2 * Copyright (c) 1994 Christopher G. Demetriou
3 * Copyright (c) 1982, 1986, 1989, 1993
4 * The Regents of the University of California. All rights reserved.
5 * (c) UNIX System Laboratories, Inc.
6 * All or some portions of this file are derived from material licensed
7 * to the University of California by American Telephone and Telegraph
8 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
9 * the permission of UNIX System Laboratories, Inc.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93
40 * $FreeBSD: src/sys/kern/kern_acct.c,v 1.23.2.1 2002/07/24 18:33:55 johan Exp $
41 * $DragonFly: src/sys/kern/kern_acct.c,v 1.23 2006/05/06 18:48:52 dillon Exp $
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/sysproto.h>
48 #include <sys/mount.h>
49 #include <sys/vnode.h>
50 #include <sys/fcntl.h>
51 #include <sys/syslog.h>
52 #include <sys/kernel.h>
53 #include <sys/sysent.h>
54 #include <sys/sysctl.h>
55 #include <sys/nlookup.h>
57 #include <sys/resourcevar.h>
60 #include <vm/vm_zone.h>
63 * The routines implemented in this file are described in:
64 * Leffler, et al.: The Design and Implementation of the 4.3BSD
65 * UNIX Operating System (Addison Welley, 1989)
68 * Arguably, to simplify accounting operations, this mechanism should
69 * be replaced by one in which an accounting log file (similar to /dev/klog)
70 * is read by a user process, etc. However, that has its own problems.
74 * Internal accounting functions.
75 * The former's operation is described in Leffler, et al., and the latter
76 * was provided by UCB with the 4.4BSD-Lite release
78 static comp_t encode_comp_t (u_long, u_long);
79 static void acctwatch (void *);
82 * Accounting callout handle used for periodic scheduling of
85 static struct callout acctwatch_handle;
88 * Accounting vnode pointer, and saved vnode pointer.
90 static struct vnode *acctp;
91 static struct vnode *savacctp;
94 * Values associated with enabling and disabling accounting
96 static int acctsuspend = 2; /* stop accounting when < 2% free space left */
97 SYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW,
98 &acctsuspend, 0, "Percentage of free disk space below which accounting will be suspended");
100 static int acctresume = 4; /* resume when free space risen to > 4% */
101 SYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW,
102 &acctresume, 0, "Minimum percentage of free disk space needed to resume accounting");
104 static int acctchkfreq = 15; /* frequency (in seconds) to check space */
105 SYSCTL_INT(_kern, OID_AUTO, acct_chkfreq, CTLFLAG_RW,
106 &acctchkfreq, 0, "Frequency (in seconds) of free disk space checking");
109 acct_init(void *arg __unused)
111 callout_init(&acctwatch_handle);
113 SYSINIT(acct, SI_SUB_DRIVERS, SI_ORDER_ANY, acct_init, NULL);
116 * Accounting system call. Written based on the specification and
117 * previous implementation done by Mark Tinguely.
122 acct(struct acct_args *uap)
124 struct thread *td = curthread;
125 struct nlookupdata nd;
129 /* Make sure that the caller is root. */
135 * If accounting is to be started to a file, open that file for
136 * appending and make sure it's a 'normal'.
138 if (uap->path != NULL) {
139 error = nlookup_init(&nd, uap->path, UIO_USERSPACE,
142 error = vn_open(&nd, NULL, FWRITE | O_APPEND, 0);
143 if (error == 0 && nd.nl_open_vp->v_type != VREG)
150 nd.nl_open_vp = NULL;
159 * If accounting was previously enabled, kill the old space-watcher,
162 if (acctp != NULLVP || savacctp != NULLVP) {
163 callout_stop(&acctwatch_handle);
164 error = vn_close((acctp != NULLVP ? acctp : savacctp),
166 acctp = savacctp = NULLVP;
170 * If no new file opened then leave. We never did an nlookup so
171 * don't try cleaning it up.
173 if (uap->path == NULL)
177 * Save the new accounting file vnode, and schedule the new
178 * free space watcher.
186 * Write out process accounting information, on process exit.
187 * Data to be written out is specified in Leffler, et al.
188 * and are enumerated below. (They're also noted in the system
189 * "acct.h" header file.)
193 acct_process(struct proc *p)
197 struct timeval ut, st, tmp;
201 /* If accounting isn't enabled, don't bother */
207 * Get process accounting information.
210 /* (1) The name of the command that ran */
211 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm);
213 /* (2) The amount of user and system time that was used */
214 calcru(p, &ut, &st, NULL);
215 acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec);
216 acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec);
218 /* (3) The elapsed time the commmand ran (and its starting time) */
219 acct.ac_btime = p->p_start.tv_sec;
221 timevalsub(&tmp, &p->p_start);
222 acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec);
224 /* (4) The average amount of memory used */
225 r = &p->p_stats->p_ru;
227 timevaladd(&tmp, &st);
228 t = tmp.tv_sec * hz + tmp.tv_usec / tick;
230 acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t;
234 /* (5) The number of disk I/O operations done */
235 acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0);
237 /* (6) The UID and GID of the process */
238 acct.ac_uid = p->p_ucred->cr_ruid;
239 acct.ac_gid = p->p_ucred->cr_rgid;
241 /* (7) The terminal from which the process was started */
242 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp)
243 acct.ac_tty = dev2udev(p->p_pgrp->pg_session->s_ttyp->t_dev);
245 acct.ac_tty = NOUDEV;
247 /* (8) The boolean flags that tell how the process terminated, etc. */
248 acct.ac_flag = p->p_acflag;
251 * Eliminate any file size rlimit.
253 if (p->p_limit->p_refcnt > 1 &&
254 (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
255 p->p_limit->p_refcnt--;
256 p->p_limit = limcopy(p->p_limit);
258 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
261 * Write the accounting information to the file.
263 return (vn_rdwr(UIO_WRITE, vp, (caddr_t)&acct, sizeof (acct),
264 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred,
269 * Encode_comp_t converts from ticks in seconds and microseconds
270 * to ticks in 1/AHZ seconds. The encoding is described in
271 * Leffler, et al., on page 63.
274 #define MANTSIZE 13 /* 13 bit mantissa. */
275 #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
276 #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
279 encode_comp_t(u_long s, u_long us)
286 s += us / (1000000 / AHZ); /* Maximize precision. */
288 while (s > MAXFRACT) {
289 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */
290 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
294 /* If we need to round up, do it (and handle overflow correctly). */
295 if (rnd && (++s > MAXFRACT)) {
300 /* Clean it up and polish it off. */
301 exp <<= MANTSIZE; /* Shift the exponent into place */
302 exp += s; /* and add on the mantissa. */
307 * Periodically check the file system to see if accounting
308 * should be turned on or off. Beware the case where the vnode
309 * has been vgone()'d out from underneath us, e.g. when the file
310 * system containing the accounting file has been forcibly unmounted.
318 if (savacctp != NULLVP) {
319 if (savacctp->v_type == VBAD) {
320 (void) vn_close(savacctp, FWRITE | O_APPEND);
324 (void)VFS_STATFS(savacctp->v_mount, &sb, proc0.p_ucred);
325 if (sb.f_bavail > acctresume * sb.f_blocks / 100) {
328 log(LOG_NOTICE, "Accounting resumed\n");
333 if (acctp->v_type == VBAD) {
334 (void) vn_close(acctp, FWRITE | O_APPEND);
338 (void)VFS_STATFS(acctp->v_mount, &sb, proc0.p_ucred);
339 if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) {
342 log(LOG_NOTICE, "Accounting suspended\n");
345 callout_reset(&acctwatch_handle, acctchkfreq * hz, acctwatch, NULL);