On Mon, Sep 15, 2014 at 03:02:21PM -0400, Jeff Layton wrote:
> On Mon, 15 Sep 2014 09:14:02 -0400
> Jeff Layton <jlayton@xxxxxxxxxxxxxxx> 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.
> >
> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
> > ---
> > fs/Kconfig | 6 ++-
> > fs/lockd/Makefile | 2 +-
> > fs/lockd/grace.c | 65 ----------------------------
> > fs/lockd/netns.h | 1 -
> > fs/lockd/svc.c | 1 -
> > fs/nfs_common/Makefile | 3 +-
> > fs/nfs_common/grace.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++
> > fs/nfsd/Kconfig | 1 +
> > include/linux/proc_fs.h | 2 +
> > 9 files changed, 124 insertions(+), 70 deletions(-)
> > delete mode 100644 fs/lockd/grace.c
> > create mode 100644 fs/nfs_common/grace.c
> >
> > 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/grace.c b/fs/lockd/grace.c
> > deleted file mode 100644
> > index 6d1ee7204c88..000000000000
> > --- a/fs/lockd/grace.c
> > +++ /dev/null
> > @@ -1,65 +0,0 @@
> > -/*
> > - * Common code for control of lockd and nfsv4 grace periods.
> > - */
> > -
> > -#include <linux/module.h>
> > -#include <linux/lockd/bind.h>
> > -#include <net/net_namespace.h>
> > -
> > -#include "netns.h"
> > -
> > -static DEFINE_SPINLOCK(grace_lock);
> > -
> > -/**
> > - * locks_start_grace
> > - * @lm: who this grace period is for
> > - *
> > - * A grace period is a period during which locks should not be given
> > - * out. Currently grace periods are only enforced by the two lock
> > - * managers (lockd and nfsd), using the locks_in_grace() function to
> > - * check when they are in a grace period.
> > - *
> > - * This function is called to start a grace period.
> > - */
> > -void locks_start_grace(struct net *net, struct lock_manager *lm)
> > -{
> > - struct lockd_net *ln = net_generic(net, lockd_net_id);
> > -
> > - spin_lock(&grace_lock);
> > - list_add(&lm->list, &ln->grace_list);
> > - spin_unlock(&grace_lock);
> > -}
> > -EXPORT_SYMBOL_GPL(locks_start_grace);
> > -
> > -/**
> > - * locks_end_grace
> > - * @lm: who this grace period is for
> > - *
> > - * Call this function to state that the given lock manager is ready to
> > - * resume regular locking. The grace period will not end until all lock
> > - * managers that called locks_start_grace() also call locks_end_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)
> > -{
> > - spin_lock(&grace_lock);
> > - list_del_init(&lm->list);
> > - spin_unlock(&grace_lock);
> > -}
> > -EXPORT_SYMBOL_GPL(locks_end_grace);
> > -
> > -/**
> > - * locks_in_grace
> > - *
> > - * Lock managers call this function to determine when it is OK for them
> > - * to answer ordinary lock requests, and when they should accept only
> > - * lock reclaims.
> > - */
> > -int locks_in_grace(struct net *net)
> > -{
> > - struct lockd_net *ln = net_generic(net, lockd_net_id);
> > -
> > - return !list_empty(&ln->grace_list);
> > -}
> > -EXPORT_SYMBOL_GPL(locks_in_grace);
> > 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 09857b48d0c3..c35cd43a06e6 100644
> > --- a/fs/lockd/svc.c
> > +++ b/fs/lockd/svc.c
> > @@ -586,7 +586,6 @@ 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);
>
> Ahh, just found a bug. Now that we can initialize the grace_list
> independently of the lockd_manager, we must ensure that we initialize
> the lockd_manager's list_head in lockd_init_net. So, we need to add
> this in here:
>
> INIT_LIST_HEAD(&ln->lockd_manager.list);
>
> ...or we can end up oopsing if sm-notify runs and writes to the
> nlm_grace_end file before lockd comes up.
>
> I've fixed this in my tree, but I'll wait to resend just yet to see
> whether there are any more comments on the rest of the set.
I don't have any more comments. I can fix this up if this is all there
is to do, or you can resend or give me a git url.--b.
>
> > 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/nfs_common/grace.c b/fs/nfs_common/grace.c
> > new file mode 100644
> > index 000000000000..ae6e58ea4de5
> > --- /dev/null
> > +++ b/fs/nfs_common/grace.c
> > @@ -0,0 +1,113 @@
> > +/*
> > + * Common code for control of lockd and nfsv4 grace periods.
> > + *
> > + * Transplanted from lockd code
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <net/net_namespace.h>
> > +#include <net/netns/generic.h>
> > +#include <linux/fs.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
> > + * out. Currently grace periods are only enforced by the two lock
> > + * managers (lockd and nfsd), using the locks_in_grace() function to
> > + * check when they are in a grace period.
> > + *
> > + * This function is called to start a grace period.
> > + */
> > +void
> > +locks_start_grace(struct net *net, struct lock_manager *lm)
> > +{
> > + struct list_head *grace_list = net_generic(net, grace_net_id);
> > +
> > + spin_lock(&grace_lock);
> > + 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
> > + * resume regular locking. The grace period will not end until all lock
> > + * managers that called locks_start_grace() also call locks_end_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)
> > +{
> > + spin_lock(&grace_lock);
> > + list_del_init(&lm->list);
> > + spin_unlock(&grace_lock);
> > +}
> > +EXPORT_SYMBOL_GPL(locks_end_grace);
> > +
> > +/**
> > + * locks_in_grace
> > + *
> > + * Lock managers call this function to determine when it is OK for them
> > + * to answer ordinary lock requests, and when they should accept only
> > + * lock reclaims.
> > + */
> > +int
> > +locks_in_grace(struct net *net)
> > +{
> > + struct list_head *grace_list = net_generic(net, grace_net_id);
> > +
> > + 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@xxxxxxxxxxxxxxx>");
> > +MODULE_LICENSE("GPL");
> > +module_init(init_grace)
> > +module_exit(exit_grace)
> > diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
> > index f3586b645d7d..73395156bdb4 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)
> > {
>
>
> --
> Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
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