(cc-ing Laurent in case he wants to test. Laurent, a "git am"-ready
patch is at [1])
Ben Hutchings wrote:
> 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.
>
> Reported-and-tested-by: Chris Hiestand <chiestand@xxxxxxxx>
> Reference: http://bugs.debian.org/669314
> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # v2.6.39+
Changing the content of /proc/mounts broke
user@hostname:/proc/self$ sudo umount.nfs nfsserver:/srv/ubuntu-32
umount.nfs: nfsserver:/srv/ubuntu-32: not found
with nfs2 and nfs3 and this looks like the minimal change to get it
working again, so for what it's worth,
Reviewed-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
How about something like the following on top?
-- >8 --
Subject: nfs: convert boolean nfs_path() argument to a flag word
If nfs_path() gains any other boolean settings, they can share the
flag argument, and this way call sites look like "nfs_path(&limit,
dentry, buffer, buflen, NFS_PATH_CANONICAL);" so the reader does not
need to guess the sense of true and false. No functional change
intended.
Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
---
[1] http://download.gmane.org/gmane.linux.nfs/52755/52756
fs/nfs/internal.h | 5 +++--
fs/nfs/namespace.c | 14 +++++++++-----
fs/nfs/nfs4namespace.c | 3 ++-
fs/nfs/super.c | 2 +-
4 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 9c9603373d64..a54fe51c1dfb 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -353,8 +353,9 @@ extern void nfs_sb_active(struct super_block *sb);
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, bool canonical);
+ char *buffer, ssize_t buflen, unsigned flags);
extern struct vfsmount *nfs_d_automount(struct path *path);
struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
struct nfs_fh *, struct nfs_fattr *);
@@ -498,7 +499,7 @@ static inline char *nfs_devname(struct dentry *dentry,
char *buffer, ssize_t buflen)
{
char *dummy;
- return nfs_path(&dummy, dentry, buffer, buflen, true);
+ return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
}
/*
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 059975e492e1..dd057bc6b65b 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -33,8 +33,7 @@ int nfs_mountpoint_expiry_timeout = 500 * HZ;
* @dentry - pointer to dentry
* @buffer - result buffer
* @buflen - length of buffer
- * @canonical - ensure there is exactly one slash after the original
- * device (export) name; if false, return it verbatim
+ * @flags - options (see below)
*
* Helper function for constructing the server pathname
* by arbitrary hashed dentry.
@@ -42,9 +41,14 @@ int nfs_mountpoint_expiry_timeout = 500 * HZ;
* 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,
- bool canonical)
+ unsigned flags)
{
char *end;
int namelen;
@@ -77,7 +81,7 @@ rename_retry:
rcu_read_unlock();
goto rename_retry;
}
- if (canonical && *end != '/') {
+ if ((flags & NFS_PATH_CANONICAL) && *end != '/') {
if (--buflen < 0) {
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
@@ -94,7 +98,7 @@ rename_retry:
return end;
}
namelen = strlen(base);
- if (canonical) {
+ if (flags & NFS_PATH_CANONICAL) {
/* Strip off excess slashes in base string */
while (namelen > 0 && base[namelen - 1] == '/')
namelen--;
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 2f6f16331769..1e09eb78543b 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -81,7 +81,8 @@ static char *nfs_path_component(const char *nfspath, const char *end)
static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
{
char *limit;
- char *path = nfs_path(&limit, dentry, buffer, buflen, true);
+ char *path = nfs_path(&limit, dentry, buffer, buflen,
+ NFS_PATH_CANONICAL);
if (!IS_ERR(path)) {
char *path_component = nfs_path_component(path, limit);
if (path_component)
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index c89a73da13d9..13c2a5be4765 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -771,7 +771,7 @@ int nfs_show_devname(struct seq_file *m, struct dentry *root)
int err = 0;
if (!page)
return -ENOMEM;
- devname = nfs_path(&dummy, root, page, PAGE_SIZE, false);
+ devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
if (IS_ERR(devname))
err = PTR_ERR(devname);
else
--
1.8.0.rc3
--
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