xref: /openbmc/linux/fs/gfs2/quota.c (revision bc000245)
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 for 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/mm.h>
42 #include <linux/spinlock.h>
43 #include <linux/completion.h>
44 #include <linux/buffer_head.h>
45 #include <linux/sort.h>
46 #include <linux/fs.h>
47 #include <linux/bio.h>
48 #include <linux/gfs2_ondisk.h>
49 #include <linux/kthread.h>
50 #include <linux/freezer.h>
51 #include <linux/quota.h>
52 #include <linux/dqblk_xfs.h>
53 #include <linux/lockref.h>
54 #include <linux/list_lru.h>
55 
56 #include "gfs2.h"
57 #include "incore.h"
58 #include "bmap.h"
59 #include "glock.h"
60 #include "glops.h"
61 #include "log.h"
62 #include "meta_io.h"
63 #include "quota.h"
64 #include "rgrp.h"
65 #include "super.h"
66 #include "trans.h"
67 #include "inode.h"
68 #include "util.h"
69 
70 struct gfs2_quota_change_host {
71 	u64 qc_change;
72 	u32 qc_flags; /* GFS2_QCF_... */
73 	struct kqid qc_id;
74 };
75 
76 /* Lock order: qd_lock -> qd->lockref.lock -> lru lock */
77 static DEFINE_SPINLOCK(qd_lock);
78 struct list_lru gfs2_qd_lru;
79 
80 static void gfs2_qd_dispose(struct list_head *list)
81 {
82 	struct gfs2_quota_data *qd;
83 	struct gfs2_sbd *sdp;
84 
85 	while (!list_empty(list)) {
86 		qd = list_entry(list->next, struct gfs2_quota_data, qd_lru);
87 		sdp = qd->qd_gl->gl_sbd;
88 
89 		list_del(&qd->qd_lru);
90 
91 		/* Free from the filesystem-specific list */
92 		spin_lock(&qd_lock);
93 		list_del(&qd->qd_list);
94 		spin_unlock(&qd_lock);
95 
96 		gfs2_assert_warn(sdp, !qd->qd_change);
97 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
98 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
99 
100 		gfs2_glock_put(qd->qd_gl);
101 		atomic_dec(&sdp->sd_quota_count);
102 
103 		/* Delete it from the common reclaim list */
104 		kmem_cache_free(gfs2_quotad_cachep, qd);
105 	}
106 }
107 
108 
109 static enum lru_status gfs2_qd_isolate(struct list_head *item, spinlock_t *lock, void *arg)
110 {
111 	struct list_head *dispose = arg;
112 	struct gfs2_quota_data *qd = list_entry(item, struct gfs2_quota_data, qd_lru);
113 
114 	if (!spin_trylock(&qd->qd_lockref.lock))
115 		return LRU_SKIP;
116 
117 	if (qd->qd_lockref.count == 0) {
118 		lockref_mark_dead(&qd->qd_lockref);
119 		list_move(&qd->qd_lru, dispose);
120 	}
121 
122 	spin_unlock(&qd->qd_lockref.lock);
123 	return LRU_REMOVED;
124 }
125 
126 static unsigned long gfs2_qd_shrink_scan(struct shrinker *shrink,
127 					 struct shrink_control *sc)
128 {
129 	LIST_HEAD(dispose);
130 	unsigned long freed;
131 
132 	if (!(sc->gfp_mask & __GFP_FS))
133 		return SHRINK_STOP;
134 
135 	freed = list_lru_walk_node(&gfs2_qd_lru, sc->nid, gfs2_qd_isolate,
136 				   &dispose, &sc->nr_to_scan);
137 
138 	gfs2_qd_dispose(&dispose);
139 
140 	return freed;
141 }
142 
143 static unsigned long gfs2_qd_shrink_count(struct shrinker *shrink,
144 					  struct shrink_control *sc)
145 {
146 	return vfs_pressure_ratio(list_lru_count_node(&gfs2_qd_lru, sc->nid));
147 }
148 
149 struct shrinker gfs2_qd_shrinker = {
150 	.count_objects = gfs2_qd_shrink_count,
151 	.scan_objects = gfs2_qd_shrink_scan,
152 	.seeks = DEFAULT_SEEKS,
153 	.flags = SHRINKER_NUMA_AWARE,
154 };
155 
156 
157 static u64 qd2index(struct gfs2_quota_data *qd)
158 {
159 	struct kqid qid = qd->qd_id;
160 	return (2 * (u64)from_kqid(&init_user_ns, qid)) +
161 		((qid.type == USRQUOTA) ? 0 : 1);
162 }
163 
164 static u64 qd2offset(struct gfs2_quota_data *qd)
165 {
166 	u64 offset;
167 
168 	offset = qd2index(qd);
169 	offset *= sizeof(struct gfs2_quota);
170 
171 	return offset;
172 }
173 
174 static int qd_alloc(struct gfs2_sbd *sdp, struct kqid qid,
175 		    struct gfs2_quota_data **qdp)
176 {
177 	struct gfs2_quota_data *qd;
178 	int error;
179 
180 	qd = kmem_cache_zalloc(gfs2_quotad_cachep, GFP_NOFS);
181 	if (!qd)
182 		return -ENOMEM;
183 
184 	qd->qd_lockref.count = 1;
185 	spin_lock_init(&qd->qd_lockref.lock);
186 	qd->qd_id = qid;
187 	qd->qd_slot = -1;
188 	INIT_LIST_HEAD(&qd->qd_lru);
189 
190 	error = gfs2_glock_get(sdp, qd2index(qd),
191 			      &gfs2_quota_glops, CREATE, &qd->qd_gl);
192 	if (error)
193 		goto fail;
194 
195 	*qdp = qd;
196 
197 	return 0;
198 
199 fail:
200 	kmem_cache_free(gfs2_quotad_cachep, qd);
201 	return error;
202 }
203 
204 static int qd_get(struct gfs2_sbd *sdp, struct kqid qid,
205 		  struct gfs2_quota_data **qdp)
206 {
207 	struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
208 	int error, found;
209 
210 	*qdp = NULL;
211 
212 	for (;;) {
213 		found = 0;
214 		spin_lock(&qd_lock);
215 		list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
216 			if (qid_eq(qd->qd_id, qid) &&
217 			    lockref_get_not_dead(&qd->qd_lockref)) {
218 				list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
219 				found = 1;
220 				break;
221 			}
222 		}
223 
224 		if (!found)
225 			qd = NULL;
226 
227 		if (!qd && new_qd) {
228 			qd = new_qd;
229 			list_add(&qd->qd_list, &sdp->sd_quota_list);
230 			atomic_inc(&sdp->sd_quota_count);
231 			new_qd = NULL;
232 		}
233 
234 		spin_unlock(&qd_lock);
235 
236 		if (qd) {
237 			if (new_qd) {
238 				gfs2_glock_put(new_qd->qd_gl);
239 				kmem_cache_free(gfs2_quotad_cachep, new_qd);
240 			}
241 			*qdp = qd;
242 			return 0;
243 		}
244 
245 		error = qd_alloc(sdp, qid, &new_qd);
246 		if (error)
247 			return error;
248 	}
249 }
250 
251 static void qd_hold(struct gfs2_quota_data *qd)
252 {
253 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
254 	gfs2_assert(sdp, !__lockref_is_dead(&qd->qd_lockref));
255 	lockref_get(&qd->qd_lockref);
256 }
257 
258 static void qd_put(struct gfs2_quota_data *qd)
259 {
260 	if (lockref_put_or_lock(&qd->qd_lockref))
261 		return;
262 
263 	qd->qd_lockref.count = 0;
264 	list_lru_add(&gfs2_qd_lru, &qd->qd_lru);
265 	spin_unlock(&qd->qd_lockref.lock);
266 
267 }
268 
269 static int slot_get(struct gfs2_quota_data *qd)
270 {
271 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
272 	unsigned int c, o = 0, b;
273 	unsigned char byte = 0;
274 
275 	spin_lock(&qd_lock);
276 
277 	if (qd->qd_slot_count++) {
278 		spin_unlock(&qd_lock);
279 		return 0;
280 	}
281 
282 	for (c = 0; c < sdp->sd_quota_chunks; c++)
283 		for (o = 0; o < PAGE_SIZE; o++) {
284 			byte = sdp->sd_quota_bitmap[c][o];
285 			if (byte != 0xFF)
286 				goto found;
287 		}
288 
289 	goto fail;
290 
291 found:
292 	for (b = 0; b < 8; b++)
293 		if (!(byte & (1 << b)))
294 			break;
295 	qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
296 
297 	if (qd->qd_slot >= sdp->sd_quota_slots)
298 		goto fail;
299 
300 	sdp->sd_quota_bitmap[c][o] |= 1 << b;
301 
302 	spin_unlock(&qd_lock);
303 
304 	return 0;
305 
306 fail:
307 	qd->qd_slot_count--;
308 	spin_unlock(&qd_lock);
309 	return -ENOSPC;
310 }
311 
312 static void slot_hold(struct gfs2_quota_data *qd)
313 {
314 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
315 
316 	spin_lock(&qd_lock);
317 	gfs2_assert(sdp, qd->qd_slot_count);
318 	qd->qd_slot_count++;
319 	spin_unlock(&qd_lock);
320 }
321 
322 static void gfs2_icbit_munge(struct gfs2_sbd *sdp, unsigned char **bitmap,
323 			     unsigned int bit, int new_value)
324 {
325 	unsigned int c, o, b = bit;
326 	int old_value;
327 
328 	c = b / (8 * PAGE_SIZE);
329 	b %= 8 * PAGE_SIZE;
330 	o = b / 8;
331 	b %= 8;
332 
333 	old_value = (bitmap[c][o] & (1 << b));
334 	gfs2_assert_withdraw(sdp, !old_value != !new_value);
335 
336 	if (new_value)
337 		bitmap[c][o] |= 1 << b;
338 	else
339 		bitmap[c][o] &= ~(1 << b);
340 }
341 
342 static void slot_put(struct gfs2_quota_data *qd)
343 {
344 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
345 
346 	spin_lock(&qd_lock);
347 	gfs2_assert(sdp, qd->qd_slot_count);
348 	if (!--qd->qd_slot_count) {
349 		gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
350 		qd->qd_slot = -1;
351 	}
352 	spin_unlock(&qd_lock);
353 }
354 
355 static int bh_get(struct gfs2_quota_data *qd)
356 {
357 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
358 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
359 	unsigned int block, offset;
360 	struct buffer_head *bh;
361 	int error;
362 	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
363 
364 	mutex_lock(&sdp->sd_quota_mutex);
365 
366 	if (qd->qd_bh_count++) {
367 		mutex_unlock(&sdp->sd_quota_mutex);
368 		return 0;
369 	}
370 
371 	block = qd->qd_slot / sdp->sd_qc_per_block;
372 	offset = qd->qd_slot % sdp->sd_qc_per_block;
373 
374 	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
375 	error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
376 	if (error)
377 		goto fail;
378 	error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
379 	if (error)
380 		goto fail;
381 	error = -EIO;
382 	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
383 		goto fail_brelse;
384 
385 	qd->qd_bh = bh;
386 	qd->qd_bh_qc = (struct gfs2_quota_change *)
387 		(bh->b_data + sizeof(struct gfs2_meta_header) +
388 		 offset * sizeof(struct gfs2_quota_change));
389 
390 	mutex_unlock(&sdp->sd_quota_mutex);
391 
392 	return 0;
393 
394 fail_brelse:
395 	brelse(bh);
396 fail:
397 	qd->qd_bh_count--;
398 	mutex_unlock(&sdp->sd_quota_mutex);
399 	return error;
400 }
401 
402 static void bh_put(struct gfs2_quota_data *qd)
403 {
404 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
405 
406 	mutex_lock(&sdp->sd_quota_mutex);
407 	gfs2_assert(sdp, qd->qd_bh_count);
408 	if (!--qd->qd_bh_count) {
409 		brelse(qd->qd_bh);
410 		qd->qd_bh = NULL;
411 		qd->qd_bh_qc = NULL;
412 	}
413 	mutex_unlock(&sdp->sd_quota_mutex);
414 }
415 
416 static int qd_check_sync(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd,
417 			 u64 *sync_gen)
418 {
419 	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
420 	    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
421 	    (sync_gen && (qd->qd_sync_gen >= *sync_gen)))
422 		return 0;
423 
424 	if (!lockref_get_not_dead(&qd->qd_lockref))
425 		return 0;
426 
427 	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
428 	set_bit(QDF_LOCKED, &qd->qd_flags);
429 	qd->qd_change_sync = qd->qd_change;
430 	gfs2_assert_warn(sdp, qd->qd_slot_count);
431 	qd->qd_slot_count++;
432 	return 1;
433 }
434 
435 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
436 {
437 	struct gfs2_quota_data *qd = NULL;
438 	int error;
439 	int found = 0;
440 
441 	*qdp = NULL;
442 
443 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
444 		return 0;
445 
446 	spin_lock(&qd_lock);
447 
448 	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
449 		found = qd_check_sync(sdp, qd, &sdp->sd_quota_sync_gen);
450 		if (found)
451 			break;
452 	}
453 
454 	if (!found)
455 		qd = NULL;
456 
457 	spin_unlock(&qd_lock);
458 
459 	if (qd) {
460 		gfs2_assert_warn(sdp, qd->qd_change_sync);
461 		error = bh_get(qd);
462 		if (error) {
463 			clear_bit(QDF_LOCKED, &qd->qd_flags);
464 			slot_put(qd);
465 			qd_put(qd);
466 			return error;
467 		}
468 	}
469 
470 	*qdp = qd;
471 
472 	return 0;
473 }
474 
475 static void qd_unlock(struct gfs2_quota_data *qd)
476 {
477 	gfs2_assert_warn(qd->qd_gl->gl_sbd,
478 			 test_bit(QDF_LOCKED, &qd->qd_flags));
479 	clear_bit(QDF_LOCKED, &qd->qd_flags);
480 	bh_put(qd);
481 	slot_put(qd);
482 	qd_put(qd);
483 }
484 
485 static int qdsb_get(struct gfs2_sbd *sdp, struct kqid qid,
486 		    struct gfs2_quota_data **qdp)
487 {
488 	int error;
489 
490 	error = qd_get(sdp, qid, qdp);
491 	if (error)
492 		return error;
493 
494 	error = slot_get(*qdp);
495 	if (error)
496 		goto fail;
497 
498 	error = bh_get(*qdp);
499 	if (error)
500 		goto fail_slot;
501 
502 	return 0;
503 
504 fail_slot:
505 	slot_put(*qdp);
506 fail:
507 	qd_put(*qdp);
508 	return error;
509 }
510 
511 static void qdsb_put(struct gfs2_quota_data *qd)
512 {
513 	bh_put(qd);
514 	slot_put(qd);
515 	qd_put(qd);
516 }
517 
518 int gfs2_quota_hold(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
519 {
520 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
521 	struct gfs2_quota_data **qd;
522 	int error;
523 
524 	if (ip->i_res == NULL) {
525 		error = gfs2_rs_alloc(ip);
526 		if (error)
527 			return error;
528 	}
529 
530 	qd = ip->i_res->rs_qa_qd;
531 
532 	if (gfs2_assert_warn(sdp, !ip->i_res->rs_qa_qd_num) ||
533 	    gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
534 		return -EIO;
535 
536 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
537 		return 0;
538 
539 	error = qdsb_get(sdp, make_kqid_uid(ip->i_inode.i_uid), qd);
540 	if (error)
541 		goto out;
542 	ip->i_res->rs_qa_qd_num++;
543 	qd++;
544 
545 	error = qdsb_get(sdp, make_kqid_gid(ip->i_inode.i_gid), qd);
546 	if (error)
547 		goto out;
548 	ip->i_res->rs_qa_qd_num++;
549 	qd++;
550 
551 	if (!uid_eq(uid, NO_UID_QUOTA_CHANGE) &&
552 	    !uid_eq(uid, ip->i_inode.i_uid)) {
553 		error = qdsb_get(sdp, make_kqid_uid(uid), qd);
554 		if (error)
555 			goto out;
556 		ip->i_res->rs_qa_qd_num++;
557 		qd++;
558 	}
559 
560 	if (!gid_eq(gid, NO_GID_QUOTA_CHANGE) &&
561 	    !gid_eq(gid, ip->i_inode.i_gid)) {
562 		error = qdsb_get(sdp, make_kqid_gid(gid), qd);
563 		if (error)
564 			goto out;
565 		ip->i_res->rs_qa_qd_num++;
566 		qd++;
567 	}
568 
569 out:
570 	if (error)
571 		gfs2_quota_unhold(ip);
572 	return error;
573 }
574 
575 void gfs2_quota_unhold(struct gfs2_inode *ip)
576 {
577 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
578 	unsigned int x;
579 
580 	if (ip->i_res == NULL)
581 		return;
582 	gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
583 
584 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
585 		qdsb_put(ip->i_res->rs_qa_qd[x]);
586 		ip->i_res->rs_qa_qd[x] = NULL;
587 	}
588 	ip->i_res->rs_qa_qd_num = 0;
589 }
590 
591 static int sort_qd(const void *a, const void *b)
592 {
593 	const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
594 	const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
595 
596 	if (qid_lt(qd_a->qd_id, qd_b->qd_id))
597 		return -1;
598 	if (qid_lt(qd_b->qd_id, qd_a->qd_id))
599 		return 1;
600 	return 0;
601 }
602 
603 static void do_qc(struct gfs2_quota_data *qd, s64 change)
604 {
605 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
606 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
607 	struct gfs2_quota_change *qc = qd->qd_bh_qc;
608 	s64 x;
609 
610 	mutex_lock(&sdp->sd_quota_mutex);
611 	gfs2_trans_add_meta(ip->i_gl, qd->qd_bh);
612 
613 	if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
614 		qc->qc_change = 0;
615 		qc->qc_flags = 0;
616 		if (qd->qd_id.type == USRQUOTA)
617 			qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
618 		qc->qc_id = cpu_to_be32(from_kqid(&init_user_ns, qd->qd_id));
619 	}
620 
621 	x = be64_to_cpu(qc->qc_change) + change;
622 	qc->qc_change = cpu_to_be64(x);
623 
624 	spin_lock(&qd_lock);
625 	qd->qd_change = x;
626 	spin_unlock(&qd_lock);
627 
628 	if (!x) {
629 		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
630 		clear_bit(QDF_CHANGE, &qd->qd_flags);
631 		qc->qc_flags = 0;
632 		qc->qc_id = 0;
633 		slot_put(qd);
634 		qd_put(qd);
635 	} else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
636 		qd_hold(qd);
637 		slot_hold(qd);
638 	}
639 
640 	mutex_unlock(&sdp->sd_quota_mutex);
641 }
642 
643 /**
644  * gfs2_adjust_quota - adjust record of current block usage
645  * @ip: The quota inode
646  * @loc: Offset of the entry in the quota file
647  * @change: The amount of usage change to record
648  * @qd: The quota data
649  * @fdq: The updated limits to record
650  *
651  * This function was mostly borrowed from gfs2_block_truncate_page which was
652  * in turn mostly borrowed from ext3
653  *
654  * Returns: 0 or -ve on error
655  */
656 
657 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
658 			     s64 change, struct gfs2_quota_data *qd,
659 			     struct fs_disk_quota *fdq)
660 {
661 	struct inode *inode = &ip->i_inode;
662 	struct gfs2_sbd *sdp = GFS2_SB(inode);
663 	struct address_space *mapping = inode->i_mapping;
664 	unsigned long index = loc >> PAGE_CACHE_SHIFT;
665 	unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
666 	unsigned blocksize, iblock, pos;
667 	struct buffer_head *bh;
668 	struct page *page;
669 	void *kaddr, *ptr;
670 	struct gfs2_quota q;
671 	int err, nbytes;
672 	u64 size;
673 
674 	if (gfs2_is_stuffed(ip)) {
675 		err = gfs2_unstuff_dinode(ip, NULL);
676 		if (err)
677 			return err;
678 	}
679 
680 	memset(&q, 0, sizeof(struct gfs2_quota));
681 	err = gfs2_internal_read(ip, (char *)&q, &loc, sizeof(q));
682 	if (err < 0)
683 		return err;
684 
685 	err = -EIO;
686 	be64_add_cpu(&q.qu_value, change);
687 	qd->qd_qb.qb_value = q.qu_value;
688 	if (fdq) {
689 		if (fdq->d_fieldmask & FS_DQ_BSOFT) {
690 			q.qu_warn = cpu_to_be64(fdq->d_blk_softlimit >> sdp->sd_fsb2bb_shift);
691 			qd->qd_qb.qb_warn = q.qu_warn;
692 		}
693 		if (fdq->d_fieldmask & FS_DQ_BHARD) {
694 			q.qu_limit = cpu_to_be64(fdq->d_blk_hardlimit >> sdp->sd_fsb2bb_shift);
695 			qd->qd_qb.qb_limit = q.qu_limit;
696 		}
697 		if (fdq->d_fieldmask & FS_DQ_BCOUNT) {
698 			q.qu_value = cpu_to_be64(fdq->d_bcount >> sdp->sd_fsb2bb_shift);
699 			qd->qd_qb.qb_value = q.qu_value;
700 		}
701 	}
702 
703 	/* Write the quota into the quota file on disk */
704 	ptr = &q;
705 	nbytes = sizeof(struct gfs2_quota);
706 get_a_page:
707 	page = find_or_create_page(mapping, index, GFP_NOFS);
708 	if (!page)
709 		return -ENOMEM;
710 
711 	blocksize = inode->i_sb->s_blocksize;
712 	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
713 
714 	if (!page_has_buffers(page))
715 		create_empty_buffers(page, blocksize, 0);
716 
717 	bh = page_buffers(page);
718 	pos = blocksize;
719 	while (offset >= pos) {
720 		bh = bh->b_this_page;
721 		iblock++;
722 		pos += blocksize;
723 	}
724 
725 	if (!buffer_mapped(bh)) {
726 		gfs2_block_map(inode, iblock, bh, 1);
727 		if (!buffer_mapped(bh))
728 			goto unlock_out;
729 		/* If it's a newly allocated disk block for quota, zero it */
730 		if (buffer_new(bh))
731 			zero_user(page, pos - blocksize, bh->b_size);
732 	}
733 
734 	if (PageUptodate(page))
735 		set_buffer_uptodate(bh);
736 
737 	if (!buffer_uptodate(bh)) {
738 		ll_rw_block(READ | REQ_META, 1, &bh);
739 		wait_on_buffer(bh);
740 		if (!buffer_uptodate(bh))
741 			goto unlock_out;
742 	}
743 
744 	gfs2_trans_add_data(ip->i_gl, bh);
745 
746 	kaddr = kmap_atomic(page);
747 	if (offset + sizeof(struct gfs2_quota) > PAGE_CACHE_SIZE)
748 		nbytes = PAGE_CACHE_SIZE - offset;
749 	memcpy(kaddr + offset, ptr, nbytes);
750 	flush_dcache_page(page);
751 	kunmap_atomic(kaddr);
752 	unlock_page(page);
753 	page_cache_release(page);
754 
755 	/* If quota straddles page boundary, we need to update the rest of the
756 	 * quota at the beginning of the next page */
757 	if ((offset + sizeof(struct gfs2_quota)) > PAGE_CACHE_SIZE) {
758 		ptr = ptr + nbytes;
759 		nbytes = sizeof(struct gfs2_quota) - nbytes;
760 		offset = 0;
761 		index++;
762 		goto get_a_page;
763 	}
764 
765 	size = loc + sizeof(struct gfs2_quota);
766 	if (size > inode->i_size)
767 		i_size_write(inode, size);
768 	inode->i_mtime = inode->i_atime = CURRENT_TIME;
769 	mark_inode_dirty(inode);
770 	return 0;
771 
772 unlock_out:
773 	unlock_page(page);
774 	page_cache_release(page);
775 	return err;
776 }
777 
778 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
779 {
780 	struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
781 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
782 	struct gfs2_alloc_parms ap = { .aflags = 0, };
783 	unsigned int data_blocks, ind_blocks;
784 	struct gfs2_holder *ghs, i_gh;
785 	unsigned int qx, x;
786 	struct gfs2_quota_data *qd;
787 	unsigned reserved;
788 	loff_t offset;
789 	unsigned int nalloc = 0, blocks;
790 	int error;
791 
792 	error = gfs2_rs_alloc(ip);
793 	if (error)
794 		return error;
795 
796 	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
797 			      &data_blocks, &ind_blocks);
798 
799 	ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
800 	if (!ghs)
801 		return -ENOMEM;
802 
803 	sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
804 	mutex_lock(&ip->i_inode.i_mutex);
805 	for (qx = 0; qx < num_qd; qx++) {
806 		error = gfs2_glock_nq_init(qda[qx]->qd_gl, LM_ST_EXCLUSIVE,
807 					   GL_NOCACHE, &ghs[qx]);
808 		if (error)
809 			goto out;
810 	}
811 
812 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
813 	if (error)
814 		goto out;
815 
816 	for (x = 0; x < num_qd; x++) {
817 		offset = qd2offset(qda[x]);
818 		if (gfs2_write_alloc_required(ip, offset,
819 					      sizeof(struct gfs2_quota)))
820 			nalloc++;
821 	}
822 
823 	/*
824 	 * 1 blk for unstuffing inode if stuffed. We add this extra
825 	 * block to the reservation unconditionally. If the inode
826 	 * doesn't need unstuffing, the block will be released to the
827 	 * rgrp since it won't be allocated during the transaction
828 	 */
829 	/* +3 in the end for unstuffing block, inode size update block
830 	 * and another block in case quota straddles page boundary and
831 	 * two blocks need to be updated instead of 1 */
832 	blocks = num_qd * data_blocks + RES_DINODE + num_qd + 3;
833 
834 	reserved = 1 + (nalloc * (data_blocks + ind_blocks));
835 	ap.target = reserved;
836 	error = gfs2_inplace_reserve(ip, &ap);
837 	if (error)
838 		goto out_alloc;
839 
840 	if (nalloc)
841 		blocks += gfs2_rg_blocks(ip, reserved) + nalloc * ind_blocks + RES_STATFS;
842 
843 	error = gfs2_trans_begin(sdp, blocks, 0);
844 	if (error)
845 		goto out_ipres;
846 
847 	for (x = 0; x < num_qd; x++) {
848 		qd = qda[x];
849 		offset = qd2offset(qd);
850 		error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync, qd, NULL);
851 		if (error)
852 			goto out_end_trans;
853 
854 		do_qc(qd, -qd->qd_change_sync);
855 		set_bit(QDF_REFRESH, &qd->qd_flags);
856 	}
857 
858 	error = 0;
859 
860 out_end_trans:
861 	gfs2_trans_end(sdp);
862 out_ipres:
863 	gfs2_inplace_release(ip);
864 out_alloc:
865 	gfs2_glock_dq_uninit(&i_gh);
866 out:
867 	while (qx--)
868 		gfs2_glock_dq_uninit(&ghs[qx]);
869 	mutex_unlock(&ip->i_inode.i_mutex);
870 	kfree(ghs);
871 	gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
872 	return error;
873 }
874 
875 static int update_qd(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd)
876 {
877 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
878 	struct gfs2_quota q;
879 	struct gfs2_quota_lvb *qlvb;
880 	loff_t pos;
881 	int error;
882 
883 	memset(&q, 0, sizeof(struct gfs2_quota));
884 	pos = qd2offset(qd);
885 	error = gfs2_internal_read(ip, (char *)&q, &pos, sizeof(q));
886 	if (error < 0)
887 		return error;
888 
889 	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
890 	qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
891 	qlvb->__pad = 0;
892 	qlvb->qb_limit = q.qu_limit;
893 	qlvb->qb_warn = q.qu_warn;
894 	qlvb->qb_value = q.qu_value;
895 	qd->qd_qb = *qlvb;
896 
897 	return 0;
898 }
899 
900 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
901 		    struct gfs2_holder *q_gh)
902 {
903 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
904 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
905 	struct gfs2_holder i_gh;
906 	int error;
907 
908 restart:
909 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
910 	if (error)
911 		return error;
912 
913 	qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
914 
915 	if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
916 		gfs2_glock_dq_uninit(q_gh);
917 		error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE,
918 					   GL_NOCACHE, q_gh);
919 		if (error)
920 			return error;
921 
922 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
923 		if (error)
924 			goto fail;
925 
926 		error = update_qd(sdp, qd);
927 		if (error)
928 			goto fail_gunlock;
929 
930 		gfs2_glock_dq_uninit(&i_gh);
931 		gfs2_glock_dq_uninit(q_gh);
932 		force_refresh = 0;
933 		goto restart;
934 	}
935 
936 	return 0;
937 
938 fail_gunlock:
939 	gfs2_glock_dq_uninit(&i_gh);
940 fail:
941 	gfs2_glock_dq_uninit(q_gh);
942 	return error;
943 }
944 
945 int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
946 {
947 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
948 	struct gfs2_quota_data *qd;
949 	unsigned int x;
950 	int error = 0;
951 
952 	error = gfs2_quota_hold(ip, uid, gid);
953 	if (error)
954 		return error;
955 
956 	if (capable(CAP_SYS_RESOURCE) ||
957 	    sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
958 		return 0;
959 
960 	sort(ip->i_res->rs_qa_qd, ip->i_res->rs_qa_qd_num,
961 	     sizeof(struct gfs2_quota_data *), sort_qd, NULL);
962 
963 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
964 		int force = NO_FORCE;
965 		qd = ip->i_res->rs_qa_qd[x];
966 		if (test_and_clear_bit(QDF_REFRESH, &qd->qd_flags))
967 			force = FORCE;
968 		error = do_glock(qd, force, &ip->i_res->rs_qa_qd_ghs[x]);
969 		if (error)
970 			break;
971 	}
972 
973 	if (!error)
974 		set_bit(GIF_QD_LOCKED, &ip->i_flags);
975 	else {
976 		while (x--)
977 			gfs2_glock_dq_uninit(&ip->i_res->rs_qa_qd_ghs[x]);
978 		gfs2_quota_unhold(ip);
979 	}
980 
981 	return error;
982 }
983 
984 static int need_sync(struct gfs2_quota_data *qd)
985 {
986 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
987 	struct gfs2_tune *gt = &sdp->sd_tune;
988 	s64 value;
989 	unsigned int num, den;
990 	int do_sync = 1;
991 
992 	if (!qd->qd_qb.qb_limit)
993 		return 0;
994 
995 	spin_lock(&qd_lock);
996 	value = qd->qd_change;
997 	spin_unlock(&qd_lock);
998 
999 	spin_lock(&gt->gt_spin);
1000 	num = gt->gt_quota_scale_num;
1001 	den = gt->gt_quota_scale_den;
1002 	spin_unlock(&gt->gt_spin);
1003 
1004 	if (value < 0)
1005 		do_sync = 0;
1006 	else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
1007 		 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
1008 		do_sync = 0;
1009 	else {
1010 		value *= gfs2_jindex_size(sdp) * num;
1011 		value = div_s64(value, den);
1012 		value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
1013 		if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
1014 			do_sync = 0;
1015 	}
1016 
1017 	return do_sync;
1018 }
1019 
1020 void gfs2_quota_unlock(struct gfs2_inode *ip)
1021 {
1022 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1023 	struct gfs2_quota_data *qda[4];
1024 	unsigned int count = 0;
1025 	unsigned int x;
1026 	int found;
1027 
1028 	if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
1029 		goto out;
1030 
1031 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1032 		struct gfs2_quota_data *qd;
1033 		int sync;
1034 
1035 		qd = ip->i_res->rs_qa_qd[x];
1036 		sync = need_sync(qd);
1037 
1038 		gfs2_glock_dq_uninit(&ip->i_res->rs_qa_qd_ghs[x]);
1039 		if (!sync)
1040 			continue;
1041 
1042 		spin_lock(&qd_lock);
1043 		found = qd_check_sync(sdp, qd, NULL);
1044 		spin_unlock(&qd_lock);
1045 
1046 		if (!found)
1047 			continue;
1048 
1049 		gfs2_assert_warn(sdp, qd->qd_change_sync);
1050 		if (bh_get(qd)) {
1051 			clear_bit(QDF_LOCKED, &qd->qd_flags);
1052 			slot_put(qd);
1053 			qd_put(qd);
1054 			continue;
1055 		}
1056 
1057 		qda[count++] = qd;
1058 	}
1059 
1060 	if (count) {
1061 		do_sync(count, qda);
1062 		for (x = 0; x < count; x++)
1063 			qd_unlock(qda[x]);
1064 	}
1065 
1066 out:
1067 	gfs2_quota_unhold(ip);
1068 }
1069 
1070 #define MAX_LINE 256
1071 
1072 static int print_message(struct gfs2_quota_data *qd, char *type)
1073 {
1074 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
1075 
1076 	printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\n",
1077 	       sdp->sd_fsname, type,
1078 	       (qd->qd_id.type == USRQUOTA) ? "user" : "group",
1079 	       from_kqid(&init_user_ns, qd->qd_id));
1080 
1081 	return 0;
1082 }
1083 
1084 int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
1085 {
1086 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1087 	struct gfs2_quota_data *qd;
1088 	s64 value;
1089 	unsigned int x;
1090 	int error = 0;
1091 
1092 	if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
1093 		return 0;
1094 
1095         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
1096                 return 0;
1097 
1098 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1099 		qd = ip->i_res->rs_qa_qd[x];
1100 
1101 		if (!(qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
1102 		      qid_eq(qd->qd_id, make_kqid_gid(gid))))
1103 			continue;
1104 
1105 		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
1106 		spin_lock(&qd_lock);
1107 		value += qd->qd_change;
1108 		spin_unlock(&qd_lock);
1109 
1110 		if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
1111 			print_message(qd, "exceeded");
1112 			quota_send_warning(qd->qd_id,
1113 					   sdp->sd_vfs->s_dev, QUOTA_NL_BHARDWARN);
1114 
1115 			error = -EDQUOT;
1116 			break;
1117 		} else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
1118 			   (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
1119 			   time_after_eq(jiffies, qd->qd_last_warn +
1120 					 gfs2_tune_get(sdp,
1121 						gt_quota_warn_period) * HZ)) {
1122 			quota_send_warning(qd->qd_id,
1123 					   sdp->sd_vfs->s_dev, QUOTA_NL_BSOFTWARN);
1124 			error = print_message(qd, "warning");
1125 			qd->qd_last_warn = jiffies;
1126 		}
1127 	}
1128 
1129 	return error;
1130 }
1131 
1132 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1133 		       kuid_t uid, kgid_t gid)
1134 {
1135 	struct gfs2_quota_data *qd;
1136 	unsigned int x;
1137 
1138 	if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1139 		return;
1140 	if (ip->i_diskflags & GFS2_DIF_SYSTEM)
1141 		return;
1142 
1143 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1144 		qd = ip->i_res->rs_qa_qd[x];
1145 
1146 		if (qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
1147 		    qid_eq(qd->qd_id, make_kqid_gid(gid))) {
1148 			do_qc(qd, change);
1149 		}
1150 	}
1151 }
1152 
1153 int gfs2_quota_sync(struct super_block *sb, int type)
1154 {
1155 	struct gfs2_sbd *sdp = sb->s_fs_info;
1156 	struct gfs2_quota_data **qda;
1157 	unsigned int max_qd = PAGE_SIZE/sizeof(struct gfs2_holder);
1158 	unsigned int num_qd;
1159 	unsigned int x;
1160 	int error = 0;
1161 
1162 	qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1163 	if (!qda)
1164 		return -ENOMEM;
1165 
1166 	mutex_lock(&sdp->sd_quota_sync_mutex);
1167 	sdp->sd_quota_sync_gen++;
1168 
1169 	do {
1170 		num_qd = 0;
1171 
1172 		for (;;) {
1173 			error = qd_fish(sdp, qda + num_qd);
1174 			if (error || !qda[num_qd])
1175 				break;
1176 			if (++num_qd == max_qd)
1177 				break;
1178 		}
1179 
1180 		if (num_qd) {
1181 			if (!error)
1182 				error = do_sync(num_qd, qda);
1183 			if (!error)
1184 				for (x = 0; x < num_qd; x++)
1185 					qda[x]->qd_sync_gen =
1186 						sdp->sd_quota_sync_gen;
1187 
1188 			for (x = 0; x < num_qd; x++)
1189 				qd_unlock(qda[x]);
1190 		}
1191 	} while (!error && num_qd == max_qd);
1192 
1193 	mutex_unlock(&sdp->sd_quota_sync_mutex);
1194 	kfree(qda);
1195 
1196 	return error;
1197 }
1198 
1199 int gfs2_quota_refresh(struct gfs2_sbd *sdp, struct kqid qid)
1200 {
1201 	struct gfs2_quota_data *qd;
1202 	struct gfs2_holder q_gh;
1203 	int error;
1204 
1205 	error = qd_get(sdp, qid, &qd);
1206 	if (error)
1207 		return error;
1208 
1209 	error = do_glock(qd, FORCE, &q_gh);
1210 	if (!error)
1211 		gfs2_glock_dq_uninit(&q_gh);
1212 
1213 	qd_put(qd);
1214 	return error;
1215 }
1216 
1217 static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
1218 {
1219 	const struct gfs2_quota_change *str = buf;
1220 
1221 	qc->qc_change = be64_to_cpu(str->qc_change);
1222 	qc->qc_flags = be32_to_cpu(str->qc_flags);
1223 	qc->qc_id = make_kqid(&init_user_ns,
1224 			      (qc->qc_flags & GFS2_QCF_USER)?USRQUOTA:GRPQUOTA,
1225 			      be32_to_cpu(str->qc_id));
1226 }
1227 
1228 int gfs2_quota_init(struct gfs2_sbd *sdp)
1229 {
1230 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1231 	u64 size = i_size_read(sdp->sd_qc_inode);
1232 	unsigned int blocks = size >> sdp->sd_sb.sb_bsize_shift;
1233 	unsigned int x, slot = 0;
1234 	unsigned int found = 0;
1235 	u64 dblock;
1236 	u32 extlen = 0;
1237 	int error;
1238 
1239 	if (gfs2_check_internal_file_size(sdp->sd_qc_inode, 1, 64 << 20))
1240 		return -EIO;
1241 
1242 	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1243 	sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1244 
1245 	error = -ENOMEM;
1246 
1247 	sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1248 				       sizeof(unsigned char *), GFP_NOFS);
1249 	if (!sdp->sd_quota_bitmap)
1250 		return error;
1251 
1252 	for (x = 0; x < sdp->sd_quota_chunks; x++) {
1253 		sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_NOFS);
1254 		if (!sdp->sd_quota_bitmap[x])
1255 			goto fail;
1256 	}
1257 
1258 	for (x = 0; x < blocks; x++) {
1259 		struct buffer_head *bh;
1260 		unsigned int y;
1261 
1262 		if (!extlen) {
1263 			int new = 0;
1264 			error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1265 			if (error)
1266 				goto fail;
1267 		}
1268 		error = -EIO;
1269 		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1270 		if (!bh)
1271 			goto fail;
1272 		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1273 			brelse(bh);
1274 			goto fail;
1275 		}
1276 
1277 		for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1278 		     y++, slot++) {
1279 			struct gfs2_quota_change_host qc;
1280 			struct gfs2_quota_data *qd;
1281 
1282 			gfs2_quota_change_in(&qc, bh->b_data +
1283 					  sizeof(struct gfs2_meta_header) +
1284 					  y * sizeof(struct gfs2_quota_change));
1285 			if (!qc.qc_change)
1286 				continue;
1287 
1288 			error = qd_alloc(sdp, qc.qc_id, &qd);
1289 			if (error) {
1290 				brelse(bh);
1291 				goto fail;
1292 			}
1293 
1294 			set_bit(QDF_CHANGE, &qd->qd_flags);
1295 			qd->qd_change = qc.qc_change;
1296 			qd->qd_slot = slot;
1297 			qd->qd_slot_count = 1;
1298 
1299 			spin_lock(&qd_lock);
1300 			gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1301 			list_add(&qd->qd_list, &sdp->sd_quota_list);
1302 			atomic_inc(&sdp->sd_quota_count);
1303 			spin_unlock(&qd_lock);
1304 
1305 			found++;
1306 		}
1307 
1308 		brelse(bh);
1309 		dblock++;
1310 		extlen--;
1311 	}
1312 
1313 	if (found)
1314 		fs_info(sdp, "found %u quota changes\n", found);
1315 
1316 	return 0;
1317 
1318 fail:
1319 	gfs2_quota_cleanup(sdp);
1320 	return error;
1321 }
1322 
1323 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1324 {
1325 	struct list_head *head = &sdp->sd_quota_list;
1326 	struct gfs2_quota_data *qd;
1327 	unsigned int x;
1328 
1329 	spin_lock(&qd_lock);
1330 	while (!list_empty(head)) {
1331 		qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1332 
1333 		/*
1334 		 * To be removed in due course... we should be able to
1335 		 * ensure that all refs to the qd have done by this point
1336 		 * so that this rather odd test is not required
1337 		 */
1338 		spin_lock(&qd->qd_lockref.lock);
1339 		if (qd->qd_lockref.count > 1 ||
1340 		    (qd->qd_lockref.count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1341 			spin_unlock(&qd->qd_lockref.lock);
1342 			list_move(&qd->qd_list, head);
1343 			spin_unlock(&qd_lock);
1344 			schedule();
1345 			spin_lock(&qd_lock);
1346 			continue;
1347 		}
1348 		spin_unlock(&qd->qd_lockref.lock);
1349 
1350 		list_del(&qd->qd_list);
1351 		/* Also remove if this qd exists in the reclaim list */
1352 		list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
1353 		atomic_dec(&sdp->sd_quota_count);
1354 		spin_unlock(&qd_lock);
1355 
1356 		if (!qd->qd_lockref.count) {
1357 			gfs2_assert_warn(sdp, !qd->qd_change);
1358 			gfs2_assert_warn(sdp, !qd->qd_slot_count);
1359 		} else
1360 			gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1361 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1362 
1363 		gfs2_glock_put(qd->qd_gl);
1364 		kmem_cache_free(gfs2_quotad_cachep, qd);
1365 
1366 		spin_lock(&qd_lock);
1367 	}
1368 	spin_unlock(&qd_lock);
1369 
1370 	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1371 
1372 	if (sdp->sd_quota_bitmap) {
1373 		for (x = 0; x < sdp->sd_quota_chunks; x++)
1374 			kfree(sdp->sd_quota_bitmap[x]);
1375 		kfree(sdp->sd_quota_bitmap);
1376 	}
1377 }
1378 
1379 static void quotad_error(struct gfs2_sbd *sdp, const char *msg, int error)
1380 {
1381 	if (error == 0 || error == -EROFS)
1382 		return;
1383 	if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
1384 		fs_err(sdp, "gfs2_quotad: %s error %d\n", msg, error);
1385 }
1386 
1387 static void quotad_check_timeo(struct gfs2_sbd *sdp, const char *msg,
1388 			       int (*fxn)(struct super_block *sb, int type),
1389 			       unsigned long t, unsigned long *timeo,
1390 			       unsigned int *new_timeo)
1391 {
1392 	if (t >= *timeo) {
1393 		int error = fxn(sdp->sd_vfs, 0);
1394 		quotad_error(sdp, msg, error);
1395 		*timeo = gfs2_tune_get_i(&sdp->sd_tune, new_timeo) * HZ;
1396 	} else {
1397 		*timeo -= t;
1398 	}
1399 }
1400 
1401 static void quotad_check_trunc_list(struct gfs2_sbd *sdp)
1402 {
1403 	struct gfs2_inode *ip;
1404 
1405 	while(1) {
1406 		ip = NULL;
1407 		spin_lock(&sdp->sd_trunc_lock);
1408 		if (!list_empty(&sdp->sd_trunc_list)) {
1409 			ip = list_entry(sdp->sd_trunc_list.next,
1410 					struct gfs2_inode, i_trunc_list);
1411 			list_del_init(&ip->i_trunc_list);
1412 		}
1413 		spin_unlock(&sdp->sd_trunc_lock);
1414 		if (ip == NULL)
1415 			return;
1416 		gfs2_glock_finish_truncate(ip);
1417 	}
1418 }
1419 
1420 void gfs2_wake_up_statfs(struct gfs2_sbd *sdp) {
1421 	if (!sdp->sd_statfs_force_sync) {
1422 		sdp->sd_statfs_force_sync = 1;
1423 		wake_up(&sdp->sd_quota_wait);
1424 	}
1425 }
1426 
1427 
1428 /**
1429  * gfs2_quotad - Write cached quota changes into the quota file
1430  * @sdp: Pointer to GFS2 superblock
1431  *
1432  */
1433 
1434 int gfs2_quotad(void *data)
1435 {
1436 	struct gfs2_sbd *sdp = data;
1437 	struct gfs2_tune *tune = &sdp->sd_tune;
1438 	unsigned long statfs_timeo = 0;
1439 	unsigned long quotad_timeo = 0;
1440 	unsigned long t = 0;
1441 	DEFINE_WAIT(wait);
1442 	int empty;
1443 
1444 	while (!kthread_should_stop()) {
1445 
1446 		/* Update the master statfs file */
1447 		if (sdp->sd_statfs_force_sync) {
1448 			int error = gfs2_statfs_sync(sdp->sd_vfs, 0);
1449 			quotad_error(sdp, "statfs", error);
1450 			statfs_timeo = gfs2_tune_get(sdp, gt_statfs_quantum) * HZ;
1451 		}
1452 		else
1453 			quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
1454 				   	   &statfs_timeo,
1455 					   &tune->gt_statfs_quantum);
1456 
1457 		/* Update quota file */
1458 		quotad_check_timeo(sdp, "sync", gfs2_quota_sync, t,
1459 				   &quotad_timeo, &tune->gt_quota_quantum);
1460 
1461 		/* Check for & recover partially truncated inodes */
1462 		quotad_check_trunc_list(sdp);
1463 
1464 		try_to_freeze();
1465 
1466 		t = min(quotad_timeo, statfs_timeo);
1467 
1468 		prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);
1469 		spin_lock(&sdp->sd_trunc_lock);
1470 		empty = list_empty(&sdp->sd_trunc_list);
1471 		spin_unlock(&sdp->sd_trunc_lock);
1472 		if (empty && !sdp->sd_statfs_force_sync)
1473 			t -= schedule_timeout(t);
1474 		else
1475 			t = 0;
1476 		finish_wait(&sdp->sd_quota_wait, &wait);
1477 	}
1478 
1479 	return 0;
1480 }
1481 
1482 static int gfs2_quota_get_xstate(struct super_block *sb,
1483 				 struct fs_quota_stat *fqs)
1484 {
1485 	struct gfs2_sbd *sdp = sb->s_fs_info;
1486 
1487 	memset(fqs, 0, sizeof(struct fs_quota_stat));
1488 	fqs->qs_version = FS_QSTAT_VERSION;
1489 
1490 	switch (sdp->sd_args.ar_quota) {
1491 	case GFS2_QUOTA_ON:
1492 		fqs->qs_flags |= (FS_QUOTA_UDQ_ENFD | FS_QUOTA_GDQ_ENFD);
1493 		/*FALLTHRU*/
1494 	case GFS2_QUOTA_ACCOUNT:
1495 		fqs->qs_flags |= (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT);
1496 		break;
1497 	case GFS2_QUOTA_OFF:
1498 		break;
1499 	}
1500 
1501 	if (sdp->sd_quota_inode) {
1502 		fqs->qs_uquota.qfs_ino = GFS2_I(sdp->sd_quota_inode)->i_no_addr;
1503 		fqs->qs_uquota.qfs_nblks = sdp->sd_quota_inode->i_blocks;
1504 	}
1505 	fqs->qs_uquota.qfs_nextents = 1; /* unsupported */
1506 	fqs->qs_gquota = fqs->qs_uquota; /* its the same inode in both cases */
1507 	fqs->qs_incoredqs = list_lru_count(&gfs2_qd_lru);
1508 	return 0;
1509 }
1510 
1511 static int gfs2_get_dqblk(struct super_block *sb, struct kqid qid,
1512 			  struct fs_disk_quota *fdq)
1513 {
1514 	struct gfs2_sbd *sdp = sb->s_fs_info;
1515 	struct gfs2_quota_lvb *qlvb;
1516 	struct gfs2_quota_data *qd;
1517 	struct gfs2_holder q_gh;
1518 	int error;
1519 
1520 	memset(fdq, 0, sizeof(struct fs_disk_quota));
1521 
1522 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1523 		return -ESRCH; /* Crazy XFS error code */
1524 
1525 	if ((qid.type != USRQUOTA) &&
1526 	    (qid.type != GRPQUOTA))
1527 		return -EINVAL;
1528 
1529 	error = qd_get(sdp, qid, &qd);
1530 	if (error)
1531 		return error;
1532 	error = do_glock(qd, FORCE, &q_gh);
1533 	if (error)
1534 		goto out;
1535 
1536 	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
1537 	fdq->d_version = FS_DQUOT_VERSION;
1538 	fdq->d_flags = (qid.type == USRQUOTA) ? FS_USER_QUOTA : FS_GROUP_QUOTA;
1539 	fdq->d_id = from_kqid_munged(current_user_ns(), qid);
1540 	fdq->d_blk_hardlimit = be64_to_cpu(qlvb->qb_limit) << sdp->sd_fsb2bb_shift;
1541 	fdq->d_blk_softlimit = be64_to_cpu(qlvb->qb_warn) << sdp->sd_fsb2bb_shift;
1542 	fdq->d_bcount = be64_to_cpu(qlvb->qb_value) << sdp->sd_fsb2bb_shift;
1543 
1544 	gfs2_glock_dq_uninit(&q_gh);
1545 out:
1546 	qd_put(qd);
1547 	return error;
1548 }
1549 
1550 /* GFS2 only supports a subset of the XFS fields */
1551 #define GFS2_FIELDMASK (FS_DQ_BSOFT|FS_DQ_BHARD|FS_DQ_BCOUNT)
1552 
1553 static int gfs2_set_dqblk(struct super_block *sb, struct kqid qid,
1554 			  struct fs_disk_quota *fdq)
1555 {
1556 	struct gfs2_sbd *sdp = sb->s_fs_info;
1557 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
1558 	struct gfs2_quota_data *qd;
1559 	struct gfs2_holder q_gh, i_gh;
1560 	unsigned int data_blocks, ind_blocks;
1561 	unsigned int blocks = 0;
1562 	int alloc_required;
1563 	loff_t offset;
1564 	int error;
1565 
1566 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1567 		return -ESRCH; /* Crazy XFS error code */
1568 
1569 	if ((qid.type != USRQUOTA) &&
1570 	    (qid.type != GRPQUOTA))
1571 		return -EINVAL;
1572 
1573 	if (fdq->d_fieldmask & ~GFS2_FIELDMASK)
1574 		return -EINVAL;
1575 
1576 	error = qd_get(sdp, qid, &qd);
1577 	if (error)
1578 		return error;
1579 
1580 	error = gfs2_rs_alloc(ip);
1581 	if (error)
1582 		goto out_put;
1583 
1584 	mutex_lock(&ip->i_inode.i_mutex);
1585 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE, 0, &q_gh);
1586 	if (error)
1587 		goto out_unlockput;
1588 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
1589 	if (error)
1590 		goto out_q;
1591 
1592 	/* Check for existing entry, if none then alloc new blocks */
1593 	error = update_qd(sdp, qd);
1594 	if (error)
1595 		goto out_i;
1596 
1597 	/* If nothing has changed, this is a no-op */
1598 	if ((fdq->d_fieldmask & FS_DQ_BSOFT) &&
1599 	    ((fdq->d_blk_softlimit >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_warn)))
1600 		fdq->d_fieldmask ^= FS_DQ_BSOFT;
1601 
1602 	if ((fdq->d_fieldmask & FS_DQ_BHARD) &&
1603 	    ((fdq->d_blk_hardlimit >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_limit)))
1604 		fdq->d_fieldmask ^= FS_DQ_BHARD;
1605 
1606 	if ((fdq->d_fieldmask & FS_DQ_BCOUNT) &&
1607 	    ((fdq->d_bcount >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_value)))
1608 		fdq->d_fieldmask ^= FS_DQ_BCOUNT;
1609 
1610 	if (fdq->d_fieldmask == 0)
1611 		goto out_i;
1612 
1613 	offset = qd2offset(qd);
1614 	alloc_required = gfs2_write_alloc_required(ip, offset, sizeof(struct gfs2_quota));
1615 	if (gfs2_is_stuffed(ip))
1616 		alloc_required = 1;
1617 	if (alloc_required) {
1618 		struct gfs2_alloc_parms ap = { .aflags = 0, };
1619 		gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
1620 				       &data_blocks, &ind_blocks);
1621 		blocks = 1 + data_blocks + ind_blocks;
1622 		ap.target = blocks;
1623 		error = gfs2_inplace_reserve(ip, &ap);
1624 		if (error)
1625 			goto out_i;
1626 		blocks += gfs2_rg_blocks(ip, blocks);
1627 	}
1628 
1629 	/* Some quotas span block boundaries and can update two blocks,
1630 	   adding an extra block to the transaction to handle such quotas */
1631 	error = gfs2_trans_begin(sdp, blocks + RES_DINODE + 2, 0);
1632 	if (error)
1633 		goto out_release;
1634 
1635 	/* Apply changes */
1636 	error = gfs2_adjust_quota(ip, offset, 0, qd, fdq);
1637 
1638 	gfs2_trans_end(sdp);
1639 out_release:
1640 	if (alloc_required)
1641 		gfs2_inplace_release(ip);
1642 out_i:
1643 	gfs2_glock_dq_uninit(&i_gh);
1644 out_q:
1645 	gfs2_glock_dq_uninit(&q_gh);
1646 out_unlockput:
1647 	mutex_unlock(&ip->i_inode.i_mutex);
1648 out_put:
1649 	qd_put(qd);
1650 	return error;
1651 }
1652 
1653 const struct quotactl_ops gfs2_quotactl_ops = {
1654 	.quota_sync     = gfs2_quota_sync,
1655 	.get_xstate     = gfs2_quota_get_xstate,
1656 	.get_dqblk	= gfs2_get_dqblk,
1657 	.set_dqblk	= gfs2_set_dqblk,
1658 };
1659