Return-Path: Received: from mail-pa0-f66.google.com ([209.85.220.66]:35109 "EHLO mail-pa0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753549AbbFMCHG (ORCPT ); Fri, 12 Jun 2015 22:07:06 -0400 Received: by pabli10 with SMTP id li10so9580648pab.2 for ; Fri, 12 Jun 2015 19:07:05 -0700 (PDT) Message-ID: <557B9044.8060105@gmail.com> Date: Sat, 13 Jun 2015 10:07:00 +0800 From: Kinglong Mee MIME-Version: 1.0 To: Trond Myklebust CC: "linux-nfs@vger.kernel.org" , David Howells , kinglongmee@gmail.com Subject: [PATCH v2] nfs: Fix showing truncated fsid/dev in, /proc/net/nfsfs/volumes References: <557AE2E7.1090908@gmail.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: A truncated fsid showing from /proc/fs/nfsfs/volumes as, NV SERVER PORT DEV FSID FSC v4 c0a80881 801 0:43 34931f044c2a439b no It should be as, NV SERVER PORT DEV FSID FSC v4 c0a80881 801 0:43 34931f044c2a439b:954c5d830fa4be8c no The max buffer length for storing "%llx:%llx" format should be 16 + 1 + 16 + 1 = 34 (16 for %llx, 1 for ':', 1 for '\0'). Also, for storing "%u:%u" of MAJOR() and MINOR() should be 8 + 1 + 3 + 1 = 13 (8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0'). v2, add comments for dev/fsid buffer and use sizeof in snprintf. Signed-off-by: Kinglong Mee --- fs/nfs/client.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 892aeff..1e37491 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -1364,27 +1364,29 @@ static int nfs_volume_list_show(struct seq_file *m, void *v) { struct nfs_server *server; struct nfs_client *clp; - char dev[8], fsid[17]; + char dev[13]; // 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0' + char fsid[34]; // 2 * 16 for %llx, 1 for ':', 1 for '\0' struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id); /* display header on line 1 */ if (v == &nn->nfs_volume_list) { - seq_puts(m, "NV SERVER PORT DEV FSID FSC\n"); + seq_puts(m, "NV SERVER PORT DEV FSID" + " FSC\n"); return 0; } /* display one transport per line on subsequent lines */ server = list_entry(v, struct nfs_server, master_link); clp = server->nfs_client; - snprintf(dev, 8, "%u:%u", + snprintf(dev, sizeof(dev), "%u:%u", MAJOR(server->s_dev), MINOR(server->s_dev)); - snprintf(fsid, 17, "%llx:%llx", + snprintf(fsid, sizeof(fsid), "%llx:%llx", (unsigned long long) server->fsid.major, (unsigned long long) server->fsid.minor); rcu_read_lock(); - seq_printf(m, "v%u %s %s %-7s %-17s %s\n", + seq_printf(m, "v%u %s %s %-12s %-33s %s\n", clp->rpc_ops->version, rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR), rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT), -- 2.4.3