From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [REVIEW][PATCH 3/4] vfs: Add a function to lazily unmount all mounts from any dentry. v3 Date: Tue, 22 Oct 2013 19:08:25 +0000 Message-ID: <20131022190825.GC10600@mail.hallyn.com> References: <20131008161135.GK14242@tucsk.piliscsaba.szeredi.hu> <87li23trll.fsf@tw-ebiederman.twitter.com> <87vc15mjuw.fsf@xmission.com> <87iox38fkv.fsf@xmission.com> <87d2nb8dxy.fsf@xmission.com> <87iowyxpci.fsf_-_@xmission.com> <871u3mxp8s.fsf_-_@xmission.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <871u3mxp8s.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "Eric W. Biederman" Cc: Miklos Szeredi , Linux Containers , Kernel Mailing List , Andy Lutomirski , Al Viro , Linux-Fsdevel , Matthias Schniedermeyer , Linus Torvalds List-Id: containers.vger.kernel.org Quoting Eric W. Biederman (ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org): > > v2: Always drop the lock when exiting early. > v3: Make detach_mounts robust about freeing several > mounts on the same mountpoint at one time, and remove > the unneeded mnt_list list test. > > Signed-off-by: Eric W. Biederman Acked-by: Serge Hallyn > --- > fs/mount.h | 1 + > fs/namespace.c | 24 ++++++++++++++++++++++++ > 2 files changed, 25 insertions(+), 0 deletions(-) > > diff --git a/fs/mount.h b/fs/mount.h > index e4342b8dfab1..7a6a2bb3f290 100644 > --- a/fs/mount.h > +++ b/fs/mount.h > @@ -79,6 +79,7 @@ static inline int is_mounted(struct vfsmount *mnt) > } > > extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int); > +extern void detach_mounts(struct dentry *dentry); > > static inline void get_mnt_ns(struct mnt_namespace *ns) > { > diff --git a/fs/namespace.c b/fs/namespace.c > index e4fe22c23e00..78f7c5c9e673 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -1295,6 +1295,30 @@ static int do_umount(struct mount *mnt, int flags) > return retval; > } > > +void detach_mounts(struct dentry *dentry) > +{ > + struct mountpoint *mp; > + struct mount *mnt; > + > + namespace_lock(); > + if (!d_mountpoint(dentry)) > + goto out_unlock; > + > + mp = new_mountpoint(dentry); > + if (IS_ERR(mp)) > + goto out_unlock; > + > + br_write_lock(&vfsmount_lock); > + while (!list_empty(&mp->m_list)) { > + mnt = list_first_entry(&mp->m_list, struct mount, mnt_mp_list); > + umount_tree(mnt, 1); > + } > + br_write_unlock(&vfsmount_lock); > + put_mountpoint(mp); > +out_unlock: > + namespace_unlock(); > +} > + > /* > * Is the caller allowed to modify his namespace? > */ > -- > 1.7.5.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754856Ab3JVTI1 (ORCPT ); Tue, 22 Oct 2013 15:08:27 -0400 Received: from static.92.5.9.176.clients.your-server.de ([176.9.5.92]:55664 "EHLO hallynmail2" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753537Ab3JVTI0 (ORCPT ); Tue, 22 Oct 2013 15:08:26 -0400 Date: Tue, 22 Oct 2013 19:08:25 +0000 From: "Serge E. Hallyn" To: "Eric W. Biederman" Cc: Miklos Szeredi , Andy Lutomirski , "Serge E. Hallyn" , Al Viro , Linux-Fsdevel , Kernel Mailing List , Rob Landley , Linus Torvalds , Matthias Schniedermeyer , Linux Containers Subject: Re: [REVIEW][PATCH 3/4] vfs: Add a function to lazily unmount all mounts from any dentry. v3 Message-ID: <20131022190825.GC10600@mail.hallyn.com> References: <20131008161135.GK14242@tucsk.piliscsaba.szeredi.hu> <87li23trll.fsf@tw-ebiederman.twitter.com> <87vc15mjuw.fsf@xmission.com> <87iox38fkv.fsf@xmission.com> <87d2nb8dxy.fsf@xmission.com> <87iowyxpci.fsf_-_@xmission.com> <871u3mxp8s.fsf_-_@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871u3mxp8s.fsf_-_@xmission.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Eric W. Biederman (ebiederm@xmission.com): > > v2: Always drop the lock when exiting early. > v3: Make detach_mounts robust about freeing several > mounts on the same mountpoint at one time, and remove > the unneeded mnt_list list test. > > Signed-off-by: Eric W. Biederman Acked-by: Serge Hallyn > --- > fs/mount.h | 1 + > fs/namespace.c | 24 ++++++++++++++++++++++++ > 2 files changed, 25 insertions(+), 0 deletions(-) > > diff --git a/fs/mount.h b/fs/mount.h > index e4342b8dfab1..7a6a2bb3f290 100644 > --- a/fs/mount.h > +++ b/fs/mount.h > @@ -79,6 +79,7 @@ static inline int is_mounted(struct vfsmount *mnt) > } > > extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int); > +extern void detach_mounts(struct dentry *dentry); > > static inline void get_mnt_ns(struct mnt_namespace *ns) > { > diff --git a/fs/namespace.c b/fs/namespace.c > index e4fe22c23e00..78f7c5c9e673 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -1295,6 +1295,30 @@ static int do_umount(struct mount *mnt, int flags) > return retval; > } > > +void detach_mounts(struct dentry *dentry) > +{ > + struct mountpoint *mp; > + struct mount *mnt; > + > + namespace_lock(); > + if (!d_mountpoint(dentry)) > + goto out_unlock; > + > + mp = new_mountpoint(dentry); > + if (IS_ERR(mp)) > + goto out_unlock; > + > + br_write_lock(&vfsmount_lock); > + while (!list_empty(&mp->m_list)) { > + mnt = list_first_entry(&mp->m_list, struct mount, mnt_mp_list); > + umount_tree(mnt, 1); > + } > + br_write_unlock(&vfsmount_lock); > + put_mountpoint(mp); > +out_unlock: > + namespace_unlock(); > +} > + > /* > * Is the caller allowed to modify his namespace? > */ > -- > 1.7.5.4