nfsd4: add a client info file

Add a new nfsd/clients/#/info file with some basic information about
each NFSv4 client.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 37 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 8f9747d84525..a6c722dc7e5e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2214,6 +2214,41 @@ find_stateid_by_type(struct nfs4_client *cl, stateid_t *t, char typemask)
 	return s;
 }
 
+static int client_info_show(struct seq_file *m, void *v)
+{
+	struct inode *inode = m->private;
+	struct nfsdfs_client *nc;
+	struct nfs4_client *clp;
+	u64 clid;
+
+	nc = get_nfsdfs_client(inode);
+	if (!nc)
+		return -ENXIO;
+	clp = container_of(nc, struct nfs4_client, cl_nfsdfs);
+	memcpy(&clid, &clp->cl_clientid, sizeof(clid));
+	seq_printf(m, "clientid: 0x%llx\n", clid);
+	drop_client(clp);
+
+	return 0;
+}
+
+static int client_info_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, client_info_show, inode);
+}
+
+static const struct file_operations client_info_fops = {
+	.open		= client_info_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static const struct tree_descr client_files[] = {
+	[0] = {"info", &client_info_fops, S_IRUSR},
+	[1] = {""},
+};
+
 static struct nfs4_client *create_client(struct xdr_netobj name,
 		struct svc_rqst *rqstp, nfs4_verifier *verf)
 {
@@ -2242,7 +2277,8 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
 	clp->cl_cb_session = NULL;
 	clp->net = net;
 	clp->cl_nfsd_dentry = nfsd_client_mkdir(nn, &clp->cl_nfsdfs,
-			clp->cl_clientid.cl_id - nn->clientid_base);
+			clp->cl_clientid.cl_id - nn->clientid_base,
+			client_files);
 	if (!clp->cl_nfsd_dentry) {
 		free_client(clp);
 		return NULL;