xref: /original-bsd/sys/ufs/ufs/ufs_quota.c (revision bc3affee)
1 /*
2  * Copyright (c) 1982, 1986, 1990, 1993, 1995
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Robert Elz at The University of Melbourne.
7  *
8  * %sccs.include.redist.c%
9  *
10  *	@(#)ufs_quota.c	8.5 (Berkeley) 05/20/95
11  */
12 #include <sys/param.h>
13 #include <sys/kernel.h>
14 #include <sys/systm.h>
15 #include <sys/namei.h>
16 #include <sys/malloc.h>
17 #include <sys/file.h>
18 #include <sys/proc.h>
19 #include <sys/vnode.h>
20 #include <sys/mount.h>
21 
22 #include <ufs/ufs/quota.h>
23 #include <ufs/ufs/inode.h>
24 #include <ufs/ufs/ufsmount.h>
25 #include <ufs/ufs/ufs_extern.h>
26 
27 /*
28  * Quota name to error message mapping.
29  */
30 static char *quotatypes[] = INITQFNAMES;
31 
32 /*
33  * Set up the quotas for an inode.
34  *
35  * This routine completely defines the semantics of quotas.
36  * If other criterion want to be used to establish quotas, the
37  * MAXQUOTAS value in quotas.h should be increased, and the
38  * additional dquots set up here.
39  */
40 int
getinoquota(ip)41 getinoquota(ip)
42 	register struct inode *ip;
43 {
44 	struct ufsmount *ump;
45 	struct vnode *vp = ITOV(ip);
46 	int error;
47 
48 	ump = VFSTOUFS(vp->v_mount);
49 	/*
50 	 * Set up the user quota based on file uid.
51 	 * EINVAL means that quotas are not enabled.
52 	 */
53 	if (ip->i_dquot[USRQUOTA] == NODQUOT &&
54 	    (error =
55 		dqget(vp, ip->i_uid, ump, USRQUOTA, &ip->i_dquot[USRQUOTA])) &&
56 	    error != EINVAL)
57 		return (error);
58 	/*
59 	 * Set up the group quota based on file gid.
60 	 * EINVAL means that quotas are not enabled.
61 	 */
62 	if (ip->i_dquot[GRPQUOTA] == NODQUOT &&
63 	    (error =
64 		dqget(vp, ip->i_gid, ump, GRPQUOTA, &ip->i_dquot[GRPQUOTA])) &&
65 	    error != EINVAL)
66 		return (error);
67 	return (0);
68 }
69 
70 /*
71  * Update disk usage, and take corrective action.
72  */
73 int
chkdq(ip,change,cred,flags)74 chkdq(ip, change, cred, flags)
75 	register struct inode *ip;
76 	long change;
77 	struct ucred *cred;
78 	int flags;
79 {
80 	register struct dquot *dq;
81 	register int i;
82 	int ncurblocks, error;
83 
84 #ifdef DIAGNOSTIC
85 	if ((flags & CHOWN) == 0)
86 		chkdquot(ip);
87 #endif
88 	if (change == 0)
89 		return (0);
90 	if (change < 0) {
91 		for (i = 0; i < MAXQUOTAS; i++) {
92 			if ((dq = ip->i_dquot[i]) == NODQUOT)
93 				continue;
94 			while (dq->dq_flags & DQ_LOCK) {
95 				dq->dq_flags |= DQ_WANT;
96 				sleep((caddr_t)dq, PINOD+1);
97 			}
98 			ncurblocks = dq->dq_curblocks + change;
99 			if (ncurblocks >= 0)
100 				dq->dq_curblocks = ncurblocks;
101 			else
102 				dq->dq_curblocks = 0;
103 			dq->dq_flags &= ~DQ_BLKS;
104 			dq->dq_flags |= DQ_MOD;
105 		}
106 		return (0);
107 	}
108 	if ((flags & FORCE) == 0 && cred->cr_uid != 0) {
109 		for (i = 0; i < MAXQUOTAS; i++) {
110 			if ((dq = ip->i_dquot[i]) == NODQUOT)
111 				continue;
112 			if (error = chkdqchg(ip, change, cred, i))
113 				return (error);
114 		}
115 	}
116 	for (i = 0; i < MAXQUOTAS; i++) {
117 		if ((dq = ip->i_dquot[i]) == NODQUOT)
118 			continue;
119 		while (dq->dq_flags & DQ_LOCK) {
120 			dq->dq_flags |= DQ_WANT;
121 			sleep((caddr_t)dq, PINOD+1);
122 		}
123 		dq->dq_curblocks += change;
124 		dq->dq_flags |= DQ_MOD;
125 	}
126 	return (0);
127 }
128 
129 /*
130  * Check for a valid change to a users allocation.
131  * Issue an error message if appropriate.
132  */
133 int
chkdqchg(ip,change,cred,type)134 chkdqchg(ip, change, cred, type)
135 	struct inode *ip;
136 	long change;
137 	struct ucred *cred;
138 	int type;
139 {
140 	register struct dquot *dq = ip->i_dquot[type];
141 	long ncurblocks = dq->dq_curblocks + change;
142 
143 	/*
144 	 * If user would exceed their hard limit, disallow space allocation.
145 	 */
146 	if (ncurblocks >= dq->dq_bhardlimit && dq->dq_bhardlimit) {
147 		if ((dq->dq_flags & DQ_BLKS) == 0 &&
148 		    ip->i_uid == cred->cr_uid) {
149 			uprintf("\n%s: write failed, %s disk limit reached\n",
150 			    ITOV(ip)->v_mount->mnt_stat.f_mntonname,
151 			    quotatypes[type]);
152 			dq->dq_flags |= DQ_BLKS;
153 		}
154 		return (EDQUOT);
155 	}
156 	/*
157 	 * If user is over their soft limit for too long, disallow space
158 	 * allocation. Reset time limit as they cross their soft limit.
159 	 */
160 	if (ncurblocks >= dq->dq_bsoftlimit && dq->dq_bsoftlimit) {
161 		if (dq->dq_curblocks < dq->dq_bsoftlimit) {
162 			dq->dq_btime = time.tv_sec +
163 			    VFSTOUFS(ITOV(ip)->v_mount)->um_btime[type];
164 			if (ip->i_uid == cred->cr_uid)
165 				uprintf("\n%s: warning, %s %s\n",
166 				    ITOV(ip)->v_mount->mnt_stat.f_mntonname,
167 				    quotatypes[type], "disk quota exceeded");
168 			return (0);
169 		}
170 		if (time.tv_sec > dq->dq_btime) {
171 			if ((dq->dq_flags & DQ_BLKS) == 0 &&
172 			    ip->i_uid == cred->cr_uid) {
173 				uprintf("\n%s: write failed, %s %s\n",
174 				    ITOV(ip)->v_mount->mnt_stat.f_mntonname,
175 				    quotatypes[type],
176 				    "disk quota exceeded for too long");
177 				dq->dq_flags |= DQ_BLKS;
178 			}
179 			return (EDQUOT);
180 		}
181 	}
182 	return (0);
183 }
184 
185 /*
186  * Check the inode limit, applying corrective action.
187  */
188 int
chkiq(ip,change,cred,flags)189 chkiq(ip, change, cred, flags)
190 	register struct inode *ip;
191 	long change;
192 	struct ucred *cred;
193 	int flags;
194 {
195 	register struct dquot *dq;
196 	register int i;
197 	int ncurinodes, error;
198 
199 #ifdef DIAGNOSTIC
200 	if ((flags & CHOWN) == 0)
201 		chkdquot(ip);
202 #endif
203 	if (change == 0)
204 		return (0);
205 	if (change < 0) {
206 		for (i = 0; i < MAXQUOTAS; i++) {
207 			if ((dq = ip->i_dquot[i]) == NODQUOT)
208 				continue;
209 			while (dq->dq_flags & DQ_LOCK) {
210 				dq->dq_flags |= DQ_WANT;
211 				sleep((caddr_t)dq, PINOD+1);
212 			}
213 			ncurinodes = dq->dq_curinodes + change;
214 			if (ncurinodes >= 0)
215 				dq->dq_curinodes = ncurinodes;
216 			else
217 				dq->dq_curinodes = 0;
218 			dq->dq_flags &= ~DQ_INODS;
219 			dq->dq_flags |= DQ_MOD;
220 		}
221 		return (0);
222 	}
223 	if ((flags & FORCE) == 0 && cred->cr_uid != 0) {
224 		for (i = 0; i < MAXQUOTAS; i++) {
225 			if ((dq = ip->i_dquot[i]) == NODQUOT)
226 				continue;
227 			if (error = chkiqchg(ip, change, cred, i))
228 				return (error);
229 		}
230 	}
231 	for (i = 0; i < MAXQUOTAS; i++) {
232 		if ((dq = ip->i_dquot[i]) == NODQUOT)
233 			continue;
234 		while (dq->dq_flags & DQ_LOCK) {
235 			dq->dq_flags |= DQ_WANT;
236 			sleep((caddr_t)dq, PINOD+1);
237 		}
238 		dq->dq_curinodes += change;
239 		dq->dq_flags |= DQ_MOD;
240 	}
241 	return (0);
242 }
243 
244 /*
245  * Check for a valid change to a users allocation.
246  * Issue an error message if appropriate.
247  */
248 int
chkiqchg(ip,change,cred,type)249 chkiqchg(ip, change, cred, type)
250 	struct inode *ip;
251 	long change;
252 	struct ucred *cred;
253 	int type;
254 {
255 	register struct dquot *dq = ip->i_dquot[type];
256 	long ncurinodes = dq->dq_curinodes + change;
257 
258 	/*
259 	 * If user would exceed their hard limit, disallow inode allocation.
260 	 */
261 	if (ncurinodes >= dq->dq_ihardlimit && dq->dq_ihardlimit) {
262 		if ((dq->dq_flags & DQ_INODS) == 0 &&
263 		    ip->i_uid == cred->cr_uid) {
264 			uprintf("\n%s: write failed, %s inode limit reached\n",
265 			    ITOV(ip)->v_mount->mnt_stat.f_mntonname,
266 			    quotatypes[type]);
267 			dq->dq_flags |= DQ_INODS;
268 		}
269 		return (EDQUOT);
270 	}
271 	/*
272 	 * If user is over their soft limit for too long, disallow inode
273 	 * allocation. Reset time limit as they cross their soft limit.
274 	 */
275 	if (ncurinodes >= dq->dq_isoftlimit && dq->dq_isoftlimit) {
276 		if (dq->dq_curinodes < dq->dq_isoftlimit) {
277 			dq->dq_itime = time.tv_sec +
278 			    VFSTOUFS(ITOV(ip)->v_mount)->um_itime[type];
279 			if (ip->i_uid == cred->cr_uid)
280 				uprintf("\n%s: warning, %s %s\n",
281 				    ITOV(ip)->v_mount->mnt_stat.f_mntonname,
282 				    quotatypes[type], "inode quota exceeded");
283 			return (0);
284 		}
285 		if (time.tv_sec > dq->dq_itime) {
286 			if ((dq->dq_flags & DQ_INODS) == 0 &&
287 			    ip->i_uid == cred->cr_uid) {
288 				uprintf("\n%s: write failed, %s %s\n",
289 				    ITOV(ip)->v_mount->mnt_stat.f_mntonname,
290 				    quotatypes[type],
291 				    "inode quota exceeded for too long");
292 				dq->dq_flags |= DQ_INODS;
293 			}
294 			return (EDQUOT);
295 		}
296 	}
297 	return (0);
298 }
299 
300 #ifdef DIAGNOSTIC
301 /*
302  * On filesystems with quotas enabled, it is an error for a file to change
303  * size and not to have a dquot structure associated with it.
304  */
305 void
chkdquot(ip)306 chkdquot(ip)
307 	register struct inode *ip;
308 {
309 	struct ufsmount *ump = VFSTOUFS(ITOV(ip)->v_mount);
310 	register int i;
311 
312 	for (i = 0; i < MAXQUOTAS; i++) {
313 		if (ump->um_quotas[i] == NULLVP ||
314 		    (ump->um_qflags[i] & (QTF_OPENING|QTF_CLOSING)))
315 			continue;
316 		if (ip->i_dquot[i] == NODQUOT) {
317 			vprint("chkdquot: missing dquot", ITOV(ip));
318 			panic("missing dquot");
319 		}
320 	}
321 }
322 #endif
323 
324 /*
325  * Code to process quotactl commands.
326  */
327 
328 /*
329  * Q_QUOTAON - set up a quota file for a particular file system.
330  */
331 int
quotaon(p,mp,type,fname)332 quotaon(p, mp, type, fname)
333 	struct proc *p;
334 	struct mount *mp;
335 	register int type;
336 	caddr_t fname;
337 {
338 	struct ufsmount *ump = VFSTOUFS(mp);
339 	struct vnode *vp, **vpp;
340 	struct vnode *nextvp;
341 	struct dquot *dq;
342 	int error;
343 	struct nameidata nd;
344 
345 	vpp = &ump->um_quotas[type];
346 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, fname, p);
347 	if (error = vn_open(&nd, FREAD|FWRITE, 0))
348 		return (error);
349 	vp = nd.ni_vp;
350 	VOP_UNLOCK(vp, 0, p);
351 	if (vp->v_type != VREG) {
352 		(void) vn_close(vp, FREAD|FWRITE, p->p_ucred, p);
353 		return (EACCES);
354 	}
355 	if (*vpp != vp)
356 		quotaoff(p, mp, type);
357 	ump->um_qflags[type] |= QTF_OPENING;
358 	mp->mnt_flag |= MNT_QUOTA;
359 	vp->v_flag |= VSYSTEM;
360 	*vpp = vp;
361 	/*
362 	 * Save the credential of the process that turned on quotas.
363 	 * Set up the time limits for this quota.
364 	 */
365 	crhold(p->p_ucred);
366 	ump->um_cred[type] = p->p_ucred;
367 	ump->um_btime[type] = MAX_DQ_TIME;
368 	ump->um_itime[type] = MAX_IQ_TIME;
369 	if (dqget(NULLVP, 0, ump, type, &dq) == 0) {
370 		if (dq->dq_btime > 0)
371 			ump->um_btime[type] = dq->dq_btime;
372 		if (dq->dq_itime > 0)
373 			ump->um_itime[type] = dq->dq_itime;
374 		dqrele(NULLVP, dq);
375 	}
376 	/*
377 	 * Search vnodes associated with this mount point,
378 	 * adding references to quota file being opened.
379 	 * NB: only need to add dquot's for inodes being modified.
380 	 */
381 again:
382 	for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nextvp) {
383 		nextvp = vp->v_mntvnodes.le_next;
384 		if (vp->v_writecount == 0)
385 			continue;
386 		if (vget(vp, LK_EXCLUSIVE, p))
387 			goto again;
388 		if (error = getinoquota(VTOI(vp))) {
389 			vput(vp);
390 			break;
391 		}
392 		vput(vp);
393 		if (vp->v_mntvnodes.le_next != nextvp || vp->v_mount != mp)
394 			goto again;
395 	}
396 	ump->um_qflags[type] &= ~QTF_OPENING;
397 	if (error)
398 		quotaoff(p, mp, type);
399 	return (error);
400 }
401 
402 /*
403  * Q_QUOTAOFF - turn off disk quotas for a filesystem.
404  */
405 int
quotaoff(p,mp,type)406 quotaoff(p, mp, type)
407 	struct proc *p;
408 	struct mount *mp;
409 	register int type;
410 {
411 	struct vnode *vp;
412 	struct vnode *qvp, *nextvp;
413 	struct ufsmount *ump = VFSTOUFS(mp);
414 	struct dquot *dq;
415 	struct inode *ip;
416 	int error;
417 
418 	if ((qvp = ump->um_quotas[type]) == NULLVP)
419 		return (0);
420 	ump->um_qflags[type] |= QTF_CLOSING;
421 	/*
422 	 * Search vnodes associated with this mount point,
423 	 * deleting any references to quota file being closed.
424 	 */
425 again:
426 	for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nextvp) {
427 		nextvp = vp->v_mntvnodes.le_next;
428 		if (vget(vp, LK_EXCLUSIVE, p))
429 			goto again;
430 		ip = VTOI(vp);
431 		dq = ip->i_dquot[type];
432 		ip->i_dquot[type] = NODQUOT;
433 		dqrele(vp, dq);
434 		vput(vp);
435 		if (vp->v_mntvnodes.le_next != nextvp || vp->v_mount != mp)
436 			goto again;
437 	}
438 	dqflush(qvp);
439 	qvp->v_flag &= ~VSYSTEM;
440 	error = vn_close(qvp, FREAD|FWRITE, p->p_ucred, p);
441 	ump->um_quotas[type] = NULLVP;
442 	crfree(ump->um_cred[type]);
443 	ump->um_cred[type] = NOCRED;
444 	ump->um_qflags[type] &= ~QTF_CLOSING;
445 	for (type = 0; type < MAXQUOTAS; type++)
446 		if (ump->um_quotas[type] != NULLVP)
447 			break;
448 	if (type == MAXQUOTAS)
449 		mp->mnt_flag &= ~MNT_QUOTA;
450 	return (error);
451 }
452 
453 /*
454  * Q_GETQUOTA - return current values in a dqblk structure.
455  */
456 int
getquota(mp,id,type,addr)457 getquota(mp, id, type, addr)
458 	struct mount *mp;
459 	u_long id;
460 	int type;
461 	caddr_t addr;
462 {
463 	struct dquot *dq;
464 	int error;
465 
466 	if (error = dqget(NULLVP, id, VFSTOUFS(mp), type, &dq))
467 		return (error);
468 	error = copyout((caddr_t)&dq->dq_dqb, addr, sizeof (struct dqblk));
469 	dqrele(NULLVP, dq);
470 	return (error);
471 }
472 
473 /*
474  * Q_SETQUOTA - assign an entire dqblk structure.
475  */
476 int
setquota(mp,id,type,addr)477 setquota(mp, id, type, addr)
478 	struct mount *mp;
479 	u_long id;
480 	int type;
481 	caddr_t addr;
482 {
483 	register struct dquot *dq;
484 	struct dquot *ndq;
485 	struct ufsmount *ump = VFSTOUFS(mp);
486 	struct dqblk newlim;
487 	int error;
488 
489 	if (error = copyin(addr, (caddr_t)&newlim, sizeof (struct dqblk)))
490 		return (error);
491 	if (error = dqget(NULLVP, id, ump, type, &ndq))
492 		return (error);
493 	dq = ndq;
494 	while (dq->dq_flags & DQ_LOCK) {
495 		dq->dq_flags |= DQ_WANT;
496 		sleep((caddr_t)dq, PINOD+1);
497 	}
498 	/*
499 	 * Copy all but the current values.
500 	 * Reset time limit if previously had no soft limit or were
501 	 * under it, but now have a soft limit and are over it.
502 	 */
503 	newlim.dqb_curblocks = dq->dq_curblocks;
504 	newlim.dqb_curinodes = dq->dq_curinodes;
505 	if (dq->dq_id != 0) {
506 		newlim.dqb_btime = dq->dq_btime;
507 		newlim.dqb_itime = dq->dq_itime;
508 	}
509 	if (newlim.dqb_bsoftlimit &&
510 	    dq->dq_curblocks >= newlim.dqb_bsoftlimit &&
511 	    (dq->dq_bsoftlimit == 0 || dq->dq_curblocks < dq->dq_bsoftlimit))
512 		newlim.dqb_btime = time.tv_sec + ump->um_btime[type];
513 	if (newlim.dqb_isoftlimit &&
514 	    dq->dq_curinodes >= newlim.dqb_isoftlimit &&
515 	    (dq->dq_isoftlimit == 0 || dq->dq_curinodes < dq->dq_isoftlimit))
516 		newlim.dqb_itime = time.tv_sec + ump->um_itime[type];
517 	dq->dq_dqb = newlim;
518 	if (dq->dq_curblocks < dq->dq_bsoftlimit)
519 		dq->dq_flags &= ~DQ_BLKS;
520 	if (dq->dq_curinodes < dq->dq_isoftlimit)
521 		dq->dq_flags &= ~DQ_INODS;
522 	if (dq->dq_isoftlimit == 0 && dq->dq_bsoftlimit == 0 &&
523 	    dq->dq_ihardlimit == 0 && dq->dq_bhardlimit == 0)
524 		dq->dq_flags |= DQ_FAKE;
525 	else
526 		dq->dq_flags &= ~DQ_FAKE;
527 	dq->dq_flags |= DQ_MOD;
528 	dqrele(NULLVP, dq);
529 	return (0);
530 }
531 
532 /*
533  * Q_SETUSE - set current inode and block usage.
534  */
535 int
setuse(mp,id,type,addr)536 setuse(mp, id, type, addr)
537 	struct mount *mp;
538 	u_long id;
539 	int type;
540 	caddr_t addr;
541 {
542 	register struct dquot *dq;
543 	struct ufsmount *ump = VFSTOUFS(mp);
544 	struct dquot *ndq;
545 	struct dqblk usage;
546 	int error;
547 
548 	if (error = copyin(addr, (caddr_t)&usage, sizeof (struct dqblk)))
549 		return (error);
550 	if (error = dqget(NULLVP, id, ump, type, &ndq))
551 		return (error);
552 	dq = ndq;
553 	while (dq->dq_flags & DQ_LOCK) {
554 		dq->dq_flags |= DQ_WANT;
555 		sleep((caddr_t)dq, PINOD+1);
556 	}
557 	/*
558 	 * Reset time limit if have a soft limit and were
559 	 * previously under it, but are now over it.
560 	 */
561 	if (dq->dq_bsoftlimit && dq->dq_curblocks < dq->dq_bsoftlimit &&
562 	    usage.dqb_curblocks >= dq->dq_bsoftlimit)
563 		dq->dq_btime = time.tv_sec + ump->um_btime[type];
564 	if (dq->dq_isoftlimit && dq->dq_curinodes < dq->dq_isoftlimit &&
565 	    usage.dqb_curinodes >= dq->dq_isoftlimit)
566 		dq->dq_itime = time.tv_sec + ump->um_itime[type];
567 	dq->dq_curblocks = usage.dqb_curblocks;
568 	dq->dq_curinodes = usage.dqb_curinodes;
569 	if (dq->dq_curblocks < dq->dq_bsoftlimit)
570 		dq->dq_flags &= ~DQ_BLKS;
571 	if (dq->dq_curinodes < dq->dq_isoftlimit)
572 		dq->dq_flags &= ~DQ_INODS;
573 	dq->dq_flags |= DQ_MOD;
574 	dqrele(NULLVP, dq);
575 	return (0);
576 }
577 
578 /*
579  * Q_SYNC - sync quota files to disk.
580  */
581 int
qsync(mp)582 qsync(mp)
583 	struct mount *mp;
584 {
585 	struct ufsmount *ump = VFSTOUFS(mp);
586 	struct proc *p = curproc;		/* XXX */
587 	struct vnode *vp, *nextvp;
588 	struct dquot *dq;
589 	int i, error;
590 
591 	/*
592 	 * Check if the mount point has any quotas.
593 	 * If not, simply return.
594 	 */
595 	for (i = 0; i < MAXQUOTAS; i++)
596 		if (ump->um_quotas[i] != NULLVP)
597 			break;
598 	if (i == MAXQUOTAS)
599 		return (0);
600 	/*
601 	 * Search vnodes associated with this mount point,
602 	 * synchronizing any modified dquot structures.
603 	 */
604 	simple_lock(&mntvnode_slock);
605 again:
606 	for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nextvp) {
607 		if (vp->v_mount != mp)
608 			goto again;
609 		nextvp = vp->v_mntvnodes.le_next;
610 		simple_lock(&vp->v_interlock);
611 		simple_unlock(&mntvnode_slock);
612 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, p);
613 		if (error) {
614 			simple_lock(&mntvnode_slock);
615 			if (error == ENOENT)
616 				goto again;
617 			continue;
618 		}
619 		for (i = 0; i < MAXQUOTAS; i++) {
620 			dq = VTOI(vp)->i_dquot[i];
621 			if (dq != NODQUOT && (dq->dq_flags & DQ_MOD))
622 				dqsync(vp, dq);
623 		}
624 		vput(vp);
625 		simple_lock(&mntvnode_slock);
626 		if (vp->v_mntvnodes.le_next != nextvp)
627 			goto again;
628 	}
629 	simple_unlock(&mntvnode_slock);
630 	return (0);
631 }
632 
633 /*
634  * Code pertaining to management of the in-core dquot data structures.
635  */
636 #define DQHASH(dqvp, id) \
637 	(&dqhashtbl[((((int)(dqvp)) >> 8) + id) & dqhash])
638 LIST_HEAD(dqhash, dquot) *dqhashtbl;
639 u_long dqhash;
640 
641 /*
642  * Dquot free list.
643  */
644 #define	DQUOTINC	5	/* minimum free dquots desired */
645 TAILQ_HEAD(dqfreelist, dquot) dqfreelist;
646 long numdquot, desireddquot = DQUOTINC;
647 
648 /*
649  * Initialize the quota system.
650  */
651 void
dqinit()652 dqinit()
653 {
654 
655 	dqhashtbl = hashinit(desiredvnodes, M_DQUOT, &dqhash);
656 	TAILQ_INIT(&dqfreelist);
657 }
658 
659 /*
660  * Obtain a dquot structure for the specified identifier and quota file
661  * reading the information from the file if necessary.
662  */
663 int
dqget(vp,id,ump,type,dqp)664 dqget(vp, id, ump, type, dqp)
665 	struct vnode *vp;
666 	u_long id;
667 	register struct ufsmount *ump;
668 	register int type;
669 	struct dquot **dqp;
670 {
671 	struct proc *p = curproc;		/* XXX */
672 	struct dquot *dq;
673 	struct dqhash *dqh;
674 	struct vnode *dqvp;
675 	struct iovec aiov;
676 	struct uio auio;
677 	int error;
678 
679 	dqvp = ump->um_quotas[type];
680 	if (dqvp == NULLVP || (ump->um_qflags[type] & QTF_CLOSING)) {
681 		*dqp = NODQUOT;
682 		return (EINVAL);
683 	}
684 	/*
685 	 * Check the cache first.
686 	 */
687 	dqh = DQHASH(dqvp, id);
688 	for (dq = dqh->lh_first; dq; dq = dq->dq_hash.le_next) {
689 		if (dq->dq_id != id ||
690 		    dq->dq_ump->um_quotas[dq->dq_type] != dqvp)
691 			continue;
692 		/*
693 		 * Cache hit with no references.  Take
694 		 * the structure off the free list.
695 		 */
696 		if (dq->dq_cnt == 0)
697 			TAILQ_REMOVE(&dqfreelist, dq, dq_freelist);
698 		DQREF(dq);
699 		*dqp = dq;
700 		return (0);
701 	}
702 	/*
703 	 * Not in cache, allocate a new one.
704 	 */
705 	if (dqfreelist.tqh_first == NODQUOT &&
706 	    numdquot < MAXQUOTAS * desiredvnodes)
707 		desireddquot += DQUOTINC;
708 	if (numdquot < desireddquot) {
709 		dq = (struct dquot *)malloc(sizeof *dq, M_DQUOT, M_WAITOK);
710 		bzero((char *)dq, sizeof *dq);
711 		numdquot++;
712 	} else {
713 		if ((dq = dqfreelist.tqh_first) == NULL) {
714 			tablefull("dquot");
715 			*dqp = NODQUOT;
716 			return (EUSERS);
717 		}
718 		if (dq->dq_cnt || (dq->dq_flags & DQ_MOD))
719 			panic("free dquot isn't");
720 		TAILQ_REMOVE(&dqfreelist, dq, dq_freelist);
721 		LIST_REMOVE(dq, dq_hash);
722 	}
723 	/*
724 	 * Initialize the contents of the dquot structure.
725 	 */
726 	if (vp != dqvp)
727 		vn_lock(dqvp, LK_EXCLUSIVE | LK_RETRY, p);
728 	LIST_INSERT_HEAD(dqh, dq, dq_hash);
729 	DQREF(dq);
730 	dq->dq_flags = DQ_LOCK;
731 	dq->dq_id = id;
732 	dq->dq_ump = ump;
733 	dq->dq_type = type;
734 	auio.uio_iov = &aiov;
735 	auio.uio_iovcnt = 1;
736 	aiov.iov_base = (caddr_t)&dq->dq_dqb;
737 	aiov.iov_len = sizeof (struct dqblk);
738 	auio.uio_resid = sizeof (struct dqblk);
739 	auio.uio_offset = (off_t)(id * sizeof (struct dqblk));
740 	auio.uio_segflg = UIO_SYSSPACE;
741 	auio.uio_rw = UIO_READ;
742 	auio.uio_procp = (struct proc *)0;
743 	error = VOP_READ(dqvp, &auio, 0, ump->um_cred[type]);
744 	if (auio.uio_resid == sizeof(struct dqblk) && error == 0)
745 		bzero((caddr_t)&dq->dq_dqb, sizeof(struct dqblk));
746 	if (vp != dqvp)
747 		VOP_UNLOCK(dqvp, 0, p);
748 	if (dq->dq_flags & DQ_WANT)
749 		wakeup((caddr_t)dq);
750 	dq->dq_flags = 0;
751 	/*
752 	 * I/O error in reading quota file, release
753 	 * quota structure and reflect problem to caller.
754 	 */
755 	if (error) {
756 		LIST_REMOVE(dq, dq_hash);
757 		dqrele(vp, dq);
758 		*dqp = NODQUOT;
759 		return (error);
760 	}
761 	/*
762 	 * Check for no limit to enforce.
763 	 * Initialize time values if necessary.
764 	 */
765 	if (dq->dq_isoftlimit == 0 && dq->dq_bsoftlimit == 0 &&
766 	    dq->dq_ihardlimit == 0 && dq->dq_bhardlimit == 0)
767 		dq->dq_flags |= DQ_FAKE;
768 	if (dq->dq_id != 0) {
769 		if (dq->dq_btime == 0)
770 			dq->dq_btime = time.tv_sec + ump->um_btime[type];
771 		if (dq->dq_itime == 0)
772 			dq->dq_itime = time.tv_sec + ump->um_itime[type];
773 	}
774 	*dqp = dq;
775 	return (0);
776 }
777 
778 /*
779  * Obtain a reference to a dquot.
780  */
781 void
dqref(dq)782 dqref(dq)
783 	struct dquot *dq;
784 {
785 
786 	dq->dq_cnt++;
787 }
788 
789 /*
790  * Release a reference to a dquot.
791  */
792 void
dqrele(vp,dq)793 dqrele(vp, dq)
794 	struct vnode *vp;
795 	register struct dquot *dq;
796 {
797 
798 	if (dq == NODQUOT)
799 		return;
800 	if (dq->dq_cnt > 1) {
801 		dq->dq_cnt--;
802 		return;
803 	}
804 	if (dq->dq_flags & DQ_MOD)
805 		(void) dqsync(vp, dq);
806 	if (--dq->dq_cnt > 0)
807 		return;
808 	TAILQ_INSERT_TAIL(&dqfreelist, dq, dq_freelist);
809 }
810 
811 /*
812  * Update the disk quota in the quota file.
813  */
814 int
dqsync(vp,dq)815 dqsync(vp, dq)
816 	struct vnode *vp;
817 	struct dquot *dq;
818 {
819 	struct proc *p = curproc;		/* XXX */
820 	struct vnode *dqvp;
821 	struct iovec aiov;
822 	struct uio auio;
823 	int error;
824 
825 	if (dq == NODQUOT)
826 		panic("dqsync: dquot");
827 	if ((dq->dq_flags & DQ_MOD) == 0)
828 		return (0);
829 	if ((dqvp = dq->dq_ump->um_quotas[dq->dq_type]) == NULLVP)
830 		panic("dqsync: file");
831 	if (vp != dqvp)
832 		vn_lock(dqvp, LK_EXCLUSIVE | LK_RETRY, p);
833 	while (dq->dq_flags & DQ_LOCK) {
834 		dq->dq_flags |= DQ_WANT;
835 		sleep((caddr_t)dq, PINOD+2);
836 		if ((dq->dq_flags & DQ_MOD) == 0) {
837 			if (vp != dqvp)
838 				VOP_UNLOCK(dqvp, 0, p);
839 			return (0);
840 		}
841 	}
842 	dq->dq_flags |= DQ_LOCK;
843 	auio.uio_iov = &aiov;
844 	auio.uio_iovcnt = 1;
845 	aiov.iov_base = (caddr_t)&dq->dq_dqb;
846 	aiov.iov_len = sizeof (struct dqblk);
847 	auio.uio_resid = sizeof (struct dqblk);
848 	auio.uio_offset = (off_t)(dq->dq_id * sizeof (struct dqblk));
849 	auio.uio_segflg = UIO_SYSSPACE;
850 	auio.uio_rw = UIO_WRITE;
851 	auio.uio_procp = (struct proc *)0;
852 	error = VOP_WRITE(dqvp, &auio, 0, dq->dq_ump->um_cred[dq->dq_type]);
853 	if (auio.uio_resid && error == 0)
854 		error = EIO;
855 	if (dq->dq_flags & DQ_WANT)
856 		wakeup((caddr_t)dq);
857 	dq->dq_flags &= ~(DQ_MOD|DQ_LOCK|DQ_WANT);
858 	if (vp != dqvp)
859 		VOP_UNLOCK(dqvp, 0, p);
860 	return (error);
861 }
862 
863 /*
864  * Flush all entries from the cache for a particular vnode.
865  */
866 void
dqflush(vp)867 dqflush(vp)
868 	register struct vnode *vp;
869 {
870 	register struct dquot *dq, *nextdq;
871 	struct dqhash *dqh;
872 
873 	/*
874 	 * Move all dquot's that used to refer to this quota
875 	 * file off their hash chains (they will eventually
876 	 * fall off the head of the free list and be re-used).
877 	 */
878 	for (dqh = &dqhashtbl[dqhash]; dqh >= dqhashtbl; dqh--) {
879 		for (dq = dqh->lh_first; dq; dq = nextdq) {
880 			nextdq = dq->dq_hash.le_next;
881 			if (dq->dq_ump->um_quotas[dq->dq_type] != vp)
882 				continue;
883 			if (dq->dq_cnt)
884 				panic("dqflush: stray dquot");
885 			LIST_REMOVE(dq, dq_hash);
886 			dq->dq_ump = (struct ufsmount *)0;
887 		}
888 	}
889 }
890