[Devel] [PATCH 1/6] SUNRPC: split cache creation and PipeFS registration

[Stanislav Kinsbursky]

This precursor patch splits SUNRPC cache creation and PipeFS registartion.
It's required for latter split of NFS DNS resolver cache creation per network
namespace context and PipeFS registration/unregistration on MOUNT/UMOUNT
events.

Signed-off-by: Stanislav Kinsbursky <skinsbursky at parallels.com>

---
 fs/nfs/cache_lib.c           |    3 +++
 include/linux/sunrpc/cache.h |    2 ++
 net/sunrpc/cache.c           |   12 +++++-------
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/cache_lib.c b/fs/nfs/cache_lib.c
index c98b439..d62a895 100644
--- a/fs/nfs/cache_lib.c
+++ b/fs/nfs/cache_lib.c
@@ -120,6 +120,7 @@ int nfs_cache_register(struct cache_detail *cd)
 	mnt = rpc_get_mount();
 	if (IS_ERR(mnt))
 		return PTR_ERR(mnt);
+	sunrpc_init_cache_detail(cd);
 	ret = vfs_path_lookup(mnt->mnt_root, mnt, "/cache", 0, &path);
 	if (ret)
 		goto err;
@@ -128,6 +129,7 @@ int nfs_cache_register(struct cache_detail *cd)
 	if (!ret)
 		return ret;
 err:
+	sunrpc_destroy_cache_detail(cd);
 	rpc_put_mount();
 	return ret;
 }
@@ -135,6 +137,7 @@ err:
 void nfs_cache_unregister(struct cache_detail *cd)
 {
 	sunrpc_cache_unregister_pipefs(cd);
+	sunrpc_destroy_cache_detail(cd);
 	rpc_put_mount();
 }
 
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 5efd8ce..57d9fa7 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -202,6 +202,8 @@ extern int cache_register_net(struct cache_detail *cd, struct net *net);
 extern void cache_unregister(struct cache_detail *cd);
 extern void cache_unregister_net(struct cache_detail *cd, struct net *net);
 
+extern void sunrpc_init_cache_detail(struct cache_detail *cd);
+extern void sunrpc_destroy_cache_detail(struct cache_detail *cd);
 extern int sunrpc_cache_register_pipefs(struct dentry *parent, const char *,
 					mode_t, struct cache_detail *);
 extern void sunrpc_cache_unregister_pipefs(struct cache_detail *);
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 72ad836..320e549 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -344,7 +344,7 @@ static int current_index;
 static void do_cache_clean(struct work_struct *work);
 static struct delayed_work cache_cleaner;
 
-static void sunrpc_init_cache_detail(struct cache_detail *cd)
+void sunrpc_init_cache_detail(struct cache_detail *cd)
 {
 	rwlock_init(&cd->hash_lock);
 	INIT_LIST_HEAD(&cd->queue);
@@ -360,8 +360,9 @@ static void sunrpc_init_cache_detail(struct cache_detail *cd)
 	/* start the cleaning process */
 	schedule_delayed_work(&cache_cleaner, 0);
 }
+EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail);
 
-static void sunrpc_destroy_cache_detail(struct cache_detail *cd)
+void sunrpc_destroy_cache_detail(struct cache_detail *cd)
 {
 	cache_purge(cd);
 	spin_lock(&cache_list_lock);
@@ -384,6 +385,7 @@ static void sunrpc_destroy_cache_detail(struct cache_detail *cd)
 out:
 	printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
 }
+EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
 
 /* clean cache tries to find something to clean
  * and cleans it.
@@ -1785,17 +1787,14 @@ int sunrpc_cache_register_pipefs(struct dentry *parent,
 	struct dentry *dir;
 	int ret = 0;
 
-	sunrpc_init_cache_detail(cd);
 	q.name = name;
 	q.len = strlen(name);
 	q.hash = full_name_hash(q.name, q.len);
 	dir = rpc_create_cache_dir(parent, &q, umode, cd);
 	if (!IS_ERR(dir))
 		cd->u.pipefs.dir = dir;
-	else {
-		sunrpc_destroy_cache_detail(cd);
+	else
 		ret = PTR_ERR(dir);
-	}
 	return ret;
 }
 EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
@@ -1804,7 +1803,6 @@ void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
 {
 	rpc_remove_cache_dir(cd->u.pipefs.dir);
 	cd->u.pipefs.dir = NULL;
-	sunrpc_destroy_cache_detail(cd);
 }
 EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);