From d6a7ce424f9e32b6a5589f6bb96e0d1381479d48 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 3 Aug 2014 13:03:07 -0400 Subject: lockd: Ensure that lockd_start_svc sets the server rq_task... Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- fs/lockd/svc.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/lockd') diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index 8f27c93..b416b33 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -313,6 +313,8 @@ static int lockd_start_svc(struct svc_serv *serv) "lockd_up: kthread_run failed, error=%d\n", error); goto out_task; } + nlmsvc_rqst->rq_task = nlmsvc_task; + dprintk("lockd_up: service started\n"); return 0; -- cgit v1.1 From d4e89902990e3fae1b8d2ca501d2fa5f0657c053 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 2 Sep 2014 13:58:57 -0400 Subject: lockd: Do not start the lockd thread before we've set nlmsvc_rqst->rq_task This fixes an Oopsable race when starting lockd. Signed-off-by: Trond Myklebust Reviewed-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/lockd/svc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/lockd') diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index b416b33..09857b4 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -306,7 +306,7 @@ static int lockd_start_svc(struct svc_serv *serv) svc_sock_update_bufs(serv); serv->sv_maxconn = nlm_max_connections; - nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, "%s", serv->sv_name); + nlmsvc_task = kthread_create(lockd, nlmsvc_rqst, "%s", serv->sv_name); if (IS_ERR(nlmsvc_task)) { error = PTR_ERR(nlmsvc_task); printk(KERN_WARNING @@ -314,6 +314,7 @@ static int lockd_start_svc(struct svc_serv *serv) goto out_task; } nlmsvc_rqst->rq_task = nlmsvc_task; + wake_up_process(nlmsvc_task); dprintk("lockd_up: service started\n"); return 0; -- cgit v1.1 From f7790029655f79cdcee4fa7c7884e0c2795ebebe Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 12 Sep 2014 16:40:20 -0400 Subject: lockd: move lockd's grace period handling into its own module 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 --- fs/lockd/Makefile | 2 +- fs/lockd/grace.c | 65 ------------------------------------------------------- fs/lockd/netns.h | 1 - fs/lockd/svc.c | 2 +- 4 files changed, 2 insertions(+), 68 deletions(-) delete mode 100644 fs/lockd/grace.c (limited to 'fs/lockd') diff --git a/fs/lockd/Makefile b/fs/lockd/Makefile index ca58d64..6a0b351 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 6d1ee72..0000000 --- a/fs/lockd/grace.c +++ /dev/null @@ -1,65 +0,0 @@ -/* - * Common code for control of lockd and nfsv4 grace periods. - */ - -#include -#include -#include - -#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 5010b55..097bfa3 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 09857b4..266b679 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -586,7 +586,7 @@ 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); + INIT_LIST_HEAD(&ln->lockd_manager.list); spin_lock_init(&ln->nsm_clnt_lock); return 0; } -- cgit v1.1 From d68e3c4aa416d592d79152a49af121e4ecb204e3 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 12 Sep 2014 16:40:20 -0400 Subject: lockd: add a /proc/fs/lockd/nlm_end_grace file Add a new procfile that will allow a (privileged) userland process to end the NLM grace period early. The basic idea here will be to have sm-notify write to this file, if it sent out no NOTIFY requests when it runs. In that situation, we can generally expect that there will be no reclaim requests so the grace period can be lifted early. Signed-off-by: Jeff Layton --- fs/lockd/Makefile | 1 + fs/lockd/procfs.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/lockd/procfs.h | 28 +++++++++++++++++ fs/lockd/svc.c | 9 ++++++ 4 files changed, 130 insertions(+) create mode 100644 fs/lockd/procfs.c create mode 100644 fs/lockd/procfs.h (limited to 'fs/lockd') diff --git a/fs/lockd/Makefile b/fs/lockd/Makefile index 6a0b351..9b320cc 100644 --- a/fs/lockd/Makefile +++ b/fs/lockd/Makefile @@ -7,4 +7,5 @@ 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 lockd-objs-$(CONFIG_LOCKD_V4) += clnt4xdr.o xdr4.o svc4proc.o +lockd-objs-$(CONFIG_PROC_FS) += procfs.o lockd-objs := $(lockd-objs-y) diff --git a/fs/lockd/procfs.c b/fs/lockd/procfs.c new file mode 100644 index 0000000..2a0a984 --- /dev/null +++ b/fs/lockd/procfs.c @@ -0,0 +1,92 @@ +/* + * Procfs support for lockd + * + * Copyright (c) 2014 Jeff Layton + */ + +#include +#include +#include +#include +#include + +#include "netns.h" +#include "procfs.h" + +/* + * We only allow strings that start with 'Y', 'y', or '1'. + */ +static ssize_t +nlm_end_grace_write(struct file *file, const char __user *buf, size_t size, + loff_t *pos) +{ + char *data; + struct lockd_net *ln = net_generic(current->nsproxy->net_ns, + lockd_net_id); + + if (size < 1) + return -EINVAL; + + data = simple_transaction_get(file, buf, size); + if (IS_ERR(data)) + return PTR_ERR(data); + + switch(data[0]) { + case 'Y': + case 'y': + case '1': + locks_end_grace(&ln->lockd_manager); + break; + default: + return -EINVAL; + } + + return size; +} + +static ssize_t +nlm_end_grace_read(struct file *file, char __user *buf, size_t size, + loff_t *pos) +{ + struct lockd_net *ln = net_generic(current->nsproxy->net_ns, + lockd_net_id); + char resp[3]; + + resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N'; + resp[1] = '\n'; + resp[2] = '\0'; + + return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp)); +} + +static const struct file_operations lockd_end_grace_operations = { + .write = nlm_end_grace_write, + .read = nlm_end_grace_read, + .llseek = default_llseek, + .release = simple_transaction_release, + .owner = THIS_MODULE, +}; + +int __init +lockd_create_procfs(void) +{ + struct proc_dir_entry *entry; + + entry = proc_mkdir("fs/lockd", NULL); + if (!entry) + return -ENOMEM; + entry = proc_create("nlm_end_grace", S_IRUGO|S_IWUSR, entry, + &lockd_end_grace_operations); + if (!entry) { + remove_proc_entry("fs/lockd", NULL); + return -ENOMEM; + } + return 0; +} + +void __exit +lockd_remove_procfs(void) +{ + remove_proc_entry("fs/lockd/nlm_end_grace", NULL); + remove_proc_entry("fs/lockd", NULL); +} diff --git a/fs/lockd/procfs.h b/fs/lockd/procfs.h new file mode 100644 index 0000000..2257a13 --- /dev/null +++ b/fs/lockd/procfs.h @@ -0,0 +1,28 @@ +/* + * Procfs support for lockd + * + * Copyright (c) 2014 Jeff Layton + */ +#ifndef _LOCKD_PROCFS_H +#define _LOCKD_PROCFS_H + +#include + +#if IS_ENABLED(CONFIG_PROC_FS) +int lockd_create_procfs(void); +void lockd_remove_procfs(void); +#else +static inline int +lockd_create_procfs(void) +{ + return 0; +} + +static inline void +lockd_remove_procfs(void) +{ + return; +} +#endif /* IS_ENABLED(CONFIG_PROC_FS) */ + +#endif /* _LOCKD_PROCFS_H */ diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index 266b679..8146cfe 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -36,6 +36,7 @@ #include #include "netns.h" +#include "procfs.h" #define NLMDBG_FACILITY NLMDBG_SVC #define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE) @@ -620,8 +621,15 @@ static int __init init_nlm(void) err = register_pernet_subsys(&lockd_net_ops); if (err) goto err_pernet; + + err = lockd_create_procfs(); + if (err) + goto err_procfs; + return 0; +err_procfs: + unregister_pernet_subsys(&lockd_net_ops); err_pernet: #ifdef CONFIG_SYSCTL unregister_sysctl_table(nlm_sysctl_table); @@ -634,6 +642,7 @@ static void __exit exit_nlm(void) { /* FIXME: delete all NLM clients */ nlm_shutdown_hosts(); + lockd_remove_procfs(); unregister_pernet_subsys(&lockd_net_ops); #ifdef CONFIG_SYSCTL unregister_sysctl_table(nlm_sysctl_table); -- cgit v1.1