The patch titled
vfs: fix sys_getcwd for detached mounts
has been added to the -mm tree. Its filename is
vfs-fix-sys_getcwd-for-detached-mounts.patch
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------------------------------------------------------
Subject: vfs: fix sys_getcwd for detached mounts
From: Miklos Szeredi <mszeredi@xxxxxxx>
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 a much saner "/skel" result.
Thanks to John Johansen for pointing out this bug.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Reported-by: John Johansen <jjohansen@xxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dcache.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff -puN fs/dcache.c~vfs-fix-sys_getcwd-for-detached-mounts fs/dcache.c
--- a/fs/dcache.c~vfs-fix-sys_getcwd-for-detached-mounts
+++ a/fs/dcache.c
@@ -1952,10 +1952,20 @@ char *__d_path(const struct path *path,
return retval;
global_root:
- retval += 1; /* hit the slash */
- name = &dentry->d_name;
- if (prepend(&retval, &buflen, name->name, name->len) != 0)
- goto Elong;
+ /*
+ * If this is a root dentry, then overwrite the slash. This
+ * will also DTRT with pseudo filesystems which have root
+ * dentries named "foo:".
+ *
+ * Otherwise this is the root of a detached mount, so don't do
+ * anything.
+ */
+ if (IS_ROOT(dentry)) {
+ retval += 1;
+ name = &dentry->d_name;
+ if (prepend(&retval, &buflen, name->name, name->len) != 0)
+ goto Elong;
+ }
root->mnt = vfsmnt;
root->dentry = dentry;
return retval;
_
Patches currently in -mm which might be from mszeredi@xxxxxxx are
git-unprivileged-mounts.patch
lockd-dont-return-eagain-for-a-permanent-error.patch
locks-add-special-return-value-for-asynchronous-locks.patch
locks-cleanup-code-duplication.patch
locks-allow-lock-to-return-file_lock_deferred.patch
fuse-prepare-lookup-for-nfs-export.patch
fuse-add-export-operations.patch
fuse-add-fuse_lookup_name-helper.patch
fuse-nfs-export-special-lookups.patch
fuse-lockd-support.patch
nfsd-clean-up-mnt_want_write-calls.patch
cgroup-dont-call-vfs_mkdir.patch
reiserfs-dont-call-vfs_rmdir.patch
reiserfs-dont-call-notify_change.patch
sysfs-dont-call-notify_change.patch
hpfs-dont-call-notify_change.patch
fat-dont-call-notify_change.patch
hpfs-dont-call-permission.patch
hppfs-remove-hppfs_permission.patch
gfs2-dont-call-permission.patch
vfs-immutable-inode-checking-cleanup.patch
vfs-truncate-dont-check-immutable-twice.patch
vfs-create-file_truncate-helper.patch
vfs-utimes-immutable-fix.patch
vfs-utimes-cleanup.patch
vfs-dcache-cleanups.patch
vfs-fix-sys_getcwd-for-detached-mounts.patch
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