diff options
| -rw-r--r-- | fs/nfsd/nfsctl.c | 37 | ||||
| -rw-r--r-- | fs/nfsd/nfssvc.c | 45 | ||||
| -rw-r--r-- | include/linux/nfsd/nfsd.h | 1 | ||||
| -rw-r--r-- | net/sunrpc/svc.c | 15 |
4 files changed, 65 insertions, 33 deletions
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 5ac00c4..049d2a9 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -450,22 +450,26 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size) int i; int rv; int len; - int npools = nfsd_nrpools(); + int npools; int *nthreads; + mutex_lock(&nfsd_mutex); + npools = nfsd_nrpools(); if (npools == 0) { /* * NFS is shut down. The admin can start it by * writing to the threads file but NOT the pool_threads * file, sorry. Report zero threads. */ + mutex_unlock(&nfsd_mutex); strcpy(buf, "0\n"); return strlen(buf); } nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL); + rv = -ENOMEM; if (nthreads == NULL) - return -ENOMEM; + goto out_free; if (size > 0) { for (i = 0; i < npools; i++) { @@ -496,10 +500,12 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size) mesg += len; } + mutex_unlock(&nfsd_mutex); return (mesg-buf); out_free: kfree(nthreads); + mutex_unlock(&nfsd_mutex); return rv; } @@ -566,14 +572,13 @@ static ssize_t write_versions(struct file *file, char *buf, size_t size) return len; } -static ssize_t write_ports(struct file *file, char *buf, size_t size) +static ssize_t __write_ports(struct file *file, char *buf, size_t size) { if (size == 0) { int len = 0; - lock_kernel(); + if (nfsd_serv) len = svc_xprt_names(nfsd_serv, buf, 0); - unlock_kernel(); return len; } /* Either a single 'fd' number is written, in which @@ -603,9 +608,7 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size) /* Decrease the count, but don't shutdown the * the service */ - lock_kernel(); nfsd_serv->sv_nrthreads--; - unlock_kernel(); } return err < 0 ? err : 0; } @@ -614,10 +617,8 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size) int len = 0; if (!toclose) return -ENOMEM; - lock_kernel(); if (nfsd_serv) len = svc_sock_names(buf, nfsd_serv, toclose); - unlock_kernel(); if (len >= 0) lockd_down(); kfree(toclose); @@ -655,7 +656,6 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size) if (sscanf(&buf[1], "%15s %4d", transport, &port) == 2) { if (port == 0) return -EINVAL; - lock_kernel(); if (nfsd_serv) { xprt = svc_find_xprt(nfsd_serv, transport, AF_UNSPEC, port); @@ -666,13 +666,22 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size) } else err = -ENOTCONN; } - unlock_kernel(); return err < 0 ? err : 0; } } return -EINVAL; } +static ssize_t write_ports(struct file *file, char *buf, size_t size) +{ + ssize_t rv; + mutex_lock(&nfsd_mutex); + rv = __write_ports(file, buf, size); + mutex_unlock(&nfsd_mutex); + return rv; +} + + int nfsd_max_blksize; static ssize_t write_maxblksize(struct file *file, char *buf, size_t size) @@ -691,13 +700,13 @@ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size) if (bsize > NFSSVC_MAXBLKSIZE) bsize = NFSSVC_MAXBLKSIZE; bsize &= ~(1024-1); - lock_kernel(); + mutex_lock(&nfsd_mutex); if (nfsd_serv && nfsd_serv->sv_nrthreads) { - unlock_kernel(); + mutex_unlock(&nfsd_mutex); return -EBUSY; } nfsd_max_blksize = bsize; - unlock_kernel(); + mutex_unlock(&nfsd_mutex); } return sprintf(buf, "%d\n", nfsd_max_blksize); } diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 941041f..512bd04 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -53,11 +53,27 @@ extern struct svc_program nfsd_program; static void nfsd(struct svc_rqst *rqstp); struct timeval nfssvc_boot; - struct svc_serv *nfsd_serv; static atomic_t nfsd_busy; static unsigned long nfsd_last_call; static DEFINE_SPINLOCK(nfsd_call_lock); +/* + * nfsd_mutex protects nfsd_serv -- both the pointer itself and the members + * of the svc_serv struct. In particular, ->sv_nrthreads but also to some + * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt + * + * If (out side the lock) nfsd_serv is non-NULL, then it must point to a + * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number + * of nfsd threads must exist and each must listed in ->sp_all_threads in each + * entry of ->sv_pools[]. + * + * Transitions of the thread count between zero and non-zero are of particular + * interest since the svc_serv needs to be created and initialized at that + * point, or freed. + */ +DEFINE_MUTEX(nfsd_mutex); +struct svc_serv *nfsd_serv; + #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) static struct svc_stat nfsd_acl_svcstats; static struct svc_version * nfsd_acl_version[] = { @@ -190,13 +206,14 @@ void nfsd_reset_versions(void) } } + int nfsd_create_serv(void) { int err = 0; - lock_kernel(); + + WARN_ON(!mutex_is_locked(&nfsd_mutex)); if (nfsd_serv) { svc_get(nfsd_serv); - unlock_kernel(); return 0; } if (nfsd_max_blksize == 0) { @@ -223,7 +240,7 @@ int nfsd_create_serv(void) nfsd, SIG_NOCLEAN, THIS_MODULE); if (nfsd_serv == NULL) err = -ENOMEM; - unlock_kernel(); + do_gettimeofday(&nfssvc_boot); /* record boot time */ return err; } @@ -282,6 +299,8 @@ int nfsd_set_nrthreads(int n, int *nthreads) int tot = 0; int err = 0; + WARN_ON(!mutex_is_locked(&nfsd_mutex)); + if (nfsd_serv == NULL || n <= 0) return 0; @@ -316,7 +335,6 @@ int nfsd_set_nrthreads(int n, int *nthreads) nthreads[0] = 1; /* apply the new numbers */ - lock_kernel(); svc_get(nfsd_serv); for (i = 0; i < n; i++) { err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i], @@ -325,7 +343,6 @@ int nfsd_set_nrthreads(int n, int *nthreads) break; } svc_destroy(nfsd_serv); - unlock_kernel(); return err; } @@ -334,8 +351,8 @@ int nfsd_svc(unsigned short port, int nrservs) { int error; - - lock_kernel(); + + mutex_lock(&nfsd_mutex); dprintk("nfsd: creating service\n"); error = -EINVAL; if (nrservs <= 0) @@ -363,7 +380,7 @@ nfsd_svc(unsigned short port, int nrservs) failure: svc_destroy(nfsd_serv); /* Release server */ out: - unlock_kernel(); + mutex_unlock(&nfsd_mutex); return error; } @@ -399,7 +416,7 @@ nfsd(struct svc_rqst *rqstp) sigset_t shutdown_mask, allowed_mask; /* Lock module and set up kernel thread */ - lock_kernel(); + mutex_lock(&nfsd_mutex); daemonize("nfsd"); /* After daemonize() this kernel thread shares current->fs @@ -417,11 +434,13 @@ nfsd(struct svc_rqst *rqstp) siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS); siginitsetinv(&allowed_mask, ALLOWED_SIGS); + nfsdstats.th_cnt++; rqstp->rq_task = current; - unlock_kernel(); + mutex_unlock(&nfsd_mutex); + /* * We want less throttling in balance_dirty_pages() so that nfs to @@ -477,7 +496,7 @@ nfsd(struct svc_rqst *rqstp) /* Clear signals before calling svc_exit_thread() */ flush_signals(current); - lock_kernel(); + mutex_lock(&nfsd_mutex); nfsdstats.th_cnt --; @@ -486,7 +505,7 @@ out: svc_exit_thread(rqstp); /* Release module */ - unlock_kernel(); + mutex_unlock(&nfsd_mutex); module_put_and_exit(0); } diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h index 41d30c9..88d85b9 100644 --- a/include/linux/nfsd/nfsd.h +++ b/include/linux/nfsd/nfsd.h @@ -54,6 +54,7 @@ typedef int (*nfsd_dirop_t)(struct inode *, struct dentry *, int, int); extern struct svc_program nfsd_program; extern struct svc_version nfsd_version2, nfsd_version3, nfsd_version4; +extern struct mutex nfsd_mutex; extern struct svc_serv *nfsd_serv; extern struct seq_operations nfs_exports_op; diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 01c7e31..7bffaff 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -461,7 +461,8 @@ svc_create_pooled(struct svc_program *prog, unsigned int bufsize, EXPORT_SYMBOL(svc_create_pooled); /* - * Destroy an RPC service. Should be called with the BKL held + * Destroy an RPC service. Should be called with appropriate locking to + * protect the sv_nrthreads, sv_permsocks and sv_tempsocks. */ void svc_destroy(struct svc_serv *serv) @@ -578,9 +579,10 @@ out_enomem: EXPORT_SYMBOL(svc_prepare_thread); /* - * Create a thread in the given pool. Caller must hold BKL. - * On a NUMA or SMP machine, with a multi-pool serv, the thread - * will be restricted to run on the cpus belonging to the pool. + * Create a thread in the given pool. Caller must hold BKL or another lock to + * serialize access to the svc_serv struct. On a NUMA or SMP machine, with a + * multi-pool serv, the thread will be restricted to run on the cpus belonging + * to the pool. */ static int __svc_create_thread(svc_thread_fn func, struct svc_serv *serv, @@ -674,7 +676,7 @@ found_pool: * of threads the given number. If `pool' is non-NULL, applies * only to threads in that pool, otherwise round-robins between * all pools. Must be called with a svc_get() reference and - * the BKL held. + * the BKL or another lock to protect access to svc_serv fields. * * Destroying threads relies on the service threads filling in * rqstp->rq_task, which only the nfs ones do. Assumes the serv @@ -722,7 +724,8 @@ svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) EXPORT_SYMBOL(svc_set_num_threads); /* - * Called from a server thread as it's exiting. Caller must hold BKL. + * Called from a server thread as it's exiting. Caller must hold the BKL or + * the "service mutex", whichever is appropriate for the service. */ void svc_exit_thread(struct svc_rqst *rqstp) |
