1 | /* |
2 | * Copyright (c) 2002-2006 Apple Computer, Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | /* |
29 | * Copyright (c) 1982, 1986, 1990, 1993, 1995 |
30 | * The Regents of the University of California. All rights reserved. |
31 | * |
32 | * This code is derived from software contributed to Berkeley by |
33 | * Robert Elz at The University of Melbourne. |
34 | * |
35 | * Redistribution and use in source and binary forms, with or without |
36 | * modification, are permitted provided that the following conditions |
37 | * are met: |
38 | * 1. Redistributions of source code must retain the above copyright |
39 | * notice, this list of conditions and the following disclaimer. |
40 | * 2. Redistributions in binary form must reproduce the above copyright |
41 | * notice, this list of conditions and the following disclaimer in the |
42 | * documentation and/or other materials provided with the distribution. |
43 | * 3. All advertising materials mentioning features or use of this software |
44 | * must display the following acknowledgement: |
45 | * This product includes software developed by the University of |
46 | * California, Berkeley and its contributors. |
47 | * 4. Neither the name of the University nor the names of its contributors |
48 | * may be used to endorse or promote products derived from this software |
49 | * without specific prior written permission. |
50 | * |
51 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
52 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
53 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
54 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
55 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
56 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
57 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
58 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
59 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
60 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
61 | * SUCH DAMAGE. |
62 | * |
63 | * @(#)vfs_quota.c |
64 | * derived from @(#)ufs_quota.c 8.5 (Berkeley) 5/20/95 |
65 | */ |
66 | |
67 | #include <sys/param.h> |
68 | #include <sys/kernel.h> |
69 | #include <sys/systm.h> |
70 | #include <sys/malloc.h> |
71 | #include <sys/file_internal.h> |
72 | #include <sys/proc_internal.h> |
73 | #include <sys/vnode_internal.h> |
74 | #include <sys/mount_internal.h> |
75 | #include <sys/quota.h> |
76 | #include <sys/uio_internal.h> |
77 | |
78 | #include <libkern/OSByteOrder.h> |
79 | |
80 | |
81 | /* vars for quota file lock */ |
82 | lck_grp_t * qf_lck_grp; |
83 | lck_grp_attr_t * qf_lck_grp_attr; |
84 | lck_attr_t * qf_lck_attr; |
85 | |
86 | /* vars for quota list lock */ |
87 | lck_grp_t * quota_list_lck_grp; |
88 | lck_grp_attr_t * quota_list_lck_grp_attr; |
89 | lck_attr_t * quota_list_lck_attr; |
90 | lck_mtx_t * quota_list_mtx_lock; |
91 | |
92 | /* Routines to lock and unlock the quota global data */ |
93 | static int dq_list_lock(void); |
94 | static void dq_list_unlock(void); |
95 | |
96 | static void dq_lock_internal(struct dquot *dq); |
97 | static void dq_unlock_internal(struct dquot *dq); |
98 | |
99 | static u_int32_t quotamagic[MAXQUOTAS] = INITQMAGICS; |
100 | |
101 | |
102 | /* |
103 | * Code pertaining to management of the in-core dquot data structures. |
104 | */ |
105 | #define DQHASH(dqvp, id) \ |
106 | (&dqhashtbl[((((intptr_t)(dqvp)) >> 8) + id) & dqhash]) |
107 | LIST_HEAD(dqhash, dquot) *dqhashtbl; |
108 | u_long dqhash; |
109 | |
110 | #define DQUOTINC 5 /* minimum free dquots desired */ |
111 | long numdquot, desireddquot = DQUOTINC; |
112 | |
113 | /* |
114 | * Dquot free list. |
115 | */ |
116 | TAILQ_HEAD(dqfreelist, dquot) dqfreelist; |
117 | /* |
118 | * Dquot dirty orphans list |
119 | */ |
120 | TAILQ_HEAD(dqdirtylist, dquot) dqdirtylist; |
121 | |
122 | |
123 | static int dqlookup(struct quotafile *, u_int32_t, struct dqblk *, u_int32_t *); |
124 | static int dqsync_locked(struct dquot *dq); |
125 | |
126 | static void qf_lock(struct quotafile *); |
127 | static void qf_unlock(struct quotafile *); |
128 | static int qf_ref(struct quotafile *); |
129 | static void qf_rele(struct quotafile *); |
130 | |
131 | |
132 | /* |
133 | * Initialize locks for the quota system. |
134 | */ |
135 | void |
136 | dqinit(void) |
137 | { |
138 | /* |
139 | * Allocate quota list lock group attribute and group |
140 | */ |
141 | quota_list_lck_grp_attr= lck_grp_attr_alloc_init(); |
142 | quota_list_lck_grp = lck_grp_alloc_init("quota list" , quota_list_lck_grp_attr); |
143 | |
144 | /* |
145 | * Allocate qouta list lock attribute |
146 | */ |
147 | quota_list_lck_attr = lck_attr_alloc_init(); |
148 | |
149 | /* |
150 | * Allocate quota list lock |
151 | */ |
152 | quota_list_mtx_lock = lck_mtx_alloc_init(quota_list_lck_grp, quota_list_lck_attr); |
153 | |
154 | |
155 | /* |
156 | * allocate quota file lock group attribute and group |
157 | */ |
158 | qf_lck_grp_attr= lck_grp_attr_alloc_init(); |
159 | qf_lck_grp = lck_grp_alloc_init("quota file" , qf_lck_grp_attr); |
160 | |
161 | /* |
162 | * Allocate quota file lock attribute |
163 | */ |
164 | qf_lck_attr = lck_attr_alloc_init(); |
165 | } |
166 | |
167 | /* |
168 | * Report whether dqhashinit has been run. |
169 | */ |
170 | int |
171 | dqisinitialized(void) |
172 | { |
173 | return (dqhashtbl != NULL); |
174 | } |
175 | |
176 | /* |
177 | * Initialize hash table for dquot structures. |
178 | */ |
179 | void |
180 | dqhashinit(void) |
181 | { |
182 | dq_list_lock(); |
183 | if (dqisinitialized()) |
184 | goto out; |
185 | |
186 | TAILQ_INIT(&dqfreelist); |
187 | TAILQ_INIT(&dqdirtylist); |
188 | dqhashtbl = hashinit(desiredvnodes, M_DQUOT, &dqhash); |
189 | out: |
190 | dq_list_unlock(); |
191 | } |
192 | |
193 | |
194 | static volatile int dq_list_lock_cnt = 0; |
195 | |
196 | static int |
197 | dq_list_lock(void) |
198 | { |
199 | lck_mtx_lock(quota_list_mtx_lock); |
200 | return ++dq_list_lock_cnt; |
201 | } |
202 | |
203 | static int |
204 | dq_list_lock_changed(int oldval) { |
205 | return (dq_list_lock_cnt != oldval); |
206 | } |
207 | |
208 | static int |
209 | dq_list_lock_val(void) { |
210 | return dq_list_lock_cnt; |
211 | } |
212 | |
213 | void |
214 | dq_list_unlock(void) |
215 | { |
216 | lck_mtx_unlock(quota_list_mtx_lock); |
217 | } |
218 | |
219 | |
220 | /* |
221 | * must be called with the quota_list_lock held |
222 | */ |
223 | void |
224 | dq_lock_internal(struct dquot *dq) |
225 | { |
226 | while (dq->dq_lflags & DQ_LLOCK) { |
227 | dq->dq_lflags |= DQ_LWANT; |
228 | msleep(&dq->dq_lflags, quota_list_mtx_lock, PVFS, "dq_lock_internal" , NULL); |
229 | } |
230 | dq->dq_lflags |= DQ_LLOCK; |
231 | } |
232 | |
233 | /* |
234 | * must be called with the quota_list_lock held |
235 | */ |
236 | void |
237 | dq_unlock_internal(struct dquot *dq) |
238 | { |
239 | int wanted = dq->dq_lflags & DQ_LWANT; |
240 | |
241 | dq->dq_lflags &= ~(DQ_LLOCK | DQ_LWANT); |
242 | |
243 | if (wanted) |
244 | wakeup(&dq->dq_lflags); |
245 | } |
246 | |
247 | void |
248 | dqlock(struct dquot *dq) { |
249 | |
250 | lck_mtx_lock(quota_list_mtx_lock); |
251 | |
252 | dq_lock_internal(dq); |
253 | |
254 | lck_mtx_unlock(quota_list_mtx_lock); |
255 | } |
256 | |
257 | void |
258 | dqunlock(struct dquot *dq) { |
259 | |
260 | lck_mtx_lock(quota_list_mtx_lock); |
261 | |
262 | dq_unlock_internal(dq); |
263 | |
264 | lck_mtx_unlock(quota_list_mtx_lock); |
265 | } |
266 | |
267 | |
268 | |
269 | int |
270 | qf_get(struct quotafile *qfp, int type) |
271 | { |
272 | int error = 0; |
273 | |
274 | dq_list_lock(); |
275 | |
276 | switch (type) { |
277 | |
278 | case QTF_OPENING: |
279 | while ( (qfp->qf_qflags & (QTF_OPENING | QTF_CLOSING)) ) { |
280 | if ( (qfp->qf_qflags & QTF_OPENING) ) { |
281 | error = EBUSY; |
282 | break; |
283 | } |
284 | if ( (qfp->qf_qflags & QTF_CLOSING) ) { |
285 | qfp->qf_qflags |= QTF_WANTED; |
286 | msleep(&qfp->qf_qflags, quota_list_mtx_lock, PVFS, "qf_get" , NULL); |
287 | } |
288 | } |
289 | if (qfp->qf_vp != NULLVP) |
290 | error = EBUSY; |
291 | if (error == 0) |
292 | qfp->qf_qflags |= QTF_OPENING; |
293 | break; |
294 | |
295 | case QTF_CLOSING: |
296 | if ( (qfp->qf_qflags & QTF_CLOSING) ) { |
297 | error = EBUSY; |
298 | break; |
299 | } |
300 | qfp->qf_qflags |= QTF_CLOSING; |
301 | |
302 | while ( (qfp->qf_qflags & QTF_OPENING) || qfp->qf_refcnt ) { |
303 | qfp->qf_qflags |= QTF_WANTED; |
304 | msleep(&qfp->qf_qflags, quota_list_mtx_lock, PVFS, "qf_get" , NULL); |
305 | } |
306 | if (qfp->qf_vp == NULLVP) { |
307 | qfp->qf_qflags &= ~QTF_CLOSING; |
308 | error = EBUSY; |
309 | } |
310 | break; |
311 | } |
312 | dq_list_unlock(); |
313 | |
314 | return (error); |
315 | } |
316 | |
317 | void |
318 | qf_put(struct quotafile *qfp, int type) |
319 | { |
320 | |
321 | dq_list_lock(); |
322 | |
323 | switch (type) { |
324 | |
325 | case QTF_OPENING: |
326 | case QTF_CLOSING: |
327 | qfp->qf_qflags &= ~type; |
328 | break; |
329 | } |
330 | if ( (qfp->qf_qflags & QTF_WANTED) ) { |
331 | qfp->qf_qflags &= ~QTF_WANTED; |
332 | wakeup(&qfp->qf_qflags); |
333 | } |
334 | dq_list_unlock(); |
335 | } |
336 | |
337 | |
338 | static void |
339 | qf_lock(struct quotafile *qfp) |
340 | { |
341 | lck_mtx_lock(&qfp->qf_lock); |
342 | } |
343 | |
344 | static void |
345 | qf_unlock(struct quotafile *qfp) |
346 | { |
347 | lck_mtx_unlock(&qfp->qf_lock); |
348 | } |
349 | |
350 | |
351 | /* |
352 | * take a reference on the quota file while we're |
353 | * in dqget... this will prevent a quota_off from |
354 | * occurring while we're potentially playing with |
355 | * the quota file... the quota_off will stall until |
356 | * all the current references 'die'... once we start |
357 | * into quoto_off, all new references will be rejected |
358 | * we also don't want any dqgets being processed while |
359 | * we're in the middle of the quota_on... once we've |
360 | * actually got the quota file open and the associated |
361 | * struct quotafile inited, we can let them come through |
362 | * |
363 | * quota list lock must be held on entry |
364 | */ |
365 | static int |
366 | qf_ref(struct quotafile *qfp) |
367 | { |
368 | int error = 0; |
369 | |
370 | if ( (qfp->qf_qflags & (QTF_OPENING | QTF_CLOSING)) || (qfp->qf_vp == NULLVP) ) |
371 | error = EINVAL; |
372 | else |
373 | qfp->qf_refcnt++; |
374 | |
375 | return (error); |
376 | } |
377 | |
378 | /* |
379 | * drop our reference and wakeup any waiters if |
380 | * we were the last one holding a ref |
381 | * |
382 | * quota list lock must be held on entry |
383 | */ |
384 | static void |
385 | qf_rele(struct quotafile *qfp) |
386 | { |
387 | qfp->qf_refcnt--; |
388 | |
389 | if ( (qfp->qf_qflags & QTF_WANTED) && qfp->qf_refcnt == 0) { |
390 | qfp->qf_qflags &= ~QTF_WANTED; |
391 | wakeup(&qfp->qf_qflags); |
392 | } |
393 | } |
394 | |
395 | |
396 | void |
397 | dqfileinit(struct quotafile *qfp) |
398 | { |
399 | qfp->qf_vp = NULLVP; |
400 | qfp->qf_qflags = 0; |
401 | |
402 | lck_mtx_init(&qfp->qf_lock, qf_lck_grp, qf_lck_attr); |
403 | } |
404 | |
405 | |
406 | /* |
407 | * Initialize a quota file |
408 | * |
409 | * must be called with the quota file lock held |
410 | */ |
411 | int |
412 | dqfileopen(struct quotafile *qfp, int type) |
413 | { |
414 | struct dqfilehdr ; |
415 | struct vfs_context context; |
416 | off_t file_size; |
417 | uio_t auio; |
418 | int error = 0; |
419 | char uio_buf[ UIO_SIZEOF(1) ]; |
420 | |
421 | context.vc_thread = current_thread(); |
422 | context.vc_ucred = qfp->qf_cred; |
423 | |
424 | /* Obtain the file size */ |
425 | if ((error = vnode_size(qfp->qf_vp, &file_size, &context)) != 0) |
426 | goto out; |
427 | |
428 | /* Read the file header */ |
429 | auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_READ, |
430 | &uio_buf[0], sizeof(uio_buf)); |
431 | uio_addiov(auio, CAST_USER_ADDR_T(&header), sizeof (header)); |
432 | error = VNOP_READ(qfp->qf_vp, auio, 0, &context); |
433 | if (error) |
434 | goto out; |
435 | else if (uio_resid(auio)) { |
436 | error = EINVAL; |
437 | goto out; |
438 | } |
439 | /* Sanity check the quota file header. */ |
440 | if ((OSSwapBigToHostInt32(header.dqh_magic) != quotamagic[type]) || |
441 | (OSSwapBigToHostInt32(header.dqh_version) > QF_VERSION) || |
442 | (!powerof2(OSSwapBigToHostInt32(header.dqh_maxentries))) || |
443 | (OSSwapBigToHostInt32(header.dqh_maxentries) > (file_size / sizeof(struct dqblk)))) { |
444 | error = EINVAL; |
445 | goto out; |
446 | } |
447 | /* Set up the time limits for this quota. */ |
448 | if (header.dqh_btime != 0) |
449 | qfp->qf_btime = OSSwapBigToHostInt32(header.dqh_btime); |
450 | else |
451 | qfp->qf_btime = MAX_DQ_TIME; |
452 | if (header.dqh_itime != 0) |
453 | qfp->qf_itime = OSSwapBigToHostInt32(header.dqh_itime); |
454 | else |
455 | qfp->qf_itime = MAX_IQ_TIME; |
456 | |
457 | /* Calculate the hash table constants. */ |
458 | qfp->qf_maxentries = OSSwapBigToHostInt32(header.dqh_maxentries); |
459 | qfp->qf_entrycnt = OSSwapBigToHostInt32(header.dqh_entrycnt); |
460 | qfp->qf_shift = dqhashshift(qfp->qf_maxentries); |
461 | out: |
462 | return (error); |
463 | } |
464 | |
465 | /* |
466 | * Close down a quota file |
467 | */ |
468 | void |
469 | dqfileclose(struct quotafile *qfp, __unused int type) |
470 | { |
471 | struct dqfilehdr ; |
472 | struct vfs_context context; |
473 | uio_t auio; |
474 | char uio_buf[ UIO_SIZEOF(1) ]; |
475 | |
476 | auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_READ, |
477 | &uio_buf[0], sizeof(uio_buf)); |
478 | uio_addiov(auio, CAST_USER_ADDR_T(&header), sizeof (header)); |
479 | |
480 | context.vc_thread = current_thread(); |
481 | context.vc_ucred = qfp->qf_cred; |
482 | |
483 | if (VNOP_READ(qfp->qf_vp, auio, 0, &context) == 0) { |
484 | header.dqh_entrycnt = OSSwapHostToBigInt32(qfp->qf_entrycnt); |
485 | uio_reset(auio, 0, UIO_SYSSPACE, UIO_WRITE); |
486 | uio_addiov(auio, CAST_USER_ADDR_T(&header), sizeof (header)); |
487 | (void) VNOP_WRITE(qfp->qf_vp, auio, 0, &context); |
488 | } |
489 | } |
490 | |
491 | |
492 | /* |
493 | * Obtain a dquot structure for the specified identifier and quota file |
494 | * reading the information from the file if necessary. |
495 | */ |
496 | int |
497 | dqget(u_int32_t id, struct quotafile *qfp, int type, struct dquot **dqp) |
498 | { |
499 | struct dquot *dq; |
500 | struct dquot *ndq = NULL; |
501 | struct dquot *fdq = NULL; |
502 | struct dqhash *dqh; |
503 | struct vnode *dqvp; |
504 | int error = 0; |
505 | int listlockval = 0; |
506 | |
507 | if (!dqisinitialized()) { |
508 | *dqp = NODQUOT; |
509 | return (EINVAL); |
510 | } |
511 | |
512 | if ( id == 0 || qfp->qf_vp == NULLVP ) { |
513 | *dqp = NODQUOT; |
514 | return (EINVAL); |
515 | } |
516 | dq_list_lock(); |
517 | |
518 | if ( (qf_ref(qfp)) ) { |
519 | dq_list_unlock(); |
520 | |
521 | *dqp = NODQUOT; |
522 | return (EINVAL); |
523 | } |
524 | if ( (dqvp = qfp->qf_vp) == NULLVP ) { |
525 | qf_rele(qfp); |
526 | dq_list_unlock(); |
527 | |
528 | *dqp = NODQUOT; |
529 | return (EINVAL); |
530 | } |
531 | dqh = DQHASH(dqvp, id); |
532 | |
533 | relookup: |
534 | listlockval = dq_list_lock_val(); |
535 | |
536 | /* |
537 | * Check the cache first. |
538 | */ |
539 | for (dq = dqh->lh_first; dq; dq = dq->dq_hash.le_next) { |
540 | if (dq->dq_id != id || |
541 | dq->dq_qfile->qf_vp != dqvp) |
542 | continue; |
543 | |
544 | dq_lock_internal(dq); |
545 | if (dq_list_lock_changed(listlockval)) { |
546 | dq_unlock_internal(dq); |
547 | goto relookup; |
548 | } |
549 | |
550 | /* |
551 | * dq_lock_internal may drop the quota_list_lock to msleep, so |
552 | * we need to re-evaluate the identity of this dq |
553 | */ |
554 | if (dq->dq_id != id || dq->dq_qfile == NULL || |
555 | dq->dq_qfile->qf_vp != dqvp) { |
556 | dq_unlock_internal(dq); |
557 | goto relookup; |
558 | } |
559 | /* |
560 | * Cache hit with no references. Take |
561 | * the structure off the free list. |
562 | */ |
563 | if (dq->dq_cnt++ == 0) { |
564 | if (dq->dq_flags & DQ_MOD) |
565 | TAILQ_REMOVE(&dqdirtylist, dq, dq_freelist); |
566 | else |
567 | TAILQ_REMOVE(&dqfreelist, dq, dq_freelist); |
568 | } |
569 | dq_unlock_internal(dq); |
570 | |
571 | if (fdq != NULL) { |
572 | /* |
573 | * we grabbed this from the free list in the first pass |
574 | * but we found the dq we were looking for in |
575 | * the cache the 2nd time through |
576 | * so stick it back on the free list and return the cached entry |
577 | */ |
578 | TAILQ_INSERT_HEAD(&dqfreelist, fdq, dq_freelist); |
579 | } |
580 | qf_rele(qfp); |
581 | dq_list_unlock(); |
582 | |
583 | if (ndq != NULL) { |
584 | /* |
585 | * we allocated this in the first pass |
586 | * but we found the dq we were looking for in |
587 | * the cache the 2nd time through so free it |
588 | */ |
589 | _FREE(ndq, M_DQUOT); |
590 | } |
591 | *dqp = dq; |
592 | |
593 | return (0); |
594 | } |
595 | /* |
596 | * Not in cache, allocate a new one. |
597 | */ |
598 | if (TAILQ_EMPTY(&dqfreelist) && |
599 | numdquot < MAXQUOTAS * desiredvnodes) |
600 | desireddquot += DQUOTINC; |
601 | |
602 | if (fdq != NULL) { |
603 | /* |
604 | * we captured this from the free list |
605 | * in the first pass through, so go |
606 | * ahead and use it |
607 | */ |
608 | dq = fdq; |
609 | fdq = NULL; |
610 | } else if (numdquot < desireddquot) { |
611 | if (ndq == NULL) { |
612 | /* |
613 | * drop the quota list lock since MALLOC may block |
614 | */ |
615 | dq_list_unlock(); |
616 | |
617 | ndq = (struct dquot *)_MALLOC(sizeof *dq, M_DQUOT, M_WAITOK); |
618 | bzero((char *)ndq, sizeof *dq); |
619 | |
620 | listlockval = dq_list_lock(); |
621 | /* |
622 | * need to look for the entry again in the cache |
623 | * since we dropped the quota list lock and |
624 | * someone else may have beaten us to creating it |
625 | */ |
626 | goto relookup; |
627 | } else { |
628 | /* |
629 | * we allocated this in the first pass through |
630 | * and we're still under out target, so go |
631 | * ahead and use it |
632 | */ |
633 | dq = ndq; |
634 | ndq = NULL; |
635 | numdquot++; |
636 | } |
637 | } else { |
638 | if (TAILQ_EMPTY(&dqfreelist)) { |
639 | qf_rele(qfp); |
640 | dq_list_unlock(); |
641 | |
642 | if (ndq) { |
643 | /* |
644 | * we allocated this in the first pass through |
645 | * but we're now at the limit of our cache size |
646 | * so free it |
647 | */ |
648 | _FREE(ndq, M_DQUOT); |
649 | } |
650 | tablefull("dquot" ); |
651 | *dqp = NODQUOT; |
652 | return (EUSERS); |
653 | } |
654 | dq = TAILQ_FIRST(&dqfreelist); |
655 | |
656 | dq_lock_internal(dq); |
657 | |
658 | if (dq_list_lock_changed(listlockval) || dq->dq_cnt || (dq->dq_flags & DQ_MOD)) { |
659 | /* |
660 | * we lost the race while we weren't holding |
661 | * the quota list lock... dq_lock_internal |
662 | * will drop it to msleep... this dq has been |
663 | * reclaimed... go find another |
664 | */ |
665 | dq_unlock_internal(dq); |
666 | |
667 | /* |
668 | * need to look for the entry again in the cache |
669 | * since we dropped the quota list lock and |
670 | * someone else may have beaten us to creating it |
671 | */ |
672 | goto relookup; |
673 | } |
674 | TAILQ_REMOVE(&dqfreelist, dq, dq_freelist); |
675 | |
676 | if (dq->dq_qfile != NULL) { |
677 | LIST_REMOVE(dq, dq_hash); |
678 | dq->dq_qfile = NULL; |
679 | dq->dq_id = 0; |
680 | } |
681 | dq_unlock_internal(dq); |
682 | |
683 | /* |
684 | * because we may have dropped the quota list lock |
685 | * in the call to dq_lock_internal, we need to |
686 | * relookup in the hash in case someone else |
687 | * caused a dq with this identity to be created... |
688 | * if we don't find it, we'll use this one |
689 | */ |
690 | fdq = dq; |
691 | goto relookup; |
692 | } |
693 | /* |
694 | * we've either freshly allocated a dq |
695 | * or we've atomically pulled it out of |
696 | * the hash and freelists... no one else |
697 | * can have a reference, which means no |
698 | * one else can be trying to use this dq |
699 | */ |
700 | dq_lock_internal(dq); |
701 | if (dq_list_lock_changed(listlockval)) { |
702 | dq_unlock_internal(dq); |
703 | goto relookup; |
704 | } |
705 | |
706 | /* |
707 | * Initialize the contents of the dquot structure. |
708 | */ |
709 | dq->dq_cnt = 1; |
710 | dq->dq_flags = 0; |
711 | dq->dq_id = id; |
712 | dq->dq_qfile = qfp; |
713 | dq->dq_type = type; |
714 | /* |
715 | * once we insert it in the hash and |
716 | * drop the quota_list_lock, it can be |
717 | * 'found'... however, we're still holding |
718 | * the dq_lock which will keep us from doing |
719 | * anything with it until we've finished |
720 | * initializing it... |
721 | */ |
722 | LIST_INSERT_HEAD(dqh, dq, dq_hash); |
723 | dq_list_unlock(); |
724 | |
725 | if (ndq) { |
726 | /* |
727 | * we allocated this in the first pass through |
728 | * but we didn't need it, so free it after |
729 | * we've droped the quota list lock |
730 | */ |
731 | _FREE(ndq, M_DQUOT); |
732 | } |
733 | |
734 | error = dqlookup(qfp, id, &dq->dq_dqb, &dq->dq_index); |
735 | |
736 | /* |
737 | * I/O error in reading quota file, release |
738 | * quota structure and reflect problem to caller. |
739 | */ |
740 | if (error) { |
741 | dq_list_lock(); |
742 | |
743 | dq->dq_id = 0; |
744 | dq->dq_qfile = NULL; |
745 | LIST_REMOVE(dq, dq_hash); |
746 | |
747 | dq_unlock_internal(dq); |
748 | qf_rele(qfp); |
749 | dq_list_unlock(); |
750 | |
751 | dqrele(dq); |
752 | |
753 | *dqp = NODQUOT; |
754 | return (error); |
755 | } |
756 | /* |
757 | * Check for no limit to enforce. |
758 | * Initialize time values if necessary. |
759 | */ |
760 | if (dq->dq_isoftlimit == 0 && dq->dq_bsoftlimit == 0 && |
761 | dq->dq_ihardlimit == 0 && dq->dq_bhardlimit == 0) |
762 | dq->dq_flags |= DQ_FAKE; |
763 | if (dq->dq_id != 0) { |
764 | struct timeval tv; |
765 | |
766 | microtime(&tv); |
767 | if (dq->dq_btime == 0) |
768 | dq->dq_btime = tv.tv_sec + qfp->qf_btime; |
769 | if (dq->dq_itime == 0) |
770 | dq->dq_itime = tv.tv_sec + qfp->qf_itime; |
771 | } |
772 | dq_list_lock(); |
773 | dq_unlock_internal(dq); |
774 | qf_rele(qfp); |
775 | dq_list_unlock(); |
776 | |
777 | *dqp = dq; |
778 | return (0); |
779 | } |
780 | |
781 | /* |
782 | * Lookup a dqblk structure for the specified identifier and |
783 | * quota file. If there is no entry for this identifier then |
784 | * one is inserted. The actual hash table index is returned. |
785 | */ |
786 | static int |
787 | dqlookup(struct quotafile *qfp, u_int32_t id, struct dqblk *dqb, uint32_t *index) |
788 | { |
789 | struct vnode *dqvp; |
790 | struct vfs_context context; |
791 | uio_t auio; |
792 | int i, skip, last; |
793 | u_int32_t mask; |
794 | int error = 0; |
795 | char uio_buf[ UIO_SIZEOF(1) ]; |
796 | |
797 | |
798 | qf_lock(qfp); |
799 | |
800 | dqvp = qfp->qf_vp; |
801 | |
802 | context.vc_thread = current_thread(); |
803 | context.vc_ucred = qfp->qf_cred; |
804 | |
805 | mask = qfp->qf_maxentries - 1; |
806 | i = dqhash1(id, qfp->qf_shift, mask); |
807 | skip = dqhash2(id, mask); |
808 | |
809 | for (last = (i + (qfp->qf_maxentries-1) * skip) & mask; |
810 | i != last; |
811 | i = (i + skip) & mask) { |
812 | auio = uio_createwithbuffer(1, dqoffset(i), UIO_SYSSPACE, UIO_READ, |
813 | &uio_buf[0], sizeof(uio_buf)); |
814 | uio_addiov(auio, CAST_USER_ADDR_T(dqb), sizeof (struct dqblk)); |
815 | error = VNOP_READ(dqvp, auio, 0, &context); |
816 | if (error) { |
817 | printf("dqlookup: error %d looking up id %u at index %d\n" , error, id, i); |
818 | break; |
819 | } else if (uio_resid(auio)) { |
820 | error = EIO; |
821 | printf("dqlookup: error looking up id %u at index %d\n" , id, i); |
822 | break; |
823 | } |
824 | /* |
825 | * An empty entry means there is no entry |
826 | * with that id. In this case a new dqb |
827 | * record will be inserted. |
828 | */ |
829 | if (dqb->dqb_id == 0) { |
830 | bzero(dqb, sizeof(struct dqblk)); |
831 | dqb->dqb_id = OSSwapHostToBigInt32(id); |
832 | /* |
833 | * Write back to reserve entry for this id |
834 | */ |
835 | uio_reset(auio, dqoffset(i), UIO_SYSSPACE, UIO_WRITE); |
836 | uio_addiov(auio, CAST_USER_ADDR_T(dqb), sizeof (struct dqblk)); |
837 | error = VNOP_WRITE(dqvp, auio, 0, &context); |
838 | if (uio_resid(auio) && error == 0) |
839 | error = EIO; |
840 | if (error == 0) |
841 | ++qfp->qf_entrycnt; |
842 | dqb->dqb_id = id; |
843 | break; |
844 | } |
845 | /* An id match means an entry was found. */ |
846 | if (OSSwapBigToHostInt32(dqb->dqb_id) == id) { |
847 | dqb->dqb_bhardlimit = OSSwapBigToHostInt64(dqb->dqb_bhardlimit); |
848 | dqb->dqb_bsoftlimit = OSSwapBigToHostInt64(dqb->dqb_bsoftlimit); |
849 | dqb->dqb_curbytes = OSSwapBigToHostInt64(dqb->dqb_curbytes); |
850 | dqb->dqb_ihardlimit = OSSwapBigToHostInt32(dqb->dqb_ihardlimit); |
851 | dqb->dqb_isoftlimit = OSSwapBigToHostInt32(dqb->dqb_isoftlimit); |
852 | dqb->dqb_curinodes = OSSwapBigToHostInt32(dqb->dqb_curinodes); |
853 | dqb->dqb_btime = OSSwapBigToHostInt32(dqb->dqb_btime); |
854 | dqb->dqb_itime = OSSwapBigToHostInt32(dqb->dqb_itime); |
855 | dqb->dqb_id = OSSwapBigToHostInt32(dqb->dqb_id); |
856 | break; |
857 | } |
858 | } |
859 | qf_unlock(qfp); |
860 | |
861 | *index = i; /* remember index so we don't have to recompute it later */ |
862 | |
863 | return (error); |
864 | } |
865 | |
866 | |
867 | /* |
868 | * Release a reference to a dquot. |
869 | */ |
870 | void |
871 | dqrele(struct dquot *dq) |
872 | { |
873 | |
874 | if (dq == NODQUOT) |
875 | return; |
876 | dqlock(dq); |
877 | |
878 | if (dq->dq_cnt > 1) { |
879 | dq->dq_cnt--; |
880 | |
881 | dqunlock(dq); |
882 | return; |
883 | } |
884 | if (dq->dq_flags & DQ_MOD) |
885 | (void) dqsync_locked(dq); |
886 | dq->dq_cnt--; |
887 | |
888 | dq_list_lock(); |
889 | TAILQ_INSERT_TAIL(&dqfreelist, dq, dq_freelist); |
890 | dq_unlock_internal(dq); |
891 | dq_list_unlock(); |
892 | } |
893 | |
894 | /* |
895 | * Release a reference to a dquot but don't do any I/O. |
896 | */ |
897 | void |
898 | dqreclaim(struct dquot *dq) |
899 | { |
900 | |
901 | if (dq == NODQUOT) |
902 | return; |
903 | |
904 | dq_list_lock(); |
905 | dq_lock_internal(dq); |
906 | |
907 | if (--dq->dq_cnt > 0) { |
908 | dq_unlock_internal(dq); |
909 | dq_list_unlock(); |
910 | return; |
911 | } |
912 | if (dq->dq_flags & DQ_MOD) |
913 | TAILQ_INSERT_TAIL(&dqdirtylist, dq, dq_freelist); |
914 | else |
915 | TAILQ_INSERT_TAIL(&dqfreelist, dq, dq_freelist); |
916 | |
917 | dq_unlock_internal(dq); |
918 | dq_list_unlock(); |
919 | } |
920 | |
921 | /* |
922 | * Update a quota file's orphaned disk quotas. |
923 | */ |
924 | void |
925 | dqsync_orphans(struct quotafile *qfp) |
926 | { |
927 | struct dquot *dq; |
928 | |
929 | dq_list_lock(); |
930 | loop: |
931 | TAILQ_FOREACH(dq, &dqdirtylist, dq_freelist) { |
932 | if (dq->dq_qfile != qfp) |
933 | continue; |
934 | |
935 | dq_lock_internal(dq); |
936 | |
937 | if (dq->dq_qfile != qfp) { |
938 | /* |
939 | * the identity of this dq changed while |
940 | * the quota_list_lock was dropped |
941 | * dq_lock_internal can drop it to msleep |
942 | */ |
943 | dq_unlock_internal(dq); |
944 | goto loop; |
945 | } |
946 | if ((dq->dq_flags & DQ_MOD) == 0) { |
947 | /* |
948 | * someone cleaned and removed this from |
949 | * the dq from the dirty list while the |
950 | * quota_list_lock was dropped |
951 | */ |
952 | dq_unlock_internal(dq); |
953 | goto loop; |
954 | } |
955 | if (dq->dq_cnt != 0) |
956 | panic("dqsync_orphans: dquot in use" ); |
957 | |
958 | TAILQ_REMOVE(&dqdirtylist, dq, dq_freelist); |
959 | |
960 | dq_list_unlock(); |
961 | /* |
962 | * we're still holding the dqlock at this point |
963 | * with the reference count == 0 |
964 | * we shouldn't be able |
965 | * to pick up another one since we hold dqlock |
966 | */ |
967 | (void) dqsync_locked(dq); |
968 | |
969 | dq_list_lock(); |
970 | |
971 | TAILQ_INSERT_TAIL(&dqfreelist, dq, dq_freelist); |
972 | |
973 | dq_unlock_internal(dq); |
974 | goto loop; |
975 | } |
976 | dq_list_unlock(); |
977 | } |
978 | |
979 | int |
980 | dqsync(struct dquot *dq) |
981 | { |
982 | int error = 0; |
983 | |
984 | if (dq != NODQUOT) { |
985 | dqlock(dq); |
986 | |
987 | if ( (dq->dq_flags & DQ_MOD) ) |
988 | error = dqsync_locked(dq); |
989 | |
990 | dqunlock(dq); |
991 | } |
992 | return (error); |
993 | } |
994 | |
995 | |
996 | /* |
997 | * Update the disk quota in the quota file. |
998 | */ |
999 | int |
1000 | dqsync_locked(struct dquot *dq) |
1001 | { |
1002 | struct vfs_context context; |
1003 | struct vnode *dqvp; |
1004 | struct dqblk dqb, *dqblkp; |
1005 | uio_t auio; |
1006 | int error; |
1007 | char uio_buf[ UIO_SIZEOF(1) ]; |
1008 | |
1009 | if (dq->dq_id == 0) { |
1010 | dq->dq_flags &= ~DQ_MOD; |
1011 | return (0); |
1012 | } |
1013 | if (dq->dq_qfile == NULL) |
1014 | panic("dqsync: NULL dq_qfile" ); |
1015 | if ((dqvp = dq->dq_qfile->qf_vp) == NULLVP) |
1016 | panic("dqsync: NULL qf_vp" ); |
1017 | |
1018 | auio = uio_createwithbuffer(1, dqoffset(dq->dq_index), UIO_SYSSPACE, |
1019 | UIO_WRITE, &uio_buf[0], sizeof(uio_buf)); |
1020 | uio_addiov(auio, CAST_USER_ADDR_T(&dqb), sizeof (struct dqblk)); |
1021 | |
1022 | context.vc_thread = current_thread(); /* XXX */ |
1023 | context.vc_ucred = dq->dq_qfile->qf_cred; |
1024 | |
1025 | dqblkp = &dq->dq_dqb; |
1026 | dqb.dqb_bhardlimit = OSSwapHostToBigInt64(dqblkp->dqb_bhardlimit); |
1027 | dqb.dqb_bsoftlimit = OSSwapHostToBigInt64(dqblkp->dqb_bsoftlimit); |
1028 | dqb.dqb_curbytes = OSSwapHostToBigInt64(dqblkp->dqb_curbytes); |
1029 | dqb.dqb_ihardlimit = OSSwapHostToBigInt32(dqblkp->dqb_ihardlimit); |
1030 | dqb.dqb_isoftlimit = OSSwapHostToBigInt32(dqblkp->dqb_isoftlimit); |
1031 | dqb.dqb_curinodes = OSSwapHostToBigInt32(dqblkp->dqb_curinodes); |
1032 | dqb.dqb_btime = OSSwapHostToBigInt32(dqblkp->dqb_btime); |
1033 | dqb.dqb_itime = OSSwapHostToBigInt32(dqblkp->dqb_itime); |
1034 | dqb.dqb_id = OSSwapHostToBigInt32(dqblkp->dqb_id); |
1035 | dqb.dqb_spare[0] = 0; |
1036 | dqb.dqb_spare[1] = 0; |
1037 | dqb.dqb_spare[2] = 0; |
1038 | dqb.dqb_spare[3] = 0; |
1039 | |
1040 | error = VNOP_WRITE(dqvp, auio, 0, &context); |
1041 | if (uio_resid(auio) && error == 0) |
1042 | error = EIO; |
1043 | dq->dq_flags &= ~DQ_MOD; |
1044 | |
1045 | return (error); |
1046 | } |
1047 | |
1048 | /* |
1049 | * Flush all entries from the cache for a particular vnode. |
1050 | */ |
1051 | void |
1052 | dqflush(struct vnode *vp) |
1053 | { |
1054 | struct dquot *dq, *nextdq; |
1055 | struct dqhash *dqh; |
1056 | |
1057 | if (!dqisinitialized()) |
1058 | return; |
1059 | |
1060 | /* |
1061 | * Move all dquot's that used to refer to this quota |
1062 | * file off their hash chains (they will eventually |
1063 | * fall off the head of the free list and be re-used). |
1064 | */ |
1065 | dq_list_lock(); |
1066 | |
1067 | for (dqh = &dqhashtbl[dqhash]; dqh >= dqhashtbl; dqh--) { |
1068 | for (dq = dqh->lh_first; dq; dq = nextdq) { |
1069 | nextdq = dq->dq_hash.le_next; |
1070 | if (dq->dq_qfile->qf_vp != vp) |
1071 | continue; |
1072 | if (dq->dq_cnt) |
1073 | panic("dqflush: stray dquot" ); |
1074 | LIST_REMOVE(dq, dq_hash); |
1075 | dq->dq_qfile = NULL; |
1076 | } |
1077 | } |
1078 | dq_list_unlock(); |
1079 | } |
1080 | |
1081 | /* |
1082 | * LP64 support for munging dqblk structure. |
1083 | * XXX conversion of user_time_t to time_t loses precision; not an issue for |
1084 | * XXX us now, since we are only ever setting 32 bits worth of time into it. |
1085 | */ |
1086 | __private_extern__ void |
1087 | munge_dqblk(struct dqblk *dqblkp, struct user_dqblk *user_dqblkp, boolean_t to64) |
1088 | { |
1089 | if (to64) { |
1090 | /* munge kernel (32 bit) dqblk into user (64 bit) dqblk */ |
1091 | bcopy((caddr_t)dqblkp, (caddr_t)user_dqblkp, offsetof(struct dqblk, dqb_btime)); |
1092 | user_dqblkp->dqb_id = dqblkp->dqb_id; |
1093 | user_dqblkp->dqb_itime = dqblkp->dqb_itime; |
1094 | user_dqblkp->dqb_btime = dqblkp->dqb_btime; |
1095 | } |
1096 | else { |
1097 | |
1098 | /* munge user (64 bit) dqblk into kernel (32 bit) dqblk */ |
1099 | bcopy((caddr_t)user_dqblkp, (caddr_t)dqblkp, offsetof(struct dqblk, dqb_btime)); |
1100 | dqblkp->dqb_id = user_dqblkp->dqb_id; |
1101 | dqblkp->dqb_itime = user_dqblkp->dqb_itime; /* XXX - lose precision */ |
1102 | dqblkp->dqb_btime = user_dqblkp->dqb_btime; /* XXX - lose precision */ |
1103 | } |
1104 | } |
1105 | |