NFS: Clean up nfs_sb_active/nfs_sb_deactive

Instead of causing umount requests to block on server->active_wq while the
asynchronous sillyrename deletes are executing, we can use the sb->s_active
counter to obtain a reference to the super_block, and then release that
reference in nfs_async_unlink_release().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 5ee23e7..2accb67 100644 (file)
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -850,7 +850,6 @@ static struct nfs_server *nfs_alloc_server(void)
        INIT_LIST_HEAD(&server->client_link);
        INIT_LIST_HEAD(&server->master_link);
 
-       init_waitqueue_head(&server->active_wq);
        atomic_set(&server->active, 0);
 
        server->io_stats = nfs_alloc_iostats();

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 24241fc..7bcf6ec 100644 (file)
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -163,8 +163,8 @@ extern struct rpc_stat nfs_rpcstat;
 
 extern int __init register_nfs_fs(void);
 extern void __exit unregister_nfs_fs(void);
-extern void nfs_sb_active(struct nfs_server *server);
-extern void nfs_sb_deactive(struct nfs_server *server);
+extern void nfs_sb_active(struct super_block *sb);
+extern void nfs_sb_deactive(struct super_block *sb);
 
 /* namespace.c */
 extern char *nfs_path(const char *base,

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index e9b2017..e527fab 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -209,7 +209,6 @@ static int nfs_get_sb(struct file_system_type *, int, const char *, void *, stru
 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
                int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 static void nfs_kill_super(struct super_block *);
-static void nfs_put_super(struct super_block *);
 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 
 static struct file_system_type nfs_fs_type = {
@@ -232,7 +231,6 @@ static const struct super_operations nfs_sops = {
        .alloc_inode    = nfs_alloc_inode,
        .destroy_inode  = nfs_destroy_inode,
        .write_inode    = nfs_write_inode,
-       .put_super      = nfs_put_super,
        .statfs         = nfs_statfs,
        .clear_inode    = nfs_clear_inode,
        .umount_begin   = nfs_umount_begin,
@@ -337,26 +335,20 @@ void __exit unregister_nfs_fs(void)
        unregister_filesystem(&nfs_fs_type);
 }
 
-void nfs_sb_active(struct nfs_server *server)
+void nfs_sb_active(struct super_block *sb)
 {
-       atomic_inc(&server->active);
-}
+       struct nfs_server *server = NFS_SB(sb);
 
-void nfs_sb_deactive(struct nfs_server *server)
-{
-       if (atomic_dec_and_test(&server->active))
-               wake_up(&server->active_wq);
+       if (atomic_inc_return(&server->active) == 1)
+               atomic_inc(&sb->s_active);
 }
 
-static void nfs_put_super(struct super_block *sb)
+void nfs_sb_deactive(struct super_block *sb)
 {
        struct nfs_server *server = NFS_SB(sb);
-       /*
-        * Make sure there are no outstanding ops to this server.
-        * If so, wait for them to finish before allowing the
-        * unmount to continue.
-        */
-       wait_event(server->active_wq, atomic_read(&server->active) == 0);
+
+       if (atomic_dec_and_test(&server->active))
+               deactivate_super(sb);
 }
 
 /*

diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
index f089e58..ecc2953 100644 (file)
--- a/fs/nfs/unlink.c
+++ b/fs/nfs/unlink.c
@@ -99,7 +99,7 @@ static void nfs_async_unlink_release(void *calldata)
 
        nfs_dec_sillycount(data->dir);
        nfs_free_unlinkdata(data);
-       nfs_sb_deactive(NFS_SB(sb));
+       nfs_sb_deactive(sb);
 }
 
 static const struct rpc_call_ops nfs_unlink_ops = {
@@ -118,6 +118,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
                .rpc_message = &msg,
                .callback_ops = &nfs_unlink_ops,
                .callback_data = data,
+               .workqueue = nfsiod_workqueue,
                .flags = RPC_TASK_ASYNC,
        };
        struct rpc_task *task;
@@ -149,7 +150,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
                nfs_dec_sillycount(dir);
                return 0;
        }
-       nfs_sb_active(NFS_SERVER(dir));
+       nfs_sb_active(dir->i_sb);
        data->args.fh = NFS_FH(dir);
        nfs_fattr_init(&data->res.dir_attr);
 

diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index c9beacd..4e477ae 100644 (file)
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -119,7 +119,6 @@ struct nfs_server {
        void (*destroy)(struct nfs_server *);
 
        atomic_t active; /* Keep trace of any activity to this server */
-       wait_queue_head_t active_wq;  /* Wait for any activity to stop  */
 
        /* mountd-related mount options */
        struct sockaddr_storage mountd_address;