NFS: add superblock sysfs entries

Create a sysfs directory for each mount that corresponds to the mount's
nfs_server struct.  As the mount is being constructed, use the name
"server-n", but rename it to the "MAJOR:MINOR" of the mount after assigning
a device_id. The rename approach allows us to populate the mount's directory
with links to the various rpc_client objects during the mount's
construction.  The naming convention (MAJOR:MINOR) can be used to reference
a particular NFS mount's sysfs tree.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index d5441e60d7e1..e95672a9bcd6 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -698,6 +698,7 @@ static int nfs_init_server(struct nfs_server *server,
 		return PTR_ERR(clp);
 
 	server->nfs_client = clp;
+	nfs_sysfs_add_server(server);
 
 	/* Initialise the client representation from the mount data */
 	server->flags = ctx->flags;
@@ -952,6 +953,8 @@ void nfs_server_remove_lists(struct nfs_server *server)
 }
 EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
 
+static DEFINE_IDA(s_sysfs_ids);
+
 /*
  * Allocate and initialise a server record
  */
@@ -963,6 +966,12 @@ struct nfs_server *nfs_alloc_server(void)
 	if (!server)
 		return NULL;
 
+	server->s_sysfs_id = ida_alloc(&s_sysfs_ids, GFP_KERNEL);
+	if (server->s_sysfs_id < 0) {
+		kfree(server);
+		return NULL;
+	}
+
 	server->client = server->client_acl = ERR_PTR(-EINVAL);
 
 	/* Zero out the NFS state stuff */
@@ -1009,6 +1018,10 @@ void nfs_free_server(struct nfs_server *server)
 
 	nfs_put_client(server->nfs_client);
 
+	nfs_sysfs_remove_server(server);
+	kobject_put(&server->kobj);
+	ida_free(&s_sysfs_ids, server->s_sysfs_id);
+
 	ida_destroy(&server->lockowner_id);
 	ida_destroy(&server->openowner_id);
 	nfs_free_iostats(server->io_stats);
@@ -1110,6 +1123,8 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source,
 
 	server->fsid = fattr->fsid;
 
+	nfs_sysfs_add_server(server);
+
 	error = nfs_init_server_rpcclient(server,
 			source->client->cl_timeout,
 			flavor);
@@ -1393,6 +1408,7 @@ error_0:
 void nfs_fs_proc_exit(void)
 {
 	remove_proc_subtree("fs/nfsfs", NULL);
+	ida_destroy(&s_sysfs_ids);
 }
 
 #endif /* CONFIG_PROC_FS */