Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755480Ab2HOPu2 (ORCPT ); Wed, 15 Aug 2012 11:50:28 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:39288 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755446Ab2HOPrP (ORCPT ); Wed, 15 Aug 2012 11:47:15 -0400 From: Miklos Szeredi To: viro@ZenIV.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, hch@infradead.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, apw@canonical.com, nbd@openwrt.org, neilb@suse.de, hramrach@centrum.cz, jordipujolp@gmail.com, ezk@fsl.cs.sunysb.edu, ricwheeler@gmail.com, dhowells@redhat.com, hpj@urpla.net, sedat.dilek@googlemail.com, penberg@kernel.org, goran.cetusic@gmail.com, romain@orebokech.com, mszeredi@suse.cz Subject: [PATCH 03/13] vfs: introduce clone_private_mount() Date: Wed, 15 Aug 2012 17:48:10 +0200 Message-Id: <1345045700-9062-4-git-send-email-miklos@szeredi.hu> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1345045700-9062-1-git-send-email-miklos@szeredi.hu> References: <1345045700-9062-1-git-send-email-miklos@szeredi.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1866 Lines: 62 From: Miklos Szeredi Overlayfs needs a private clone of the mount, so create a function for this and export to modules. Signed-off-by: Miklos Szeredi --- fs/namespace.c | 18 ++++++++++++++++++ include/linux/mount.h | 3 +++ 2 files changed, 21 insertions(+), 0 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 4d31f73..b4712ea 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1387,6 +1387,24 @@ void drop_collected_mounts(struct vfsmount *mnt) release_mounts(&umount_list); } +struct vfsmount *clone_private_mount(struct path *path) +{ + struct mount *old_mnt = real_mount(path->mnt); + struct mount *new_mnt; + + if (IS_MNT_UNBINDABLE(old_mnt)) + return ERR_PTR(-EINVAL); + + down_read(&namespace_sem); + new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE); + up_read(&namespace_sem); + if (!new_mnt) + return ERR_PTR(-ENOMEM); + + return &new_mnt->mnt; +} +EXPORT_SYMBOL_GPL(clone_private_mount); + int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg, struct vfsmount *root) { diff --git a/include/linux/mount.h b/include/linux/mount.h index d7029f4..344a262 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -66,6 +66,9 @@ extern void mnt_pin(struct vfsmount *mnt); extern void mnt_unpin(struct vfsmount *mnt); extern int __mnt_is_readonly(struct vfsmount *mnt); +struct path; +extern struct vfsmount *clone_private_mount(struct path *path); + struct file_system_type; extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, int flags, const char *name, -- 1.7.7 -- 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/