/* * linux/fs/nfsd/nfssvc.c * * Central processing for nfsd. * * Authors: Olaf Kirch (okir@monad.swb.de) * * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> */ #include <linux/config.h> #include <linux/module.h> #include <linux/time.h> #include <linux/errno.h> #include <linux/nfs.h> #include <linux/in.h> #include <linux/uio.h> #include <linux/unistd.h> #include <linux/slab.h> #include <linux/smp.h> #include <linux/smp_lock.h> #include <linux/fs_struct.h> #include <linux/sunrpc/types.h> #include <linux/sunrpc/stats.h> #include <linux/sunrpc/svc.h> #include <linux/sunrpc/svcsock.h> #include <linux/sunrpc/cache.h> #include <linux/nfsd/nfsd.h> #include <linux/nfsd/stats.h> #include <linux/nfsd/cache.h> #include <linux/lockd/bind.h> #include <linux/nfsacl.h> #define NFSDDBG_FACILITY NFSDDBG_SVC /* these signals will be delivered to an nfsd thread * when handling a request */ #define ALLOWED_SIGS (sigmask(SIGKILL)) /* these signals will be delivered to an nfsd thread * when not handling a request. i.e. when waiting */ #define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT)) /* if the last thread dies with SIGHUP, then the exports table is * left unchanged ( like 2.4-{0-9} ). Any other signal will clear * the exports table (like 2.2). */ #define SIG_NOCLEAN SIGHUP extern struct svc_program nfsd_program; static void nfsd(struct svc_rqst *rqstp); struct timeval nfssvc_boot; static struct svc_serv *nfsd_serv; static atomic_t nfsd_busy; static unsigned long nfsd_last_call; static DEFINE_SPINLOCK(nfsd_call_lock); struct nfsd_list { struct list_head list; struct task_struct *task; }; static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list); /* * Maximum number of nfsd processes */ #define NFSD_MAXSERVS 8192 int nfsd_nrthreads(void) { if (nfsd_serv == NULL) return 0; else return nfsd_serv->sv_nrthreads; } int nfsd_svc(unsigned short port, int nrservs) { int error; int none_left; struct list_head *victim; lock_kernel(); dprintk("nfsd: creating service\n"); error = -EINVAL; if (nrservs <= 0) nrservs = 0; if (nrservs > NFSD_MAXSERVS) nrservs = NFSD_MAXSERVS; /* Readahead param cache - will no-op if it already exists */ error = nfsd_racache_init(2*nrservs); if (error<0) goto out; error = nfs4_state_start(); if (error<0) goto out; if (!nfsd_serv) { atomic_set(&nfsd_busy, 0); error = -ENOMEM; nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE); if (nfsd_serv == NULL) goto out; error = svc_makesock(nfsd_serv, IPPROTO_UDP, port); if (error < 0) goto failure; #ifdef CONFIG_NFSD_TCP error = svc_makesock(nfsd_serv, IPPROTO_TCP, port); if (error < 0) goto failure; #endif do_gettimeofday(&nfssvc_boot); /* record boot time */ } else nfsd_serv->sv_nrthreads++; nrservs -= (nfsd_serv->sv_nrthreads-1); while (nrservs > 0) { nrservs--; __module_get(THIS_MODULE); error = svc_create_thread(nfsd, nfsd_serv); if (error < 0) { module_put(THIS_MODULE); break; } } victim = nfsd_list.next; while (nrservs < 0 && victim != &nfsd_list) { struct nfsd_list *nl = list_entry(victim,struct nfsd_list, list); victim = victim->next; send_sig(SIG_NOCLEAN, nl->task, 1); nrservs++; } failure: none_left = (nfsd_serv->sv_nrthreads == 1); svc_destroy(nfsd_serv); /* Release server */ if (none_left) { nfsd_serv = NULL; nfsd_racache_shutdown(); nfs4_state_shutdown(); } out: unlock_kernel(); return error; } static inline void update_thread_usage(int busy_threads) { unsigned long prev_call; unsigned long diff; int decile; spin_lock(&nfsd_call_lock); prev_call = nfsd_last_call; nfsd_last_call = jiffies; decile = busy_threads*10/nfsdstats.th_cnt; if (decile>0 && decile <= 10) { diff = nfsd_last_call - prev_call; if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP) nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP; if (decile == 10) nfsdstats.th_fullcnt++; } spin_unlock(&nfsd_call_lock); } /* * This is the NFS server kernel thread */ static void nfsd(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; struct fs_struct *fsp; int err; struct nfsd_list me; sigset_t shutdown_mask, allowed_mask; /* Lock module and set up kernel thread */ lock_kernel(); daemonize("nfsd"); /* After daemonize() this kernel thread shares current->fs * with the init process. We need to create files with a * umask of 0 instead of init's umask. */ fsp = copy_fs_struct(current->fs); if (!fsp) { printk("Unable to start nfsd thread: out of memory\n"); goto out; } exit_fs(current); current->fs = fsp; current->fs->umask = 0; siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS); siginitsetinv(&allowed_mask, ALLOWED_SIGS); nfsdstats.th_cnt++; lockd_up(); /* start lockd */ me.task = current; list_add(&me.list, &nfsd_list); unlock_kernel(); /* * We want less throttling in balance_dirty_pages() so that nfs to * localhost doesn't cause nfsd to lock up due to all the client's * dirty pages. */ current->flags |= PF_LESS_THROTTLE; /* * The main request loop */ for (;;) { /* Block all but the shutdown signals */ sigprocmask(SIG_SETMASK, &shutdown_mask, NULL); /* * Find a socket with data available and call its * recvfrom routine. */ while ((err = svc_recv(serv, rqstp, 60*60*HZ)) == -EAGAIN) ; if (err < 0) break; update_thread_usage(atomic_read(&nfsd_busy)); atomic_inc(&nfsd_busy); /* Lock the export hash tables for reading. */ exp_readlock(); /* Process request with signals blocked. */ sigprocmask(SIG_SETMASK, &allowed_mask, NULL); svc_process(serv, rqstp); /* Unlock export hash tables */ exp_readunlock(); update_thread_usage(atomic_read(&nfsd_busy)); atomic_dec(&nfsd_busy); } if (err != -EINTR) { printk(KERN_WARNING "nfsd: terminating on error %d\n", -err); } else { unsigned int signo; for (signo = 1; signo <= _NSIG; signo++) if (sigismember(¤t->pending.signal, signo) && !sigismember(¤t->blocked, signo)) break; err = signo; } /* Clear signals before calling lockd_down() and svc_exit_thread() */ flush_signals(current); lock_kernel(); /* Release lockd */ lockd_down(); /* Check if this is last thread */ if (serv->sv_nrthreads==1) { printk(KERN_WARNING "nfsd: last server has exited\n"); if (err != SIG_NOCLEAN) { printk(KERN_WARNING "nfsd: unexporting all filesystems\n"); nfsd_export_flush(); } nfsd_serv = NULL; nfsd_racache_shutdown(); /* release read-ahead cache */ nfs4_state_shutdown(); } list_del(&me.list); nfsdstats.th_cnt --; out: /* Release the thread */ svc_exit_thread(rqstp); /* Release module */ unlock_kernel(); module_put_and_exit(0); } int nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp) { struct svc_procedure *proc; kxdrproc_t xdr; u32 nfserr; u32 *nfserrp; dprintk("nfsd_dispatch: vers %d proc %d\n", rqstp->rq_vers, rqstp->rq_proc); proc = rqstp->rq_procinfo; /* Check whether we have this call in the cache. */ switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) { case RC_INTR: case RC_DROPIT: return 0; case RC_REPLY: return 1; case RC_DOIT:; /* do it */ } /* Decode arguments */ xdr = proc->pc_decode; if (xdr && !xdr(rqstp, (u32*)rqstp->rq_arg.head[0].iov_base, rqstp->rq_argp)) { dprintk("nfsd: failed to decode arguments!\n"); nfsd_cache_update(rqstp, RC_NOCACHE, NULL); *statp = rpc_garbage_args; return 1; } /* need to grab the location to store the status, as * nfsv4 does some encoding while processing */ nfserrp = rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len; rqstp->rq_res.head[0].iov_len += sizeof(u32); /* Now call the procedure handler, and encode NFS status. */ nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp); if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2) nfserr = nfserr_dropit; if (nfserr == nfserr_dropit) { dprintk("nfsd: Dropping request due to malloc failure!\n"); nfsd_cache_update(rqstp, RC_NOCACHE, NULL); return 0; } if (rqstp->rq_proc != 0) *nfserrp++ = nfserr; /* Encode result. * For NFSv2, additional info is never returned in case of an error. */ if (!(nfserr && rqstp->rq_vers == 2)) { xdr = proc->pc_encode; if (xdr && !xdr(rqstp, nfserrp, rqstp->rq_resp)) { /* Failed to encode result. Release cache entry */ dprintk("nfsd: failed to encode result!\n"); nfsd_cache_update(rqstp, RC_NOCACHE, NULL); *statp = rpc_system_err; return 1; } } /* Store reply in cache. */ nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1); return 1; } #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[] = { [2] = &nfsd_acl_version2, [3] = &nfsd_acl_version3, }; #define NFSD_ACL_NRVERS (sizeof(nfsd_acl_version)/sizeof(nfsd_acl_version[0])) static struct svc_program nfsd_acl_program = { .pg_prog = NFS_ACL_PROGRAM, .pg_nvers = NFSD_ACL_NRVERS, .pg_vers = nfsd_acl_version, .pg_name = "nfsd", .pg_class = "nfsd", .pg_stats = &nfsd_acl_svcstats, }; static struct svc_stat nfsd_acl_svcstats = { .program = &nfsd_acl_program, }; #define nfsd_acl_program_p &nfsd_acl_program #else #define nfsd_acl_program_p NULL #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ extern struct svc_version nfsd_version2, nfsd_version3, nfsd_version4; static struct svc_version * nfsd_version[] = { [2] = &nfsd_version2, #if defined(CONFIG_NFSD_V3) [3] = &nfsd_version3, #endif #if defined(CONFIG_NFSD_V4) [4] = &nfsd_version4, #endif }; #define NFSD_NRVERS (sizeof(nfsd_version)/sizeof(nfsd_version[0])) struct svc_program nfsd_program = { .pg_next = nfsd_acl_program_p, .pg_prog = NFS_PROGRAM, /* program number */ .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */ .pg_vers = nfsd_version, /* version table */ .pg_name = "nfsd", /* program name */ .pg_class = "nfsd", /* authentication class */ .pg_stats = &nfsd_svcstats, /* version table */ .pg_authenticate = &svc_set_client, /* export authentication */ };