xref: /openbmc/linux/fs/gfs2/quota.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 /*
11  * Quota change tags are associated with each transaction that allocates or
12  * deallocates space.  Those changes are accumulated locally to each node (in a
13  * per-node file) and then are periodically synced to the quota file.  This
14  * avoids the bottleneck of constantly touching the quota file, but introduces
15  * fuzziness in the current usage value of IDs that are being used on different
16  * nodes in the cluster simultaneously.  So, it is possible for a user on
17  * multiple nodes to overrun their quota, but that overrun is controlable.
18  * Since quota tags are part of transactions, there is no need to a quota check
19  * program to be run on node crashes or anything like that.
20  *
21  * There are couple of knobs that let the administrator manage the quota
22  * fuzziness.  "quota_quantum" sets the maximum time a quota change can be
23  * sitting on one node before being synced to the quota file.  (The default is
24  * 60 seconds.)  Another knob, "quota_scale" controls how quickly the frequency
25  * of quota file syncs increases as the user moves closer to their limit.  The
26  * more frequent the syncs, the more accurate the quota enforcement, but that
27  * means that there is more contention between the nodes for the quota file.
28  * The default value is one.  This sets the maximum theoretical quota overrun
29  * (with infinite node with infinite bandwidth) to twice the user's limit.  (In
30  * practice, the maximum overrun you see should be much less.)  A "quota_scale"
31  * number greater than one makes quota syncs more frequent and reduces the
32  * maximum overrun.  Numbers less than one (but greater than zero) make quota
33  * syncs less frequent.
34  *
35  * GFS quotas also use per-ID Lock Value Blocks (LVBs) to cache the contents of
36  * the quota file, so it is not being constantly read.
37  */
38 
39 #include <linux/sched.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/completion.h>
43 #include <linux/buffer_head.h>
44 #include <linux/sort.h>
45 #include <linux/fs.h>
46 #include <linux/bio.h>
47 #include <linux/gfs2_ondisk.h>
48 #include <linux/lm_interface.h>
49 
50 #include "gfs2.h"
51 #include "incore.h"
52 #include "bmap.h"
53 #include "glock.h"
54 #include "glops.h"
55 #include "log.h"
56 #include "meta_io.h"
57 #include "quota.h"
58 #include "rgrp.h"
59 #include "super.h"
60 #include "trans.h"
61 #include "inode.h"
62 #include "ops_file.h"
63 #include "ops_address.h"
64 #include "util.h"
65 
66 #define QUOTA_USER 1
67 #define QUOTA_GROUP 0
68 
69 struct gfs2_quota_host {
70 	u64 qu_limit;
71 	u64 qu_warn;
72 	s64 qu_value;
73 	u32 qu_ll_next;
74 };
75 
76 struct gfs2_quota_change_host {
77 	u64 qc_change;
78 	u32 qc_flags; /* GFS2_QCF_... */
79 	u32 qc_id;
80 };
81 
82 static u64 qd2offset(struct gfs2_quota_data *qd)
83 {
84 	u64 offset;
85 
86 	offset = 2 * (u64)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
87 	offset *= sizeof(struct gfs2_quota);
88 
89 	return offset;
90 }
91 
92 static int qd_alloc(struct gfs2_sbd *sdp, int user, u32 id,
93 		    struct gfs2_quota_data **qdp)
94 {
95 	struct gfs2_quota_data *qd;
96 	int error;
97 
98 	qd = kzalloc(sizeof(struct gfs2_quota_data), GFP_KERNEL);
99 	if (!qd)
100 		return -ENOMEM;
101 
102 	qd->qd_count = 1;
103 	qd->qd_id = id;
104 	if (user)
105 		set_bit(QDF_USER, &qd->qd_flags);
106 	qd->qd_slot = -1;
107 
108 	error = gfs2_glock_get(sdp, 2 * (u64)id + !user,
109 			      &gfs2_quota_glops, CREATE, &qd->qd_gl);
110 	if (error)
111 		goto fail;
112 
113 	error = gfs2_lvb_hold(qd->qd_gl);
114 	gfs2_glock_put(qd->qd_gl);
115 	if (error)
116 		goto fail;
117 
118 	*qdp = qd;
119 
120 	return 0;
121 
122 fail:
123 	kfree(qd);
124 	return error;
125 }
126 
127 static int qd_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
128 		  struct gfs2_quota_data **qdp)
129 {
130 	struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
131 	int error, found;
132 
133 	*qdp = NULL;
134 
135 	for (;;) {
136 		found = 0;
137 		spin_lock(&sdp->sd_quota_spin);
138 		list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
139 			if (qd->qd_id == id &&
140 			    !test_bit(QDF_USER, &qd->qd_flags) == !user) {
141 				qd->qd_count++;
142 				found = 1;
143 				break;
144 			}
145 		}
146 
147 		if (!found)
148 			qd = NULL;
149 
150 		if (!qd && new_qd) {
151 			qd = new_qd;
152 			list_add(&qd->qd_list, &sdp->sd_quota_list);
153 			atomic_inc(&sdp->sd_quota_count);
154 			new_qd = NULL;
155 		}
156 
157 		spin_unlock(&sdp->sd_quota_spin);
158 
159 		if (qd || !create) {
160 			if (new_qd) {
161 				gfs2_lvb_unhold(new_qd->qd_gl);
162 				kfree(new_qd);
163 			}
164 			*qdp = qd;
165 			return 0;
166 		}
167 
168 		error = qd_alloc(sdp, user, id, &new_qd);
169 		if (error)
170 			return error;
171 	}
172 }
173 
174 static void qd_hold(struct gfs2_quota_data *qd)
175 {
176 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
177 
178 	spin_lock(&sdp->sd_quota_spin);
179 	gfs2_assert(sdp, qd->qd_count);
180 	qd->qd_count++;
181 	spin_unlock(&sdp->sd_quota_spin);
182 }
183 
184 static void qd_put(struct gfs2_quota_data *qd)
185 {
186 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
187 	spin_lock(&sdp->sd_quota_spin);
188 	gfs2_assert(sdp, qd->qd_count);
189 	if (!--qd->qd_count)
190 		qd->qd_last_touched = jiffies;
191 	spin_unlock(&sdp->sd_quota_spin);
192 }
193 
194 static int slot_get(struct gfs2_quota_data *qd)
195 {
196 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
197 	unsigned int c, o = 0, b;
198 	unsigned char byte = 0;
199 
200 	spin_lock(&sdp->sd_quota_spin);
201 
202 	if (qd->qd_slot_count++) {
203 		spin_unlock(&sdp->sd_quota_spin);
204 		return 0;
205 	}
206 
207 	for (c = 0; c < sdp->sd_quota_chunks; c++)
208 		for (o = 0; o < PAGE_SIZE; o++) {
209 			byte = sdp->sd_quota_bitmap[c][o];
210 			if (byte != 0xFF)
211 				goto found;
212 		}
213 
214 	goto fail;
215 
216 found:
217 	for (b = 0; b < 8; b++)
218 		if (!(byte & (1 << b)))
219 			break;
220 	qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
221 
222 	if (qd->qd_slot >= sdp->sd_quota_slots)
223 		goto fail;
224 
225 	sdp->sd_quota_bitmap[c][o] |= 1 << b;
226 
227 	spin_unlock(&sdp->sd_quota_spin);
228 
229 	return 0;
230 
231 fail:
232 	qd->qd_slot_count--;
233 	spin_unlock(&sdp->sd_quota_spin);
234 	return -ENOSPC;
235 }
236 
237 static void slot_hold(struct gfs2_quota_data *qd)
238 {
239 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
240 
241 	spin_lock(&sdp->sd_quota_spin);
242 	gfs2_assert(sdp, qd->qd_slot_count);
243 	qd->qd_slot_count++;
244 	spin_unlock(&sdp->sd_quota_spin);
245 }
246 
247 static void slot_put(struct gfs2_quota_data *qd)
248 {
249 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
250 
251 	spin_lock(&sdp->sd_quota_spin);
252 	gfs2_assert(sdp, qd->qd_slot_count);
253 	if (!--qd->qd_slot_count) {
254 		gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
255 		qd->qd_slot = -1;
256 	}
257 	spin_unlock(&sdp->sd_quota_spin);
258 }
259 
260 static int bh_get(struct gfs2_quota_data *qd)
261 {
262 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
263 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
264 	unsigned int block, offset;
265 	struct buffer_head *bh;
266 	int error;
267 	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
268 
269 	mutex_lock(&sdp->sd_quota_mutex);
270 
271 	if (qd->qd_bh_count++) {
272 		mutex_unlock(&sdp->sd_quota_mutex);
273 		return 0;
274 	}
275 
276 	block = qd->qd_slot / sdp->sd_qc_per_block;
277 	offset = qd->qd_slot % sdp->sd_qc_per_block;;
278 
279 	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
280 	error = gfs2_block_map(&ip->i_inode, block, 0, &bh_map);
281 	if (error)
282 		goto fail;
283 	error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
284 	if (error)
285 		goto fail;
286 	error = -EIO;
287 	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
288 		goto fail_brelse;
289 
290 	qd->qd_bh = bh;
291 	qd->qd_bh_qc = (struct gfs2_quota_change *)
292 		(bh->b_data + sizeof(struct gfs2_meta_header) +
293 		 offset * sizeof(struct gfs2_quota_change));
294 
295 	mutex_unlock(&sdp->sd_quota_mutex);
296 
297 	return 0;
298 
299 fail_brelse:
300 	brelse(bh);
301 fail:
302 	qd->qd_bh_count--;
303 	mutex_unlock(&sdp->sd_quota_mutex);
304 	return error;
305 }
306 
307 static void bh_put(struct gfs2_quota_data *qd)
308 {
309 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
310 
311 	mutex_lock(&sdp->sd_quota_mutex);
312 	gfs2_assert(sdp, qd->qd_bh_count);
313 	if (!--qd->qd_bh_count) {
314 		brelse(qd->qd_bh);
315 		qd->qd_bh = NULL;
316 		qd->qd_bh_qc = NULL;
317 	}
318 	mutex_unlock(&sdp->sd_quota_mutex);
319 }
320 
321 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
322 {
323 	struct gfs2_quota_data *qd = NULL;
324 	int error;
325 	int found = 0;
326 
327 	*qdp = NULL;
328 
329 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
330 		return 0;
331 
332 	spin_lock(&sdp->sd_quota_spin);
333 
334 	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
335 		if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
336 		    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
337 		    qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
338 			continue;
339 
340 		list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
341 
342 		set_bit(QDF_LOCKED, &qd->qd_flags);
343 		gfs2_assert_warn(sdp, qd->qd_count);
344 		qd->qd_count++;
345 		qd->qd_change_sync = qd->qd_change;
346 		gfs2_assert_warn(sdp, qd->qd_slot_count);
347 		qd->qd_slot_count++;
348 		found = 1;
349 
350 		break;
351 	}
352 
353 	if (!found)
354 		qd = NULL;
355 
356 	spin_unlock(&sdp->sd_quota_spin);
357 
358 	if (qd) {
359 		gfs2_assert_warn(sdp, qd->qd_change_sync);
360 		error = bh_get(qd);
361 		if (error) {
362 			clear_bit(QDF_LOCKED, &qd->qd_flags);
363 			slot_put(qd);
364 			qd_put(qd);
365 			return error;
366 		}
367 	}
368 
369 	*qdp = qd;
370 
371 	return 0;
372 }
373 
374 static int qd_trylock(struct gfs2_quota_data *qd)
375 {
376 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
377 
378 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
379 		return 0;
380 
381 	spin_lock(&sdp->sd_quota_spin);
382 
383 	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
384 	    !test_bit(QDF_CHANGE, &qd->qd_flags)) {
385 		spin_unlock(&sdp->sd_quota_spin);
386 		return 0;
387 	}
388 
389 	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
390 
391 	set_bit(QDF_LOCKED, &qd->qd_flags);
392 	gfs2_assert_warn(sdp, qd->qd_count);
393 	qd->qd_count++;
394 	qd->qd_change_sync = qd->qd_change;
395 	gfs2_assert_warn(sdp, qd->qd_slot_count);
396 	qd->qd_slot_count++;
397 
398 	spin_unlock(&sdp->sd_quota_spin);
399 
400 	gfs2_assert_warn(sdp, qd->qd_change_sync);
401 	if (bh_get(qd)) {
402 		clear_bit(QDF_LOCKED, &qd->qd_flags);
403 		slot_put(qd);
404 		qd_put(qd);
405 		return 0;
406 	}
407 
408 	return 1;
409 }
410 
411 static void qd_unlock(struct gfs2_quota_data *qd)
412 {
413 	gfs2_assert_warn(qd->qd_gl->gl_sbd,
414 			 test_bit(QDF_LOCKED, &qd->qd_flags));
415 	clear_bit(QDF_LOCKED, &qd->qd_flags);
416 	bh_put(qd);
417 	slot_put(qd);
418 	qd_put(qd);
419 }
420 
421 static int qdsb_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
422 		    struct gfs2_quota_data **qdp)
423 {
424 	int error;
425 
426 	error = qd_get(sdp, user, id, create, qdp);
427 	if (error)
428 		return error;
429 
430 	error = slot_get(*qdp);
431 	if (error)
432 		goto fail;
433 
434 	error = bh_get(*qdp);
435 	if (error)
436 		goto fail_slot;
437 
438 	return 0;
439 
440 fail_slot:
441 	slot_put(*qdp);
442 fail:
443 	qd_put(*qdp);
444 	return error;
445 }
446 
447 static void qdsb_put(struct gfs2_quota_data *qd)
448 {
449 	bh_put(qd);
450 	slot_put(qd);
451 	qd_put(qd);
452 }
453 
454 int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
455 {
456 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
457 	struct gfs2_alloc *al = &ip->i_alloc;
458 	struct gfs2_quota_data **qd = al->al_qd;
459 	int error;
460 
461 	if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
462 	    gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
463 		return -EIO;
464 
465 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
466 		return 0;
467 
468 	error = qdsb_get(sdp, QUOTA_USER, ip->i_inode.i_uid, CREATE, qd);
469 	if (error)
470 		goto out;
471 	al->al_qd_num++;
472 	qd++;
473 
474 	error = qdsb_get(sdp, QUOTA_GROUP, ip->i_inode.i_gid, CREATE, qd);
475 	if (error)
476 		goto out;
477 	al->al_qd_num++;
478 	qd++;
479 
480 	if (uid != NO_QUOTA_CHANGE && uid != ip->i_inode.i_uid) {
481 		error = qdsb_get(sdp, QUOTA_USER, uid, CREATE, qd);
482 		if (error)
483 			goto out;
484 		al->al_qd_num++;
485 		qd++;
486 	}
487 
488 	if (gid != NO_QUOTA_CHANGE && gid != ip->i_inode.i_gid) {
489 		error = qdsb_get(sdp, QUOTA_GROUP, gid, CREATE, qd);
490 		if (error)
491 			goto out;
492 		al->al_qd_num++;
493 		qd++;
494 	}
495 
496 out:
497 	if (error)
498 		gfs2_quota_unhold(ip);
499 	return error;
500 }
501 
502 void gfs2_quota_unhold(struct gfs2_inode *ip)
503 {
504 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
505 	struct gfs2_alloc *al = &ip->i_alloc;
506 	unsigned int x;
507 
508 	gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
509 
510 	for (x = 0; x < al->al_qd_num; x++) {
511 		qdsb_put(al->al_qd[x]);
512 		al->al_qd[x] = NULL;
513 	}
514 	al->al_qd_num = 0;
515 }
516 
517 static int sort_qd(const void *a, const void *b)
518 {
519 	const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
520 	const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
521 
522 	if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
523 	    !test_bit(QDF_USER, &qd_b->qd_flags)) {
524 		if (test_bit(QDF_USER, &qd_a->qd_flags))
525 			return -1;
526 		else
527 			return 1;
528 	}
529 	if (qd_a->qd_id < qd_b->qd_id)
530 		return -1;
531 	if (qd_a->qd_id > qd_b->qd_id)
532 		return 1;
533 
534 	return 0;
535 }
536 
537 static void do_qc(struct gfs2_quota_data *qd, s64 change)
538 {
539 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
540 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
541 	struct gfs2_quota_change *qc = qd->qd_bh_qc;
542 	s64 x;
543 
544 	mutex_lock(&sdp->sd_quota_mutex);
545 	gfs2_trans_add_bh(ip->i_gl, qd->qd_bh, 1);
546 
547 	if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
548 		qc->qc_change = 0;
549 		qc->qc_flags = 0;
550 		if (test_bit(QDF_USER, &qd->qd_flags))
551 			qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
552 		qc->qc_id = cpu_to_be32(qd->qd_id);
553 	}
554 
555 	x = be64_to_cpu(qc->qc_change) + change;
556 	qc->qc_change = cpu_to_be64(x);
557 
558 	spin_lock(&sdp->sd_quota_spin);
559 	qd->qd_change = x;
560 	spin_unlock(&sdp->sd_quota_spin);
561 
562 	if (!x) {
563 		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
564 		clear_bit(QDF_CHANGE, &qd->qd_flags);
565 		qc->qc_flags = 0;
566 		qc->qc_id = 0;
567 		slot_put(qd);
568 		qd_put(qd);
569 	} else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
570 		qd_hold(qd);
571 		slot_hold(qd);
572 	}
573 
574 	mutex_unlock(&sdp->sd_quota_mutex);
575 }
576 
577 static void gfs2_quota_in(struct gfs2_quota_host *qu, const void *buf)
578 {
579 	const struct gfs2_quota *str = buf;
580 
581 	qu->qu_limit = be64_to_cpu(str->qu_limit);
582 	qu->qu_warn = be64_to_cpu(str->qu_warn);
583 	qu->qu_value = be64_to_cpu(str->qu_value);
584 	qu->qu_ll_next = be32_to_cpu(str->qu_ll_next);
585 }
586 
587 static void gfs2_quota_out(const struct gfs2_quota_host *qu, void *buf)
588 {
589 	struct gfs2_quota *str = buf;
590 
591 	str->qu_limit = cpu_to_be64(qu->qu_limit);
592 	str->qu_warn = cpu_to_be64(qu->qu_warn);
593 	str->qu_value = cpu_to_be64(qu->qu_value);
594 	str->qu_ll_next = cpu_to_be32(qu->qu_ll_next);
595 	memset(&str->qu_reserved, 0, sizeof(str->qu_reserved));
596 }
597 
598 /**
599  * gfs2_adjust_quota
600  *
601  * This function was mostly borrowed from gfs2_block_truncate_page which was
602  * in turn mostly borrowed from ext3
603  */
604 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
605 			     s64 change, struct gfs2_quota_data *qd)
606 {
607 	struct inode *inode = &ip->i_inode;
608 	struct address_space *mapping = inode->i_mapping;
609 	unsigned long index = loc >> PAGE_CACHE_SHIFT;
610 	unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
611 	unsigned blocksize, iblock, pos;
612 	struct buffer_head *bh;
613 	struct page *page;
614 	void *kaddr;
615 	char *ptr;
616 	struct gfs2_quota_host qp;
617 	s64 value;
618 	int err = -EIO;
619 
620 	if (gfs2_is_stuffed(ip)) {
621 		struct gfs2_alloc *al = NULL;
622 		al = gfs2_alloc_get(ip);
623 		/* just request 1 blk */
624 		al->al_requested = 1;
625 		gfs2_inplace_reserve(ip);
626 		gfs2_unstuff_dinode(ip, NULL);
627 		gfs2_inplace_release(ip);
628 		gfs2_alloc_put(ip);
629 	}
630 	page = grab_cache_page(mapping, index);
631 	if (!page)
632 		return -ENOMEM;
633 
634 	blocksize = inode->i_sb->s_blocksize;
635 	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
636 
637 	if (!page_has_buffers(page))
638 		create_empty_buffers(page, blocksize, 0);
639 
640 	bh = page_buffers(page);
641 	pos = blocksize;
642 	while (offset >= pos) {
643 		bh = bh->b_this_page;
644 		iblock++;
645 		pos += blocksize;
646 	}
647 
648 	if (!buffer_mapped(bh)) {
649 		gfs2_get_block(inode, iblock, bh, 1);
650 		if (!buffer_mapped(bh))
651 			goto unlock;
652 	}
653 
654 	if (PageUptodate(page))
655 		set_buffer_uptodate(bh);
656 
657 	if (!buffer_uptodate(bh)) {
658 		ll_rw_block(READ_META, 1, &bh);
659 		wait_on_buffer(bh);
660 		if (!buffer_uptodate(bh))
661 			goto unlock;
662 	}
663 
664 	gfs2_trans_add_bh(ip->i_gl, bh, 0);
665 
666 	kaddr = kmap_atomic(page, KM_USER0);
667 	ptr = kaddr + offset;
668 	gfs2_quota_in(&qp, ptr);
669 	qp.qu_value += change;
670 	value = qp.qu_value;
671 	gfs2_quota_out(&qp, ptr);
672 	flush_dcache_page(page);
673 	kunmap_atomic(kaddr, KM_USER0);
674 	err = 0;
675 	qd->qd_qb.qb_magic = cpu_to_be32(GFS2_MAGIC);
676 	qd->qd_qb.qb_value = cpu_to_be64(value);
677 	((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_magic = cpu_to_be32(GFS2_MAGIC);
678 	((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_value = cpu_to_be64(value);
679 unlock:
680 	unlock_page(page);
681 	page_cache_release(page);
682 	return err;
683 }
684 
685 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
686 {
687 	struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
688 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
689 	unsigned int data_blocks, ind_blocks;
690 	struct gfs2_holder *ghs, i_gh;
691 	unsigned int qx, x;
692 	struct gfs2_quota_data *qd;
693 	loff_t offset;
694 	unsigned int nalloc = 0;
695 	struct gfs2_alloc *al = NULL;
696 	int error;
697 
698 	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
699 			      &data_blocks, &ind_blocks);
700 
701 	ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_KERNEL);
702 	if (!ghs)
703 		return -ENOMEM;
704 
705 	sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
706 	for (qx = 0; qx < num_qd; qx++) {
707 		error = gfs2_glock_nq_init(qda[qx]->qd_gl,
708 					   LM_ST_EXCLUSIVE,
709 					   GL_NOCACHE, &ghs[qx]);
710 		if (error)
711 			goto out;
712 	}
713 
714 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
715 	if (error)
716 		goto out;
717 
718 	for (x = 0; x < num_qd; x++) {
719 		int alloc_required;
720 
721 		offset = qd2offset(qda[x]);
722 		error = gfs2_write_alloc_required(ip, offset,
723 						  sizeof(struct gfs2_quota),
724 						  &alloc_required);
725 		if (error)
726 			goto out_gunlock;
727 		if (alloc_required)
728 			nalloc++;
729 	}
730 
731 	if (nalloc) {
732 		al = gfs2_alloc_get(ip);
733 
734 		al->al_requested = nalloc * (data_blocks + ind_blocks);
735 
736 		error = gfs2_inplace_reserve(ip);
737 		if (error)
738 			goto out_alloc;
739 
740 		error = gfs2_trans_begin(sdp,
741 					 al->al_rgd->rd_length +
742 					 num_qd * data_blocks +
743 					 nalloc * ind_blocks +
744 					 RES_DINODE + num_qd +
745 					 RES_STATFS, 0);
746 		if (error)
747 			goto out_ipres;
748 	} else {
749 		error = gfs2_trans_begin(sdp,
750 					 num_qd * data_blocks +
751 					 RES_DINODE + num_qd, 0);
752 		if (error)
753 			goto out_gunlock;
754 	}
755 
756 	for (x = 0; x < num_qd; x++) {
757 		qd = qda[x];
758 		offset = qd2offset(qd);
759 		error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync,
760 					  (struct gfs2_quota_data *)
761 					  qd);
762 		if (error)
763 			goto out_end_trans;
764 
765 		do_qc(qd, -qd->qd_change_sync);
766 	}
767 
768 	error = 0;
769 
770 out_end_trans:
771 	gfs2_trans_end(sdp);
772 out_ipres:
773 	if (nalloc)
774 		gfs2_inplace_release(ip);
775 out_alloc:
776 	if (nalloc)
777 		gfs2_alloc_put(ip);
778 out_gunlock:
779 	gfs2_glock_dq_uninit(&i_gh);
780 out:
781 	while (qx--)
782 		gfs2_glock_dq_uninit(&ghs[qx]);
783 	kfree(ghs);
784 	gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
785 	return error;
786 }
787 
788 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
789 		    struct gfs2_holder *q_gh)
790 {
791 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
792 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
793 	struct gfs2_holder i_gh;
794 	struct gfs2_quota_host q;
795 	char buf[sizeof(struct gfs2_quota)];
796 	struct file_ra_state ra_state;
797 	int error;
798 	struct gfs2_quota_lvb *qlvb;
799 
800 	file_ra_state_init(&ra_state, sdp->sd_quota_inode->i_mapping);
801 restart:
802 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
803 	if (error)
804 		return error;
805 
806 	qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
807 
808 	if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
809 		loff_t pos;
810 		gfs2_glock_dq_uninit(q_gh);
811 		error = gfs2_glock_nq_init(qd->qd_gl,
812 					  LM_ST_EXCLUSIVE, GL_NOCACHE,
813 					  q_gh);
814 		if (error)
815 			return error;
816 
817 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
818 		if (error)
819 			goto fail;
820 
821 		memset(buf, 0, sizeof(struct gfs2_quota));
822 		pos = qd2offset(qd);
823 		error = gfs2_internal_read(ip, &ra_state, buf,
824 					   &pos, sizeof(struct gfs2_quota));
825 		if (error < 0)
826 			goto fail_gunlock;
827 
828 		gfs2_glock_dq_uninit(&i_gh);
829 
830 
831 		gfs2_quota_in(&q, buf);
832 		qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
833 		qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
834 		qlvb->__pad = 0;
835 		qlvb->qb_limit = cpu_to_be64(q.qu_limit);
836 		qlvb->qb_warn = cpu_to_be64(q.qu_warn);
837 		qlvb->qb_value = cpu_to_be64(q.qu_value);
838 		qd->qd_qb = *qlvb;
839 
840 		if (gfs2_glock_is_blocking(qd->qd_gl)) {
841 			gfs2_glock_dq_uninit(q_gh);
842 			force_refresh = 0;
843 			goto restart;
844 		}
845 	}
846 
847 	return 0;
848 
849 fail_gunlock:
850 	gfs2_glock_dq_uninit(&i_gh);
851 fail:
852 	gfs2_glock_dq_uninit(q_gh);
853 	return error;
854 }
855 
856 int gfs2_quota_lock(struct gfs2_inode *ip, u32 uid, u32 gid)
857 {
858 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
859 	struct gfs2_alloc *al = &ip->i_alloc;
860 	unsigned int x;
861 	int error = 0;
862 
863 	gfs2_quota_hold(ip, uid, gid);
864 
865 	if (capable(CAP_SYS_RESOURCE) ||
866 	    sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
867 		return 0;
868 
869 	sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
870 	     sort_qd, NULL);
871 
872 	for (x = 0; x < al->al_qd_num; x++) {
873 		error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
874 		if (error)
875 			break;
876 	}
877 
878 	if (!error)
879 		set_bit(GIF_QD_LOCKED, &ip->i_flags);
880 	else {
881 		while (x--)
882 			gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
883 		gfs2_quota_unhold(ip);
884 	}
885 
886 	return error;
887 }
888 
889 static int need_sync(struct gfs2_quota_data *qd)
890 {
891 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
892 	struct gfs2_tune *gt = &sdp->sd_tune;
893 	s64 value;
894 	unsigned int num, den;
895 	int do_sync = 1;
896 
897 	if (!qd->qd_qb.qb_limit)
898 		return 0;
899 
900 	spin_lock(&sdp->sd_quota_spin);
901 	value = qd->qd_change;
902 	spin_unlock(&sdp->sd_quota_spin);
903 
904 	spin_lock(&gt->gt_spin);
905 	num = gt->gt_quota_scale_num;
906 	den = gt->gt_quota_scale_den;
907 	spin_unlock(&gt->gt_spin);
908 
909 	if (value < 0)
910 		do_sync = 0;
911 	else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
912 		 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
913 		do_sync = 0;
914 	else {
915 		value *= gfs2_jindex_size(sdp) * num;
916 		do_div(value, den);
917 		value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
918 		if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
919 			do_sync = 0;
920 	}
921 
922 	return do_sync;
923 }
924 
925 void gfs2_quota_unlock(struct gfs2_inode *ip)
926 {
927 	struct gfs2_alloc *al = &ip->i_alloc;
928 	struct gfs2_quota_data *qda[4];
929 	unsigned int count = 0;
930 	unsigned int x;
931 
932 	if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
933 		goto out;
934 
935 	for (x = 0; x < al->al_qd_num; x++) {
936 		struct gfs2_quota_data *qd;
937 		int sync;
938 
939 		qd = al->al_qd[x];
940 		sync = need_sync(qd);
941 
942 		gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
943 
944 		if (sync && qd_trylock(qd))
945 			qda[count++] = qd;
946 	}
947 
948 	if (count) {
949 		do_sync(count, qda);
950 		for (x = 0; x < count; x++)
951 			qd_unlock(qda[x]);
952 	}
953 
954 out:
955 	gfs2_quota_unhold(ip);
956 }
957 
958 #define MAX_LINE 256
959 
960 static int print_message(struct gfs2_quota_data *qd, char *type)
961 {
962 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
963 
964 	printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\r\n",
965 	       sdp->sd_fsname, type,
966 	       (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
967 	       qd->qd_id);
968 
969 	return 0;
970 }
971 
972 int gfs2_quota_check(struct gfs2_inode *ip, u32 uid, u32 gid)
973 {
974 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
975 	struct gfs2_alloc *al = &ip->i_alloc;
976 	struct gfs2_quota_data *qd;
977 	s64 value;
978 	unsigned int x;
979 	int error = 0;
980 
981 	if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
982 		return 0;
983 
984         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
985                 return 0;
986 
987 	for (x = 0; x < al->al_qd_num; x++) {
988 		qd = al->al_qd[x];
989 
990 		if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
991 		      (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
992 			continue;
993 
994 		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
995 		spin_lock(&sdp->sd_quota_spin);
996 		value += qd->qd_change;
997 		spin_unlock(&sdp->sd_quota_spin);
998 
999 		if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
1000 			print_message(qd, "exceeded");
1001 			error = -EDQUOT;
1002 			break;
1003 		} else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
1004 			   (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
1005 			   time_after_eq(jiffies, qd->qd_last_warn +
1006 					 gfs2_tune_get(sdp,
1007 						gt_quota_warn_period) * HZ)) {
1008 			error = print_message(qd, "warning");
1009 			qd->qd_last_warn = jiffies;
1010 		}
1011 	}
1012 
1013 	return error;
1014 }
1015 
1016 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1017 		       u32 uid, u32 gid)
1018 {
1019 	struct gfs2_alloc *al = &ip->i_alloc;
1020 	struct gfs2_quota_data *qd;
1021 	unsigned int x;
1022 	unsigned int found = 0;
1023 
1024 	if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1025 		return;
1026 	if (ip->i_di.di_flags & GFS2_DIF_SYSTEM)
1027 		return;
1028 
1029 	for (x = 0; x < al->al_qd_num; x++) {
1030 		qd = al->al_qd[x];
1031 
1032 		if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1033 		    (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
1034 			do_qc(qd, change);
1035 			found++;
1036 		}
1037 	}
1038 }
1039 
1040 int gfs2_quota_sync(struct gfs2_sbd *sdp)
1041 {
1042 	struct gfs2_quota_data **qda;
1043 	unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
1044 	unsigned int num_qd;
1045 	unsigned int x;
1046 	int error = 0;
1047 
1048 	sdp->sd_quota_sync_gen++;
1049 
1050 	qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1051 	if (!qda)
1052 		return -ENOMEM;
1053 
1054 	do {
1055 		num_qd = 0;
1056 
1057 		for (;;) {
1058 			error = qd_fish(sdp, qda + num_qd);
1059 			if (error || !qda[num_qd])
1060 				break;
1061 			if (++num_qd == max_qd)
1062 				break;
1063 		}
1064 
1065 		if (num_qd) {
1066 			if (!error)
1067 				error = do_sync(num_qd, qda);
1068 			if (!error)
1069 				for (x = 0; x < num_qd; x++)
1070 					qda[x]->qd_sync_gen =
1071 						sdp->sd_quota_sync_gen;
1072 
1073 			for (x = 0; x < num_qd; x++)
1074 				qd_unlock(qda[x]);
1075 		}
1076 	} while (!error && num_qd == max_qd);
1077 
1078 	kfree(qda);
1079 
1080 	return error;
1081 }
1082 
1083 int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, u32 id)
1084 {
1085 	struct gfs2_quota_data *qd;
1086 	struct gfs2_holder q_gh;
1087 	int error;
1088 
1089 	error = qd_get(sdp, user, id, CREATE, &qd);
1090 	if (error)
1091 		return error;
1092 
1093 	error = do_glock(qd, FORCE, &q_gh);
1094 	if (!error)
1095 		gfs2_glock_dq_uninit(&q_gh);
1096 
1097 	qd_put(qd);
1098 
1099 	return error;
1100 }
1101 
1102 static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
1103 {
1104 	const struct gfs2_quota_change *str = buf;
1105 
1106 	qc->qc_change = be64_to_cpu(str->qc_change);
1107 	qc->qc_flags = be32_to_cpu(str->qc_flags);
1108 	qc->qc_id = be32_to_cpu(str->qc_id);
1109 }
1110 
1111 int gfs2_quota_init(struct gfs2_sbd *sdp)
1112 {
1113 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1114 	unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
1115 	unsigned int x, slot = 0;
1116 	unsigned int found = 0;
1117 	u64 dblock;
1118 	u32 extlen = 0;
1119 	int error;
1120 
1121 	if (!ip->i_di.di_size || ip->i_di.di_size > (64 << 20) ||
1122 	    ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
1123 		gfs2_consist_inode(ip);
1124 		return -EIO;
1125 	}
1126 	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1127 	sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1128 
1129 	error = -ENOMEM;
1130 
1131 	sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1132 				       sizeof(unsigned char *), GFP_KERNEL);
1133 	if (!sdp->sd_quota_bitmap)
1134 		return error;
1135 
1136 	for (x = 0; x < sdp->sd_quota_chunks; x++) {
1137 		sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL);
1138 		if (!sdp->sd_quota_bitmap[x])
1139 			goto fail;
1140 	}
1141 
1142 	for (x = 0; x < blocks; x++) {
1143 		struct buffer_head *bh;
1144 		unsigned int y;
1145 
1146 		if (!extlen) {
1147 			int new = 0;
1148 			error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1149 			if (error)
1150 				goto fail;
1151 		}
1152 		error = -EIO;
1153 		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1154 		if (!bh)
1155 			goto fail;
1156 		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1157 			brelse(bh);
1158 			goto fail;
1159 		}
1160 
1161 		for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1162 		     y++, slot++) {
1163 			struct gfs2_quota_change_host qc;
1164 			struct gfs2_quota_data *qd;
1165 
1166 			gfs2_quota_change_in(&qc, bh->b_data +
1167 					  sizeof(struct gfs2_meta_header) +
1168 					  y * sizeof(struct gfs2_quota_change));
1169 			if (!qc.qc_change)
1170 				continue;
1171 
1172 			error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1173 					 qc.qc_id, &qd);
1174 			if (error) {
1175 				brelse(bh);
1176 				goto fail;
1177 			}
1178 
1179 			set_bit(QDF_CHANGE, &qd->qd_flags);
1180 			qd->qd_change = qc.qc_change;
1181 			qd->qd_slot = slot;
1182 			qd->qd_slot_count = 1;
1183 			qd->qd_last_touched = jiffies;
1184 
1185 			spin_lock(&sdp->sd_quota_spin);
1186 			gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1187 			list_add(&qd->qd_list, &sdp->sd_quota_list);
1188 			atomic_inc(&sdp->sd_quota_count);
1189 			spin_unlock(&sdp->sd_quota_spin);
1190 
1191 			found++;
1192 		}
1193 
1194 		brelse(bh);
1195 		dblock++;
1196 		extlen--;
1197 	}
1198 
1199 	if (found)
1200 		fs_info(sdp, "found %u quota changes\n", found);
1201 
1202 	return 0;
1203 
1204 fail:
1205 	gfs2_quota_cleanup(sdp);
1206 	return error;
1207 }
1208 
1209 void gfs2_quota_scan(struct gfs2_sbd *sdp)
1210 {
1211 	struct gfs2_quota_data *qd, *safe;
1212 	LIST_HEAD(dead);
1213 
1214 	spin_lock(&sdp->sd_quota_spin);
1215 	list_for_each_entry_safe(qd, safe, &sdp->sd_quota_list, qd_list) {
1216 		if (!qd->qd_count &&
1217 		    time_after_eq(jiffies, qd->qd_last_touched +
1218 			        gfs2_tune_get(sdp, gt_quota_cache_secs) * HZ)) {
1219 			list_move(&qd->qd_list, &dead);
1220 			gfs2_assert_warn(sdp,
1221 					 atomic_read(&sdp->sd_quota_count) > 0);
1222 			atomic_dec(&sdp->sd_quota_count);
1223 		}
1224 	}
1225 	spin_unlock(&sdp->sd_quota_spin);
1226 
1227 	while (!list_empty(&dead)) {
1228 		qd = list_entry(dead.next, struct gfs2_quota_data, qd_list);
1229 		list_del(&qd->qd_list);
1230 
1231 		gfs2_assert_warn(sdp, !qd->qd_change);
1232 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
1233 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1234 
1235 		gfs2_lvb_unhold(qd->qd_gl);
1236 		kfree(qd);
1237 	}
1238 }
1239 
1240 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1241 {
1242 	struct list_head *head = &sdp->sd_quota_list;
1243 	struct gfs2_quota_data *qd;
1244 	unsigned int x;
1245 
1246 	spin_lock(&sdp->sd_quota_spin);
1247 	while (!list_empty(head)) {
1248 		qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1249 
1250 		if (qd->qd_count > 1 ||
1251 		    (qd->qd_count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1252 			list_move(&qd->qd_list, head);
1253 			spin_unlock(&sdp->sd_quota_spin);
1254 			schedule();
1255 			spin_lock(&sdp->sd_quota_spin);
1256 			continue;
1257 		}
1258 
1259 		list_del(&qd->qd_list);
1260 		atomic_dec(&sdp->sd_quota_count);
1261 		spin_unlock(&sdp->sd_quota_spin);
1262 
1263 		if (!qd->qd_count) {
1264 			gfs2_assert_warn(sdp, !qd->qd_change);
1265 			gfs2_assert_warn(sdp, !qd->qd_slot_count);
1266 		} else
1267 			gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1268 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1269 
1270 		gfs2_lvb_unhold(qd->qd_gl);
1271 		kfree(qd);
1272 
1273 		spin_lock(&sdp->sd_quota_spin);
1274 	}
1275 	spin_unlock(&sdp->sd_quota_spin);
1276 
1277 	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1278 
1279 	if (sdp->sd_quota_bitmap) {
1280 		for (x = 0; x < sdp->sd_quota_chunks; x++)
1281 			kfree(sdp->sd_quota_bitmap[x]);
1282 		kfree(sdp->sd_quota_bitmap);
1283 	}
1284 }
1285 
1286