From: Dan Williams <dan.j.williams@intel.com>
Date: Sat, 27 Sep 2008 02:01:20 +0000 (-0700)
Subject: [RFC PATCH] touch_mnt_namespace when the mount flags change
X-Git-Tag: v3.12-rc1~17530^2~6
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0e55a7cca4b66f625d67b292f80b6a976e77c51b;p=kernel%2Fkernel-generic.git

[RFC PATCH] touch_mnt_namespace when the mount flags change

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>
---

diff --git a/fs/namespace.c b/fs/namespace.c
index f527a0d..cce4670 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1550,8 +1550,13 @@ static int do_remount(struct path *path, int flags, int mnt_flags,
 	if (!err)
 		path->mnt->mnt_flags = mnt_flags;
 	up_write(&sb->s_umount);
-	if (!err)
+	if (!err) {
 		security_sb_post_remount(path->mnt, flags, data);
+
+		spin_lock(&vfsmount_lock);
+		touch_mnt_namespace(path->mnt->mnt_ns);
+		spin_unlock(&vfsmount_lock);
+	}
 	return err;
 }