Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932369AbZJUTYN (ORCPT ); Wed, 21 Oct 2009 15:24:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755233AbZJUTXy (ORCPT ); Wed, 21 Oct 2009 15:23:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:17285 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755255AbZJUTVe (ORCPT ); Wed, 21 Oct 2009 15:21:34 -0400 From: Valerie Aurora To: Jan Blunck , Alexander Viro , Christoph Hellwig , Andy Whitcroft , Scott James Remnant , Sandu Popa Marius , Jan Rekorajski , "J. R. Okajima" , Arnd Bergmann , Vladimir Dronnikov , Felix Fietkau Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 36/41] union-mount: Increment read-only users count for read-only layer Date: Wed, 21 Oct 2009 12:19:34 -0700 Message-Id: <1256152779-10054-37-git-send-email-vaurora@redhat.com> In-Reply-To: <1256152779-10054-36-git-send-email-vaurora@redhat.com> References: <1256152779-10054-1-git-send-email-vaurora@redhat.com> <1256152779-10054-2-git-send-email-vaurora@redhat.com> <1256152779-10054-3-git-send-email-vaurora@redhat.com> <1256152779-10054-4-git-send-email-vaurora@redhat.com> <1256152779-10054-5-git-send-email-vaurora@redhat.com> <1256152779-10054-6-git-send-email-vaurora@redhat.com> <1256152779-10054-7-git-send-email-vaurora@redhat.com> <1256152779-10054-8-git-send-email-vaurora@redhat.com> <1256152779-10054-9-git-send-email-vaurora@redhat.com> <1256152779-10054-10-git-send-email-vaurora@redhat.com> <1256152779-10054-11-git-send-email-vaurora@redhat.com> <1256152779-10054-12-git-send-email-vaurora@redhat.com> <1256152779-10054-13-git-send-email-vaurora@redhat.com> <1256152779-10054-14-git-send-email-vaurora@redhat.com> <1256152779-10054-15-git-send-email-vaurora@redhat.com> <1256152779-10054-16-git-send-email-vaurora@redhat.com> <1256152779-10054-17-git-send-email-vaurora@redhat.com> <1256152779-10054-18-git-send-email-vaurora@redhat.com> <1256152779-10054-19-git-send-email-vaurora@redhat.com> <1256152779-10054-20-git-send-email-vaurora@redhat.com> <1256152779-10054-21-git-send-email-vaurora@redhat.com> <1256152779-10054-22-git-send-email-vaurora@redhat.com> <1256152779-10054-23-git-send-email-vaurora@redhat.com> <1256152779-10054-24-git-send-email-vaurora@redhat.com> <1256152779-10054-25-git-send-email-vaurora@redhat.com> <1256152779-10054-26-git-send-email-vaurora@redhat.com> <1256152779-10054-27-git-send-email-vaurora@redhat.com> <1256152779-10054-28-git-send-email-vaurora@redhat.com> <1256152779-10054-29-git-send-email-vaurora@redhat.com> <1256152779-10054-30-git-send-email-vaurora@redhat.com> <1256152779-10054-31-git-send-email-vaurora@redhat.com> <1256152779-10054-32-git-send-email-vaurora@redhat.com> <1256152779-10054-33-git-send-email-vaurora@redhat.com> <1256152779-10054-34-git-send-email-vaurora@redhat.com> <1256152779-10054-35-git-send-email-vaurora@redhat.com> <1256152779-10054-36-git-send-email-vaurora@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1879 Lines: 56 Union mounts want to guarantee that the read-only layer is read-only - and stays read-only. Use the new superblock read-only user count. XXX - Put common code in loopback and regular mounts in a function Signed-off-by: Valerie Aurora --- fs/namespace.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 0280e5b..505974a 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1111,6 +1111,11 @@ static int do_umount(struct vfsmount *mnt, int flags) spin_unlock(&vfsmount_lock); if (retval) security_sb_umount_busy(mnt); + /* If this was a union mount, we are no longer a read-only + * user on the underlying mount */ + if (mnt->mnt_flags & MNT_UNION) + mnt->mnt_parent->mnt_sb->s_readonly_users--; + up_write(&namespace_sem); release_mounts(&umount_list); return retval; @@ -1511,6 +1516,10 @@ static int do_loopback(struct path *path, char *old_name, int recurse, release_mounts(&umount_list); } + /* If this is a union mount, add ourselves to the readonly users */ + if (mnt_flags & MNT_UNION) + mnt->mnt_parent->mnt_sb->s_readonly_users++; + out: up_write(&namespace_sem); path_put(&old_path); @@ -1730,6 +1739,10 @@ int do_add_mount(struct vfsmount *newmnt, struct path *path, if ((err = graft_tree(newmnt, path))) goto unlock; + /* If this is a union mount, add ourselves to the readonly users */ + if (mnt_flags & MNT_UNION) + newmnt->mnt_parent->mnt_sb->s_readonly_users++; + if (fslist) /* add to the specified expiration list */ list_add_tail(&newmnt->mnt_expire, fslist); -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/