[patch 01/22] touch_mnt_namespace when the mount flags change

[Greg KH <gregkh@suse.de>]

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2.6.27-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Dan Williams <dan.j.williams@intel.com>

commit 0e55a7cca4b66f625d67b292f80b6a976e77c51b upstream

Daemons that need to be launched while the rootfs is read-only can now
poll /proc/mounts to be notified when their O_RDWR requests may no
longer end in EROFS.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/namespace.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1553,8 +1553,13 @@ static noinline int do_remount(struct na
 	if (!err)
 		nd->path.mnt->mnt_flags = mnt_flags;
 	up_write(&sb->s_umount);
-	if (!err)
+	if (!err) {
 		security_sb_post_remount(nd->path.mnt, flags, data);
+
+		spin_lock(&vfsmount_lock);
+		touch_mnt_namespace(nd->path.mnt->mnt_ns);
+		spin_unlock(&vfsmount_lock);
+	}
 	return err;
 }
 

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