1/*-
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.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
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.
26 *
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
37 * SUCH DAMAGE.
38 *
39 * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93
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40 * $FreeBSD: head/sys/kern/kern_acct.c 62550 2000-07-04 03:34:11Z mckusick $
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| 40 * $FreeBSD: head/sys/kern/kern_acct.c 69286 2000-11-27 22:52:31Z jake $ |
41 */
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/sysproto.h>
46#include <sys/proc.h>
47#include <sys/mount.h>
48#include <sys/vnode.h>
49#include <sys/fcntl.h>
50#include <sys/syslog.h>
51#include <sys/kernel.h>
52#include <sys/sysent.h>
53#include <sys/sysctl.h>
54#include <sys/namei.h>
55#include <sys/acct.h>
56#include <sys/resourcevar.h>
57#include <sys/tty.h>
58
59
60/*
61 * The routines implemented in this file are described in:
62 * Leffler, et al.: The Design and Implementation of the 4.3BSD
63 * UNIX Operating System (Addison Welley, 1989)
64 * on pages 62-63.
65 *
66 * Arguably, to simplify accounting operations, this mechanism should
67 * be replaced by one in which an accounting log file (similar to /dev/klog)
68 * is read by a user process, etc. However, that has its own problems.
69 */
70
71/*
72 * Internal accounting functions.
73 * The former's operation is described in Leffler, et al., and the latter
74 * was provided by UCB with the 4.4BSD-Lite release
75 */
76static comp_t encode_comp_t __P((u_long, u_long));
77static void acctwatch __P((void *));
78
79/*
|
80 * Accounting callout handle used for periodic scheduling of
81 * acctwatch.
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| 80 * Accounting callout used for periodic scheduling of acctwatch. |
81 */
|
83static struct callout_handle acctwatch_handle
84 = CALLOUT_HANDLE_INITIALIZER(&acctwatch_handle);
|
| 82static struct callout acctwatch_callout; |
83
84/*
85 * Accounting vnode pointer, and saved vnode pointer.
86 */
87static struct vnode *acctp;
88static struct vnode *savacctp;
89
90/*
91 * Values associated with enabling and disabling accounting
92 */
93static int acctsuspend = 2; /* stop accounting when < 2% free space left */
94SYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW,
95 &acctsuspend, 0, "percentage of free disk space below which accounting stops");
96
97static int acctresume = 4; /* resume when free space risen to > 4% */
98SYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW,
99 &acctresume, 0, "percentage of free disk space above which accounting resumes");
100
101static int acctchkfreq = 15; /* frequency (in seconds) to check space */
102SYSCTL_INT(_kern, OID_AUTO, acct_chkfreq, CTLFLAG_RW,
103 &acctchkfreq, 0, "frequency for checking the free space");
104
105/*
106 * Accounting system call. Written based on the specification and
107 * previous implementation done by Mark Tinguely.
108 */
109int
110acct(a1, uap)
111 struct proc *a1;
112 struct acct_args /* {
113 syscallarg(char *) path;
114 } */ *uap;
115{
116 struct proc *p = curproc; /* XXX */
117 struct nameidata nd;
118 int error, flags;
119
120 /* Make sure that the caller is root. */
121 error = suser(p);
122 if (error)
123 return (error);
124
125 /*
126 * If accounting is to be started to a file, open that file for
127 * writing and make sure it's a 'normal'.
128 */
129 if (SCARG(uap, path) != NULL) {
130 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path),
131 p);
132 flags = FWRITE;
133 error = vn_open(&nd, &flags, 0);
134 if (error)
135 return (error);
136 NDFREE(&nd, NDF_ONLY_PNBUF);
137 VOP_UNLOCK(nd.ni_vp, 0, p);
138 if (nd.ni_vp->v_type != VREG) {
139 vn_close(nd.ni_vp, FWRITE, p->p_ucred, p);
140 return (EACCES);
141 }
142 }
143
144 /*
145 * If accounting was previously enabled, kill the old space-watcher,
146 * close the file, and (if no new file was specified, leave).
147 */
148 if (acctp != NULLVP || savacctp != NULLVP) {
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151 untimeout(acctwatch, NULL, acctwatch_handle);
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| 149 callout_stop(&acctwatch_callout); |
150 error = vn_close((acctp != NULLVP ? acctp : savacctp), FWRITE,
151 p->p_ucred, p);
152 acctp = savacctp = NULLVP;
153 }
154 if (SCARG(uap, path) == NULL)
155 return (error);
156
157 /*
158 * Save the new accounting file vnode, and schedule the new
159 * free space watcher.
160 */
161 acctp = nd.ni_vp;
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| 162 callout_init(&acctwatch_callout, 0); |
163 acctwatch(NULL);
164 return (error);
165}
166
167/*
168 * Write out process accounting information, on process exit.
169 * Data to be written out is specified in Leffler, et al.
170 * and are enumerated below. (They're also noted in the system
171 * "acct.h" header file.)
172 */
173
174int
175acct_process(p)
176 struct proc *p;
177{
178 struct acct acct;
179 struct rusage *r;
180 struct timeval ut, st, tmp;
181 int t;
182 struct vnode *vp;
183
184 /* If accounting isn't enabled, don't bother */
185 vp = acctp;
186 if (vp == NULLVP)
187 return (0);
188
189 /*
190 * Get process accounting information.
191 */
192
193 /* (1) The name of the command that ran */
194 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm);
195
196 /* (2) The amount of user and system time that was used */
197 calcru(p, &ut, &st, NULL);
198 acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec);
199 acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec);
200
201 /* (3) The elapsed time the commmand ran (and its starting time) */
202 acct.ac_btime = p->p_stats->p_start.tv_sec;
203 microtime(&tmp);
204 timevalsub(&tmp, &p->p_stats->p_start);
205 acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec);
206
207 /* (4) The average amount of memory used */
208 r = &p->p_stats->p_ru;
209 tmp = ut;
210 timevaladd(&tmp, &st);
211 t = tmp.tv_sec * hz + tmp.tv_usec / tick;
212 if (t)
213 acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t;
214 else
215 acct.ac_mem = 0;
216
217 /* (5) The number of disk I/O operations done */
218 acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0);
219
220 /* (6) The UID and GID of the process */
221 acct.ac_uid = p->p_cred->p_ruid;
222 acct.ac_gid = p->p_cred->p_rgid;
223
224 /* (7) The terminal from which the process was started */
225 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp)
226 acct.ac_tty = dev2udev(p->p_pgrp->pg_session->s_ttyp->t_dev);
227 else
228 acct.ac_tty = NOUDEV;
229
230 /* (8) The boolean flags that tell how the process terminated, etc. */
231 acct.ac_flag = p->p_acflag;
232
233 /*
234 * Eliminate any file size rlimit.
235 */
236 if (p->p_limit->p_refcnt > 1 &&
237 (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
238 p->p_limit->p_refcnt--;
239 p->p_limit = limcopy(p->p_limit);
240 }
241 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
242
243 /*
244 * Write the accounting information to the file.
245 */
246 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
247 return (vn_rdwr(UIO_WRITE, vp, (caddr_t)&acct, sizeof (acct),
248 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred,
249 (int *)0, p));
250}
251
252/*
253 * Encode_comp_t converts from ticks in seconds and microseconds
254 * to ticks in 1/AHZ seconds. The encoding is described in
255 * Leffler, et al., on page 63.
256 */
257
258#define MANTSIZE 13 /* 13 bit mantissa. */
259#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
260#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
261
262static comp_t
263encode_comp_t(s, us)
264 u_long s, us;
265{
266 int exp, rnd;
267
268 exp = 0;
269 rnd = 0;
270 s *= AHZ;
271 s += us / (1000000 / AHZ); /* Maximize precision. */
272
273 while (s > MAXFRACT) {
274 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */
275 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
276 exp++;
277 }
278
279 /* If we need to round up, do it (and handle overflow correctly). */
280 if (rnd && (++s > MAXFRACT)) {
281 s >>= EXPSIZE;
282 exp++;
283 }
284
285 /* Clean it up and polish it off. */
286 exp <<= MANTSIZE; /* Shift the exponent into place */
287 exp += s; /* and add on the mantissa. */
288 return (exp);
289}
290
291/*
292 * Periodically check the file system to see if accounting
293 * should be turned on or off. Beware the case where the vnode
294 * has been vgone()'d out from underneath us, e.g. when the file
295 * system containing the accounting file has been forcibly unmounted.
296 */
297/* ARGSUSED */
298static void
299acctwatch(a)
300 void *a;
301{
302 struct statfs sb;
303
304 if (savacctp != NULLVP) {
305 if (savacctp->v_type == VBAD) {
306 (void) vn_close(savacctp, FWRITE, NOCRED, NULL);
307 savacctp = NULLVP;
308 return;
309 }
310 (void)VFS_STATFS(savacctp->v_mount, &sb, (struct proc *)0);
311 if (sb.f_bavail > acctresume * sb.f_blocks / 100) {
312 acctp = savacctp;
313 savacctp = NULLVP;
314 log(LOG_NOTICE, "Accounting resumed\n");
315 }
316 } else {
317 if (acctp == NULLVP)
318 return;
319 if (acctp->v_type == VBAD) {
320 (void) vn_close(acctp, FWRITE, NOCRED, NULL);
321 acctp = NULLVP;
322 return;
323 }
324 (void)VFS_STATFS(acctp->v_mount, &sb, (struct proc *)0);
325 if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) {
326 savacctp = acctp;
327 acctp = NULLVP;
328 log(LOG_NOTICE, "Accounting suspended\n");
329 }
330 }
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332 acctwatch_handle = timeout(acctwatch, NULL, acctchkfreq * hz);
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| 331 callout_reset(&acctwatch_callout, acctchkfreq * hz, acctwatch, NULL); |
332}
|