zfs-builds-mm/zfs-0.8.1/module/spl/spl-thread.c

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2019-07-06 23:40:11 +02:00
/*
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://zfsonlinux.org/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
*
* Solaris Porting Layer (SPL) Thread Implementation.
*/
#include <sys/thread.h>
#include <sys/kmem.h>
#include <sys/tsd.h>
/*
* Thread interfaces
*/
typedef struct thread_priv_s {
unsigned long tp_magic; /* Magic */
int tp_name_size; /* Name size */
char *tp_name; /* Name (without _thread suffix) */
void (*tp_func)(void *); /* Registered function */
void *tp_args; /* Args to be passed to function */
size_t tp_len; /* Len to be passed to function */
int tp_state; /* State to start thread at */
pri_t tp_pri; /* Priority to start threat at */
} thread_priv_t;
static int
thread_generic_wrapper(void *arg)
{
thread_priv_t *tp = (thread_priv_t *)arg;
void (*func)(void *);
void *args;
ASSERT(tp->tp_magic == TP_MAGIC);
func = tp->tp_func;
args = tp->tp_args;
set_current_state(tp->tp_state);
set_user_nice((kthread_t *)current, PRIO_TO_NICE(tp->tp_pri));
kmem_free(tp->tp_name, tp->tp_name_size);
kmem_free(tp, sizeof (thread_priv_t));
if (func)
func(args);
return (0);
}
void
__thread_exit(void)
{
tsd_exit();
complete_and_exit(NULL, 0);
/* Unreachable */
}
EXPORT_SYMBOL(__thread_exit);
/*
* thread_create() may block forever if it cannot create a thread or
* allocate memory. This is preferable to returning a NULL which Solaris
* style callers likely never check for... since it can't fail.
*/
kthread_t *
__thread_create(caddr_t stk, size_t stksize, thread_func_t func,
const char *name, void *args, size_t len, proc_t *pp, int state, pri_t pri)
{
thread_priv_t *tp;
struct task_struct *tsk;
char *p;
/* Option pp is simply ignored */
/* Variable stack size unsupported */
ASSERT(stk == NULL);
tp = kmem_alloc(sizeof (thread_priv_t), KM_PUSHPAGE);
if (tp == NULL)
return (NULL);
tp->tp_magic = TP_MAGIC;
tp->tp_name_size = strlen(name) + 1;
tp->tp_name = kmem_alloc(tp->tp_name_size, KM_PUSHPAGE);
if (tp->tp_name == NULL) {
kmem_free(tp, sizeof (thread_priv_t));
return (NULL);
}
strncpy(tp->tp_name, name, tp->tp_name_size);
/*
* Strip trailing "_thread" from passed name which will be the func
* name since the exposed API has no parameter for passing a name.
*/
p = strstr(tp->tp_name, "_thread");
if (p)
p[0] = '\0';
tp->tp_func = func;
tp->tp_args = args;
tp->tp_len = len;
tp->tp_state = state;
tp->tp_pri = pri;
tsk = spl_kthread_create(thread_generic_wrapper, (void *)tp,
"%s", tp->tp_name);
if (IS_ERR(tsk))
return (NULL);
wake_up_process(tsk);
return ((kthread_t *)tsk);
}
EXPORT_SYMBOL(__thread_create);
/*
* spl_kthread_create - Wrapper providing pre-3.13 semantics for
* kthread_create() in which it is not killable and less likely
* to return -ENOMEM.
*/
struct task_struct *
spl_kthread_create(int (*func)(void *), void *data, const char namefmt[], ...)
{
struct task_struct *tsk;
va_list args;
char name[TASK_COMM_LEN];
va_start(args, namefmt);
vsnprintf(name, sizeof (name), namefmt, args);
va_end(args);
do {
tsk = kthread_create(func, data, "%s", name);
if (IS_ERR(tsk)) {
if (signal_pending(current)) {
clear_thread_flag(TIF_SIGPENDING);
continue;
}
if (PTR_ERR(tsk) == -ENOMEM)
continue;
return (NULL);
} else
return (tsk);
} while (1);
}
EXPORT_SYMBOL(spl_kthread_create);