linux/net/sunrpc/svc.c
Neil Brown bedbdd8bad knfsd: Replace lock_kernel with a mutex for nfsd thread startup/shutdown locking.
This removes the BKL from the RPC service creation codepath. The BKL
really isn't adequate for this job since some of this info needs
protection across sleeps.

Also, add some comments to try and clarify how the locking should work
and to make it clear that the BKL isn't necessary as long as there is
adequate locking between tasks when touching the svc_serv fields.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-06-23 13:02:49 -04:00

1090 lines
25 KiB
C

/*
* linux/net/sunrpc/svc.c
*
* High-level RPC service routines
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*
* Multiple threads pools and NUMAisation
* Copyright (c) 2006 Silicon Graphics, Inc.
* by Greg Banks <gnb@melbourne.sgi.com>
*/
#include <linux/linkage.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/clnt.h>
#define RPCDBG_FACILITY RPCDBG_SVCDSP
#define svc_serv_is_pooled(serv) ((serv)->sv_function)
/*
* Mode for mapping cpus to pools.
*/
enum {
SVC_POOL_AUTO = -1, /* choose one of the others */
SVC_POOL_GLOBAL, /* no mapping, just a single global pool
* (legacy & UP mode) */
SVC_POOL_PERCPU, /* one pool per cpu */
SVC_POOL_PERNODE /* one pool per numa node */
};
#define SVC_POOL_DEFAULT SVC_POOL_GLOBAL
/*
* Structure for mapping cpus to pools and vice versa.
* Setup once during sunrpc initialisation.
*/
static struct svc_pool_map {
int count; /* How many svc_servs use us */
int mode; /* Note: int not enum to avoid
* warnings about "enumeration value
* not handled in switch" */
unsigned int npools;
unsigned int *pool_to; /* maps pool id to cpu or node */
unsigned int *to_pool; /* maps cpu or node to pool id */
} svc_pool_map = {
.count = 0,
.mode = SVC_POOL_DEFAULT
};
static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
static int
param_set_pool_mode(const char *val, struct kernel_param *kp)
{
int *ip = (int *)kp->arg;
struct svc_pool_map *m = &svc_pool_map;
int err;
mutex_lock(&svc_pool_map_mutex);
err = -EBUSY;
if (m->count)
goto out;
err = 0;
if (!strncmp(val, "auto", 4))
*ip = SVC_POOL_AUTO;
else if (!strncmp(val, "global", 6))
*ip = SVC_POOL_GLOBAL;
else if (!strncmp(val, "percpu", 6))
*ip = SVC_POOL_PERCPU;
else if (!strncmp(val, "pernode", 7))
*ip = SVC_POOL_PERNODE;
else
err = -EINVAL;
out:
mutex_unlock(&svc_pool_map_mutex);
return err;
}
static int
param_get_pool_mode(char *buf, struct kernel_param *kp)
{
int *ip = (int *)kp->arg;
switch (*ip)
{
case SVC_POOL_AUTO:
return strlcpy(buf, "auto", 20);
case SVC_POOL_GLOBAL:
return strlcpy(buf, "global", 20);
case SVC_POOL_PERCPU:
return strlcpy(buf, "percpu", 20);
case SVC_POOL_PERNODE:
return strlcpy(buf, "pernode", 20);
default:
return sprintf(buf, "%d", *ip);
}
}
module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
&svc_pool_map.mode, 0644);
/*
* Detect best pool mapping mode heuristically,
* according to the machine's topology.
*/
static int
svc_pool_map_choose_mode(void)
{
unsigned int node;
if (num_online_nodes() > 1) {
/*
* Actually have multiple NUMA nodes,
* so split pools on NUMA node boundaries
*/
return SVC_POOL_PERNODE;
}
node = any_online_node(node_online_map);
if (nr_cpus_node(node) > 2) {
/*
* Non-trivial SMP, or CONFIG_NUMA on
* non-NUMA hardware, e.g. with a generic
* x86_64 kernel on Xeons. In this case we
* want to divide the pools on cpu boundaries.
*/
return SVC_POOL_PERCPU;
}
/* default: one global pool */
return SVC_POOL_GLOBAL;
}
/*
* Allocate the to_pool[] and pool_to[] arrays.
* Returns 0 on success or an errno.
*/
static int
svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools)
{
m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
if (!m->to_pool)
goto fail;
m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
if (!m->pool_to)
goto fail_free;
return 0;
fail_free:
kfree(m->to_pool);
fail:
return -ENOMEM;
}
/*
* Initialise the pool map for SVC_POOL_PERCPU mode.
* Returns number of pools or <0 on error.
*/
static int
svc_pool_map_init_percpu(struct svc_pool_map *m)
{
unsigned int maxpools = nr_cpu_ids;
unsigned int pidx = 0;
unsigned int cpu;
int err;
err = svc_pool_map_alloc_arrays(m, maxpools);
if (err)
return err;
for_each_online_cpu(cpu) {
BUG_ON(pidx > maxpools);
m->to_pool[cpu] = pidx;
m->pool_to[pidx] = cpu;
pidx++;
}
/* cpus brought online later all get mapped to pool0, sorry */
return pidx;
};
/*
* Initialise the pool map for SVC_POOL_PERNODE mode.
* Returns number of pools or <0 on error.
*/
static int
svc_pool_map_init_pernode(struct svc_pool_map *m)
{
unsigned int maxpools = nr_node_ids;
unsigned int pidx = 0;
unsigned int node;
int err;
err = svc_pool_map_alloc_arrays(m, maxpools);
if (err)
return err;
for_each_node_with_cpus(node) {
/* some architectures (e.g. SN2) have cpuless nodes */
BUG_ON(pidx > maxpools);
m->to_pool[node] = pidx;
m->pool_to[pidx] = node;
pidx++;
}
/* nodes brought online later all get mapped to pool0, sorry */
return pidx;
}
/*
* Add a reference to the global map of cpus to pools (and
* vice versa). Initialise the map if we're the first user.
* Returns the number of pools.
*/
static unsigned int
svc_pool_map_get(void)
{
struct svc_pool_map *m = &svc_pool_map;
int npools = -1;
mutex_lock(&svc_pool_map_mutex);
if (m->count++) {
mutex_unlock(&svc_pool_map_mutex);
return m->npools;
}
if (m->mode == SVC_POOL_AUTO)
m->mode = svc_pool_map_choose_mode();
switch (m->mode) {
case SVC_POOL_PERCPU:
npools = svc_pool_map_init_percpu(m);
break;
case SVC_POOL_PERNODE:
npools = svc_pool_map_init_pernode(m);
break;
}
if (npools < 0) {
/* default, or memory allocation failure */
npools = 1;
m->mode = SVC_POOL_GLOBAL;
}
m->npools = npools;
mutex_unlock(&svc_pool_map_mutex);
return m->npools;
}
/*
* Drop a reference to the global map of cpus to pools.
* When the last reference is dropped, the map data is
* freed; this allows the sysadmin to change the pool
* mode using the pool_mode module option without
* rebooting or re-loading sunrpc.ko.
*/
static void
svc_pool_map_put(void)
{
struct svc_pool_map *m = &svc_pool_map;
mutex_lock(&svc_pool_map_mutex);
if (!--m->count) {
m->mode = SVC_POOL_DEFAULT;
kfree(m->to_pool);
kfree(m->pool_to);
m->npools = 0;
}
mutex_unlock(&svc_pool_map_mutex);
}
/*
* Set the current thread's cpus_allowed mask so that it
* will only run on cpus in the given pool.
*
* Returns 1 and fills in oldmask iff a cpumask was applied.
*/
static inline int
svc_pool_map_set_cpumask(unsigned int pidx, cpumask_t *oldmask)
{
struct svc_pool_map *m = &svc_pool_map;
/*
* The caller checks for sv_nrpools > 1, which
* implies that we've been initialized.
*/
BUG_ON(m->count == 0);
switch (m->mode)
{
default:
return 0;
case SVC_POOL_PERCPU:
{
unsigned int cpu = m->pool_to[pidx];
*oldmask = current->cpus_allowed;
set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
return 1;
}
case SVC_POOL_PERNODE:
{
unsigned int node = m->pool_to[pidx];
node_to_cpumask_ptr(nodecpumask, node);
*oldmask = current->cpus_allowed;
set_cpus_allowed_ptr(current, nodecpumask);
return 1;
}
}
}
/*
* Use the mapping mode to choose a pool for a given CPU.
* Used when enqueueing an incoming RPC. Always returns
* a non-NULL pool pointer.
*/
struct svc_pool *
svc_pool_for_cpu(struct svc_serv *serv, int cpu)
{
struct svc_pool_map *m = &svc_pool_map;
unsigned int pidx = 0;
/*
* An uninitialised map happens in a pure client when
* lockd is brought up, so silently treat it the
* same as SVC_POOL_GLOBAL.
*/
if (svc_serv_is_pooled(serv)) {
switch (m->mode) {
case SVC_POOL_PERCPU:
pidx = m->to_pool[cpu];
break;
case SVC_POOL_PERNODE:
pidx = m->to_pool[cpu_to_node(cpu)];
break;
}
}
return &serv->sv_pools[pidx % serv->sv_nrpools];
}
/*
* Create an RPC service
*/
static struct svc_serv *
__svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
void (*shutdown)(struct svc_serv *serv))
{
struct svc_serv *serv;
unsigned int vers;
unsigned int xdrsize;
unsigned int i;
if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
return NULL;
serv->sv_name = prog->pg_name;
serv->sv_program = prog;
serv->sv_nrthreads = 1;
serv->sv_stats = prog->pg_stats;
if (bufsize > RPCSVC_MAXPAYLOAD)
bufsize = RPCSVC_MAXPAYLOAD;
serv->sv_max_payload = bufsize? bufsize : 4096;
serv->sv_max_mesg = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
serv->sv_shutdown = shutdown;
xdrsize = 0;
while (prog) {
prog->pg_lovers = prog->pg_nvers-1;
for (vers=0; vers<prog->pg_nvers ; vers++)
if (prog->pg_vers[vers]) {
prog->pg_hivers = vers;
if (prog->pg_lovers > vers)
prog->pg_lovers = vers;
if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
xdrsize = prog->pg_vers[vers]->vs_xdrsize;
}
prog = prog->pg_next;
}
serv->sv_xdrsize = xdrsize;
INIT_LIST_HEAD(&serv->sv_tempsocks);
INIT_LIST_HEAD(&serv->sv_permsocks);
init_timer(&serv->sv_temptimer);
spin_lock_init(&serv->sv_lock);
serv->sv_nrpools = npools;
serv->sv_pools =
kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
GFP_KERNEL);
if (!serv->sv_pools) {
kfree(serv);
return NULL;
}
for (i = 0; i < serv->sv_nrpools; i++) {
struct svc_pool *pool = &serv->sv_pools[i];
dprintk("svc: initialising pool %u for %s\n",
i, serv->sv_name);
pool->sp_id = i;
INIT_LIST_HEAD(&pool->sp_threads);
INIT_LIST_HEAD(&pool->sp_sockets);
INIT_LIST_HEAD(&pool->sp_all_threads);
spin_lock_init(&pool->sp_lock);
}
/* Remove any stale portmap registrations */
svc_register(serv, 0, 0);
return serv;
}
struct svc_serv *
svc_create(struct svc_program *prog, unsigned int bufsize,
void (*shutdown)(struct svc_serv *serv))
{
return __svc_create(prog, bufsize, /*npools*/1, shutdown);
}
EXPORT_SYMBOL(svc_create);
struct svc_serv *
svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
void (*shutdown)(struct svc_serv *serv),
svc_thread_fn func, int sig, struct module *mod)
{
struct svc_serv *serv;
unsigned int npools = svc_pool_map_get();
serv = __svc_create(prog, bufsize, npools, shutdown);
if (serv != NULL) {
serv->sv_function = func;
serv->sv_kill_signal = sig;
serv->sv_module = mod;
}
return serv;
}
EXPORT_SYMBOL(svc_create_pooled);
/*
* 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)
{
dprintk("svc: svc_destroy(%s, %d)\n",
serv->sv_program->pg_name,
serv->sv_nrthreads);
if (serv->sv_nrthreads) {
if (--(serv->sv_nrthreads) != 0) {
svc_sock_update_bufs(serv);
return;
}
} else
printk("svc_destroy: no threads for serv=%p!\n", serv);
del_timer_sync(&serv->sv_temptimer);
svc_close_all(&serv->sv_tempsocks);
if (serv->sv_shutdown)
serv->sv_shutdown(serv);
svc_close_all(&serv->sv_permsocks);
BUG_ON(!list_empty(&serv->sv_permsocks));
BUG_ON(!list_empty(&serv->sv_tempsocks));
cache_clean_deferred(serv);
if (svc_serv_is_pooled(serv))
svc_pool_map_put();
/* Unregister service with the portmapper */
svc_register(serv, 0, 0);
kfree(serv->sv_pools);
kfree(serv);
}
EXPORT_SYMBOL(svc_destroy);
/*
* Allocate an RPC server's buffer space.
* We allocate pages and place them in rq_argpages.
*/
static int
svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
{
unsigned int pages, arghi;
pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
* We assume one is at most one page
*/
arghi = 0;
BUG_ON(pages > RPCSVC_MAXPAGES);
while (pages) {
struct page *p = alloc_page(GFP_KERNEL);
if (!p)
break;
rqstp->rq_pages[arghi++] = p;
pages--;
}
return pages == 0;
}
/*
* Release an RPC server buffer
*/
static void
svc_release_buffer(struct svc_rqst *rqstp)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++)
if (rqstp->rq_pages[i])
put_page(rqstp->rq_pages[i]);
}
struct svc_rqst *
svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool)
{
struct svc_rqst *rqstp;
rqstp = kzalloc(sizeof(*rqstp), GFP_KERNEL);
if (!rqstp)
goto out_enomem;
init_waitqueue_head(&rqstp->rq_wait);
serv->sv_nrthreads++;
spin_lock_bh(&pool->sp_lock);
pool->sp_nrthreads++;
list_add(&rqstp->rq_all, &pool->sp_all_threads);
spin_unlock_bh(&pool->sp_lock);
rqstp->rq_server = serv;
rqstp->rq_pool = pool;
rqstp->rq_argp = kmalloc(serv->sv_xdrsize, GFP_KERNEL);
if (!rqstp->rq_argp)
goto out_thread;
rqstp->rq_resp = kmalloc(serv->sv_xdrsize, GFP_KERNEL);
if (!rqstp->rq_resp)
goto out_thread;
if (!svc_init_buffer(rqstp, serv->sv_max_mesg))
goto out_thread;
return rqstp;
out_thread:
svc_exit_thread(rqstp);
out_enomem:
return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL(svc_prepare_thread);
/*
* 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,
struct svc_pool *pool)
{
struct svc_rqst *rqstp;
int error = -ENOMEM;
int have_oldmask = 0;
cpumask_t uninitialized_var(oldmask);
rqstp = svc_prepare_thread(serv, pool);
if (IS_ERR(rqstp)) {
error = PTR_ERR(rqstp);
goto out;
}
if (serv->sv_nrpools > 1)
have_oldmask = svc_pool_map_set_cpumask(pool->sp_id, &oldmask);
error = kernel_thread((int (*)(void *)) func, rqstp, 0);
if (have_oldmask)
set_cpus_allowed(current, oldmask);
if (error < 0)
goto out_thread;
svc_sock_update_bufs(serv);
error = 0;
out:
return error;
out_thread:
svc_exit_thread(rqstp);
goto out;
}
/*
* Choose a pool in which to create a new thread, for svc_set_num_threads
*/
static inline struct svc_pool *
choose_pool(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
{
if (pool != NULL)
return pool;
return &serv->sv_pools[(*state)++ % serv->sv_nrpools];
}
/*
* Choose a thread to kill, for svc_set_num_threads
*/
static inline struct task_struct *
choose_victim(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
{
unsigned int i;
struct task_struct *task = NULL;
if (pool != NULL) {
spin_lock_bh(&pool->sp_lock);
} else {
/* choose a pool in round-robin fashion */
for (i = 0; i < serv->sv_nrpools; i++) {
pool = &serv->sv_pools[--(*state) % serv->sv_nrpools];
spin_lock_bh(&pool->sp_lock);
if (!list_empty(&pool->sp_all_threads))
goto found_pool;
spin_unlock_bh(&pool->sp_lock);
}
return NULL;
}
found_pool:
if (!list_empty(&pool->sp_all_threads)) {
struct svc_rqst *rqstp;
/*
* Remove from the pool->sp_all_threads list
* so we don't try to kill it again.
*/
rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all);
list_del_init(&rqstp->rq_all);
task = rqstp->rq_task;
}
spin_unlock_bh(&pool->sp_lock);
return task;
}
/*
* Create or destroy enough new threads to make the number
* 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 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
* has been created using svc_create_pooled().
*
* Based on code that used to be in nfsd_svc() but tweaked
* to be pool-aware.
*/
int
svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
{
struct task_struct *victim;
int error = 0;
unsigned int state = serv->sv_nrthreads-1;
if (pool == NULL) {
/* The -1 assumes caller has done a svc_get() */
nrservs -= (serv->sv_nrthreads-1);
} else {
spin_lock_bh(&pool->sp_lock);
nrservs -= pool->sp_nrthreads;
spin_unlock_bh(&pool->sp_lock);
}
/* create new threads */
while (nrservs > 0) {
nrservs--;
__module_get(serv->sv_module);
error = __svc_create_thread(serv->sv_function, serv,
choose_pool(serv, pool, &state));
if (error < 0) {
module_put(serv->sv_module);
break;
}
}
/* destroy old threads */
while (nrservs < 0 &&
(victim = choose_victim(serv, pool, &state)) != NULL) {
send_sig(serv->sv_kill_signal, victim, 1);
nrservs++;
}
return error;
}
EXPORT_SYMBOL(svc_set_num_threads);
/*
* 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)
{
struct svc_serv *serv = rqstp->rq_server;
struct svc_pool *pool = rqstp->rq_pool;
svc_release_buffer(rqstp);
kfree(rqstp->rq_resp);
kfree(rqstp->rq_argp);
kfree(rqstp->rq_auth_data);
spin_lock_bh(&pool->sp_lock);
pool->sp_nrthreads--;
list_del(&rqstp->rq_all);
spin_unlock_bh(&pool->sp_lock);
kfree(rqstp);
/* Release the server */
if (serv)
svc_destroy(serv);
}
EXPORT_SYMBOL(svc_exit_thread);
/*
* Register an RPC service with the local portmapper.
* To unregister a service, call this routine with
* proto and port == 0.
*/
int
svc_register(struct svc_serv *serv, int proto, unsigned short port)
{
struct svc_program *progp;
unsigned long flags;
unsigned int i;
int error = 0, dummy;
if (!port)
clear_thread_flag(TIF_SIGPENDING);
for (progp = serv->sv_program; progp; progp = progp->pg_next) {
for (i = 0; i < progp->pg_nvers; i++) {
if (progp->pg_vers[i] == NULL)
continue;
dprintk("svc: svc_register(%s, %s, %d, %d)%s\n",
progp->pg_name,
proto == IPPROTO_UDP? "udp" : "tcp",
port,
i,
progp->pg_vers[i]->vs_hidden?
" (but not telling portmap)" : "");
if (progp->pg_vers[i]->vs_hidden)
continue;
error = rpcb_register(progp->pg_prog, i, proto, port, &dummy);
if (error < 0)
break;
if (port && !dummy) {
error = -EACCES;
break;
}
}
}
if (!port) {
spin_lock_irqsave(&current->sighand->siglock, flags);
recalc_sigpending();
spin_unlock_irqrestore(&current->sighand->siglock, flags);
}
return error;
}
/*
* Printk the given error with the address of the client that caused it.
*/
static int
__attribute__ ((format (printf, 2, 3)))
svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
{
va_list args;
int r;
char buf[RPC_MAX_ADDRBUFLEN];
if (!net_ratelimit())
return 0;
printk(KERN_WARNING "svc: %s: ",
svc_print_addr(rqstp, buf, sizeof(buf)));
va_start(args, fmt);
r = vprintk(fmt, args);
va_end(args);
return r;
}
/*
* Process the RPC request.
*/
int
svc_process(struct svc_rqst *rqstp)
{
struct svc_program *progp;
struct svc_version *versp = NULL; /* compiler food */
struct svc_procedure *procp = NULL;
struct kvec * argv = &rqstp->rq_arg.head[0];
struct kvec * resv = &rqstp->rq_res.head[0];
struct svc_serv *serv = rqstp->rq_server;
kxdrproc_t xdr;
__be32 *statp;
u32 dir, prog, vers, proc;
__be32 auth_stat, rpc_stat;
int auth_res;
__be32 *reply_statp;
rpc_stat = rpc_success;
if (argv->iov_len < 6*4)
goto err_short_len;
/* setup response xdr_buf.
* Initially it has just one page
*/
rqstp->rq_resused = 1;
resv->iov_base = page_address(rqstp->rq_respages[0]);
resv->iov_len = 0;
rqstp->rq_res.pages = rqstp->rq_respages + 1;
rqstp->rq_res.len = 0;
rqstp->rq_res.page_base = 0;
rqstp->rq_res.page_len = 0;
rqstp->rq_res.buflen = PAGE_SIZE;
rqstp->rq_res.tail[0].iov_base = NULL;
rqstp->rq_res.tail[0].iov_len = 0;
/* Will be turned off only in gss privacy case: */
rqstp->rq_splice_ok = 1;
/* Setup reply header */
rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp);
rqstp->rq_xid = svc_getu32(argv);
svc_putu32(resv, rqstp->rq_xid);
dir = svc_getnl(argv);
vers = svc_getnl(argv);
/* First words of reply: */
svc_putnl(resv, 1); /* REPLY */
if (dir != 0) /* direction != CALL */
goto err_bad_dir;
if (vers != 2) /* RPC version number */
goto err_bad_rpc;
/* Save position in case we later decide to reject: */
reply_statp = resv->iov_base + resv->iov_len;
svc_putnl(resv, 0); /* ACCEPT */
rqstp->rq_prog = prog = svc_getnl(argv); /* program number */
rqstp->rq_vers = vers = svc_getnl(argv); /* version number */
rqstp->rq_proc = proc = svc_getnl(argv); /* procedure number */
progp = serv->sv_program;
for (progp = serv->sv_program; progp; progp = progp->pg_next)
if (prog == progp->pg_prog)
break;
/*
* Decode auth data, and add verifier to reply buffer.
* We do this before anything else in order to get a decent
* auth verifier.
*/
auth_res = svc_authenticate(rqstp, &auth_stat);
/* Also give the program a chance to reject this call: */
if (auth_res == SVC_OK && progp) {
auth_stat = rpc_autherr_badcred;
auth_res = progp->pg_authenticate(rqstp);
}
switch (auth_res) {
case SVC_OK:
break;
case SVC_GARBAGE:
goto err_garbage;
case SVC_SYSERR:
rpc_stat = rpc_system_err;
goto err_bad;
case SVC_DENIED:
goto err_bad_auth;
case SVC_DROP:
goto dropit;
case SVC_COMPLETE:
goto sendit;
}
if (progp == NULL)
goto err_bad_prog;
if (vers >= progp->pg_nvers ||
!(versp = progp->pg_vers[vers]))
goto err_bad_vers;
procp = versp->vs_proc + proc;
if (proc >= versp->vs_nproc || !procp->pc_func)
goto err_bad_proc;
rqstp->rq_server = serv;
rqstp->rq_procinfo = procp;
/* Syntactic check complete */
serv->sv_stats->rpccnt++;
/* Build the reply header. */
statp = resv->iov_base +resv->iov_len;
svc_putnl(resv, RPC_SUCCESS);
/* Bump per-procedure stats counter */
procp->pc_count++;
/* Initialize storage for argp and resp */
memset(rqstp->rq_argp, 0, procp->pc_argsize);
memset(rqstp->rq_resp, 0, procp->pc_ressize);
/* un-reserve some of the out-queue now that we have a
* better idea of reply size
*/
if (procp->pc_xdrressize)
svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
/* Call the function that processes the request. */
if (!versp->vs_dispatch) {
/* Decode arguments */
xdr = procp->pc_decode;
if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
goto err_garbage;
*statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
/* Encode reply */
if (*statp == rpc_drop_reply) {
if (procp->pc_release)
procp->pc_release(rqstp, NULL, rqstp->rq_resp);
goto dropit;
}
if (*statp == rpc_success && (xdr = procp->pc_encode)
&& !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
dprintk("svc: failed to encode reply\n");
/* serv->sv_stats->rpcsystemerr++; */
*statp = rpc_system_err;
}
} else {
dprintk("svc: calling dispatcher\n");
if (!versp->vs_dispatch(rqstp, statp)) {
/* Release reply info */
if (procp->pc_release)
procp->pc_release(rqstp, NULL, rqstp->rq_resp);
goto dropit;
}
}
/* Check RPC status result */
if (*statp != rpc_success)
resv->iov_len = ((void*)statp) - resv->iov_base + 4;
/* Release reply info */
if (procp->pc_release)
procp->pc_release(rqstp, NULL, rqstp->rq_resp);
if (procp->pc_encode == NULL)
goto dropit;
sendit:
if (svc_authorise(rqstp))
goto dropit;
return svc_send(rqstp);
dropit:
svc_authorise(rqstp); /* doesn't hurt to call this twice */
dprintk("svc: svc_process dropit\n");
svc_drop(rqstp);
return 0;
err_short_len:
svc_printk(rqstp, "short len %Zd, dropping request\n",
argv->iov_len);
goto dropit; /* drop request */
err_bad_dir:
svc_printk(rqstp, "bad direction %d, dropping request\n", dir);
serv->sv_stats->rpcbadfmt++;
goto dropit; /* drop request */
err_bad_rpc:
serv->sv_stats->rpcbadfmt++;
svc_putnl(resv, 1); /* REJECT */
svc_putnl(resv, 0); /* RPC_MISMATCH */
svc_putnl(resv, 2); /* Only RPCv2 supported */
svc_putnl(resv, 2);
goto sendit;
err_bad_auth:
dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
serv->sv_stats->rpcbadauth++;
/* Restore write pointer to location of accept status: */
xdr_ressize_check(rqstp, reply_statp);
svc_putnl(resv, 1); /* REJECT */
svc_putnl(resv, 1); /* AUTH_ERROR */
svc_putnl(resv, ntohl(auth_stat)); /* status */
goto sendit;
err_bad_prog:
dprintk("svc: unknown program %d\n", prog);
serv->sv_stats->rpcbadfmt++;
svc_putnl(resv, RPC_PROG_UNAVAIL);
goto sendit;
err_bad_vers:
svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
vers, prog, progp->pg_name);
serv->sv_stats->rpcbadfmt++;
svc_putnl(resv, RPC_PROG_MISMATCH);
svc_putnl(resv, progp->pg_lovers);
svc_putnl(resv, progp->pg_hivers);
goto sendit;
err_bad_proc:
svc_printk(rqstp, "unknown procedure (%d)\n", proc);
serv->sv_stats->rpcbadfmt++;
svc_putnl(resv, RPC_PROC_UNAVAIL);
goto sendit;
err_garbage:
svc_printk(rqstp, "failed to decode args\n");
rpc_stat = rpc_garbage_args;
err_bad:
serv->sv_stats->rpcbadfmt++;
svc_putnl(resv, ntohl(rpc_stat));
goto sendit;
}
EXPORT_SYMBOL(svc_process);
/*
* Return (transport-specific) limit on the rpc payload.
*/
u32 svc_max_payload(const struct svc_rqst *rqstp)
{
u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload;
if (rqstp->rq_server->sv_max_payload < max)
max = rqstp->rq_server->sv_max_payload;
return max;
}
EXPORT_SYMBOL_GPL(svc_max_payload);