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.
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21 * This product includes software developed by the University of
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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 1.8 2003/09/29 18:52:06 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/namei.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_handle acctwatch_handle
86 = CALLOUT_HANDLE_INITIALIZER(&acctwatch_handle);
89 * Accounting vnode pointer, and saved vnode pointer.
91 static struct vnode *acctp;
92 static struct vnode *savacctp;
95 * Values associated with enabling and disabling accounting
97 static int acctsuspend = 2; /* stop accounting when < 2% free space left */
98 SYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW,
101 static int acctresume = 4; /* resume when free space risen to > 4% */
102 SYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW,
105 static int acctchkfreq = 15; /* frequency (in seconds) to check space */
106 SYSCTL_INT(_kern, OID_AUTO, acct_chkfreq, CTLFLAG_RW,
107 &acctchkfreq, 0, "");
110 * Accounting system call. Written based on the specification and
111 * previous implementation done by Mark Tinguely.
115 struct acct_args /* {
116 syscallarg(char *) path;
119 struct thread *td = curthread;
123 /* Make sure that the caller is root. */
129 * If accounting is to be started to a file, open that file for
130 * appending and make sure it's a 'normal'.
132 if (SCARG(uap, path) != NULL) {
133 NDINIT(&nd, NAMEI_LOOKUP, 0, UIO_USERSPACE,
134 SCARG(uap, path), td);
135 error = vn_open(&nd, FWRITE | O_APPEND, 0);
138 NDFREE(&nd, NDF_ONLY_PNBUF);
139 VOP_UNLOCK(nd.ni_vp, 0, td);
140 if (nd.ni_vp->v_type != VREG) {
141 vn_close(nd.ni_vp, FWRITE | O_APPEND, td);
147 * If accounting was previously enabled, kill the old space-watcher,
148 * close the file, and (if no new file was specified, leave).
150 if (acctp != NULLVP || savacctp != NULLVP) {
151 untimeout(acctwatch, NULL, acctwatch_handle);
152 error = vn_close((acctp != NULLVP ? acctp : savacctp),
153 FWRITE | O_APPEND, td);
154 acctp = savacctp = NULLVP;
156 if (SCARG(uap, path) == NULL)
160 * Save the new accounting file vnode, and schedule the new
161 * free space watcher.
169 * Write out process accounting information, on process exit.
170 * Data to be written out is specified in Leffler, et al.
171 * and are enumerated below. (They're also noted in the system
172 * "acct.h" header file.)
176 acct_process(struct proc *p)
180 struct timeval ut, st, tmp;
183 struct thread *td = p->p_thread;
185 /* If accounting isn't enabled, don't bother */
191 * Get process accounting information.
194 /* (1) The name of the command that ran */
195 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm);
197 /* (2) The amount of user and system time that was used */
198 calcru(p, &ut, &st, NULL);
199 acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec);
200 acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec);
202 /* (3) The elapsed time the commmand ran (and its starting time) */
203 acct.ac_btime = p->p_stats->p_start.tv_sec;
205 timevalsub(&tmp, &p->p_stats->p_start);
206 acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec);
208 /* (4) The average amount of memory used */
209 r = &p->p_stats->p_ru;
211 timevaladd(&tmp, &st);
212 t = tmp.tv_sec * hz + tmp.tv_usec / tick;
214 acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t;
218 /* (5) The number of disk I/O operations done */
219 acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0);
221 /* (6) The UID and GID of the process */
222 acct.ac_uid = p->p_ucred->cr_ruid;
223 acct.ac_gid = p->p_ucred->cr_rgid;
225 /* (7) The terminal from which the process was started */
226 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp)
227 acct.ac_tty = dev2udev(p->p_pgrp->pg_session->s_ttyp->t_dev);
229 acct.ac_tty = NOUDEV;
231 /* (8) The boolean flags that tell how the process terminated, etc. */
232 acct.ac_flag = p->p_acflag;
235 * Eliminate any file size rlimit.
237 if (p->p_limit->p_refcnt > 1 &&
238 (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
239 p->p_limit->p_refcnt--;
240 p->p_limit = limcopy(p->p_limit);
242 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
245 * Write the accounting information to the file.
247 VOP_LEASE(vp, td, p->p_ucred, LEASE_WRITE);
248 return (vn_rdwr(UIO_WRITE, vp, (caddr_t)&acct, sizeof (acct),
249 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred,
254 * Encode_comp_t converts from ticks in seconds and microseconds
255 * to ticks in 1/AHZ seconds. The encoding is described in
256 * Leffler, et al., on page 63.
259 #define MANTSIZE 13 /* 13 bit mantissa. */
260 #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
261 #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
272 s += us / (1000000 / AHZ); /* Maximize precision. */
274 while (s > MAXFRACT) {
275 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */
276 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
280 /* If we need to round up, do it (and handle overflow correctly). */
281 if (rnd && (++s > MAXFRACT)) {
286 /* Clean it up and polish it off. */
287 exp <<= MANTSIZE; /* Shift the exponent into place */
288 exp += s; /* and add on the mantissa. */
293 * Periodically check the file system to see if accounting
294 * should be turned on or off. Beware the case where the vnode
295 * has been vgone()'d out from underneath us, e.g. when the file
296 * system containing the accounting file has been forcibly unmounted.
305 if (savacctp != NULLVP) {
306 if (savacctp->v_type == VBAD) {
307 (void) vn_close(savacctp, FWRITE | O_APPEND, NULL);
311 (void)VFS_STATFS(savacctp->v_mount, &sb, NULL);
312 if (sb.f_bavail > acctresume * sb.f_blocks / 100) {
315 log(LOG_NOTICE, "Accounting resumed\n");
320 if (acctp->v_type == VBAD) {
321 (void) vn_close(acctp, FWRITE | O_APPEND, NULL);
325 (void)VFS_STATFS(acctp->v_mount, &sb, NULL);
326 if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) {
329 log(LOG_NOTICE, "Accounting suspended\n");
332 acctwatch_handle = timeout(acctwatch, NULL, acctchkfreq * hz);