xref: /linux/fs/gfs2/quota.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2007 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_address.h"
63 #include "util.h"
64 
65 #define QUOTA_USER 1
66 #define QUOTA_GROUP 0
67 
68 struct gfs2_quota_host {
69 	u64 qu_limit;
70 	u64 qu_warn;
71 	s64 qu_value;
72 	u32 qu_ll_next;
73 };
74 
75 struct gfs2_quota_change_host {
76 	u64 qc_change;
77 	u32 qc_flags; /* GFS2_QCF_... */
78 	u32 qc_id;
79 };
80 
81 static u64 qd2offset(struct gfs2_quota_data *qd)
82 {
83 	u64 offset;
84 
85 	offset = 2 * (u64)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
86 	offset *= sizeof(struct gfs2_quota);
87 
88 	return offset;
89 }
90 
91 static int qd_alloc(struct gfs2_sbd *sdp, int user, u32 id,
92 		    struct gfs2_quota_data **qdp)
93 {
94 	struct gfs2_quota_data *qd;
95 	int error;
96 
97 	qd = kzalloc(sizeof(struct gfs2_quota_data), GFP_NOFS);
98 	if (!qd)
99 		return -ENOMEM;
100 
101 	qd->qd_count = 1;
102 	qd->qd_id = id;
103 	if (user)
104 		set_bit(QDF_USER, &qd->qd_flags);
105 	qd->qd_slot = -1;
106 
107 	error = gfs2_glock_get(sdp, 2 * (u64)id + !user,
108 			      &gfs2_quota_glops, CREATE, &qd->qd_gl);
109 	if (error)
110 		goto fail;
111 
112 	error = gfs2_lvb_hold(qd->qd_gl);
113 	gfs2_glock_put(qd->qd_gl);
114 	if (error)
115 		goto fail;
116 
117 	*qdp = qd;
118 
119 	return 0;
120 
121 fail:
122 	kfree(qd);
123 	return error;
124 }
125 
126 static int qd_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
127 		  struct gfs2_quota_data **qdp)
128 {
129 	struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
130 	int error, found;
131 
132 	*qdp = NULL;
133 
134 	for (;;) {
135 		found = 0;
136 		spin_lock(&sdp->sd_quota_spin);
137 		list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
138 			if (qd->qd_id == id &&
139 			    !test_bit(QDF_USER, &qd->qd_flags) == !user) {
140 				qd->qd_count++;
141 				found = 1;
142 				break;
143 			}
144 		}
145 
146 		if (!found)
147 			qd = NULL;
148 
149 		if (!qd && new_qd) {
150 			qd = new_qd;
151 			list_add(&qd->qd_list, &sdp->sd_quota_list);
152 			atomic_inc(&sdp->sd_quota_count);
153 			new_qd = NULL;
154 		}
155 
156 		spin_unlock(&sdp->sd_quota_spin);
157 
158 		if (qd || !create) {
159 			if (new_qd) {
160 				gfs2_lvb_unhold(new_qd->qd_gl);
161 				kfree(new_qd);
162 			}
163 			*qdp = qd;
164 			return 0;
165 		}
166 
167 		error = qd_alloc(sdp, user, id, &new_qd);
168 		if (error)
169 			return error;
170 	}
171 }
172 
173 static void qd_hold(struct gfs2_quota_data *qd)
174 {
175 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
176 
177 	spin_lock(&sdp->sd_quota_spin);
178 	gfs2_assert(sdp, qd->qd_count);
179 	qd->qd_count++;
180 	spin_unlock(&sdp->sd_quota_spin);
181 }
182 
183 static void qd_put(struct gfs2_quota_data *qd)
184 {
185 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
186 	spin_lock(&sdp->sd_quota_spin);
187 	gfs2_assert(sdp, qd->qd_count);
188 	if (!--qd->qd_count)
189 		qd->qd_last_touched = jiffies;
190 	spin_unlock(&sdp->sd_quota_spin);
191 }
192 
193 static int slot_get(struct gfs2_quota_data *qd)
194 {
195 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
196 	unsigned int c, o = 0, b;
197 	unsigned char byte = 0;
198 
199 	spin_lock(&sdp->sd_quota_spin);
200 
201 	if (qd->qd_slot_count++) {
202 		spin_unlock(&sdp->sd_quota_spin);
203 		return 0;
204 	}
205 
206 	for (c = 0; c < sdp->sd_quota_chunks; c++)
207 		for (o = 0; o < PAGE_SIZE; o++) {
208 			byte = sdp->sd_quota_bitmap[c][o];
209 			if (byte != 0xFF)
210 				goto found;
211 		}
212 
213 	goto fail;
214 
215 found:
216 	for (b = 0; b < 8; b++)
217 		if (!(byte & (1 << b)))
218 			break;
219 	qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
220 
221 	if (qd->qd_slot >= sdp->sd_quota_slots)
222 		goto fail;
223 
224 	sdp->sd_quota_bitmap[c][o] |= 1 << b;
225 
226 	spin_unlock(&sdp->sd_quota_spin);
227 
228 	return 0;
229 
230 fail:
231 	qd->qd_slot_count--;
232 	spin_unlock(&sdp->sd_quota_spin);
233 	return -ENOSPC;
234 }
235 
236 static void slot_hold(struct gfs2_quota_data *qd)
237 {
238 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
239 
240 	spin_lock(&sdp->sd_quota_spin);
241 	gfs2_assert(sdp, qd->qd_slot_count);
242 	qd->qd_slot_count++;
243 	spin_unlock(&sdp->sd_quota_spin);
244 }
245 
246 static void slot_put(struct gfs2_quota_data *qd)
247 {
248 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
249 
250 	spin_lock(&sdp->sd_quota_spin);
251 	gfs2_assert(sdp, qd->qd_slot_count);
252 	if (!--qd->qd_slot_count) {
253 		gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
254 		qd->qd_slot = -1;
255 	}
256 	spin_unlock(&sdp->sd_quota_spin);
257 }
258 
259 static int bh_get(struct gfs2_quota_data *qd)
260 {
261 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
262 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
263 	unsigned int block, offset;
264 	struct buffer_head *bh;
265 	int error;
266 	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
267 
268 	mutex_lock(&sdp->sd_quota_mutex);
269 
270 	if (qd->qd_bh_count++) {
271 		mutex_unlock(&sdp->sd_quota_mutex);
272 		return 0;
273 	}
274 
275 	block = qd->qd_slot / sdp->sd_qc_per_block;
276 	offset = qd->qd_slot % sdp->sd_qc_per_block;
277 
278 	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
279 	error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
280 	if (error)
281 		goto fail;
282 	error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
283 	if (error)
284 		goto fail;
285 	error = -EIO;
286 	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
287 		goto fail_brelse;
288 
289 	qd->qd_bh = bh;
290 	qd->qd_bh_qc = (struct gfs2_quota_change *)
291 		(bh->b_data + sizeof(struct gfs2_meta_header) +
292 		 offset * sizeof(struct gfs2_quota_change));
293 
294 	mutex_unlock(&sdp->sd_quota_mutex);
295 
296 	return 0;
297 
298 fail_brelse:
299 	brelse(bh);
300 fail:
301 	qd->qd_bh_count--;
302 	mutex_unlock(&sdp->sd_quota_mutex);
303 	return error;
304 }
305 
306 static void bh_put(struct gfs2_quota_data *qd)
307 {
308 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
309 
310 	mutex_lock(&sdp->sd_quota_mutex);
311 	gfs2_assert(sdp, qd->qd_bh_count);
312 	if (!--qd->qd_bh_count) {
313 		brelse(qd->qd_bh);
314 		qd->qd_bh = NULL;
315 		qd->qd_bh_qc = NULL;
316 	}
317 	mutex_unlock(&sdp->sd_quota_mutex);
318 }
319 
320 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
321 {
322 	struct gfs2_quota_data *qd = NULL;
323 	int error;
324 	int found = 0;
325 
326 	*qdp = NULL;
327 
328 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
329 		return 0;
330 
331 	spin_lock(&sdp->sd_quota_spin);
332 
333 	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
334 		if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
335 		    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
336 		    qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
337 			continue;
338 
339 		list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
340 
341 		set_bit(QDF_LOCKED, &qd->qd_flags);
342 		gfs2_assert_warn(sdp, qd->qd_count);
343 		qd->qd_count++;
344 		qd->qd_change_sync = qd->qd_change;
345 		gfs2_assert_warn(sdp, qd->qd_slot_count);
346 		qd->qd_slot_count++;
347 		found = 1;
348 
349 		break;
350 	}
351 
352 	if (!found)
353 		qd = NULL;
354 
355 	spin_unlock(&sdp->sd_quota_spin);
356 
357 	if (qd) {
358 		gfs2_assert_warn(sdp, qd->qd_change_sync);
359 		error = bh_get(qd);
360 		if (error) {
361 			clear_bit(QDF_LOCKED, &qd->qd_flags);
362 			slot_put(qd);
363 			qd_put(qd);
364 			return error;
365 		}
366 	}
367 
368 	*qdp = qd;
369 
370 	return 0;
371 }
372 
373 static int qd_trylock(struct gfs2_quota_data *qd)
374 {
375 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
376 
377 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
378 		return 0;
379 
380 	spin_lock(&sdp->sd_quota_spin);
381 
382 	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
383 	    !test_bit(QDF_CHANGE, &qd->qd_flags)) {
384 		spin_unlock(&sdp->sd_quota_spin);
385 		return 0;
386 	}
387 
388 	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
389 
390 	set_bit(QDF_LOCKED, &qd->qd_flags);
391 	gfs2_assert_warn(sdp, qd->qd_count);
392 	qd->qd_count++;
393 	qd->qd_change_sync = qd->qd_change;
394 	gfs2_assert_warn(sdp, qd->qd_slot_count);
395 	qd->qd_slot_count++;
396 
397 	spin_unlock(&sdp->sd_quota_spin);
398 
399 	gfs2_assert_warn(sdp, qd->qd_change_sync);
400 	if (bh_get(qd)) {
401 		clear_bit(QDF_LOCKED, &qd->qd_flags);
402 		slot_put(qd);
403 		qd_put(qd);
404 		return 0;
405 	}
406 
407 	return 1;
408 }
409 
410 static void qd_unlock(struct gfs2_quota_data *qd)
411 {
412 	gfs2_assert_warn(qd->qd_gl->gl_sbd,
413 			 test_bit(QDF_LOCKED, &qd->qd_flags));
414 	clear_bit(QDF_LOCKED, &qd->qd_flags);
415 	bh_put(qd);
416 	slot_put(qd);
417 	qd_put(qd);
418 }
419 
420 static int qdsb_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
421 		    struct gfs2_quota_data **qdp)
422 {
423 	int error;
424 
425 	error = qd_get(sdp, user, id, create, qdp);
426 	if (error)
427 		return error;
428 
429 	error = slot_get(*qdp);
430 	if (error)
431 		goto fail;
432 
433 	error = bh_get(*qdp);
434 	if (error)
435 		goto fail_slot;
436 
437 	return 0;
438 
439 fail_slot:
440 	slot_put(*qdp);
441 fail:
442 	qd_put(*qdp);
443 	return error;
444 }
445 
446 static void qdsb_put(struct gfs2_quota_data *qd)
447 {
448 	bh_put(qd);
449 	slot_put(qd);
450 	qd_put(qd);
451 }
452 
453 int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
454 {
455 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
456 	struct gfs2_alloc *al = ip->i_alloc;
457 	struct gfs2_quota_data **qd = al->al_qd;
458 	int error;
459 
460 	if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
461 	    gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
462 		return -EIO;
463 
464 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
465 		return 0;
466 
467 	error = qdsb_get(sdp, QUOTA_USER, ip->i_inode.i_uid, CREATE, qd);
468 	if (error)
469 		goto out;
470 	al->al_qd_num++;
471 	qd++;
472 
473 	error = qdsb_get(sdp, QUOTA_GROUP, ip->i_inode.i_gid, CREATE, qd);
474 	if (error)
475 		goto out;
476 	al->al_qd_num++;
477 	qd++;
478 
479 	if (uid != NO_QUOTA_CHANGE && uid != ip->i_inode.i_uid) {
480 		error = qdsb_get(sdp, QUOTA_USER, uid, CREATE, qd);
481 		if (error)
482 			goto out;
483 		al->al_qd_num++;
484 		qd++;
485 	}
486 
487 	if (gid != NO_QUOTA_CHANGE && gid != ip->i_inode.i_gid) {
488 		error = qdsb_get(sdp, QUOTA_GROUP, gid, CREATE, qd);
489 		if (error)
490 			goto out;
491 		al->al_qd_num++;
492 		qd++;
493 	}
494 
495 out:
496 	if (error)
497 		gfs2_quota_unhold(ip);
498 	return error;
499 }
500 
501 void gfs2_quota_unhold(struct gfs2_inode *ip)
502 {
503 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
504 	struct gfs2_alloc *al = ip->i_alloc;
505 	unsigned int x;
506 
507 	gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
508 
509 	for (x = 0; x < al->al_qd_num; x++) {
510 		qdsb_put(al->al_qd[x]);
511 		al->al_qd[x] = NULL;
512 	}
513 	al->al_qd_num = 0;
514 }
515 
516 static int sort_qd(const void *a, const void *b)
517 {
518 	const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
519 	const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
520 
521 	if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
522 	    !test_bit(QDF_USER, &qd_b->qd_flags)) {
523 		if (test_bit(QDF_USER, &qd_a->qd_flags))
524 			return -1;
525 		else
526 			return 1;
527 	}
528 	if (qd_a->qd_id < qd_b->qd_id)
529 		return -1;
530 	if (qd_a->qd_id > qd_b->qd_id)
531 		return 1;
532 
533 	return 0;
534 }
535 
536 static void do_qc(struct gfs2_quota_data *qd, s64 change)
537 {
538 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
539 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
540 	struct gfs2_quota_change *qc = qd->qd_bh_qc;
541 	s64 x;
542 
543 	mutex_lock(&sdp->sd_quota_mutex);
544 	gfs2_trans_add_bh(ip->i_gl, qd->qd_bh, 1);
545 
546 	if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
547 		qc->qc_change = 0;
548 		qc->qc_flags = 0;
549 		if (test_bit(QDF_USER, &qd->qd_flags))
550 			qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
551 		qc->qc_id = cpu_to_be32(qd->qd_id);
552 	}
553 
554 	x = be64_to_cpu(qc->qc_change) + change;
555 	qc->qc_change = cpu_to_be64(x);
556 
557 	spin_lock(&sdp->sd_quota_spin);
558 	qd->qd_change = x;
559 	spin_unlock(&sdp->sd_quota_spin);
560 
561 	if (!x) {
562 		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
563 		clear_bit(QDF_CHANGE, &qd->qd_flags);
564 		qc->qc_flags = 0;
565 		qc->qc_id = 0;
566 		slot_put(qd);
567 		qd_put(qd);
568 	} else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
569 		qd_hold(qd);
570 		slot_hold(qd);
571 	}
572 
573 	mutex_unlock(&sdp->sd_quota_mutex);
574 }
575 
576 static void gfs2_quota_in(struct gfs2_quota_host *qu, const void *buf)
577 {
578 	const struct gfs2_quota *str = buf;
579 
580 	qu->qu_limit = be64_to_cpu(str->qu_limit);
581 	qu->qu_warn = be64_to_cpu(str->qu_warn);
582 	qu->qu_value = be64_to_cpu(str->qu_value);
583 	qu->qu_ll_next = be32_to_cpu(str->qu_ll_next);
584 }
585 
586 static void gfs2_quota_out(const struct gfs2_quota_host *qu, void *buf)
587 {
588 	struct gfs2_quota *str = buf;
589 
590 	str->qu_limit = cpu_to_be64(qu->qu_limit);
591 	str->qu_warn = cpu_to_be64(qu->qu_warn);
592 	str->qu_value = cpu_to_be64(qu->qu_value);
593 	str->qu_ll_next = cpu_to_be32(qu->qu_ll_next);
594 	memset(&str->qu_reserved, 0, sizeof(str->qu_reserved));
595 }
596 
597 /**
598  * gfs2_adjust_quota
599  *
600  * This function was mostly borrowed from gfs2_block_truncate_page which was
601  * in turn mostly borrowed from ext3
602  */
603 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
604 			     s64 change, struct gfs2_quota_data *qd)
605 {
606 	struct inode *inode = &ip->i_inode;
607 	struct address_space *mapping = inode->i_mapping;
608 	unsigned long index = loc >> PAGE_CACHE_SHIFT;
609 	unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
610 	unsigned blocksize, iblock, pos;
611 	struct buffer_head *bh;
612 	struct page *page;
613 	void *kaddr;
614 	char *ptr;
615 	struct gfs2_quota_host qp;
616 	s64 value;
617 	int err = -EIO;
618 
619 	if (gfs2_is_stuffed(ip))
620 		gfs2_unstuff_dinode(ip, NULL);
621 
622 	page = grab_cache_page(mapping, index);
623 	if (!page)
624 		return -ENOMEM;
625 
626 	blocksize = inode->i_sb->s_blocksize;
627 	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
628 
629 	if (!page_has_buffers(page))
630 		create_empty_buffers(page, blocksize, 0);
631 
632 	bh = page_buffers(page);
633 	pos = blocksize;
634 	while (offset >= pos) {
635 		bh = bh->b_this_page;
636 		iblock++;
637 		pos += blocksize;
638 	}
639 
640 	if (!buffer_mapped(bh)) {
641 		gfs2_block_map(inode, iblock, bh, 1);
642 		if (!buffer_mapped(bh))
643 			goto unlock;
644 	}
645 
646 	if (PageUptodate(page))
647 		set_buffer_uptodate(bh);
648 
649 	if (!buffer_uptodate(bh)) {
650 		ll_rw_block(READ_META, 1, &bh);
651 		wait_on_buffer(bh);
652 		if (!buffer_uptodate(bh))
653 			goto unlock;
654 	}
655 
656 	gfs2_trans_add_bh(ip->i_gl, bh, 0);
657 
658 	kaddr = kmap_atomic(page, KM_USER0);
659 	ptr = kaddr + offset;
660 	gfs2_quota_in(&qp, ptr);
661 	qp.qu_value += change;
662 	value = qp.qu_value;
663 	gfs2_quota_out(&qp, ptr);
664 	flush_dcache_page(page);
665 	kunmap_atomic(kaddr, KM_USER0);
666 	err = 0;
667 	qd->qd_qb.qb_magic = cpu_to_be32(GFS2_MAGIC);
668 	qd->qd_qb.qb_value = cpu_to_be64(value);
669 	((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_magic = cpu_to_be32(GFS2_MAGIC);
670 	((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_value = cpu_to_be64(value);
671 unlock:
672 	unlock_page(page);
673 	page_cache_release(page);
674 	return err;
675 }
676 
677 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
678 {
679 	struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
680 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
681 	unsigned int data_blocks, ind_blocks;
682 	struct gfs2_holder *ghs, i_gh;
683 	unsigned int qx, x;
684 	struct gfs2_quota_data *qd;
685 	loff_t offset;
686 	unsigned int nalloc = 0, blocks;
687 	struct gfs2_alloc *al = NULL;
688 	int error;
689 
690 	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
691 			      &data_blocks, &ind_blocks);
692 
693 	ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
694 	if (!ghs)
695 		return -ENOMEM;
696 
697 	sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
698 	for (qx = 0; qx < num_qd; qx++) {
699 		error = gfs2_glock_nq_init(qda[qx]->qd_gl,
700 					   LM_ST_EXCLUSIVE,
701 					   GL_NOCACHE, &ghs[qx]);
702 		if (error)
703 			goto out;
704 	}
705 
706 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
707 	if (error)
708 		goto out;
709 
710 	for (x = 0; x < num_qd; x++) {
711 		int alloc_required;
712 
713 		offset = qd2offset(qda[x]);
714 		error = gfs2_write_alloc_required(ip, offset,
715 						  sizeof(struct gfs2_quota),
716 						  &alloc_required);
717 		if (error)
718 			goto out_gunlock;
719 		if (alloc_required)
720 			nalloc++;
721 	}
722 
723 	al = gfs2_alloc_get(ip);
724 	if (!al) {
725 		error = -ENOMEM;
726 		goto out_gunlock;
727 	}
728 	/*
729 	 * 1 blk for unstuffing inode if stuffed. We add this extra
730 	 * block to the reservation unconditionally. If the inode
731 	 * doesn't need unstuffing, the block will be released to the
732 	 * rgrp since it won't be allocated during the transaction
733 	 */
734 	al->al_requested = 1;
735 	/* +1 in the end for block requested above for unstuffing */
736 	blocks = num_qd * data_blocks + RES_DINODE + num_qd + 1;
737 
738 	if (nalloc)
739 		al->al_requested += nalloc * (data_blocks + ind_blocks);
740 	error = gfs2_inplace_reserve(ip);
741 	if (error)
742 		goto out_alloc;
743 
744 	if (nalloc)
745 		blocks += al->al_rgd->rd_length + nalloc * ind_blocks + RES_STATFS;
746 
747 	error = gfs2_trans_begin(sdp, blocks, 0);
748 	if (error)
749 		goto out_ipres;
750 
751 	for (x = 0; x < num_qd; x++) {
752 		qd = qda[x];
753 		offset = qd2offset(qd);
754 		error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync,
755 					  (struct gfs2_quota_data *)
756 					  qd);
757 		if (error)
758 			goto out_end_trans;
759 
760 		do_qc(qd, -qd->qd_change_sync);
761 	}
762 
763 	error = 0;
764 
765 out_end_trans:
766 	gfs2_trans_end(sdp);
767 out_ipres:
768 	gfs2_inplace_release(ip);
769 out_alloc:
770 	gfs2_alloc_put(ip);
771 out_gunlock:
772 	gfs2_glock_dq_uninit(&i_gh);
773 out:
774 	while (qx--)
775 		gfs2_glock_dq_uninit(&ghs[qx]);
776 	kfree(ghs);
777 	gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
778 	return error;
779 }
780 
781 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
782 		    struct gfs2_holder *q_gh)
783 {
784 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
785 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
786 	struct gfs2_holder i_gh;
787 	struct gfs2_quota_host q;
788 	char buf[sizeof(struct gfs2_quota)];
789 	int error;
790 	struct gfs2_quota_lvb *qlvb;
791 
792 restart:
793 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
794 	if (error)
795 		return error;
796 
797 	qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
798 
799 	if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
800 		loff_t pos;
801 		gfs2_glock_dq_uninit(q_gh);
802 		error = gfs2_glock_nq_init(qd->qd_gl,
803 					  LM_ST_EXCLUSIVE, GL_NOCACHE,
804 					  q_gh);
805 		if (error)
806 			return error;
807 
808 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
809 		if (error)
810 			goto fail;
811 
812 		memset(buf, 0, sizeof(struct gfs2_quota));
813 		pos = qd2offset(qd);
814 		error = gfs2_internal_read(ip, NULL, buf, &pos,
815 					   sizeof(struct gfs2_quota));
816 		if (error < 0)
817 			goto fail_gunlock;
818 
819 		gfs2_glock_dq_uninit(&i_gh);
820 
821 
822 		gfs2_quota_in(&q, buf);
823 		qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
824 		qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
825 		qlvb->__pad = 0;
826 		qlvb->qb_limit = cpu_to_be64(q.qu_limit);
827 		qlvb->qb_warn = cpu_to_be64(q.qu_warn);
828 		qlvb->qb_value = cpu_to_be64(q.qu_value);
829 		qd->qd_qb = *qlvb;
830 
831 		if (gfs2_glock_is_blocking(qd->qd_gl)) {
832 			gfs2_glock_dq_uninit(q_gh);
833 			force_refresh = 0;
834 			goto restart;
835 		}
836 	}
837 
838 	return 0;
839 
840 fail_gunlock:
841 	gfs2_glock_dq_uninit(&i_gh);
842 fail:
843 	gfs2_glock_dq_uninit(q_gh);
844 	return error;
845 }
846 
847 int gfs2_quota_lock(struct gfs2_inode *ip, u32 uid, u32 gid)
848 {
849 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
850 	struct gfs2_alloc *al = ip->i_alloc;
851 	unsigned int x;
852 	int error = 0;
853 
854 	gfs2_quota_hold(ip, uid, gid);
855 
856 	if (capable(CAP_SYS_RESOURCE) ||
857 	    sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
858 		return 0;
859 
860 	sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
861 	     sort_qd, NULL);
862 
863 	for (x = 0; x < al->al_qd_num; x++) {
864 		error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
865 		if (error)
866 			break;
867 	}
868 
869 	if (!error)
870 		set_bit(GIF_QD_LOCKED, &ip->i_flags);
871 	else {
872 		while (x--)
873 			gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
874 		gfs2_quota_unhold(ip);
875 	}
876 
877 	return error;
878 }
879 
880 static int need_sync(struct gfs2_quota_data *qd)
881 {
882 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
883 	struct gfs2_tune *gt = &sdp->sd_tune;
884 	s64 value;
885 	unsigned int num, den;
886 	int do_sync = 1;
887 
888 	if (!qd->qd_qb.qb_limit)
889 		return 0;
890 
891 	spin_lock(&sdp->sd_quota_spin);
892 	value = qd->qd_change;
893 	spin_unlock(&sdp->sd_quota_spin);
894 
895 	spin_lock(&gt->gt_spin);
896 	num = gt->gt_quota_scale_num;
897 	den = gt->gt_quota_scale_den;
898 	spin_unlock(&gt->gt_spin);
899 
900 	if (value < 0)
901 		do_sync = 0;
902 	else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
903 		 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
904 		do_sync = 0;
905 	else {
906 		value *= gfs2_jindex_size(sdp) * num;
907 		value = div_s64(value, den);
908 		value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
909 		if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
910 			do_sync = 0;
911 	}
912 
913 	return do_sync;
914 }
915 
916 void gfs2_quota_unlock(struct gfs2_inode *ip)
917 {
918 	struct gfs2_alloc *al = ip->i_alloc;
919 	struct gfs2_quota_data *qda[4];
920 	unsigned int count = 0;
921 	unsigned int x;
922 
923 	if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
924 		goto out;
925 
926 	for (x = 0; x < al->al_qd_num; x++) {
927 		struct gfs2_quota_data *qd;
928 		int sync;
929 
930 		qd = al->al_qd[x];
931 		sync = need_sync(qd);
932 
933 		gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
934 
935 		if (sync && qd_trylock(qd))
936 			qda[count++] = qd;
937 	}
938 
939 	if (count) {
940 		do_sync(count, qda);
941 		for (x = 0; x < count; x++)
942 			qd_unlock(qda[x]);
943 	}
944 
945 out:
946 	gfs2_quota_unhold(ip);
947 }
948 
949 #define MAX_LINE 256
950 
951 static int print_message(struct gfs2_quota_data *qd, char *type)
952 {
953 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
954 
955 	printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\r\n",
956 	       sdp->sd_fsname, type,
957 	       (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
958 	       qd->qd_id);
959 
960 	return 0;
961 }
962 
963 int gfs2_quota_check(struct gfs2_inode *ip, u32 uid, u32 gid)
964 {
965 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
966 	struct gfs2_alloc *al = ip->i_alloc;
967 	struct gfs2_quota_data *qd;
968 	s64 value;
969 	unsigned int x;
970 	int error = 0;
971 
972 	if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
973 		return 0;
974 
975         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
976                 return 0;
977 
978 	for (x = 0; x < al->al_qd_num; x++) {
979 		qd = al->al_qd[x];
980 
981 		if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
982 		      (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
983 			continue;
984 
985 		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
986 		spin_lock(&sdp->sd_quota_spin);
987 		value += qd->qd_change;
988 		spin_unlock(&sdp->sd_quota_spin);
989 
990 		if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
991 			print_message(qd, "exceeded");
992 			error = -EDQUOT;
993 			break;
994 		} else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
995 			   (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
996 			   time_after_eq(jiffies, qd->qd_last_warn +
997 					 gfs2_tune_get(sdp,
998 						gt_quota_warn_period) * HZ)) {
999 			error = print_message(qd, "warning");
1000 			qd->qd_last_warn = jiffies;
1001 		}
1002 	}
1003 
1004 	return error;
1005 }
1006 
1007 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1008 		       u32 uid, u32 gid)
1009 {
1010 	struct gfs2_alloc *al = ip->i_alloc;
1011 	struct gfs2_quota_data *qd;
1012 	unsigned int x;
1013 
1014 	if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1015 		return;
1016 	if (ip->i_di.di_flags & GFS2_DIF_SYSTEM)
1017 		return;
1018 
1019 	for (x = 0; x < al->al_qd_num; x++) {
1020 		qd = al->al_qd[x];
1021 
1022 		if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1023 		    (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
1024 			do_qc(qd, change);
1025 		}
1026 	}
1027 }
1028 
1029 int gfs2_quota_sync(struct gfs2_sbd *sdp)
1030 {
1031 	struct gfs2_quota_data **qda;
1032 	unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
1033 	unsigned int num_qd;
1034 	unsigned int x;
1035 	int error = 0;
1036 
1037 	sdp->sd_quota_sync_gen++;
1038 
1039 	qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1040 	if (!qda)
1041 		return -ENOMEM;
1042 
1043 	do {
1044 		num_qd = 0;
1045 
1046 		for (;;) {
1047 			error = qd_fish(sdp, qda + num_qd);
1048 			if (error || !qda[num_qd])
1049 				break;
1050 			if (++num_qd == max_qd)
1051 				break;
1052 		}
1053 
1054 		if (num_qd) {
1055 			if (!error)
1056 				error = do_sync(num_qd, qda);
1057 			if (!error)
1058 				for (x = 0; x < num_qd; x++)
1059 					qda[x]->qd_sync_gen =
1060 						sdp->sd_quota_sync_gen;
1061 
1062 			for (x = 0; x < num_qd; x++)
1063 				qd_unlock(qda[x]);
1064 		}
1065 	} while (!error && num_qd == max_qd);
1066 
1067 	kfree(qda);
1068 
1069 	return error;
1070 }
1071 
1072 int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, u32 id)
1073 {
1074 	struct gfs2_quota_data *qd;
1075 	struct gfs2_holder q_gh;
1076 	int error;
1077 
1078 	error = qd_get(sdp, user, id, CREATE, &qd);
1079 	if (error)
1080 		return error;
1081 
1082 	error = do_glock(qd, FORCE, &q_gh);
1083 	if (!error)
1084 		gfs2_glock_dq_uninit(&q_gh);
1085 
1086 	qd_put(qd);
1087 
1088 	return error;
1089 }
1090 
1091 static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
1092 {
1093 	const struct gfs2_quota_change *str = buf;
1094 
1095 	qc->qc_change = be64_to_cpu(str->qc_change);
1096 	qc->qc_flags = be32_to_cpu(str->qc_flags);
1097 	qc->qc_id = be32_to_cpu(str->qc_id);
1098 }
1099 
1100 int gfs2_quota_init(struct gfs2_sbd *sdp)
1101 {
1102 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1103 	unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
1104 	unsigned int x, slot = 0;
1105 	unsigned int found = 0;
1106 	u64 dblock;
1107 	u32 extlen = 0;
1108 	int error;
1109 
1110 	if (!ip->i_di.di_size || ip->i_di.di_size > (64 << 20) ||
1111 	    ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
1112 		gfs2_consist_inode(ip);
1113 		return -EIO;
1114 	}
1115 	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1116 	sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1117 
1118 	error = -ENOMEM;
1119 
1120 	sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1121 				       sizeof(unsigned char *), GFP_NOFS);
1122 	if (!sdp->sd_quota_bitmap)
1123 		return error;
1124 
1125 	for (x = 0; x < sdp->sd_quota_chunks; x++) {
1126 		sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_NOFS);
1127 		if (!sdp->sd_quota_bitmap[x])
1128 			goto fail;
1129 	}
1130 
1131 	for (x = 0; x < blocks; x++) {
1132 		struct buffer_head *bh;
1133 		unsigned int y;
1134 
1135 		if (!extlen) {
1136 			int new = 0;
1137 			error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1138 			if (error)
1139 				goto fail;
1140 		}
1141 		error = -EIO;
1142 		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1143 		if (!bh)
1144 			goto fail;
1145 		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1146 			brelse(bh);
1147 			goto fail;
1148 		}
1149 
1150 		for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1151 		     y++, slot++) {
1152 			struct gfs2_quota_change_host qc;
1153 			struct gfs2_quota_data *qd;
1154 
1155 			gfs2_quota_change_in(&qc, bh->b_data +
1156 					  sizeof(struct gfs2_meta_header) +
1157 					  y * sizeof(struct gfs2_quota_change));
1158 			if (!qc.qc_change)
1159 				continue;
1160 
1161 			error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1162 					 qc.qc_id, &qd);
1163 			if (error) {
1164 				brelse(bh);
1165 				goto fail;
1166 			}
1167 
1168 			set_bit(QDF_CHANGE, &qd->qd_flags);
1169 			qd->qd_change = qc.qc_change;
1170 			qd->qd_slot = slot;
1171 			qd->qd_slot_count = 1;
1172 			qd->qd_last_touched = jiffies;
1173 
1174 			spin_lock(&sdp->sd_quota_spin);
1175 			gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1176 			list_add(&qd->qd_list, &sdp->sd_quota_list);
1177 			atomic_inc(&sdp->sd_quota_count);
1178 			spin_unlock(&sdp->sd_quota_spin);
1179 
1180 			found++;
1181 		}
1182 
1183 		brelse(bh);
1184 		dblock++;
1185 		extlen--;
1186 	}
1187 
1188 	if (found)
1189 		fs_info(sdp, "found %u quota changes\n", found);
1190 
1191 	return 0;
1192 
1193 fail:
1194 	gfs2_quota_cleanup(sdp);
1195 	return error;
1196 }
1197 
1198 void gfs2_quota_scan(struct gfs2_sbd *sdp)
1199 {
1200 	struct gfs2_quota_data *qd, *safe;
1201 	LIST_HEAD(dead);
1202 
1203 	spin_lock(&sdp->sd_quota_spin);
1204 	list_for_each_entry_safe(qd, safe, &sdp->sd_quota_list, qd_list) {
1205 		if (!qd->qd_count &&
1206 		    time_after_eq(jiffies, qd->qd_last_touched +
1207 			        gfs2_tune_get(sdp, gt_quota_cache_secs) * HZ)) {
1208 			list_move(&qd->qd_list, &dead);
1209 			gfs2_assert_warn(sdp,
1210 					 atomic_read(&sdp->sd_quota_count) > 0);
1211 			atomic_dec(&sdp->sd_quota_count);
1212 		}
1213 	}
1214 	spin_unlock(&sdp->sd_quota_spin);
1215 
1216 	while (!list_empty(&dead)) {
1217 		qd = list_entry(dead.next, struct gfs2_quota_data, qd_list);
1218 		list_del(&qd->qd_list);
1219 
1220 		gfs2_assert_warn(sdp, !qd->qd_change);
1221 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
1222 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1223 
1224 		gfs2_lvb_unhold(qd->qd_gl);
1225 		kfree(qd);
1226 	}
1227 }
1228 
1229 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1230 {
1231 	struct list_head *head = &sdp->sd_quota_list;
1232 	struct gfs2_quota_data *qd;
1233 	unsigned int x;
1234 
1235 	spin_lock(&sdp->sd_quota_spin);
1236 	while (!list_empty(head)) {
1237 		qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1238 
1239 		if (qd->qd_count > 1 ||
1240 		    (qd->qd_count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1241 			list_move(&qd->qd_list, head);
1242 			spin_unlock(&sdp->sd_quota_spin);
1243 			schedule();
1244 			spin_lock(&sdp->sd_quota_spin);
1245 			continue;
1246 		}
1247 
1248 		list_del(&qd->qd_list);
1249 		atomic_dec(&sdp->sd_quota_count);
1250 		spin_unlock(&sdp->sd_quota_spin);
1251 
1252 		if (!qd->qd_count) {
1253 			gfs2_assert_warn(sdp, !qd->qd_change);
1254 			gfs2_assert_warn(sdp, !qd->qd_slot_count);
1255 		} else
1256 			gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1257 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1258 
1259 		gfs2_lvb_unhold(qd->qd_gl);
1260 		kfree(qd);
1261 
1262 		spin_lock(&sdp->sd_quota_spin);
1263 	}
1264 	spin_unlock(&sdp->sd_quota_spin);
1265 
1266 	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1267 
1268 	if (sdp->sd_quota_bitmap) {
1269 		for (x = 0; x < sdp->sd_quota_chunks; x++)
1270 			kfree(sdp->sd_quota_bitmap[x]);
1271 		kfree(sdp->sd_quota_bitmap);
1272 	}
1273 }
1274 
1275