SUNRPC: send notification events on pipefs sb creation and destruction
They will be used to notify subscribers about pipefs superblock creation and
destruction.
Subcribers will have to create their dentries on passed superblock on mount
event and destroy otherwise.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index f628b0f..58a5062 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -28,8 +28,10 @@
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/cache.h>
#include <linux/nsproxy.h>
+#include <linux/notifier.h>
#include "netns.h"
+#include "sunrpc.h"
static struct vfsmount *rpc_mnt __read_mostly;
static int rpc_mount_count;
@@ -41,6 +43,20 @@
#define RPC_UPCALL_TIMEOUT (30*HZ)
+static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
+
+int rpc_pipefs_notifier_register(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
+
+void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
+{
+ blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
+
static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
void (*destroy_msg)(struct rpc_pipe_msg *), int err)
{
@@ -997,6 +1013,7 @@
struct inode *inode;
struct dentry *root;
struct net *net = data;
+ int err;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
@@ -1014,8 +1031,20 @@
}
if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
return -ENOMEM;
+ err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
+ RPC_PIPEFS_MOUNT,
+ sb);
+ if (err)
+ goto err_depopulate;
sb->s_fs_info = get_net(net);
return 0;
+
+err_depopulate:
+ blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
+ RPC_PIPEFS_UMOUNT,
+ sb);
+ __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
+ return err;
}
static struct dentry *
@@ -1030,6 +1059,9 @@
struct net *net = sb->s_fs_info;
put_net(net);
+ blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
+ RPC_PIPEFS_UMOUNT,
+ sb);
kill_litter_super(sb);
}