Re: [PATCH v2] Lockd: pass network namespace to creation and destruction routines

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, Apr 11, 2012 at 08:12:04PM +0400, Stanislav Kinsbursky wrote:
> 11.04.2012 20:11, J. Bruce Fields пишет:
> >On Thu, Mar 29, 2012 at 06:54:33PM +0400, Stanislav Kinsbursky wrote:
> >>v2: dereference of most probably already released nlm_host removed in
> >>nlmclnt_done() and reclaimer().
> >
> >Did you want this in Trond's tree or mine?
> >
> 
> Your tree is preferred since I'm working with it.

OK, applying.--b.

> 
> >--b.
> >
> >>
> >>These routines are called from locks reclaimer() kernel thread. This thread
> >>works in "init_net" network context and currently relays on persence on lockd
> >>thread and it's per-net resources. Thus lockd_up() and lockd_down() can't relay
> >>on current network context. So let's pass corrent one into them.
> >>
> >>Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
> >>
> >>Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
> >>
> >>---
> >>  fs/lockd/clntlock.c        |   13 ++++++++-----
> >>  fs/lockd/svc.c             |    7 +++----
> >>  fs/nfsd/nfssvc.c           |    6 +++---
> >>  include/linux/lockd/bind.h |    4 ++--
> >>  4 files changed, 16 insertions(+), 14 deletions(-)
> >>
> >>diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
> >>index ba1dc2e..ca0a080 100644
> >>--- a/fs/lockd/clntlock.c
> >>+++ b/fs/lockd/clntlock.c
> >>@@ -56,7 +56,7 @@ struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
> >>  	u32 nlm_version = (nlm_init->nfs_version == 2) ? 1 : 4;
> >>  	int status;
> >>
> >>-	status = lockd_up();
> >>+	status = lockd_up(nlm_init->net);
> >>  	if (status<  0)
> >>  		return ERR_PTR(status);
> >>
> >>@@ -65,7 +65,7 @@ struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
> >>  				   nlm_init->hostname, nlm_init->noresvport,
> >>  				   nlm_init->net);
> >>  	if (host == NULL) {
> >>-		lockd_down();
> >>+		lockd_down(nlm_init->net);
> >>  		return ERR_PTR(-ENOLCK);
> >>  	}
> >>
> >>@@ -80,8 +80,10 @@ EXPORT_SYMBOL_GPL(nlmclnt_init);
> >>   */
> >>  void nlmclnt_done(struct nlm_host *host)
> >>  {
> >>+	struct net *net = host->net;
> >>+
> >>  	nlmclnt_release_host(host);
> >>-	lockd_down();
> >>+	lockd_down(net);
> >>  }
> >>  EXPORT_SYMBOL_GPL(nlmclnt_done);
> >>
> >>@@ -220,11 +222,12 @@ reclaimer(void *ptr)
> >>  	struct nlm_wait	  *block;
> >>  	struct file_lock *fl, *next;
> >>  	u32 nsmstate;
> >>+	struct net *net = host->net;
> >>
> >>  	allow_signal(SIGKILL);
> >>
> >>  	down_write(&host->h_rwsem);
> >>-	lockd_up();	/* note: this cannot fail as lockd is already running */
> >>+	lockd_up(net);	/* note: this cannot fail as lockd is already running */
> >>
> >>  	dprintk("lockd: reclaiming locks for host %s\n", host->h_name);
> >>
> >>@@ -275,6 +278,6 @@ restart:
> >>
> >>  	/* Release host handle after use */
> >>  	nlmclnt_release_host(host);
> >>-	lockd_down();
> >>+	lockd_down(net);
> >>  	return 0;
> >>  }
> >>diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
> >>index b34100e..ce4c80e 100644
> >>--- a/fs/lockd/svc.c
> >>+++ b/fs/lockd/svc.c
> >>@@ -295,11 +295,10 @@ static void lockd_down_net(struct net *net)
> >>  /*
> >>   * Bring up the lockd process if it's not already up.
> >>   */
> >>-int lockd_up(void)
> >>+int lockd_up(struct net *net)
> >>  {
> >>  	struct svc_serv *serv;
> >>  	int		error = 0;
> >>-	struct net *net = current->nsproxy->net_ns;
> >>
> >>  	mutex_lock(&nlmsvc_mutex);
> >>  	/*
> >>@@ -377,12 +376,12 @@ EXPORT_SYMBOL_GPL(lockd_up);
> >>   * Decrement the user count and bring down lockd if we're the last.
> >>   */
> >>  void
> >>-lockd_down(void)
> >>+lockd_down(struct net *net)
> >>  {
> >>  	mutex_lock(&nlmsvc_mutex);
> >>  	if (nlmsvc_users) {
> >>  		if (--nlmsvc_users) {
> >>-			lockd_down_net(current->nsproxy->net_ns);
> >>+			lockd_down_net(net);
> >>  			goto out;
> >>  		}
> >>  	} else {
> >>diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
> >>index fce472f..0f3e35b 100644
> >>--- a/fs/nfsd/nfssvc.c
> >>+++ b/fs/nfsd/nfssvc.c
> >>@@ -220,7 +220,7 @@ static int nfsd_startup(unsigned short port, int nrservs)
> >>  	ret = nfsd_init_socks(port);
> >>  	if (ret)
> >>  		goto out_racache;
> >>-	ret = lockd_up();
> >>+	ret = lockd_up(&init_net);
> >>  	if (ret)
> >>  		goto out_racache;
> >>  	ret = nfs4_state_start();
> >>@@ -229,7 +229,7 @@ static int nfsd_startup(unsigned short port, int nrservs)
> >>  	nfsd_up = true;
> >>  	return 0;
> >>  out_lockd:
> >>-	lockd_down();
> >>+	lockd_down(&init_net);
> >>  out_racache:
> >>  	nfsd_racache_shutdown();
> >>  	return ret;
> >>@@ -246,7 +246,7 @@ static void nfsd_shutdown(void)
> >>  	if (!nfsd_up)
> >>  		return;
> >>  	nfs4_state_shutdown();
> >>-	lockd_down();
> >>+	lockd_down(&init_net);
> >>  	nfsd_racache_shutdown();
> >>  	nfsd_up = false;
> >>  }
> >>diff --git a/include/linux/lockd/bind.h b/include/linux/lockd/bind.h
> >>index 11a966e..4d24d64 100644
> >>--- a/include/linux/lockd/bind.h
> >>+++ b/include/linux/lockd/bind.h
> >>@@ -54,7 +54,7 @@ extern void	nlmclnt_done(struct nlm_host *host);
> >>
> >>  extern int	nlmclnt_proc(struct nlm_host *host, int cmd,
> >>  					struct file_lock *fl);
> >>-extern int	lockd_up(void);
> >>-extern void	lockd_down(void);
> >>+extern int	lockd_up(struct net *net);
> >>+extern void	lockd_down(struct net *net);
> >>
> >>  #endif /* LINUX_LOCKD_BIND_H */
> >>
> 
> 
> -- 
> Best regards,
> Stanislav Kinsbursky