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linux-next/include/linux/kmod.h
KOSAKI Motohiro ac331d158e call_usermodehelper(): increase reliability
Presently call_usermodehelper_setup() uses GFP_ATOMIC.  but it can return
NULL _very_ easily.

GFP_ATOMIC is needed only when we can't sleep.  and, GFP_KERNEL is robust
and better.

thus, I add gfp_mask argument to call_usermodehelper_setup().

So, its callers pass the gfp_t as below:

call_usermodehelper() and call_usermodehelper_keys():
	depend on 'wait' argument.
call_usermodehelper_pipe():
	always GFP_KERNEL because always run under process context.
orderly_poweroff():
	pass to GFP_ATOMIC because may run under interrupt context.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: "Paul Menage" <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:28 -07:00

103 lines
3.4 KiB
C

#ifndef __LINUX_KMOD_H__
#define __LINUX_KMOD_H__
/*
* include/linux/kmod.h
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/gfp.h>
#include <linux/stddef.h>
#include <linux/errno.h>
#include <linux/compiler.h>
#define KMOD_PATH_LEN 256
#ifdef CONFIG_MODULES
/* modprobe exit status on success, -ve on error. Return value
* usually useless though. */
extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2)));
#define try_then_request_module(x, mod...) ((x) ?: (request_module(mod), (x)))
#else
static inline int request_module(const char * name, ...) { return -ENOSYS; }
#define try_then_request_module(x, mod...) (x)
#endif
struct key;
struct file;
struct subprocess_info;
/* Allocate a subprocess_info structure */
struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
char **envp, gfp_t gfp_mask);
/* Set various pieces of state into the subprocess_info structure */
void call_usermodehelper_setkeys(struct subprocess_info *info,
struct key *session_keyring);
int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
struct file **filp);
void call_usermodehelper_setcleanup(struct subprocess_info *info,
void (*cleanup)(char **argv, char **envp));
enum umh_wait {
UMH_NO_WAIT = -1, /* don't wait at all */
UMH_WAIT_EXEC = 0, /* wait for the exec, but not the process */
UMH_WAIT_PROC = 1, /* wait for the process to complete */
};
/* Actually execute the sub-process */
int call_usermodehelper_exec(struct subprocess_info *info, enum umh_wait wait);
/* Free the subprocess_info. This is only needed if you're not going
to call call_usermodehelper_exec */
void call_usermodehelper_freeinfo(struct subprocess_info *info);
static inline int
call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
{
struct subprocess_info *info;
gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
if (info == NULL)
return -ENOMEM;
return call_usermodehelper_exec(info, wait);
}
static inline int
call_usermodehelper_keys(char *path, char **argv, char **envp,
struct key *session_keyring, enum umh_wait wait)
{
struct subprocess_info *info;
gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
if (info == NULL)
return -ENOMEM;
call_usermodehelper_setkeys(info, session_keyring);
return call_usermodehelper_exec(info, wait);
}
extern void usermodehelper_init(void);
struct file;
extern int call_usermodehelper_pipe(char *path, char *argv[], char *envp[],
struct file **filp);
#endif /* __LINUX_KMOD_H__ */