lkml.org 
[lkml]   [2008]   [Jun]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 3/3] vfs: fix sys_getcwd for detached mounts
From: Miklos Szeredi <mszeredi@suse.cz>

Currently getcwd(2) on a detached mount will give a garbled result:

> mkdir /mnt/foo
> mount --bind /etc /mnt/foo
> cd /mnt/foo/skel
> /bin/pwd
/mnt/foo/skel
> umount -l /mnt/foo
> /bin/pwd
etcskel

After the patch it will give "detached:skel" as result.

Thanks to John Johansen for pointing out this bug.

Comment from Al Viro: use "detached:" prefix to differentiate it from
attached paths.

Reported-by: John Johansen <jjohansen@suse.de>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
fs/dcache.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

Index: linux-2.6/fs/dcache.c
===================================================================
--- linux-2.6.orig/fs/dcache.c 2008-06-23 17:35:39.000000000 +0200
+++ linux-2.6/fs/dcache.c 2008-06-23 17:46:05.000000000 +0200
@@ -1828,8 +1828,16 @@ char *__d_path(const struct path *path,

global_root:
retval += 1; /* hit the slash */
- if (prepend_name(&retval, &buflen, &dentry->d_name) != 0)
- goto Elong;
+
+ if (IS_ROOT(dentry)) {
+ /* Attached, or pseudo filesystem with "foo:" prefix */
+ if (prepend_name(&retval, &buflen, &dentry->d_name) != 0)
+ goto Elong;
+ } else {
+ /* Detached */
+ if (prepend(&retval, &buflen, "detached:", 9) != 0)
+ goto Elong;
+ }
root->mnt = vfsmnt;
root->dentry = dentry;
return retval;
--


\
 
 \ /
  Last update: 2008-06-23 18:15    [W:0.041 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site