Re: [PATCH v2 1/5] lockd: move lockd's grace period handling into its own module

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

On Tue, Aug 19, 2014 at 02:38:25PM -0400, Jeff Layton wrote:
> Currently, all of the grace period handling is part of lockd. Eventually
> though we'd like to be able to build v4-only servers, at which point
> we'll need to put all of this elsewhere.
> 
> Move the code itself into fs/nfs_common and have it build a grace.ko
> module. Then, rejigger the Kconfig options so that both nfsd and lockd
> enable it automatically.

Thanks, applying this one for 3.18 indepedently of the others.

--b.

> 
> Signed-off-by: Jeff Layton <jlayton@primarydata.com>
> ---
>  fs/Kconfig                       |  6 +++-
>  fs/lockd/Makefile                |  2 +-
>  fs/lockd/netns.h                 |  1 -
>  fs/lockd/svc.c                   |  1 -
>  fs/nfs_common/Makefile           |  3 +-
>  fs/{lockd => nfs_common}/grace.c | 68 ++++++++++++++++++++++++++++++++++------
>  fs/nfsd/Kconfig                  |  1 +
>  include/linux/proc_fs.h          |  2 ++
>  8 files changed, 69 insertions(+), 15 deletions(-)
>  rename fs/{lockd => nfs_common}/grace.c (50%)
> 
> diff --git a/fs/Kconfig b/fs/Kconfig
> index 312393f32948..db5dc1598716 100644
> --- a/fs/Kconfig
> +++ b/fs/Kconfig
> @@ -233,9 +233,13 @@ if NETWORK_FILESYSTEMS
>  source "fs/nfs/Kconfig"
>  source "fs/nfsd/Kconfig"
>  
> +config GRACE_PERIOD
> +	tristate
> +
>  config LOCKD
>  	tristate
>  	depends on FILE_LOCKING
> +	select GRACE_PERIOD
>  
>  config LOCKD_V4
>  	bool
> @@ -249,7 +253,7 @@ config NFS_ACL_SUPPORT
>  
>  config NFS_COMMON
>  	bool
> -	depends on NFSD || NFS_FS
> +	depends on NFSD || NFS_FS || LOCKD
>  	default y
>  
>  source "net/sunrpc/Kconfig"
> diff --git a/fs/lockd/Makefile b/fs/lockd/Makefile
> index ca58d64374ca..6a0b351ce30e 100644
> --- a/fs/lockd/Makefile
> +++ b/fs/lockd/Makefile
> @@ -5,6 +5,6 @@
>  obj-$(CONFIG_LOCKD) += lockd.o
>  
>  lockd-objs-y := clntlock.o clntproc.o clntxdr.o host.o svc.o svclock.o \
> -	        svcshare.o svcproc.o svcsubs.o mon.o xdr.o grace.o
> +	        svcshare.o svcproc.o svcsubs.o mon.o xdr.o
>  lockd-objs-$(CONFIG_LOCKD_V4) += clnt4xdr.o xdr4.o svc4proc.o
>  lockd-objs		      := $(lockd-objs-y)
> diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h
> index 5010b55628b4..097bfa3adb1c 100644
> --- a/fs/lockd/netns.h
> +++ b/fs/lockd/netns.h
> @@ -11,7 +11,6 @@ struct lockd_net {
>  
>  	struct delayed_work grace_period_end;
>  	struct lock_manager lockd_manager;
> -	struct list_head grace_list;
>  
>  	spinlock_t nsm_clnt_lock;
>  	unsigned int nsm_users;
> diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
> index 8f27c93f8d2e..3599c9ca28ae 100644
> --- a/fs/lockd/svc.c
> +++ b/fs/lockd/svc.c
> @@ -583,7 +583,6 @@ static int lockd_init_net(struct net *net)
>  	struct lockd_net *ln = net_generic(net, lockd_net_id);
>  
>  	INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);
> -	INIT_LIST_HEAD(&ln->grace_list);
>  	spin_lock_init(&ln->nsm_clnt_lock);
>  	return 0;
>  }
> diff --git a/fs/nfs_common/Makefile b/fs/nfs_common/Makefile
> index f689ed82af3a..d153ca3ea577 100644
> --- a/fs/nfs_common/Makefile
> +++ b/fs/nfs_common/Makefile
> @@ -3,5 +3,6 @@
>  #
>  
>  obj-$(CONFIG_NFS_ACL_SUPPORT) += nfs_acl.o
> -
>  nfs_acl-objs := nfsacl.o
> +
> +obj-$(CONFIG_GRACE_PERIOD) += grace.o
> diff --git a/fs/lockd/grace.c b/fs/nfs_common/grace.c
> similarity index 50%
> rename from fs/lockd/grace.c
> rename to fs/nfs_common/grace.c
> index 6d1ee7204c88..ae6e58ea4de5 100644
> --- a/fs/lockd/grace.c
> +++ b/fs/nfs_common/grace.c
> @@ -1,17 +1,20 @@
>  /*
>   * Common code for control of lockd and nfsv4 grace periods.
> + *
> + * Transplanted from lockd code
>   */
>  
>  #include <linux/module.h>
> -#include <linux/lockd/bind.h>
>  #include <net/net_namespace.h>
> +#include <net/netns/generic.h>
> +#include <linux/fs.h>
>  
> -#include "netns.h"
> -
> +static int grace_net_id;
>  static DEFINE_SPINLOCK(grace_lock);
>  
>  /**
>   * locks_start_grace
> + * @net: net namespace that this lock manager belongs to
>   * @lm: who this grace period is for
>   *
>   * A grace period is a period during which locks should not be given
> @@ -21,18 +24,20 @@ static DEFINE_SPINLOCK(grace_lock);
>   *
>   * This function is called to start a grace period.
>   */
> -void locks_start_grace(struct net *net, struct lock_manager *lm)
> +void
> +locks_start_grace(struct net *net, struct lock_manager *lm)
>  {
> -	struct lockd_net *ln = net_generic(net, lockd_net_id);
> +	struct list_head *grace_list = net_generic(net, grace_net_id);
>  
>  	spin_lock(&grace_lock);
> -	list_add(&lm->list, &ln->grace_list);
> +	list_add(&lm->list, grace_list);
>  	spin_unlock(&grace_lock);
>  }
>  EXPORT_SYMBOL_GPL(locks_start_grace);
>  
>  /**
>   * locks_end_grace
> + * @net: net namespace that this lock manager belongs to
>   * @lm: who this grace period is for
>   *
>   * Call this function to state that the given lock manager is ready to
> @@ -41,7 +46,8 @@ EXPORT_SYMBOL_GPL(locks_start_grace);
>   * Note that callers count on it being safe to call this more than once,
>   * and the second call should be a no-op.
>   */
> -void locks_end_grace(struct lock_manager *lm)
> +void
> +locks_end_grace(struct lock_manager *lm)
>  {
>  	spin_lock(&grace_lock);
>  	list_del_init(&lm->list);
> @@ -56,10 +62,52 @@ EXPORT_SYMBOL_GPL(locks_end_grace);
>   * to answer ordinary lock requests, and when they should accept only
>   * lock reclaims.
>   */
> -int locks_in_grace(struct net *net)
> +int
> +locks_in_grace(struct net *net)
>  {
> -	struct lockd_net *ln = net_generic(net, lockd_net_id);
> +	struct list_head *grace_list = net_generic(net, grace_net_id);
>  
> -	return !list_empty(&ln->grace_list);
> +	return !list_empty(grace_list);
>  }
>  EXPORT_SYMBOL_GPL(locks_in_grace);
> +
> +static int __net_init
> +grace_init_net(struct net *net)
> +{
> +	struct list_head *grace_list = net_generic(net, grace_net_id);
> +
> +	INIT_LIST_HEAD(grace_list);
> +	return 0;
> +}
> +
> +static void __net_exit
> +grace_exit_net(struct net *net)
> +{
> +	struct list_head *grace_list = net_generic(net, grace_net_id);
> +
> +	BUG_ON(!list_empty(grace_list));
> +}
> +
> +static struct pernet_operations grace_net_ops = {
> +	.init = grace_init_net,
> +	.exit = grace_exit_net,
> +	.id   = &grace_net_id,
> +	.size = sizeof(struct list_head),
> +};
> +
> +static int __init
> +init_grace(void)
> +{
> +	return register_pernet_subsys(&grace_net_ops);
> +}
> +
> +static void __exit
> +exit_grace(void)
> +{
> +	unregister_pernet_subsys(&grace_net_ops);
> +}
> +
> +MODULE_AUTHOR("Jeff Layton <jlayton@primarydata.com>");
> +MODULE_LICENSE("GPL");
> +module_init(init_grace)
> +module_exit(exit_grace)
> diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
> index f994e750e0d1..4fa98764de21 100644
> --- a/fs/nfsd/Kconfig
> +++ b/fs/nfsd/Kconfig
> @@ -71,6 +71,7 @@ config NFSD_V4
>  	select FS_POSIX_ACL
>  	select SUNRPC_GSS
>  	select CRYPTO
> +	select GRACE_PERIOD
>  	help
>  	  This option enables support in your system's NFS server for
>  	  version 4 of the NFS protocol (RFC 3530).
> diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
> index 9d117f61d976..b97bf2ef996e 100644
> --- a/include/linux/proc_fs.h
> +++ b/include/linux/proc_fs.h
> @@ -74,6 +74,8 @@ static inline int remove_proc_subtree(const char *name, struct proc_dir_entry *p
>  
>  #endif /* CONFIG_PROC_FS */
>  
> +struct net;
> +
>  static inline struct proc_dir_entry *proc_net_mkdir(
>  	struct net *net, const char *name, struct proc_dir_entry *parent)
>  {
> -- 
> 1.9.3
>