From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756552Ab2KNF6b (ORCPT ); Wed, 14 Nov 2012 00:58:31 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55192 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756357Ab2KNFuv (ORCPT ); Wed, 14 Nov 2012 00:50:51 -0500 Message-Id: <20121114053940.508119031@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Wed, 14 Nov 2012 05:40:21 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jonathan Nieder , Trond Myklebust Subject: [ 48/82] nfs: Show original device name verbatim in /proc/*/mount{s,info} In-Reply-To: <20121114053933.726869752@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings commit 97a54868262da1629a3e65121e65b8e8c4419d9f upstream. Since commit c7f404b ('vfs: new superblock methods to override /proc/*/mount{s,info}'), nfs_path() is used to generate the mounted device name reported back to userland. nfs_path() always generates a trailing slash when the given dentry is the root of an NFS mount, but userland may expect the original device name to be returned verbatim (as it used to be). Make this canonicalisation optional and change the callers accordingly. [jrnieder@gmail.com: use flag instead of bool argument] Reported-and-tested-by: Chris Hiestand Reference: http://bugs.debian.org/669314 Signed-off-by: Ben Hutchings Signed-off-by: Jonathan Nieder Signed-off-by: Trond Myklebust [bwh: Backported to 3.2: - Adjust context - nfs_show_devname() still takes a pointer to struct vfsmount] --- fs/nfs/internal.h | 5 +++-- fs/nfs/namespace.c | 19 ++++++++++++++----- fs/nfs/nfs4namespace.c | 3 ++- fs/nfs/super.c | 2 +- 4 files changed, 20 insertions(+), 9 deletions(-) --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -274,8 +274,9 @@ extern void nfs_sb_active(struct super_b extern void nfs_sb_deactive(struct super_block *sb); /* namespace.c */ +#define NFS_PATH_CANONICAL 1 extern char *nfs_path(char **p, struct dentry *dentry, - char *buffer, ssize_t buflen); + char *buffer, ssize_t buflen, unsigned flags); extern struct vfsmount *nfs_d_automount(struct path *path); #ifdef CONFIG_NFS_V4 rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *); @@ -364,7 +365,7 @@ static inline char *nfs_devname(struct d char *buffer, ssize_t buflen) { char *dummy; - return nfs_path(&dummy, dentry, buffer, buflen); + return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL); } /* --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -37,6 +37,7 @@ static struct vfsmount *nfs_do_submount( * @dentry - pointer to dentry * @buffer - result buffer * @buflen - length of buffer + * @flags - options (see below) * * Helper function for constructing the server pathname * by arbitrary hashed dentry. @@ -44,8 +45,14 @@ static struct vfsmount *nfs_do_submount( * This is mainly for use in figuring out the path on the * server side when automounting on top of an existing partition * and in generating /proc/mounts and friends. + * + * Supported flags: + * NFS_PATH_CANONICAL: ensure there is exactly one slash after + * the original device (export) name + * (if unset, the original name is returned verbatim) */ -char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen) +char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen, + unsigned flags) { char *end; int namelen; @@ -78,7 +85,7 @@ rename_retry: rcu_read_unlock(); goto rename_retry; } - if (*end != '/') { + if ((flags & NFS_PATH_CANONICAL) && *end != '/') { if (--buflen < 0) { spin_unlock(&dentry->d_lock); rcu_read_unlock(); @@ -95,9 +102,11 @@ rename_retry: return end; } namelen = strlen(base); - /* Strip off excess slashes in base string */ - while (namelen > 0 && base[namelen - 1] == '/') - namelen--; + if (flags & NFS_PATH_CANONICAL) { + /* Strip off excess slashes in base string */ + while (namelen > 0 && base[namelen - 1] == '/') + namelen--; + } buflen -= namelen; if (buflen < 0) { spin_unlock(&dentry->d_lock); --- a/fs/nfs/nfs4namespace.c +++ b/fs/nfs/nfs4namespace.c @@ -57,7 +57,8 @@ Elong: static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen) { char *limit; - char *path = nfs_path(&limit, dentry, buffer, buflen); + char *path = nfs_path(&limit, dentry, buffer, buflen, + NFS_PATH_CANONICAL); if (!IS_ERR(path)) { char *colon = strchr(path, ':'); if (colon && colon < limit) --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -768,7 +768,7 @@ static int nfs_show_devname(struct seq_f int err = 0; if (!page) return -ENOMEM; - devname = nfs_path(&dummy, mnt->mnt_root, page, PAGE_SIZE); + devname = nfs_path(&dummy, mnt->mnt_root, page, PAGE_SIZE, 0); if (IS_ERR(devname)) err = PTR_ERR(devname); else