From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [PATCH review 05/19] mnt: Add MNT_UMOUNT flag Date: Thu, 2 Apr 2015 20:56:09 -0500 Message-ID: <1428026183-14879-5-git-send-email-ebiederm@xmission.com> References: <87a8yqou41.fsf_-_@x220.int.ebiederm.org> Cc: , "Serge E. Hallyn" , Andy Lutomirski , Richard Weinberger , Andrey Vagin , Al Viro , Jann Horn , Willy Tarreau , Omar Sandoval To: Linux Containers Return-path: Received: from out01.mta.xmission.com ([166.70.13.231]:45007 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753264AbbDCCAd (ORCPT ); Thu, 2 Apr 2015 22:00:33 -0400 In-Reply-To: <87a8yqou41.fsf_-_@x220.int.ebiederm.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: In some instances it is necessary to know if the the unmounting process has begun on a mount. Add MNT_UMOUNT to make that reliably testable. This fix gets used in fixing locked mounts in MNT_DETACH Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" --- fs/namespace.c | 4 +++- fs/pnode.c | 1 + include/linux/mount.h | 1 + 3 files changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index 54cbef129f4a..d1708147eb45 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1331,8 +1331,10 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how) struct mount *p; /* Gather the mounts to umount */ - for (p = mnt; p; p = next_mnt(p, mnt)) + for (p = mnt; p; p = next_mnt(p, mnt)) { + p->mnt.mnt_flags |= MNT_UMOUNT; list_move(&p->mnt_list, &tmp_list); + } /* Hide the mounts from lookup_mnt and mnt_mounts */ list_for_each_entry(p, &tmp_list, mnt_list) { diff --git a/fs/pnode.c b/fs/pnode.c index bf012af709dd..ac3aa0d43b90 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -384,6 +384,7 @@ static void __propagate_umount(struct mount *mnt) if (child && list_empty(&child->mnt_mounts)) { list_del_init(&child->mnt_child); hlist_del_init_rcu(&child->mnt_hash); + child->mnt.mnt_flags |= MNT_UMOUNT; list_move_tail(&child->mnt_list, &mnt->mnt_list); } } diff --git a/include/linux/mount.h b/include/linux/mount.h index c2c561dc0114..564beeec5d83 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -61,6 +61,7 @@ struct mnt_namespace; #define MNT_DOOMED 0x1000000 #define MNT_SYNC_UMOUNT 0x2000000 #define MNT_MARKED 0x4000000 +#define MNT_UMOUNT 0x8000000 struct vfsmount { struct dentry *mnt_root; /* root of the mounted tree */ -- 2.2.1