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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/net/sunrpc/svc.c

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C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* 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/signal.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/kthread.h>
#include <linux/slab.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>
#include <linux/sunrpc/bc_xprt.h>
#include <trace/events/sunrpc.h>
#include "fail.h"
#define RPCDBG_FACILITY RPCDBG_SVCDSP
static void svc_unregister(const struct svc_serv *serv, struct net *net);
#define SVC_POOL_DEFAULT SVC_POOL_GLOBAL
/*
* 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 */
};
/*
* Structure for mapping cpus to pools and vice versa.
* Setup once during sunrpc initialisation.
*/
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 */
};
static struct svc_pool_map svc_pool_map = {
.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, const 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, const struct kernel_param *kp)
{
int *ip = (int *)kp->arg;
switch (*ip)
{
case SVC_POOL_AUTO:
return strlcpy(buf, "auto\n", 20);
case SVC_POOL_GLOBAL:
return strlcpy(buf, "global\n", 20);
case SVC_POOL_PERCPU:
return strlcpy(buf, "percpu\n", 20);
case SVC_POOL_PERNODE:
return strlcpy(buf, "pernode\n", 20);
default:
return sprintf(buf, "%d\n", *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 (nr_online_nodes > 1) {
/*
* Actually have multiple NUMA nodes,
* so split pools on NUMA node boundaries
*/
return SVC_POOL_PERNODE;
}
node = first_online_node;
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);
m->to_pool = NULL;
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) if pools are in use.
* Initialise the map if we're the first user.
* Returns the number of pools. If this is '1', no reference
* was taken.
*/
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);
WARN_ON_ONCE(m->npools <= 1);
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;
if (npools == 1)
/* service is unpooled, so doesn't hold a reference */
m->count--;
mutex_unlock(&svc_pool_map_mutex);
return npools;
}
/*
* Drop a reference to the global map of cpus to pools, if
* pools were in use, i.e. if npools > 1.
* 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(int npools)
{
struct svc_pool_map *m = &svc_pool_map;
if (npools <= 1)
return;
mutex_lock(&svc_pool_map_mutex);
if (!--m->count) {
kfree(m->to_pool);
m->to_pool = NULL;
kfree(m->pool_to);
m->pool_to = NULL;
m->npools = 0;
}
mutex_unlock(&svc_pool_map_mutex);
}
static int svc_pool_map_get_node(unsigned int pidx)
{
const struct svc_pool_map *m = &svc_pool_map;
if (m->count) {
if (m->mode == SVC_POOL_PERCPU)
return cpu_to_node(m->pool_to[pidx]);
if (m->mode == SVC_POOL_PERNODE)
return m->pool_to[pidx];
}
return NUMA_NO_NODE;
}
/*
* Set the given thread's cpus_allowed mask so that it
* will only run on cpus in the given pool.
*/
static inline void
svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
{
struct svc_pool_map *m = &svc_pool_map;
unsigned int node = m->pool_to[pidx];
/*
* The caller checks for sv_nrpools > 1, which
* implies that we've been initialized.
*/
WARN_ON_ONCE(m->count == 0);
if (m->count == 0)
return;
switch (m->mode) {
case SVC_POOL_PERCPU:
{
set_cpus_allowed_ptr(task, cpumask_of(node));
break;
}
case SVC_POOL_PERNODE:
{
set_cpus_allowed_ptr(task, cpumask_of_node(node));
break;
}
}
}
/**
* svc_pool_for_cpu - Select pool to run a thread on this cpu
* @serv: An RPC service
*
* Use the active CPU and the svc_pool_map's mode setting to
* select the svc thread pool to use. Once initialized, the
* svc_pool_map does not change.
*
* Return value:
* A pointer to an svc_pool
*/
struct svc_pool *svc_pool_for_cpu(struct svc_serv *serv)
{
struct svc_pool_map *m = &svc_pool_map;
int cpu = raw_smp_processor_id();
unsigned int pidx = 0;
if (serv->sv_nrpools <= 1)
return serv->sv_pools;
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];
}
int svc_rpcb_setup(struct svc_serv *serv, struct net *net)
{
int err;
err = rpcb_create_local(net);
if (err)
return err;
/* Remove any stale portmap registrations */
svc_unregister(serv, net);
return 0;
}
EXPORT_SYMBOL_GPL(svc_rpcb_setup);
void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net)
{
svc_unregister(serv, net);
rpcb_put_local(net);
}
EXPORT_SYMBOL_GPL(svc_rpcb_cleanup);
static int svc_uses_rpcbind(struct svc_serv *serv)
{
struct svc_program *progp;
unsigned int i;
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;
if (!progp->pg_vers[i]->vs_hidden)
return 1;
}
}
return 0;
}
int svc_bind(struct svc_serv *serv, struct net *net)
{
if (!svc_uses_rpcbind(serv))
return 0;
return svc_rpcb_setup(serv, net);
}
EXPORT_SYMBOL_GPL(svc_bind);
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
static void
__svc_init_bc(struct svc_serv *serv)
{
INIT_LIST_HEAD(&serv->sv_cb_list);
spin_lock_init(&serv->sv_cb_lock);
init_waitqueue_head(&serv->sv_cb_waitq);
}
#else
static void
__svc_init_bc(struct svc_serv *serv)
{
}
#endif
/*
* Create an RPC service
*/
static struct svc_serv *
__svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
int (*threadfn)(void *data))
{
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;
kref_init(&serv->sv_refcnt);
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_threadfn = threadfn;
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);
timer_setup(&serv->sv_temptimer, NULL, 0);
spin_lock_init(&serv->sv_lock);
__svc_init_bc(serv);
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_sockets);
INIT_LIST_HEAD(&pool->sp_all_threads);
spin_lock_init(&pool->sp_lock);
}
return serv;
}
/**
* svc_create - Create an RPC service
* @prog: the RPC program the new service will handle
* @bufsize: maximum message size for @prog
* @threadfn: a function to service RPC requests for @prog
*
* Returns an instantiated struct svc_serv object or NULL.
*/
struct svc_serv *svc_create(struct svc_program *prog, unsigned int bufsize,
int (*threadfn)(void *data))
{
return __svc_create(prog, bufsize, 1, threadfn);
}
EXPORT_SYMBOL_GPL(svc_create);
/**
* svc_create_pooled - Create an RPC service with pooled threads
* @prog: the RPC program the new service will handle
* @bufsize: maximum message size for @prog
* @threadfn: a function to service RPC requests for @prog
*
* Returns an instantiated struct svc_serv object or NULL.
*/
struct svc_serv *svc_create_pooled(struct svc_program *prog,
unsigned int bufsize,
int (*threadfn)(void *data))
{
struct svc_serv *serv;
unsigned int npools = svc_pool_map_get();
serv = __svc_create(prog, bufsize, npools, threadfn);
if (!serv)
goto out_err;
return serv;
out_err:
svc_pool_map_put(npools);
return NULL;
}
EXPORT_SYMBOL_GPL(svc_create_pooled);
/*
* Destroy an RPC service. Should be called with appropriate locking to
* protect sv_permsocks and sv_tempsocks.
*/
void
svc_destroy(struct kref *ref)
{
struct svc_serv *serv = container_of(ref, struct svc_serv, sv_refcnt);
dprintk("svc: svc_destroy(%s)\n", serv->sv_program->pg_name);
del_timer_sync(&serv->sv_temptimer);
/*
* The last user is gone and thus all sockets have to be destroyed to
* the point. Check this.
*/
BUG_ON(!list_empty(&serv->sv_permsocks));
BUG_ON(!list_empty(&serv->sv_tempsocks));
cache_clean_deferred(serv);
svc_pool_map_put(serv->sv_nrpools);
kfree(serv->sv_pools);
kfree(serv);
}
EXPORT_SYMBOL_GPL(svc_destroy);
/*
* Allocate an RPC server's buffer space.
* We allocate pages and place them in rq_pages.
*/
static int
svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
{
unsigned int pages, arghi;
/* bc_xprt uses fore channel allocated buffers */
if (svc_is_backchannel(rqstp))
return 1;
pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
* We assume one is at most one page
*/
arghi = 0;
WARN_ON_ONCE(pages > RPCSVC_MAXPAGES);
if (pages > RPCSVC_MAXPAGES)
pages = RPCSVC_MAXPAGES;
while (pages) {
struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
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_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
{
struct svc_rqst *rqstp;
rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
if (!rqstp)
return rqstp;
__set_bit(RQ_BUSY, &rqstp->rq_flags);
spin_lock_init(&rqstp->rq_lock);
rqstp->rq_server = serv;
rqstp->rq_pool = pool;
rqstp->rq_scratch_page = alloc_pages_node(node, GFP_KERNEL, 0);
if (!rqstp->rq_scratch_page)
goto out_enomem;
rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
if (!rqstp->rq_argp)
goto out_enomem;
rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
if (!rqstp->rq_resp)
goto out_enomem;
if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
goto out_enomem;
return rqstp;
out_enomem:
svc_rqst_free(rqstp);
return NULL;
}
EXPORT_SYMBOL_GPL(svc_rqst_alloc);
static struct svc_rqst *
svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
{
struct svc_rqst *rqstp;
rqstp = svc_rqst_alloc(serv, pool, node);
if (!rqstp)
return ERR_PTR(-ENOMEM);
svc_get(serv);
spin_lock_bh(&serv->sv_lock);
serv->sv_nrthreads += 1;
spin_unlock_bh(&serv->sv_lock);
spin_lock_bh(&pool->sp_lock);
pool->sp_nrthreads++;
list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
spin_unlock_bh(&pool->sp_lock);
return rqstp;
}
/*
* 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);
set_bit(RQ_VICTIM, &rqstp->rq_flags);
list_del_rcu(&rqstp->rq_all);
task = rqstp->rq_task;
}
spin_unlock_bh(&pool->sp_lock);
return task;
}
/* create new threads */
static int
svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
{
struct svc_rqst *rqstp;
struct task_struct *task;
struct svc_pool *chosen_pool;
unsigned int state = serv->sv_nrthreads-1;
int node;
do {
nrservs--;
chosen_pool = choose_pool(serv, pool, &state);
node = svc_pool_map_get_node(chosen_pool->sp_id);
rqstp = svc_prepare_thread(serv, chosen_pool, node);
if (IS_ERR(rqstp))
return PTR_ERR(rqstp);
task = kthread_create_on_node(serv->sv_threadfn, rqstp,
node, "%s", serv->sv_name);
if (IS_ERR(task)) {
svc_exit_thread(rqstp);
return PTR_ERR(task);
}
rqstp->rq_task = task;
if (serv->sv_nrpools > 1)
svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
svc_sock_update_bufs(serv);
wake_up_process(task);
} while (nrservs > 0);
return 0;
}
/*
* 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. Caller must ensure that mutual exclusion between this and
* server startup or shutdown.
*/
/* destroy old threads */
static int
svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
{
struct task_struct *task;
unsigned int state = serv->sv_nrthreads-1;
/* destroy old threads */
do {
task = choose_victim(serv, pool, &state);
if (task == NULL)
break;
kthread_stop(task);
nrservs++;
} while (nrservs < 0);
return 0;
}
int
svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
{
if (pool == NULL) {
nrservs -= serv->sv_nrthreads;
} else {
spin_lock_bh(&pool->sp_lock);
nrservs -= pool->sp_nrthreads;
spin_unlock_bh(&pool->sp_lock);
}
if (nrservs > 0)
return svc_start_kthreads(serv, pool, nrservs);
if (nrservs < 0)
return svc_stop_kthreads(serv, pool, nrservs);
return 0;
}
EXPORT_SYMBOL_GPL(svc_set_num_threads);
/**
* svc_rqst_replace_page - Replace one page in rq_pages[]
* @rqstp: svc_rqst with pages to replace
* @page: replacement page
*
* When replacing a page in rq_pages, batch the release of the
* replaced pages to avoid hammering the page allocator.
*/
void svc_rqst_replace_page(struct svc_rqst *rqstp, struct page *page)
{
if (*rqstp->rq_next_page) {
if (!pagevec_space(&rqstp->rq_pvec))
__pagevec_release(&rqstp->rq_pvec);
pagevec_add(&rqstp->rq_pvec, *rqstp->rq_next_page);
}
get_page(page);
*(rqstp->rq_next_page++) = page;
}
EXPORT_SYMBOL_GPL(svc_rqst_replace_page);
/*
* Called from a server thread as it's exiting. Caller must hold the "service
* mutex" for the service.
*/
void
svc_rqst_free(struct svc_rqst *rqstp)
{
svc_release_buffer(rqstp);
if (rqstp->rq_scratch_page)
put_page(rqstp->rq_scratch_page);
kfree(rqstp->rq_resp);
kfree(rqstp->rq_argp);
kfree(rqstp->rq_auth_data);
kfree_rcu(rqstp, rq_rcu_head);
}
EXPORT_SYMBOL_GPL(svc_rqst_free);
void
svc_exit_thread(struct svc_rqst *rqstp)
{
struct svc_serv *serv = rqstp->rq_server;
struct svc_pool *pool = rqstp->rq_pool;
spin_lock_bh(&pool->sp_lock);
pool->sp_nrthreads--;
if (!test_and_set_bit(RQ_VICTIM, &rqstp->rq_flags))
list_del_rcu(&rqstp->rq_all);
spin_unlock_bh(&pool->sp_lock);
spin_lock_bh(&serv->sv_lock);
serv->sv_nrthreads -= 1;
spin_unlock_bh(&serv->sv_lock);
svc_sock_update_bufs(serv);
svc_rqst_free(rqstp);
svc_put(serv);
}
EXPORT_SYMBOL_GPL(svc_exit_thread);
/*
* Register an "inet" protocol family netid with the local
* rpcbind daemon via an rpcbind v4 SET request.
*
* No netconfig infrastructure is available in the kernel, so
* we map IP_ protocol numbers to netids by hand.
*
* Returns zero on success; a negative errno value is returned
* if any error occurs.
*/
static int __svc_rpcb_register4(struct net *net, const u32 program,
const u32 version,
const unsigned short protocol,
const unsigned short port)
{
const struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_ANY),
.sin_port = htons(port),
};
const char *netid;
int error;
switch (protocol) {
case IPPROTO_UDP:
netid = RPCBIND_NETID_UDP;
break;
case IPPROTO_TCP:
netid = RPCBIND_NETID_TCP;
break;
default:
return -ENOPROTOOPT;
}
error = rpcb_v4_register(net, program, version,
(const struct sockaddr *)&sin, netid);
/*
* User space didn't support rpcbind v4, so retry this
* registration request with the legacy rpcbind v2 protocol.
*/
if (error == -EPROTONOSUPPORT)
error = rpcb_register(net, program, version, protocol, port);
return error;
}
#if IS_ENABLED(CONFIG_IPV6)
/*
* Register an "inet6" protocol family netid with the local
* rpcbind daemon via an rpcbind v4 SET request.
*
* No netconfig infrastructure is available in the kernel, so
* we map IP_ protocol numbers to netids by hand.
*
* Returns zero on success; a negative errno value is returned
* if any error occurs.
*/
static int __svc_rpcb_register6(struct net *net, const u32 program,
const u32 version,
const unsigned short protocol,
const unsigned short port)
{
const struct sockaddr_in6 sin6 = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ANY_INIT,
.sin6_port = htons(port),
};
const char *netid;
int error;
switch (protocol) {
case IPPROTO_UDP:
netid = RPCBIND_NETID_UDP6;
break;
case IPPROTO_TCP:
netid = RPCBIND_NETID_TCP6;
break;
default:
return -ENOPROTOOPT;
}
error = rpcb_v4_register(net, program, version,
(const struct sockaddr *)&sin6, netid);
/*
* User space didn't support rpcbind version 4, so we won't
* use a PF_INET6 listener.
*/
if (error == -EPROTONOSUPPORT)
error = -EAFNOSUPPORT;
return error;
}
#endif /* IS_ENABLED(CONFIG_IPV6) */
/*
* Register a kernel RPC service via rpcbind version 4.
*
* Returns zero on success; a negative errno value is returned
* if any error occurs.
*/
static int __svc_register(struct net *net, const char *progname,
const u32 program, const u32 version,
const int family,
const unsigned short protocol,
const unsigned short port)
{
int error = -EAFNOSUPPORT;
switch (family) {
case PF_INET:
error = __svc_rpcb_register4(net, program, version,
protocol, port);
break;
#if IS_ENABLED(CONFIG_IPV6)
case PF_INET6:
error = __svc_rpcb_register6(net, program, version,
protocol, port);
#endif
}
trace_svc_register(progname, version, protocol, port, family, error);
return error;
}
int svc_rpcbind_set_version(struct net *net,
const struct svc_program *progp,
u32 version, int family,
unsigned short proto,
unsigned short port)
{
return __svc_register(net, progp->pg_name, progp->pg_prog,
version, family, proto, port);
}
EXPORT_SYMBOL_GPL(svc_rpcbind_set_version);
int svc_generic_rpcbind_set(struct net *net,
const struct svc_program *progp,
u32 version, int family,
unsigned short proto,
unsigned short port)
{
const struct svc_version *vers = progp->pg_vers[version];
int error;
if (vers == NULL)
return 0;
if (vers->vs_hidden) {
trace_svc_noregister(progp->pg_name, version, proto,
port, family, 0);
return 0;
}
/*
* Don't register a UDP port if we need congestion
* control.
*/
if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
return 0;
error = svc_rpcbind_set_version(net, progp, version,
family, proto, port);
return (vers->vs_rpcb_optnl) ? 0 : error;
}
EXPORT_SYMBOL_GPL(svc_generic_rpcbind_set);
/**
* svc_register - register an RPC service with the local portmapper
* @serv: svc_serv struct for the service to register
* @net: net namespace for the service to register
* @family: protocol family of service's listener socket
* @proto: transport protocol number to advertise
* @port: port to advertise
*
* Service is registered for any address in the passed-in protocol family
*/
int svc_register(const struct svc_serv *serv, struct net *net,
const int family, const unsigned short proto,
const unsigned short port)
{
struct svc_program *progp;
unsigned int i;
int error = 0;
WARN_ON_ONCE(proto == 0 && port == 0);
if (proto == 0 && port == 0)
return -EINVAL;
for (progp = serv->sv_program; progp; progp = progp->pg_next) {
for (i = 0; i < progp->pg_nvers; i++) {
error = progp->pg_rpcbind_set(net, progp, i,
family, proto, port);
if (error < 0) {
printk(KERN_WARNING "svc: failed to register "
"%sv%u RPC service (errno %d).\n",
progp->pg_name, i, -error);
break;
}
}
}
return error;
}
/*
* If user space is running rpcbind, it should take the v4 UNSET
* and clear everything for this [program, version]. If user space
* is running portmap, it will reject the v4 UNSET, but won't have
* any "inet6" entries anyway. So a PMAP_UNSET should be sufficient
* in this case to clear all existing entries for [program, version].
*/
static void __svc_unregister(struct net *net, const u32 program, const u32 version,
const char *progname)
{
int error;
error = rpcb_v4_register(net, program, version, NULL, "");
/*
* User space didn't support rpcbind v4, so retry this
* request with the legacy rpcbind v2 protocol.
*/
if (error == -EPROTONOSUPPORT)
error = rpcb_register(net, program, version, 0, 0);
trace_svc_unregister(progname, version, error);
}
/*
* All netids, bind addresses and ports registered for [program, version]
* are removed from the local rpcbind database (if the service is not
* hidden) to make way for a new instance of the service.
*
* The result of unregistration is reported via dprintk for those who want
* verification of the result, but is otherwise not important.
*/
static void svc_unregister(const struct svc_serv *serv, struct net *net)
{
struct svc_program *progp;
unsigned long flags;
unsigned int i;
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;
if (progp->pg_vers[i]->vs_hidden)
continue;
__svc_unregister(net, progp->pg_prog, i, progp->pg_name);
}
}
spin_lock_irqsave(&current->sighand->siglock, flags);
recalc_sigpending();
spin_unlock_irqrestore(&current->sighand->siglock, flags);
}
/*
* dprintk the given error with the address of the client that caused it.
*/
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
static __printf(2, 3)
void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
char buf[RPC_MAX_ADDRBUFLEN];
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
dprintk("svc: %s: %pV", svc_print_addr(rqstp, buf, sizeof(buf)), &vaf);
va_end(args);
}
#else
static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {}
#endif
__be32
svc_generic_init_request(struct svc_rqst *rqstp,
const struct svc_program *progp,
struct svc_process_info *ret)
{
const struct svc_version *versp = NULL; /* compiler food */
const struct svc_procedure *procp = NULL;
if (rqstp->rq_vers >= progp->pg_nvers )
goto err_bad_vers;
versp = progp->pg_vers[rqstp->rq_vers];
if (!versp)
goto err_bad_vers;
/*
* Some protocol versions (namely NFSv4) require some form of
* congestion control. (See RFC 7530 section 3.1 paragraph 2)
* In other words, UDP is not allowed. We mark those when setting
* up the svc_xprt, and verify that here.
*
* The spec is not very clear about what error should be returned
* when someone tries to access a server that is listening on UDP
* for lower versions. RPC_PROG_MISMATCH seems to be the closest
* fit.
*/
if (versp->vs_need_cong_ctrl && rqstp->rq_xprt &&
!test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
goto err_bad_vers;
if (rqstp->rq_proc >= versp->vs_nproc)
goto err_bad_proc;
rqstp->rq_procinfo = procp = &versp->vs_proc[rqstp->rq_proc];
if (!procp)
goto err_bad_proc;
/* Initialize storage for argp and resp */
memset(rqstp->rq_argp, 0, procp->pc_argzero);
memset(rqstp->rq_resp, 0, procp->pc_ressize);
/* Bump per-procedure stats counter */
versp->vs_count[rqstp->rq_proc]++;
ret->dispatch = versp->vs_dispatch;
return rpc_success;
err_bad_vers:
ret->mismatch.lovers = progp->pg_lovers;
ret->mismatch.hivers = progp->pg_hivers;
return rpc_prog_mismatch;
err_bad_proc:
return rpc_proc_unavail;
}
EXPORT_SYMBOL_GPL(svc_generic_init_request);
/*
* Common routine for processing the RPC request.
*/
static int
svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
{
struct svc_program *progp;
const struct svc_procedure *procp = NULL;
struct svc_serv *serv = rqstp->rq_server;
struct svc_process_info process;
__be32 *statp;
u32 prog, vers;
__be32 rpc_stat;
int auth_res, rc;
__be32 *reply_statp;
rpc_stat = rpc_success;
if (argv->iov_len < 6*4)
goto err_short_len;
/* Will be turned off by GSS integrity and privacy services */
__set_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
/* Will be turned off only when NFSv4 Sessions are used */
__set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
__clear_bit(RQ_DROPME, &rqstp->rq_flags);
svc_putu32(resv, rqstp->rq_xid);
vers = svc_getnl(argv);
/* First words of reply: */
svc_putnl(resv, 1); /* REPLY */
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 = svc_getnl(argv); /* version number */
rqstp->rq_proc = svc_getnl(argv); /* procedure number */
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);
/* Also give the program a chance to reject this call: */
if (auth_res == SVC_OK && progp)
auth_res = progp->pg_authenticate(rqstp);
if (auth_res != SVC_OK)
trace_svc_authenticate(rqstp, auth_res);
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_CLOSE:
goto close;
case SVC_DROP:
goto dropit;
case SVC_COMPLETE:
goto sendit;
}
if (progp == NULL)
goto err_bad_prog;
rpc_stat = progp->pg_init_request(rqstp, progp, &process);
switch (rpc_stat) {
case rpc_success:
break;
case rpc_prog_unavail:
goto err_bad_prog;
case rpc_prog_mismatch:
goto err_bad_vers;
case rpc_proc_unavail:
goto err_bad_proc;
}
procp = rqstp->rq_procinfo;
/* Should this check go into the dispatcher? */
if (!procp || !procp->pc_func)
goto err_bad_proc;
/* Syntactic check complete */
serv->sv_stats->rpccnt++;
trace_svc_process(rqstp, progp->pg_name);
/* Build the reply header. */
statp = resv->iov_base +resv->iov_len;
svc_putnl(resv, RPC_SUCCESS);
/* 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. */
rc = process.dispatch(rqstp, statp);
if (procp->pc_release)
procp->pc_release(rqstp);
if (!rc)
goto dropit;
if (rqstp->rq_auth_stat != rpc_auth_ok)
goto err_bad_auth;
/* Check RPC status result */
if (*statp != rpc_success)
resv->iov_len = ((void*)statp) - resv->iov_base + 4;
if (procp->pc_encode == NULL)
goto dropit;
sendit:
if (svc_authorise(rqstp))
goto close_xprt;
return 1; /* Caller can now send it */
dropit:
svc_authorise(rqstp); /* doesn't hurt to call this twice */
dprintk("svc: svc_process dropit\n");
return 0;
close:
svc_authorise(rqstp);
close_xprt:
if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
svc_xprt_close(rqstp->rq_xprt);
dprintk("svc: svc_process close\n");
return 0;
err_short_len:
svc_printk(rqstp, "short len %zd, dropping request\n",
argv->iov_len);
goto close_xprt;
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",
be32_to_cpu(rqstp->rq_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_putu32(resv, rqstp->rq_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",
rqstp->rq_vers, rqstp->rq_prog, progp->pg_name);
serv->sv_stats->rpcbadfmt++;
svc_putnl(resv, RPC_PROG_MISMATCH);
svc_putnl(resv, process.mismatch.lovers);
svc_putnl(resv, process.mismatch.hivers);
goto sendit;
err_bad_proc:
svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_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;
}
/*
* Process the RPC request.
*/
int
svc_process(struct svc_rqst *rqstp)
{
struct kvec *argv = &rqstp->rq_arg.head[0];
struct kvec *resv = &rqstp->rq_res.head[0];
__be32 dir;
#if IS_ENABLED(CONFIG_FAIL_SUNRPC)
if (!fail_sunrpc.ignore_server_disconnect &&
should_fail(&fail_sunrpc.attr, 1))
svc_xprt_deferred_close(rqstp->rq_xprt);
#endif
/*
* Setup response xdr_buf.
* Initially it has just one page
*/
rqstp->rq_next_page = &rqstp->rq_respages[1];
resv->iov_base = page_address(rqstp->rq_respages[0]);
resv->iov_len = 0;
rqstp->rq_res.pages = rqstp->rq_next_page;
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;
dir = svc_getu32(argv);
if (dir != rpc_call)
goto out_baddir;
if (!svc_process_common(rqstp, argv, resv))
goto out_drop;
return svc_send(rqstp);
out_baddir:
svc_printk(rqstp, "bad direction 0x%08x, dropping request\n",
be32_to_cpu(dir));
rqstp->rq_server->sv_stats->rpcbadfmt++;
out_drop:
svc_drop(rqstp);
return 0;
}
EXPORT_SYMBOL_GPL(svc_process);
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
/*
* Process a backchannel RPC request that arrived over an existing
* outbound connection
*/
int
bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
struct svc_rqst *rqstp)
{
struct kvec *argv = &rqstp->rq_arg.head[0];
struct kvec *resv = &rqstp->rq_res.head[0];
struct rpc_task *task;
int proc_error;
int error;
dprintk("svc: %s(%p)\n", __func__, req);
/* Build the svc_rqst used by the common processing routine */
rqstp->rq_xid = req->rq_xid;
rqstp->rq_prot = req->rq_xprt->prot;
rqstp->rq_server = serv;
rqstp->rq_bc_net = req->rq_xprt->xprt_net;
rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
/* Adjust the argument buffer length */
rqstp->rq_arg.len = req->rq_private_buf.len;
if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
rqstp->rq_arg.page_len = 0;
} else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len +
rqstp->rq_arg.page_len)
rqstp->rq_arg.page_len = rqstp->rq_arg.len -
rqstp->rq_arg.head[0].iov_len;
else
rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len +
rqstp->rq_arg.page_len;
/* reset result send buffer "put" position */
resv->iov_len = 0;
/*
* Skip the next two words because they've already been
* processed in the transport
*/
svc_getu32(argv); /* XID */
svc_getnl(argv); /* CALLDIR */
/* Parse and execute the bc call */
proc_error = svc_process_common(rqstp, argv, resv);
atomic_dec(&req->rq_xprt->bc_slot_count);
if (!proc_error) {
/* Processing error: drop the request */
xprt_free_bc_request(req);
error = -EINVAL;
goto out;
}
/* Finally, send the reply synchronously */
memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
task = rpc_run_bc_task(req);
if (IS_ERR(task)) {
error = PTR_ERR(task);
goto out;
}
WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
error = task->tk_status;
rpc_put_task(task);
out:
dprintk("svc: %s(), error=%d\n", __func__, error);
return error;
}
EXPORT_SYMBOL_GPL(bc_svc_process);
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
/**
* svc_max_payload - Return transport-specific limit on the RPC payload
* @rqstp: RPC transaction context
*
* Returns the maximum number of payload bytes the current transport
* allows.
*/
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);
/**
* svc_proc_name - Return RPC procedure name in string form
* @rqstp: svc_rqst to operate on
*
* Return value:
* Pointer to a NUL-terminated string
*/
const char *svc_proc_name(const struct svc_rqst *rqstp)
{
if (rqstp && rqstp->rq_procinfo)
return rqstp->rq_procinfo->pc_name;
return "unknown";
}
/**
* svc_encode_result_payload - mark a range of bytes as a result payload
* @rqstp: svc_rqst to operate on
* @offset: payload's byte offset in rqstp->rq_res
* @length: size of payload, in bytes
*
* Returns zero on success, or a negative errno if a permanent
* error occurred.
*/
int svc_encode_result_payload(struct svc_rqst *rqstp, unsigned int offset,
unsigned int length)
{
return rqstp->rq_xprt->xpt_ops->xpo_result_payload(rqstp, offset,
length);
}
EXPORT_SYMBOL_GPL(svc_encode_result_payload);
/**
* svc_fill_write_vector - Construct data argument for VFS write call
* @rqstp: svc_rqst to operate on
* @payload: xdr_buf containing only the write data payload
*
* Fills in rqstp::rq_vec, and returns the number of elements.
*/
unsigned int svc_fill_write_vector(struct svc_rqst *rqstp,
struct xdr_buf *payload)
{
struct page **pages = payload->pages;
struct kvec *first = payload->head;
struct kvec *vec = rqstp->rq_vec;
size_t total = payload->len;
unsigned int i;
/* Some types of transport can present the write payload
* entirely in rq_arg.pages. In this case, @first is empty.
*/
i = 0;
if (first->iov_len) {
vec[i].iov_base = first->iov_base;
vec[i].iov_len = min_t(size_t, total, first->iov_len);
total -= vec[i].iov_len;
++i;
}
while (total) {
vec[i].iov_base = page_address(*pages);
vec[i].iov_len = min_t(size_t, total, PAGE_SIZE);
total -= vec[i].iov_len;
++i;
++pages;
}
WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec));
return i;
}
EXPORT_SYMBOL_GPL(svc_fill_write_vector);
/**
* svc_fill_symlink_pathname - Construct pathname argument for VFS symlink call
* @rqstp: svc_rqst to operate on
* @first: buffer containing first section of pathname
* @p: buffer containing remaining section of pathname
* @total: total length of the pathname argument
*
* The VFS symlink API demands a NUL-terminated pathname in mapped memory.
* Returns pointer to a NUL-terminated string, or an ERR_PTR. Caller must free
* the returned string.
*/
char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first,
void *p, size_t total)
{
size_t len, remaining;
char *result, *dst;
result = kmalloc(total + 1, GFP_KERNEL);
if (!result)
return ERR_PTR(-ESERVERFAULT);
dst = result;
remaining = total;
len = min_t(size_t, total, first->iov_len);
if (len) {
memcpy(dst, first->iov_base, len);
dst += len;
remaining -= len;
}
if (remaining) {
len = min_t(size_t, remaining, PAGE_SIZE);
memcpy(dst, p, len);
dst += len;
}
*dst = '\0';
/* Sanity check: Linux doesn't allow the pathname argument to
* contain a NUL byte.
*/
if (strlen(result) != total) {
kfree(result);
return ERR_PTR(-EINVAL);
}
return result;
}
EXPORT_SYMBOL_GPL(svc_fill_symlink_pathname);
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