The patch titled
     r/o bind mounts: elevate write count over calls to vfs_rename()
has been added to the -mm tree.  Its filename is
     r-o-bind-mounts-elevate-write-count-over-calls-to-vfs_rename.patch

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: r/o bind mounts: elevate write count over calls to vfs_rename()
From: Dave Hansen <[EMAIL PROTECTED]>

This does create a little helper in the NFS code to make an if() a little bit
less ugly.

Signed-off-by: Dave Hansen <[EMAIL PROTECTED]>
Cc: Miklos Szeredi <[EMAIL PROTECTED]>
Cc: Ram Pai <[EMAIL PROTECTED]>
Cc: Al Viro <[EMAIL PROTECTED]>
Cc: Christoph Hellwig <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---

 fs/namei.c    |    4 ++++
 fs/nfsd/vfs.c |   23 +++++++++++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff -puN 
fs/namei.c~r-o-bind-mounts-elevate-write-count-over-calls-to-vfs_rename 
fs/namei.c
--- a/fs/namei.c~r-o-bind-mounts-elevate-write-count-over-calls-to-vfs_rename
+++ a/fs/namei.c
@@ -2563,8 +2563,12 @@ static int do_rename(int olddfd, const c
        if (new_dentry == trap)
                goto exit5;
 
+       error = mnt_want_write(oldnd.mnt);
+       if (error)
+               goto exit5;
        error = vfs_rename(old_dir->d_inode, old_dentry,
                                   new_dir->d_inode, new_dentry);
+       mnt_drop_write(oldnd.mnt);
 exit5:
        dput(new_dentry);
 exit4:
diff -puN 
fs/nfsd/vfs.c~r-o-bind-mounts-elevate-write-count-over-calls-to-vfs_rename 
fs/nfsd/vfs.c
--- a/fs/nfsd/vfs.c~r-o-bind-mounts-elevate-write-count-over-calls-to-vfs_rename
+++ a/fs/nfsd/vfs.c
@@ -1555,6 +1555,14 @@ out_nfserr:
        goto out_unlock;
 }
 
+static inline int svc_msnfs(struct svc_fh *ffhp)
+{
+#ifdef MSNFS
+       return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS);
+#else
+       return 0;
+#endif
+}
 /*
  * Rename a file
  * N.B. After this call _both_ ffhp and tfhp need an fh_put
@@ -1616,13 +1624,20 @@ nfsd_rename(struct svc_rqst *rqstp, stru
        if (ndentry == trap)
                goto out_dput_new;
 
-#ifdef MSNFS
-       if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
+       if (svc_msnfs(ffhp) &&
                ((atomic_read(&odentry->d_count) > 1)
                 || (atomic_read(&ndentry->d_count) > 1))) {
                        host_err = -EPERM;
-       } else
-#endif
+                       goto out_dput_new;
+       }
+
+       host_err = -EXDEV;
+       if (ffhp->fh_export->ex_mnt != tfhp->fh_export->ex_mnt)
+               goto out_dput_new;
+       host_err = mnt_want_write(ffhp->fh_export->ex_mnt);
+       if (host_err)
+               goto out_dput_new;
+
        host_err = vfs_rename(fdir, odentry, tdir, ndentry);
        if (!host_err && EX_ISSYNC(tfhp->fh_export)) {
                host_err = nfsd_sync_dir(tdentry);
_

Patches currently in -mm which might be from [EMAIL PROTECTED] are

r-o-bind-mounts-filesystem-helpers-for-custom-struct-files.patch
r-o-bind-mounts-add-vfsmount-writer-counts.patch
r-o-bind-mounts-record-when-sb_writer_count-elevated-for-inode.patch
r-o-bind-mounts-elevate-writer-count-for-chown-and-friends.patch
r-o-bind-mounts-elevate-mnt-writers-for-callers-of-vfs_mkdir.patch
r-o-bind-mounts-elevate-write-count-during-entire-ncp_ioctl.patch
r-o-bind-mounts-elevate-write-count-for-link-and-symlink-calls.patch
r-o-bind-mounts-elevate-mount-count-for-extended-attributes.patch
r-o-bind-mounts-mount_is_safe-add-comment.patch
r-o-bind-mounts-unix_find_other-elevate-write-count-for-touch_atime.patch
r-o-bind-mounts-elevate-write-count-over-calls-to-vfs_rename.patch
r-o-bind-mounts-elevate-write-count-files-are-opened.patch
r-o-bind-mounts-elevate-writer-count-for-do_sys_truncate.patch
r-o-bind-mounts-elevate-write-count-for-do_utimes.patch
r-o-bind-mounts-elevate-write-count-for-do_sys_utime-and-touch_atime.patch
r-o-bind-mounts-sys_mknodat-elevate-write-count-for-vfs_mknod-create.patch
r-o-bind-mounts-elevate-mnt-writers-for-vfs_unlink-callers.patch
r-o-bind-mounts-do_rmdir-elevate-write-count.patch
r-o-bind-mounts-elevate-writer-count-for-custom-struct_file.patch
r-o-bind-mounts-gfs-check-nlink-count.patch
r-o-bind-mounts-honor-r-w-changes-at-do_remount-time.patch
r-o-bind-mounts-kill-open-files-traverse-on-remount-ro.patch

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