = NULL;
+ destroy_workqueue(wq);
+}
+
/*
* Initialize NFS
*/
@@ -1226,6 +1256,10 @@
{
int err;
+ err = nfsiod_start();
+ if (err)
+ goto out6;
+
err = nfs_fs_proc_init();
if (err)
goto out5;
@@ -1272,6 +1306,8 @@
out4:
nfs_fs_proc_exit();
out5:
+ nfsiod_stop();
+out6:
return err;
}
@@ -1287,6 +1323,7 @@
#endif
unregister_nfs_fs();
nfs_fs_proc_exit();
+ nfsiod_stop();
}
/* Not quite true; I just maintain it */
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 0f56196..985dc29 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -143,6 +143,7 @@
extern int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask);
/* inode.c */
+extern struct workqueue_struct *nfsiod_workqueue;
extern struct inode *nfs_alloc_inode(struct super_block *sb);
extern void nfs_destroy_inode(struct inode *);
extern int nfs_write_inode(struct inode *,int);