From 627f30668fac12f5bd555a2cc22af2323762fe8d Mon Sep 17 00:00:00 2001 From: Stanislav Kinsbursky Date: Tue, 10 Jan 2012 17:04:32 +0400 Subject: [PATCH] NFS: blocklayout PipeFS notifier introduced This patch subscribes blocklayout pipes to RPC pipefs notifications. Notifier is registering on blocklayout module load. This notifier callback is responsible for creation/destruction of PipeFS blocklayout pipe dentry. Note that no locking required in notifier callback because PipeFS superblock pointer is passed as an argument from it's creation or destruction routine and thus we can be sure about it's validity. Signed-off-by: Stanislav Kinsbursky Signed-off-by: Trond Myklebust --- fs/nfs/blocklayout/blocklayout.c | 50 +++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index 9da72b8a5542..df05b9465146 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -1044,6 +1044,48 @@ static void nfs4blocklayout_unregister_sb(struct super_block *sb, rpc_unlink(pipe->dentry); } +static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, + void *ptr) +{ + struct super_block *sb = ptr; + struct net *net = sb->s_fs_info; + struct nfs_net *nn = net_generic(net, nfs_net_id); + struct dentry *dentry; + int ret = 0; + + if (!try_module_get(THIS_MODULE)) + return 0; + + if (nn->bl_device_pipe == NULL) { + module_put(THIS_MODULE); + return 0; + } + + switch (event) { + case RPC_PIPEFS_MOUNT: + dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + break; + } + nn->bl_device_pipe->dentry = dentry; + break; + case RPC_PIPEFS_UMOUNT: + if (nn->bl_device_pipe->dentry) + nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe); + break; + default: + ret = -ENOTSUPP; + break; + } + module_put(THIS_MODULE); + return ret; +} + +static struct notifier_block nfs4blocklayout_block = { + .notifier_call = rpc_pipefs_event, +}; + static struct dentry *nfs4blocklayout_register_net(struct net *net, struct rpc_pipe *pipe) { @@ -1119,12 +1161,17 @@ static int __init nfs4blocklayout_init(void) ret = PTR_ERR(mnt); goto out_remove; } - ret = register_pernet_subsys(&nfs4blocklayout_net_ops); + ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block); if (ret) goto out_remove; + ret = register_pernet_subsys(&nfs4blocklayout_net_ops); + if (ret) + goto out_notifier; out: return ret; +out_notifier: + rpc_pipefs_notifier_unregister(&nfs4blocklayout_block); out_remove: pnfs_unregister_layoutdriver(&blocklayout_type); return ret; @@ -1135,6 +1182,7 @@ static void __exit nfs4blocklayout_exit(void) dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n", __func__); + rpc_pipefs_notifier_unregister(&nfs4blocklayout_block); unregister_pernet_subsys(&nfs4blocklayout_net_ops); pnfs_unregister_layoutdriver(&blocklayout_type); } -- 2.20.1