linux-sg2042/include/linux/acct.h

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/*
* BSD Process Accounting for Linux - Definitions
*
* Author: Marco van Wieringen (mvw@planets.elm.net)
*
* This header file contains the definitions needed to implement
* BSD-style process accounting. The kernel accounting code and all
* user-level programs that try to do something useful with the
* process accounting log must include this file.
*
* Copyright (C) 1995 - 1997 Marco van Wieringen - ELM Consultancy B.V.
*
*/
#ifndef _LINUX_ACCT_H
#define _LINUX_ACCT_H
#include <uapi/linux/acct.h>
#ifdef CONFIG_BSD_PROCESS_ACCT
[PATCH] saner handling of auto_acct_off() and DQUOT_OFF() in umount The way we currently deal with quota and process accounting that might keep vfsmount busy at umount time is inherently broken; we try to turn them off just in case (not quite correctly, at that) and a) pray umount doesn't fail (otherwise they'll stay turned off) b) pray nobody doesn anything funny just as we turn quota off Moreover, LSM provides hooks for doing the same sort of broken logics. The proper way to deal with that is to introduce the second kind of reference to vfsmount. Semantics: - when the last normal reference is dropped, all special ones are converted to normal ones and if there had been any, cleanup is done. - normal reference can be cloned into a special one - special reference can be converted to normal one; that's a no-op if we'd already passed the point of no return (i.e. mntput() had converted special references to normal and started cleanup). The way it works: e.g. starting process accounting converts the vfsmount reference pinned by the opened file into special one and turns it back to normal when it gets shut down; acct_auto_close() is done when no normal references are left. That way it does *not* obstruct umount(2) and it silently gets turned off when the last normal reference to vfsmount is gone. Which is exactly what we want... The same should be done by LSM module that holds some internal references to vfsmount and wants to shut them down on umount - it should make them special and security_sb_umount_close() will be called exactly when the last normal reference to vfsmount is gone. quota handling is even simpler - we don't use normal file IO anymore, so there's no need to hold vfsmounts at all. DQUOT_OFF() is done from deactivate_super(), where it really belongs. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-08 06:13:39 +08:00
struct vfsmount;
struct super_block;
struct pacct_struct;
struct pid_namespace;
extern int acct_parm[]; /* for sysctl */
[PATCH] saner handling of auto_acct_off() and DQUOT_OFF() in umount The way we currently deal with quota and process accounting that might keep vfsmount busy at umount time is inherently broken; we try to turn them off just in case (not quite correctly, at that) and a) pray umount doesn't fail (otherwise they'll stay turned off) b) pray nobody doesn anything funny just as we turn quota off Moreover, LSM provides hooks for doing the same sort of broken logics. The proper way to deal with that is to introduce the second kind of reference to vfsmount. Semantics: - when the last normal reference is dropped, all special ones are converted to normal ones and if there had been any, cleanup is done. - normal reference can be cloned into a special one - special reference can be converted to normal one; that's a no-op if we'd already passed the point of no return (i.e. mntput() had converted special references to normal and started cleanup). The way it works: e.g. starting process accounting converts the vfsmount reference pinned by the opened file into special one and turns it back to normal when it gets shut down; acct_auto_close() is done when no normal references are left. That way it does *not* obstruct umount(2) and it silently gets turned off when the last normal reference to vfsmount is gone. Which is exactly what we want... The same should be done by LSM module that holds some internal references to vfsmount and wants to shut them down on umount - it should make them special and security_sb_umount_close() will be called exactly when the last normal reference to vfsmount is gone. quota handling is even simpler - we don't use normal file IO anymore, so there's no need to hold vfsmounts at all. DQUOT_OFF() is done from deactivate_super(), where it really belongs. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-08 06:13:39 +08:00
extern void acct_auto_close_mnt(struct vfsmount *m);
extern void acct_auto_close(struct super_block *sb);
extern void acct_collect(long exitcode, int group_dead);
extern void acct_process(void);
extern void acct_exit_ns(struct pid_namespace *);
#else
[PATCH] saner handling of auto_acct_off() and DQUOT_OFF() in umount The way we currently deal with quota and process accounting that might keep vfsmount busy at umount time is inherently broken; we try to turn them off just in case (not quite correctly, at that) and a) pray umount doesn't fail (otherwise they'll stay turned off) b) pray nobody doesn anything funny just as we turn quota off Moreover, LSM provides hooks for doing the same sort of broken logics. The proper way to deal with that is to introduce the second kind of reference to vfsmount. Semantics: - when the last normal reference is dropped, all special ones are converted to normal ones and if there had been any, cleanup is done. - normal reference can be cloned into a special one - special reference can be converted to normal one; that's a no-op if we'd already passed the point of no return (i.e. mntput() had converted special references to normal and started cleanup). The way it works: e.g. starting process accounting converts the vfsmount reference pinned by the opened file into special one and turns it back to normal when it gets shut down; acct_auto_close() is done when no normal references are left. That way it does *not* obstruct umount(2) and it silently gets turned off when the last normal reference to vfsmount is gone. Which is exactly what we want... The same should be done by LSM module that holds some internal references to vfsmount and wants to shut them down on umount - it should make them special and security_sb_umount_close() will be called exactly when the last normal reference to vfsmount is gone. quota handling is even simpler - we don't use normal file IO anymore, so there's no need to hold vfsmounts at all. DQUOT_OFF() is done from deactivate_super(), where it really belongs. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-08 06:13:39 +08:00
#define acct_auto_close_mnt(x) do { } while (0)
#define acct_auto_close(x) do { } while (0)
#define acct_collect(x,y) do { } while (0)
#define acct_process() do { } while (0)
#define acct_exit_ns(ns) do { } while (0)
#endif
/*
* ACCT_VERSION numbers as yet defined:
* 0: old format (until 2.6.7) with 16 bit uid/gid
* 1: extended variant (binary compatible on M68K)
* 2: extended variant (binary compatible on everything except M68K)
* 3: new binary incompatible format (64 bytes)
* 4: new binary incompatible format (128 bytes)
* 5: new binary incompatible format (128 bytes, second half)
*
*/
#undef ACCT_VERSION
#undef AHZ
#ifdef CONFIG_BSD_PROCESS_ACCT_V3
#define ACCT_VERSION 3
#define AHZ 100
typedef struct acct_v3 acct_t;
#else
#ifdef CONFIG_M68K
#define ACCT_VERSION 1
#else
#define ACCT_VERSION 2
#endif
#define AHZ (USER_HZ)
typedef struct acct acct_t;
#endif
#include <linux/jiffies.h>
/*
* Yet another set of HZ to *HZ helper functions.
* See <linux/jiffies.h> for the original.
*/
static inline u32 jiffies_to_AHZ(unsigned long x)
{
#if (TICK_NSEC % (NSEC_PER_SEC / AHZ)) == 0
# if HZ < AHZ
return x * (AHZ / HZ);
# else
return x / (HZ / AHZ);
# endif
#else
u64 tmp = (u64)x * TICK_NSEC;
do_div(tmp, (NSEC_PER_SEC / AHZ));
return (long)tmp;
#endif
}
static inline u64 nsec_to_AHZ(u64 x)
{
#if (NSEC_PER_SEC % AHZ) == 0
do_div(x, (NSEC_PER_SEC / AHZ));
#elif (AHZ % 512) == 0
x *= AHZ/512;
do_div(x, (NSEC_PER_SEC / 512));
#else
/*
* max relative error 5.7e-8 (1.8s per year) for AHZ <= 1024,
* overflow after 64.99 years.
* exact for AHZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
*/
x *= 9;
do_div(x, (unsigned long)((9ull * NSEC_PER_SEC + (AHZ/2))
/ AHZ));
#endif
return x;
}
#endif /* _LINUX_ACCT_H */