xref: /openbmc/linux/fs/gfs2/quota.c (revision b627b4ed)
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/kthread.h>
49 #include <linux/freezer.h>
50 
51 #include "gfs2.h"
52 #include "incore.h"
53 #include "bmap.h"
54 #include "glock.h"
55 #include "glops.h"
56 #include "log.h"
57 #include "meta_io.h"
58 #include "quota.h"
59 #include "rgrp.h"
60 #include "super.h"
61 #include "trans.h"
62 #include "inode.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 LIST_HEAD(qd_lru_list);
83 static atomic_t qd_lru_count = ATOMIC_INIT(0);
84 static DEFINE_SPINLOCK(qd_lru_lock);
85 
86 int gfs2_shrink_qd_memory(int nr, gfp_t gfp_mask)
87 {
88 	struct gfs2_quota_data *qd;
89 	struct gfs2_sbd *sdp;
90 
91 	if (nr == 0)
92 		goto out;
93 
94 	if (!(gfp_mask & __GFP_FS))
95 		return -1;
96 
97 	spin_lock(&qd_lru_lock);
98 	while (nr && !list_empty(&qd_lru_list)) {
99 		qd = list_entry(qd_lru_list.next,
100 				struct gfs2_quota_data, qd_reclaim);
101 		sdp = qd->qd_gl->gl_sbd;
102 
103 		/* Free from the filesystem-specific list */
104 		list_del(&qd->qd_list);
105 
106 		gfs2_assert_warn(sdp, !qd->qd_change);
107 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
108 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
109 
110 		gfs2_glock_put(qd->qd_gl);
111 		atomic_dec(&sdp->sd_quota_count);
112 
113 		/* Delete it from the common reclaim list */
114 		list_del_init(&qd->qd_reclaim);
115 		atomic_dec(&qd_lru_count);
116 		spin_unlock(&qd_lru_lock);
117 		kmem_cache_free(gfs2_quotad_cachep, qd);
118 		spin_lock(&qd_lru_lock);
119 		nr--;
120 	}
121 	spin_unlock(&qd_lru_lock);
122 
123 out:
124 	return (atomic_read(&qd_lru_count) * sysctl_vfs_cache_pressure) / 100;
125 }
126 
127 static u64 qd2offset(struct gfs2_quota_data *qd)
128 {
129 	u64 offset;
130 
131 	offset = 2 * (u64)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
132 	offset *= sizeof(struct gfs2_quota);
133 
134 	return offset;
135 }
136 
137 static int qd_alloc(struct gfs2_sbd *sdp, int user, u32 id,
138 		    struct gfs2_quota_data **qdp)
139 {
140 	struct gfs2_quota_data *qd;
141 	int error;
142 
143 	qd = kmem_cache_zalloc(gfs2_quotad_cachep, GFP_NOFS);
144 	if (!qd)
145 		return -ENOMEM;
146 
147 	atomic_set(&qd->qd_count, 1);
148 	qd->qd_id = id;
149 	if (user)
150 		set_bit(QDF_USER, &qd->qd_flags);
151 	qd->qd_slot = -1;
152 	INIT_LIST_HEAD(&qd->qd_reclaim);
153 
154 	error = gfs2_glock_get(sdp, 2 * (u64)id + !user,
155 			      &gfs2_quota_glops, CREATE, &qd->qd_gl);
156 	if (error)
157 		goto fail;
158 
159 	*qdp = qd;
160 
161 	return 0;
162 
163 fail:
164 	kmem_cache_free(gfs2_quotad_cachep, qd);
165 	return error;
166 }
167 
168 static int qd_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
169 		  struct gfs2_quota_data **qdp)
170 {
171 	struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
172 	int error, found;
173 
174 	*qdp = NULL;
175 
176 	for (;;) {
177 		found = 0;
178 		spin_lock(&qd_lru_lock);
179 		list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
180 			if (qd->qd_id == id &&
181 			    !test_bit(QDF_USER, &qd->qd_flags) == !user) {
182 				if (!atomic_read(&qd->qd_count) &&
183 				    !list_empty(&qd->qd_reclaim)) {
184 					/* Remove it from reclaim list */
185 					list_del_init(&qd->qd_reclaim);
186 					atomic_dec(&qd_lru_count);
187 				}
188 				atomic_inc(&qd->qd_count);
189 				found = 1;
190 				break;
191 			}
192 		}
193 
194 		if (!found)
195 			qd = NULL;
196 
197 		if (!qd && new_qd) {
198 			qd = new_qd;
199 			list_add(&qd->qd_list, &sdp->sd_quota_list);
200 			atomic_inc(&sdp->sd_quota_count);
201 			new_qd = NULL;
202 		}
203 
204 		spin_unlock(&qd_lru_lock);
205 
206 		if (qd || !create) {
207 			if (new_qd) {
208 				gfs2_glock_put(new_qd->qd_gl);
209 				kmem_cache_free(gfs2_quotad_cachep, new_qd);
210 			}
211 			*qdp = qd;
212 			return 0;
213 		}
214 
215 		error = qd_alloc(sdp, user, id, &new_qd);
216 		if (error)
217 			return error;
218 	}
219 }
220 
221 static void qd_hold(struct gfs2_quota_data *qd)
222 {
223 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
224 	gfs2_assert(sdp, atomic_read(&qd->qd_count));
225 	atomic_inc(&qd->qd_count);
226 }
227 
228 static void qd_put(struct gfs2_quota_data *qd)
229 {
230 	if (atomic_dec_and_lock(&qd->qd_count, &qd_lru_lock)) {
231 		/* Add to the reclaim list */
232 		list_add_tail(&qd->qd_reclaim, &qd_lru_list);
233 		atomic_inc(&qd_lru_count);
234 		spin_unlock(&qd_lru_lock);
235 	}
236 }
237 
238 static int slot_get(struct gfs2_quota_data *qd)
239 {
240 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
241 	unsigned int c, o = 0, b;
242 	unsigned char byte = 0;
243 
244 	spin_lock(&qd_lru_lock);
245 
246 	if (qd->qd_slot_count++) {
247 		spin_unlock(&qd_lru_lock);
248 		return 0;
249 	}
250 
251 	for (c = 0; c < sdp->sd_quota_chunks; c++)
252 		for (o = 0; o < PAGE_SIZE; o++) {
253 			byte = sdp->sd_quota_bitmap[c][o];
254 			if (byte != 0xFF)
255 				goto found;
256 		}
257 
258 	goto fail;
259 
260 found:
261 	for (b = 0; b < 8; b++)
262 		if (!(byte & (1 << b)))
263 			break;
264 	qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
265 
266 	if (qd->qd_slot >= sdp->sd_quota_slots)
267 		goto fail;
268 
269 	sdp->sd_quota_bitmap[c][o] |= 1 << b;
270 
271 	spin_unlock(&qd_lru_lock);
272 
273 	return 0;
274 
275 fail:
276 	qd->qd_slot_count--;
277 	spin_unlock(&qd_lru_lock);
278 	return -ENOSPC;
279 }
280 
281 static void slot_hold(struct gfs2_quota_data *qd)
282 {
283 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
284 
285 	spin_lock(&qd_lru_lock);
286 	gfs2_assert(sdp, qd->qd_slot_count);
287 	qd->qd_slot_count++;
288 	spin_unlock(&qd_lru_lock);
289 }
290 
291 static void slot_put(struct gfs2_quota_data *qd)
292 {
293 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
294 
295 	spin_lock(&qd_lru_lock);
296 	gfs2_assert(sdp, qd->qd_slot_count);
297 	if (!--qd->qd_slot_count) {
298 		gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
299 		qd->qd_slot = -1;
300 	}
301 	spin_unlock(&qd_lru_lock);
302 }
303 
304 static int bh_get(struct gfs2_quota_data *qd)
305 {
306 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
307 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
308 	unsigned int block, offset;
309 	struct buffer_head *bh;
310 	int error;
311 	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
312 
313 	mutex_lock(&sdp->sd_quota_mutex);
314 
315 	if (qd->qd_bh_count++) {
316 		mutex_unlock(&sdp->sd_quota_mutex);
317 		return 0;
318 	}
319 
320 	block = qd->qd_slot / sdp->sd_qc_per_block;
321 	offset = qd->qd_slot % sdp->sd_qc_per_block;
322 
323 	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
324 	error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
325 	if (error)
326 		goto fail;
327 	error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
328 	if (error)
329 		goto fail;
330 	error = -EIO;
331 	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
332 		goto fail_brelse;
333 
334 	qd->qd_bh = bh;
335 	qd->qd_bh_qc = (struct gfs2_quota_change *)
336 		(bh->b_data + sizeof(struct gfs2_meta_header) +
337 		 offset * sizeof(struct gfs2_quota_change));
338 
339 	mutex_unlock(&sdp->sd_quota_mutex);
340 
341 	return 0;
342 
343 fail_brelse:
344 	brelse(bh);
345 fail:
346 	qd->qd_bh_count--;
347 	mutex_unlock(&sdp->sd_quota_mutex);
348 	return error;
349 }
350 
351 static void bh_put(struct gfs2_quota_data *qd)
352 {
353 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
354 
355 	mutex_lock(&sdp->sd_quota_mutex);
356 	gfs2_assert(sdp, qd->qd_bh_count);
357 	if (!--qd->qd_bh_count) {
358 		brelse(qd->qd_bh);
359 		qd->qd_bh = NULL;
360 		qd->qd_bh_qc = NULL;
361 	}
362 	mutex_unlock(&sdp->sd_quota_mutex);
363 }
364 
365 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
366 {
367 	struct gfs2_quota_data *qd = NULL;
368 	int error;
369 	int found = 0;
370 
371 	*qdp = NULL;
372 
373 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
374 		return 0;
375 
376 	spin_lock(&qd_lru_lock);
377 
378 	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
379 		if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
380 		    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
381 		    qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
382 			continue;
383 
384 		list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
385 
386 		set_bit(QDF_LOCKED, &qd->qd_flags);
387 		gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
388 		atomic_inc(&qd->qd_count);
389 		qd->qd_change_sync = qd->qd_change;
390 		gfs2_assert_warn(sdp, qd->qd_slot_count);
391 		qd->qd_slot_count++;
392 		found = 1;
393 
394 		break;
395 	}
396 
397 	if (!found)
398 		qd = NULL;
399 
400 	spin_unlock(&qd_lru_lock);
401 
402 	if (qd) {
403 		gfs2_assert_warn(sdp, qd->qd_change_sync);
404 		error = bh_get(qd);
405 		if (error) {
406 			clear_bit(QDF_LOCKED, &qd->qd_flags);
407 			slot_put(qd);
408 			qd_put(qd);
409 			return error;
410 		}
411 	}
412 
413 	*qdp = qd;
414 
415 	return 0;
416 }
417 
418 static int qd_trylock(struct gfs2_quota_data *qd)
419 {
420 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
421 
422 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
423 		return 0;
424 
425 	spin_lock(&qd_lru_lock);
426 
427 	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
428 	    !test_bit(QDF_CHANGE, &qd->qd_flags)) {
429 		spin_unlock(&qd_lru_lock);
430 		return 0;
431 	}
432 
433 	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
434 
435 	set_bit(QDF_LOCKED, &qd->qd_flags);
436 	gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
437 	atomic_inc(&qd->qd_count);
438 	qd->qd_change_sync = qd->qd_change;
439 	gfs2_assert_warn(sdp, qd->qd_slot_count);
440 	qd->qd_slot_count++;
441 
442 	spin_unlock(&qd_lru_lock);
443 
444 	gfs2_assert_warn(sdp, qd->qd_change_sync);
445 	if (bh_get(qd)) {
446 		clear_bit(QDF_LOCKED, &qd->qd_flags);
447 		slot_put(qd);
448 		qd_put(qd);
449 		return 0;
450 	}
451 
452 	return 1;
453 }
454 
455 static void qd_unlock(struct gfs2_quota_data *qd)
456 {
457 	gfs2_assert_warn(qd->qd_gl->gl_sbd,
458 			 test_bit(QDF_LOCKED, &qd->qd_flags));
459 	clear_bit(QDF_LOCKED, &qd->qd_flags);
460 	bh_put(qd);
461 	slot_put(qd);
462 	qd_put(qd);
463 }
464 
465 static int qdsb_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
466 		    struct gfs2_quota_data **qdp)
467 {
468 	int error;
469 
470 	error = qd_get(sdp, user, id, create, qdp);
471 	if (error)
472 		return error;
473 
474 	error = slot_get(*qdp);
475 	if (error)
476 		goto fail;
477 
478 	error = bh_get(*qdp);
479 	if (error)
480 		goto fail_slot;
481 
482 	return 0;
483 
484 fail_slot:
485 	slot_put(*qdp);
486 fail:
487 	qd_put(*qdp);
488 	return error;
489 }
490 
491 static void qdsb_put(struct gfs2_quota_data *qd)
492 {
493 	bh_put(qd);
494 	slot_put(qd);
495 	qd_put(qd);
496 }
497 
498 int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
499 {
500 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
501 	struct gfs2_alloc *al = ip->i_alloc;
502 	struct gfs2_quota_data **qd = al->al_qd;
503 	int error;
504 
505 	if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
506 	    gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
507 		return -EIO;
508 
509 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
510 		return 0;
511 
512 	error = qdsb_get(sdp, QUOTA_USER, ip->i_inode.i_uid, CREATE, qd);
513 	if (error)
514 		goto out;
515 	al->al_qd_num++;
516 	qd++;
517 
518 	error = qdsb_get(sdp, QUOTA_GROUP, ip->i_inode.i_gid, CREATE, qd);
519 	if (error)
520 		goto out;
521 	al->al_qd_num++;
522 	qd++;
523 
524 	if (uid != NO_QUOTA_CHANGE && uid != ip->i_inode.i_uid) {
525 		error = qdsb_get(sdp, QUOTA_USER, uid, CREATE, qd);
526 		if (error)
527 			goto out;
528 		al->al_qd_num++;
529 		qd++;
530 	}
531 
532 	if (gid != NO_QUOTA_CHANGE && gid != ip->i_inode.i_gid) {
533 		error = qdsb_get(sdp, QUOTA_GROUP, gid, CREATE, qd);
534 		if (error)
535 			goto out;
536 		al->al_qd_num++;
537 		qd++;
538 	}
539 
540 out:
541 	if (error)
542 		gfs2_quota_unhold(ip);
543 	return error;
544 }
545 
546 void gfs2_quota_unhold(struct gfs2_inode *ip)
547 {
548 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
549 	struct gfs2_alloc *al = ip->i_alloc;
550 	unsigned int x;
551 
552 	gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
553 
554 	for (x = 0; x < al->al_qd_num; x++) {
555 		qdsb_put(al->al_qd[x]);
556 		al->al_qd[x] = NULL;
557 	}
558 	al->al_qd_num = 0;
559 }
560 
561 static int sort_qd(const void *a, const void *b)
562 {
563 	const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
564 	const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
565 
566 	if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
567 	    !test_bit(QDF_USER, &qd_b->qd_flags)) {
568 		if (test_bit(QDF_USER, &qd_a->qd_flags))
569 			return -1;
570 		else
571 			return 1;
572 	}
573 	if (qd_a->qd_id < qd_b->qd_id)
574 		return -1;
575 	if (qd_a->qd_id > qd_b->qd_id)
576 		return 1;
577 
578 	return 0;
579 }
580 
581 static void do_qc(struct gfs2_quota_data *qd, s64 change)
582 {
583 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
584 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
585 	struct gfs2_quota_change *qc = qd->qd_bh_qc;
586 	s64 x;
587 
588 	mutex_lock(&sdp->sd_quota_mutex);
589 	gfs2_trans_add_bh(ip->i_gl, qd->qd_bh, 1);
590 
591 	if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
592 		qc->qc_change = 0;
593 		qc->qc_flags = 0;
594 		if (test_bit(QDF_USER, &qd->qd_flags))
595 			qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
596 		qc->qc_id = cpu_to_be32(qd->qd_id);
597 	}
598 
599 	x = be64_to_cpu(qc->qc_change) + change;
600 	qc->qc_change = cpu_to_be64(x);
601 
602 	spin_lock(&qd_lru_lock);
603 	qd->qd_change = x;
604 	spin_unlock(&qd_lru_lock);
605 
606 	if (!x) {
607 		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
608 		clear_bit(QDF_CHANGE, &qd->qd_flags);
609 		qc->qc_flags = 0;
610 		qc->qc_id = 0;
611 		slot_put(qd);
612 		qd_put(qd);
613 	} else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
614 		qd_hold(qd);
615 		slot_hold(qd);
616 	}
617 
618 	mutex_unlock(&sdp->sd_quota_mutex);
619 }
620 
621 static void gfs2_quota_in(struct gfs2_quota_host *qu, const void *buf)
622 {
623 	const struct gfs2_quota *str = buf;
624 
625 	qu->qu_limit = be64_to_cpu(str->qu_limit);
626 	qu->qu_warn = be64_to_cpu(str->qu_warn);
627 	qu->qu_value = be64_to_cpu(str->qu_value);
628 	qu->qu_ll_next = be32_to_cpu(str->qu_ll_next);
629 }
630 
631 static void gfs2_quota_out(const struct gfs2_quota_host *qu, void *buf)
632 {
633 	struct gfs2_quota *str = buf;
634 
635 	str->qu_limit = cpu_to_be64(qu->qu_limit);
636 	str->qu_warn = cpu_to_be64(qu->qu_warn);
637 	str->qu_value = cpu_to_be64(qu->qu_value);
638 	str->qu_ll_next = cpu_to_be32(qu->qu_ll_next);
639 	memset(&str->qu_reserved, 0, sizeof(str->qu_reserved));
640 }
641 
642 /**
643  * gfs2_adjust_quota
644  *
645  * This function was mostly borrowed from gfs2_block_truncate_page which was
646  * in turn mostly borrowed from ext3
647  */
648 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
649 			     s64 change, struct gfs2_quota_data *qd)
650 {
651 	struct inode *inode = &ip->i_inode;
652 	struct address_space *mapping = inode->i_mapping;
653 	unsigned long index = loc >> PAGE_CACHE_SHIFT;
654 	unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
655 	unsigned blocksize, iblock, pos;
656 	struct buffer_head *bh;
657 	struct page *page;
658 	void *kaddr;
659 	char *ptr;
660 	struct gfs2_quota_host qp;
661 	s64 value;
662 	int err = -EIO;
663 
664 	if (gfs2_is_stuffed(ip))
665 		gfs2_unstuff_dinode(ip, NULL);
666 
667 	page = grab_cache_page(mapping, index);
668 	if (!page)
669 		return -ENOMEM;
670 
671 	blocksize = inode->i_sb->s_blocksize;
672 	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
673 
674 	if (!page_has_buffers(page))
675 		create_empty_buffers(page, blocksize, 0);
676 
677 	bh = page_buffers(page);
678 	pos = blocksize;
679 	while (offset >= pos) {
680 		bh = bh->b_this_page;
681 		iblock++;
682 		pos += blocksize;
683 	}
684 
685 	if (!buffer_mapped(bh)) {
686 		gfs2_block_map(inode, iblock, bh, 1);
687 		if (!buffer_mapped(bh))
688 			goto unlock;
689 	}
690 
691 	if (PageUptodate(page))
692 		set_buffer_uptodate(bh);
693 
694 	if (!buffer_uptodate(bh)) {
695 		ll_rw_block(READ_META, 1, &bh);
696 		wait_on_buffer(bh);
697 		if (!buffer_uptodate(bh))
698 			goto unlock;
699 	}
700 
701 	gfs2_trans_add_bh(ip->i_gl, bh, 0);
702 
703 	kaddr = kmap_atomic(page, KM_USER0);
704 	ptr = kaddr + offset;
705 	gfs2_quota_in(&qp, ptr);
706 	qp.qu_value += change;
707 	value = qp.qu_value;
708 	gfs2_quota_out(&qp, ptr);
709 	flush_dcache_page(page);
710 	kunmap_atomic(kaddr, KM_USER0);
711 	err = 0;
712 	qd->qd_qb.qb_magic = cpu_to_be32(GFS2_MAGIC);
713 	qd->qd_qb.qb_value = cpu_to_be64(value);
714 	((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_magic = cpu_to_be32(GFS2_MAGIC);
715 	((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_value = cpu_to_be64(value);
716 unlock:
717 	unlock_page(page);
718 	page_cache_release(page);
719 	return err;
720 }
721 
722 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
723 {
724 	struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
725 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
726 	unsigned int data_blocks, ind_blocks;
727 	struct gfs2_holder *ghs, i_gh;
728 	unsigned int qx, x;
729 	struct gfs2_quota_data *qd;
730 	loff_t offset;
731 	unsigned int nalloc = 0, blocks;
732 	struct gfs2_alloc *al = NULL;
733 	int error;
734 
735 	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
736 			      &data_blocks, &ind_blocks);
737 
738 	ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
739 	if (!ghs)
740 		return -ENOMEM;
741 
742 	sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
743 	for (qx = 0; qx < num_qd; qx++) {
744 		error = gfs2_glock_nq_init(qda[qx]->qd_gl,
745 					   LM_ST_EXCLUSIVE,
746 					   GL_NOCACHE, &ghs[qx]);
747 		if (error)
748 			goto out;
749 	}
750 
751 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
752 	if (error)
753 		goto out;
754 
755 	for (x = 0; x < num_qd; x++) {
756 		int alloc_required;
757 
758 		offset = qd2offset(qda[x]);
759 		error = gfs2_write_alloc_required(ip, offset,
760 						  sizeof(struct gfs2_quota),
761 						  &alloc_required);
762 		if (error)
763 			goto out_gunlock;
764 		if (alloc_required)
765 			nalloc++;
766 	}
767 
768 	al = gfs2_alloc_get(ip);
769 	if (!al) {
770 		error = -ENOMEM;
771 		goto out_gunlock;
772 	}
773 	/*
774 	 * 1 blk for unstuffing inode if stuffed. We add this extra
775 	 * block to the reservation unconditionally. If the inode
776 	 * doesn't need unstuffing, the block will be released to the
777 	 * rgrp since it won't be allocated during the transaction
778 	 */
779 	al->al_requested = 1;
780 	/* +1 in the end for block requested above for unstuffing */
781 	blocks = num_qd * data_blocks + RES_DINODE + num_qd + 1;
782 
783 	if (nalloc)
784 		al->al_requested += nalloc * (data_blocks + ind_blocks);
785 	error = gfs2_inplace_reserve(ip);
786 	if (error)
787 		goto out_alloc;
788 
789 	if (nalloc)
790 		blocks += al->al_rgd->rd_length + nalloc * ind_blocks + RES_STATFS;
791 
792 	error = gfs2_trans_begin(sdp, blocks, 0);
793 	if (error)
794 		goto out_ipres;
795 
796 	for (x = 0; x < num_qd; x++) {
797 		qd = qda[x];
798 		offset = qd2offset(qd);
799 		error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync,
800 					  (struct gfs2_quota_data *)
801 					  qd);
802 		if (error)
803 			goto out_end_trans;
804 
805 		do_qc(qd, -qd->qd_change_sync);
806 	}
807 
808 	error = 0;
809 
810 out_end_trans:
811 	gfs2_trans_end(sdp);
812 out_ipres:
813 	gfs2_inplace_release(ip);
814 out_alloc:
815 	gfs2_alloc_put(ip);
816 out_gunlock:
817 	gfs2_glock_dq_uninit(&i_gh);
818 out:
819 	while (qx--)
820 		gfs2_glock_dq_uninit(&ghs[qx]);
821 	kfree(ghs);
822 	gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
823 	return error;
824 }
825 
826 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
827 		    struct gfs2_holder *q_gh)
828 {
829 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
830 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
831 	struct gfs2_holder i_gh;
832 	struct gfs2_quota_host q;
833 	char buf[sizeof(struct gfs2_quota)];
834 	int error;
835 	struct gfs2_quota_lvb *qlvb;
836 
837 restart:
838 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
839 	if (error)
840 		return error;
841 
842 	qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
843 
844 	if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
845 		loff_t pos;
846 		gfs2_glock_dq_uninit(q_gh);
847 		error = gfs2_glock_nq_init(qd->qd_gl,
848 					   LM_ST_EXCLUSIVE, GL_NOCACHE,
849 					   q_gh);
850 		if (error)
851 			return error;
852 
853 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
854 		if (error)
855 			goto fail;
856 
857 		memset(buf, 0, sizeof(struct gfs2_quota));
858 		pos = qd2offset(qd);
859 		error = gfs2_internal_read(ip, NULL, buf, &pos,
860 					   sizeof(struct gfs2_quota));
861 		if (error < 0)
862 			goto fail_gunlock;
863 
864 		gfs2_glock_dq_uninit(&i_gh);
865 
866 		gfs2_quota_in(&q, buf);
867 		qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
868 		qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
869 		qlvb->__pad = 0;
870 		qlvb->qb_limit = cpu_to_be64(q.qu_limit);
871 		qlvb->qb_warn = cpu_to_be64(q.qu_warn);
872 		qlvb->qb_value = cpu_to_be64(q.qu_value);
873 		qd->qd_qb = *qlvb;
874 
875 		if (gfs2_glock_is_blocking(qd->qd_gl)) {
876 			gfs2_glock_dq_uninit(q_gh);
877 			force_refresh = 0;
878 			goto restart;
879 		}
880 	}
881 
882 	return 0;
883 
884 fail_gunlock:
885 	gfs2_glock_dq_uninit(&i_gh);
886 fail:
887 	gfs2_glock_dq_uninit(q_gh);
888 	return error;
889 }
890 
891 int gfs2_quota_lock(struct gfs2_inode *ip, u32 uid, u32 gid)
892 {
893 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
894 	struct gfs2_alloc *al = ip->i_alloc;
895 	unsigned int x;
896 	int error = 0;
897 
898 	gfs2_quota_hold(ip, uid, gid);
899 
900 	if (capable(CAP_SYS_RESOURCE) ||
901 	    sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
902 		return 0;
903 
904 	sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
905 	     sort_qd, NULL);
906 
907 	for (x = 0; x < al->al_qd_num; x++) {
908 		error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
909 		if (error)
910 			break;
911 	}
912 
913 	if (!error)
914 		set_bit(GIF_QD_LOCKED, &ip->i_flags);
915 	else {
916 		while (x--)
917 			gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
918 		gfs2_quota_unhold(ip);
919 	}
920 
921 	return error;
922 }
923 
924 static int need_sync(struct gfs2_quota_data *qd)
925 {
926 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
927 	struct gfs2_tune *gt = &sdp->sd_tune;
928 	s64 value;
929 	unsigned int num, den;
930 	int do_sync = 1;
931 
932 	if (!qd->qd_qb.qb_limit)
933 		return 0;
934 
935 	spin_lock(&qd_lru_lock);
936 	value = qd->qd_change;
937 	spin_unlock(&qd_lru_lock);
938 
939 	spin_lock(&gt->gt_spin);
940 	num = gt->gt_quota_scale_num;
941 	den = gt->gt_quota_scale_den;
942 	spin_unlock(&gt->gt_spin);
943 
944 	if (value < 0)
945 		do_sync = 0;
946 	else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
947 		 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
948 		do_sync = 0;
949 	else {
950 		value *= gfs2_jindex_size(sdp) * num;
951 		value = div_s64(value, den);
952 		value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
953 		if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
954 			do_sync = 0;
955 	}
956 
957 	return do_sync;
958 }
959 
960 void gfs2_quota_unlock(struct gfs2_inode *ip)
961 {
962 	struct gfs2_alloc *al = ip->i_alloc;
963 	struct gfs2_quota_data *qda[4];
964 	unsigned int count = 0;
965 	unsigned int x;
966 
967 	if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
968 		goto out;
969 
970 	for (x = 0; x < al->al_qd_num; x++) {
971 		struct gfs2_quota_data *qd;
972 		int sync;
973 
974 		qd = al->al_qd[x];
975 		sync = need_sync(qd);
976 
977 		gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
978 
979 		if (sync && qd_trylock(qd))
980 			qda[count++] = qd;
981 	}
982 
983 	if (count) {
984 		do_sync(count, qda);
985 		for (x = 0; x < count; x++)
986 			qd_unlock(qda[x]);
987 	}
988 
989 out:
990 	gfs2_quota_unhold(ip);
991 }
992 
993 #define MAX_LINE 256
994 
995 static int print_message(struct gfs2_quota_data *qd, char *type)
996 {
997 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
998 
999 	printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\r\n",
1000 	       sdp->sd_fsname, type,
1001 	       (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
1002 	       qd->qd_id);
1003 
1004 	return 0;
1005 }
1006 
1007 int gfs2_quota_check(struct gfs2_inode *ip, u32 uid, u32 gid)
1008 {
1009 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1010 	struct gfs2_alloc *al = ip->i_alloc;
1011 	struct gfs2_quota_data *qd;
1012 	s64 value;
1013 	unsigned int x;
1014 	int error = 0;
1015 
1016 	if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
1017 		return 0;
1018 
1019         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
1020                 return 0;
1021 
1022 	for (x = 0; x < al->al_qd_num; x++) {
1023 		qd = al->al_qd[x];
1024 
1025 		if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1026 		      (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
1027 			continue;
1028 
1029 		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
1030 		spin_lock(&qd_lru_lock);
1031 		value += qd->qd_change;
1032 		spin_unlock(&qd_lru_lock);
1033 
1034 		if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
1035 			print_message(qd, "exceeded");
1036 			error = -EDQUOT;
1037 			break;
1038 		} else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
1039 			   (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
1040 			   time_after_eq(jiffies, qd->qd_last_warn +
1041 					 gfs2_tune_get(sdp,
1042 						gt_quota_warn_period) * HZ)) {
1043 			error = print_message(qd, "warning");
1044 			qd->qd_last_warn = jiffies;
1045 		}
1046 	}
1047 
1048 	return error;
1049 }
1050 
1051 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1052 		       u32 uid, u32 gid)
1053 {
1054 	struct gfs2_alloc *al = ip->i_alloc;
1055 	struct gfs2_quota_data *qd;
1056 	unsigned int x;
1057 
1058 	if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1059 		return;
1060 	if (ip->i_diskflags & GFS2_DIF_SYSTEM)
1061 		return;
1062 
1063 	for (x = 0; x < al->al_qd_num; x++) {
1064 		qd = al->al_qd[x];
1065 
1066 		if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1067 		    (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
1068 			do_qc(qd, change);
1069 		}
1070 	}
1071 }
1072 
1073 int gfs2_quota_sync(struct gfs2_sbd *sdp)
1074 {
1075 	struct gfs2_quota_data **qda;
1076 	unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
1077 	unsigned int num_qd;
1078 	unsigned int x;
1079 	int error = 0;
1080 
1081 	sdp->sd_quota_sync_gen++;
1082 
1083 	qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1084 	if (!qda)
1085 		return -ENOMEM;
1086 
1087 	do {
1088 		num_qd = 0;
1089 
1090 		for (;;) {
1091 			error = qd_fish(sdp, qda + num_qd);
1092 			if (error || !qda[num_qd])
1093 				break;
1094 			if (++num_qd == max_qd)
1095 				break;
1096 		}
1097 
1098 		if (num_qd) {
1099 			if (!error)
1100 				error = do_sync(num_qd, qda);
1101 			if (!error)
1102 				for (x = 0; x < num_qd; x++)
1103 					qda[x]->qd_sync_gen =
1104 						sdp->sd_quota_sync_gen;
1105 
1106 			for (x = 0; x < num_qd; x++)
1107 				qd_unlock(qda[x]);
1108 		}
1109 	} while (!error && num_qd == max_qd);
1110 
1111 	kfree(qda);
1112 
1113 	return error;
1114 }
1115 
1116 int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, u32 id)
1117 {
1118 	struct gfs2_quota_data *qd;
1119 	struct gfs2_holder q_gh;
1120 	int error;
1121 
1122 	error = qd_get(sdp, user, id, CREATE, &qd);
1123 	if (error)
1124 		return error;
1125 
1126 	error = do_glock(qd, FORCE, &q_gh);
1127 	if (!error)
1128 		gfs2_glock_dq_uninit(&q_gh);
1129 
1130 	qd_put(qd);
1131 
1132 	return error;
1133 }
1134 
1135 static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
1136 {
1137 	const struct gfs2_quota_change *str = buf;
1138 
1139 	qc->qc_change = be64_to_cpu(str->qc_change);
1140 	qc->qc_flags = be32_to_cpu(str->qc_flags);
1141 	qc->qc_id = be32_to_cpu(str->qc_id);
1142 }
1143 
1144 int gfs2_quota_init(struct gfs2_sbd *sdp)
1145 {
1146 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1147 	unsigned int blocks = ip->i_disksize >> sdp->sd_sb.sb_bsize_shift;
1148 	unsigned int x, slot = 0;
1149 	unsigned int found = 0;
1150 	u64 dblock;
1151 	u32 extlen = 0;
1152 	int error;
1153 
1154 	if (!ip->i_disksize || ip->i_disksize > (64 << 20) ||
1155 	    ip->i_disksize & (sdp->sd_sb.sb_bsize - 1)) {
1156 		gfs2_consist_inode(ip);
1157 		return -EIO;
1158 	}
1159 	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1160 	sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1161 
1162 	error = -ENOMEM;
1163 
1164 	sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1165 				       sizeof(unsigned char *), GFP_NOFS);
1166 	if (!sdp->sd_quota_bitmap)
1167 		return error;
1168 
1169 	for (x = 0; x < sdp->sd_quota_chunks; x++) {
1170 		sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_NOFS);
1171 		if (!sdp->sd_quota_bitmap[x])
1172 			goto fail;
1173 	}
1174 
1175 	for (x = 0; x < blocks; x++) {
1176 		struct buffer_head *bh;
1177 		unsigned int y;
1178 
1179 		if (!extlen) {
1180 			int new = 0;
1181 			error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1182 			if (error)
1183 				goto fail;
1184 		}
1185 		error = -EIO;
1186 		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1187 		if (!bh)
1188 			goto fail;
1189 		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1190 			brelse(bh);
1191 			goto fail;
1192 		}
1193 
1194 		for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1195 		     y++, slot++) {
1196 			struct gfs2_quota_change_host qc;
1197 			struct gfs2_quota_data *qd;
1198 
1199 			gfs2_quota_change_in(&qc, bh->b_data +
1200 					  sizeof(struct gfs2_meta_header) +
1201 					  y * sizeof(struct gfs2_quota_change));
1202 			if (!qc.qc_change)
1203 				continue;
1204 
1205 			error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1206 					 qc.qc_id, &qd);
1207 			if (error) {
1208 				brelse(bh);
1209 				goto fail;
1210 			}
1211 
1212 			set_bit(QDF_CHANGE, &qd->qd_flags);
1213 			qd->qd_change = qc.qc_change;
1214 			qd->qd_slot = slot;
1215 			qd->qd_slot_count = 1;
1216 
1217 			spin_lock(&qd_lru_lock);
1218 			gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1219 			list_add(&qd->qd_list, &sdp->sd_quota_list);
1220 			atomic_inc(&sdp->sd_quota_count);
1221 			spin_unlock(&qd_lru_lock);
1222 
1223 			found++;
1224 		}
1225 
1226 		brelse(bh);
1227 		dblock++;
1228 		extlen--;
1229 	}
1230 
1231 	if (found)
1232 		fs_info(sdp, "found %u quota changes\n", found);
1233 
1234 	return 0;
1235 
1236 fail:
1237 	gfs2_quota_cleanup(sdp);
1238 	return error;
1239 }
1240 
1241 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1242 {
1243 	struct list_head *head = &sdp->sd_quota_list;
1244 	struct gfs2_quota_data *qd;
1245 	unsigned int x;
1246 
1247 	spin_lock(&qd_lru_lock);
1248 	while (!list_empty(head)) {
1249 		qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1250 
1251 		if (atomic_read(&qd->qd_count) > 1 ||
1252 		    (atomic_read(&qd->qd_count) &&
1253 		     !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1254 			list_move(&qd->qd_list, head);
1255 			spin_unlock(&qd_lru_lock);
1256 			schedule();
1257 			spin_lock(&qd_lru_lock);
1258 			continue;
1259 		}
1260 
1261 		list_del(&qd->qd_list);
1262 		/* Also remove if this qd exists in the reclaim list */
1263 		if (!list_empty(&qd->qd_reclaim)) {
1264 			list_del_init(&qd->qd_reclaim);
1265 			atomic_dec(&qd_lru_count);
1266 		}
1267 		atomic_dec(&sdp->sd_quota_count);
1268 		spin_unlock(&qd_lru_lock);
1269 
1270 		if (!atomic_read(&qd->qd_count)) {
1271 			gfs2_assert_warn(sdp, !qd->qd_change);
1272 			gfs2_assert_warn(sdp, !qd->qd_slot_count);
1273 		} else
1274 			gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1275 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1276 
1277 		gfs2_glock_put(qd->qd_gl);
1278 		kmem_cache_free(gfs2_quotad_cachep, qd);
1279 
1280 		spin_lock(&qd_lru_lock);
1281 	}
1282 	spin_unlock(&qd_lru_lock);
1283 
1284 	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1285 
1286 	if (sdp->sd_quota_bitmap) {
1287 		for (x = 0; x < sdp->sd_quota_chunks; x++)
1288 			kfree(sdp->sd_quota_bitmap[x]);
1289 		kfree(sdp->sd_quota_bitmap);
1290 	}
1291 }
1292 
1293 static void quotad_error(struct gfs2_sbd *sdp, const char *msg, int error)
1294 {
1295 	if (error == 0 || error == -EROFS)
1296 		return;
1297 	if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
1298 		fs_err(sdp, "gfs2_quotad: %s error %d\n", msg, error);
1299 }
1300 
1301 static void quotad_check_timeo(struct gfs2_sbd *sdp, const char *msg,
1302 			       int (*fxn)(struct gfs2_sbd *sdp),
1303 			       unsigned long t, unsigned long *timeo,
1304 			       unsigned int *new_timeo)
1305 {
1306 	if (t >= *timeo) {
1307 		int error = fxn(sdp);
1308 		quotad_error(sdp, msg, error);
1309 		*timeo = gfs2_tune_get_i(&sdp->sd_tune, new_timeo) * HZ;
1310 	} else {
1311 		*timeo -= t;
1312 	}
1313 }
1314 
1315 static void quotad_check_trunc_list(struct gfs2_sbd *sdp)
1316 {
1317 	struct gfs2_inode *ip;
1318 
1319 	while(1) {
1320 		ip = NULL;
1321 		spin_lock(&sdp->sd_trunc_lock);
1322 		if (!list_empty(&sdp->sd_trunc_list)) {
1323 			ip = list_entry(sdp->sd_trunc_list.next,
1324 					struct gfs2_inode, i_trunc_list);
1325 			list_del_init(&ip->i_trunc_list);
1326 		}
1327 		spin_unlock(&sdp->sd_trunc_lock);
1328 		if (ip == NULL)
1329 			return;
1330 		gfs2_glock_finish_truncate(ip);
1331 	}
1332 }
1333 
1334 /**
1335  * gfs2_quotad - Write cached quota changes into the quota file
1336  * @sdp: Pointer to GFS2 superblock
1337  *
1338  */
1339 
1340 int gfs2_quotad(void *data)
1341 {
1342 	struct gfs2_sbd *sdp = data;
1343 	struct gfs2_tune *tune = &sdp->sd_tune;
1344 	unsigned long statfs_timeo = 0;
1345 	unsigned long quotad_timeo = 0;
1346 	unsigned long t = 0;
1347 	DEFINE_WAIT(wait);
1348 	int empty;
1349 
1350 	while (!kthread_should_stop()) {
1351 
1352 		/* Update the master statfs file */
1353 		quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
1354 				   &statfs_timeo, &tune->gt_statfs_quantum);
1355 
1356 		/* Update quota file */
1357 		quotad_check_timeo(sdp, "sync", gfs2_quota_sync, t,
1358 				   &quotad_timeo, &tune->gt_quota_quantum);
1359 
1360 		/* Check for & recover partially truncated inodes */
1361 		quotad_check_trunc_list(sdp);
1362 
1363 		if (freezing(current))
1364 			refrigerator();
1365 		t = min(quotad_timeo, statfs_timeo);
1366 
1367 		prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);
1368 		spin_lock(&sdp->sd_trunc_lock);
1369 		empty = list_empty(&sdp->sd_trunc_list);
1370 		spin_unlock(&sdp->sd_trunc_lock);
1371 		if (empty)
1372 			t -= schedule_timeout(t);
1373 		else
1374 			t = 0;
1375 		finish_wait(&sdp->sd_quota_wait, &wait);
1376 	}
1377 
1378 	return 0;
1379 }
1380 
1381