xref: /linux/fs/gfs2/quota.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
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 
54 #include "gfs2.h"
55 #include "incore.h"
56 #include "bmap.h"
57 #include "glock.h"
58 #include "glops.h"
59 #include "log.h"
60 #include "meta_io.h"
61 #include "quota.h"
62 #include "rgrp.h"
63 #include "super.h"
64 #include "trans.h"
65 #include "inode.h"
66 #include "util.h"
67 
68 struct gfs2_quota_change_host {
69 	u64 qc_change;
70 	u32 qc_flags; /* GFS2_QCF_... */
71 	struct kqid qc_id;
72 };
73 
74 static LIST_HEAD(qd_lru_list);
75 static atomic_t qd_lru_count = ATOMIC_INIT(0);
76 static DEFINE_SPINLOCK(qd_lru_lock);
77 
78 int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
79 {
80 	struct gfs2_quota_data *qd;
81 	struct gfs2_sbd *sdp;
82 	int nr_to_scan = sc->nr_to_scan;
83 
84 	if (nr_to_scan == 0)
85 		goto out;
86 
87 	if (!(sc->gfp_mask & __GFP_FS))
88 		return -1;
89 
90 	spin_lock(&qd_lru_lock);
91 	while (nr_to_scan && !list_empty(&qd_lru_list)) {
92 		qd = list_entry(qd_lru_list.next,
93 				struct gfs2_quota_data, qd_reclaim);
94 		sdp = qd->qd_gl->gl_sbd;
95 
96 		/* Free from the filesystem-specific list */
97 		list_del(&qd->qd_list);
98 
99 		gfs2_assert_warn(sdp, !qd->qd_change);
100 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
101 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
102 
103 		gfs2_glock_put(qd->qd_gl);
104 		atomic_dec(&sdp->sd_quota_count);
105 
106 		/* Delete it from the common reclaim list */
107 		list_del_init(&qd->qd_reclaim);
108 		atomic_dec(&qd_lru_count);
109 		spin_unlock(&qd_lru_lock);
110 		kmem_cache_free(gfs2_quotad_cachep, qd);
111 		spin_lock(&qd_lru_lock);
112 		nr_to_scan--;
113 	}
114 	spin_unlock(&qd_lru_lock);
115 
116 out:
117 	return (atomic_read(&qd_lru_count) * sysctl_vfs_cache_pressure) / 100;
118 }
119 
120 static u64 qd2index(struct gfs2_quota_data *qd)
121 {
122 	struct kqid qid = qd->qd_id;
123 	return (2 * (u64)from_kqid(&init_user_ns, qid)) +
124 		((qid.type == USRQUOTA) ? 0 : 1);
125 }
126 
127 static u64 qd2offset(struct gfs2_quota_data *qd)
128 {
129 	u64 offset;
130 
131 	offset = qd2index(qd);
132 	offset *= sizeof(struct gfs2_quota);
133 
134 	return offset;
135 }
136 
137 static int qd_alloc(struct gfs2_sbd *sdp, struct kqid qid,
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 = qid;
149 	qd->qd_slot = -1;
150 	INIT_LIST_HEAD(&qd->qd_reclaim);
151 
152 	error = gfs2_glock_get(sdp, qd2index(qd),
153 			      &gfs2_quota_glops, CREATE, &qd->qd_gl);
154 	if (error)
155 		goto fail;
156 
157 	*qdp = qd;
158 
159 	return 0;
160 
161 fail:
162 	kmem_cache_free(gfs2_quotad_cachep, qd);
163 	return error;
164 }
165 
166 static int qd_get(struct gfs2_sbd *sdp, struct kqid qid,
167 		  struct gfs2_quota_data **qdp)
168 {
169 	struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
170 	int error, found;
171 
172 	*qdp = NULL;
173 
174 	for (;;) {
175 		found = 0;
176 		spin_lock(&qd_lru_lock);
177 		list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
178 			if (qid_eq(qd->qd_id, qid)) {
179 				if (!atomic_read(&qd->qd_count) &&
180 				    !list_empty(&qd->qd_reclaim)) {
181 					/* Remove it from reclaim list */
182 					list_del_init(&qd->qd_reclaim);
183 					atomic_dec(&qd_lru_count);
184 				}
185 				atomic_inc(&qd->qd_count);
186 				found = 1;
187 				break;
188 			}
189 		}
190 
191 		if (!found)
192 			qd = NULL;
193 
194 		if (!qd && new_qd) {
195 			qd = new_qd;
196 			list_add(&qd->qd_list, &sdp->sd_quota_list);
197 			atomic_inc(&sdp->sd_quota_count);
198 			new_qd = NULL;
199 		}
200 
201 		spin_unlock(&qd_lru_lock);
202 
203 		if (qd) {
204 			if (new_qd) {
205 				gfs2_glock_put(new_qd->qd_gl);
206 				kmem_cache_free(gfs2_quotad_cachep, new_qd);
207 			}
208 			*qdp = qd;
209 			return 0;
210 		}
211 
212 		error = qd_alloc(sdp, qid, &new_qd);
213 		if (error)
214 			return error;
215 	}
216 }
217 
218 static void qd_hold(struct gfs2_quota_data *qd)
219 {
220 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
221 	gfs2_assert(sdp, atomic_read(&qd->qd_count));
222 	atomic_inc(&qd->qd_count);
223 }
224 
225 static void qd_put(struct gfs2_quota_data *qd)
226 {
227 	if (atomic_dec_and_lock(&qd->qd_count, &qd_lru_lock)) {
228 		/* Add to the reclaim list */
229 		list_add_tail(&qd->qd_reclaim, &qd_lru_list);
230 		atomic_inc(&qd_lru_count);
231 		spin_unlock(&qd_lru_lock);
232 	}
233 }
234 
235 static int slot_get(struct gfs2_quota_data *qd)
236 {
237 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
238 	unsigned int c, o = 0, b;
239 	unsigned char byte = 0;
240 
241 	spin_lock(&qd_lru_lock);
242 
243 	if (qd->qd_slot_count++) {
244 		spin_unlock(&qd_lru_lock);
245 		return 0;
246 	}
247 
248 	for (c = 0; c < sdp->sd_quota_chunks; c++)
249 		for (o = 0; o < PAGE_SIZE; o++) {
250 			byte = sdp->sd_quota_bitmap[c][o];
251 			if (byte != 0xFF)
252 				goto found;
253 		}
254 
255 	goto fail;
256 
257 found:
258 	for (b = 0; b < 8; b++)
259 		if (!(byte & (1 << b)))
260 			break;
261 	qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
262 
263 	if (qd->qd_slot >= sdp->sd_quota_slots)
264 		goto fail;
265 
266 	sdp->sd_quota_bitmap[c][o] |= 1 << b;
267 
268 	spin_unlock(&qd_lru_lock);
269 
270 	return 0;
271 
272 fail:
273 	qd->qd_slot_count--;
274 	spin_unlock(&qd_lru_lock);
275 	return -ENOSPC;
276 }
277 
278 static void slot_hold(struct gfs2_quota_data *qd)
279 {
280 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
281 
282 	spin_lock(&qd_lru_lock);
283 	gfs2_assert(sdp, qd->qd_slot_count);
284 	qd->qd_slot_count++;
285 	spin_unlock(&qd_lru_lock);
286 }
287 
288 static void slot_put(struct gfs2_quota_data *qd)
289 {
290 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
291 
292 	spin_lock(&qd_lru_lock);
293 	gfs2_assert(sdp, qd->qd_slot_count);
294 	if (!--qd->qd_slot_count) {
295 		gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
296 		qd->qd_slot = -1;
297 	}
298 	spin_unlock(&qd_lru_lock);
299 }
300 
301 static int bh_get(struct gfs2_quota_data *qd)
302 {
303 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
304 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
305 	unsigned int block, offset;
306 	struct buffer_head *bh;
307 	int error;
308 	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
309 
310 	mutex_lock(&sdp->sd_quota_mutex);
311 
312 	if (qd->qd_bh_count++) {
313 		mutex_unlock(&sdp->sd_quota_mutex);
314 		return 0;
315 	}
316 
317 	block = qd->qd_slot / sdp->sd_qc_per_block;
318 	offset = qd->qd_slot % sdp->sd_qc_per_block;
319 
320 	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
321 	error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
322 	if (error)
323 		goto fail;
324 	error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
325 	if (error)
326 		goto fail;
327 	error = -EIO;
328 	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
329 		goto fail_brelse;
330 
331 	qd->qd_bh = bh;
332 	qd->qd_bh_qc = (struct gfs2_quota_change *)
333 		(bh->b_data + sizeof(struct gfs2_meta_header) +
334 		 offset * sizeof(struct gfs2_quota_change));
335 
336 	mutex_unlock(&sdp->sd_quota_mutex);
337 
338 	return 0;
339 
340 fail_brelse:
341 	brelse(bh);
342 fail:
343 	qd->qd_bh_count--;
344 	mutex_unlock(&sdp->sd_quota_mutex);
345 	return error;
346 }
347 
348 static void bh_put(struct gfs2_quota_data *qd)
349 {
350 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
351 
352 	mutex_lock(&sdp->sd_quota_mutex);
353 	gfs2_assert(sdp, qd->qd_bh_count);
354 	if (!--qd->qd_bh_count) {
355 		brelse(qd->qd_bh);
356 		qd->qd_bh = NULL;
357 		qd->qd_bh_qc = NULL;
358 	}
359 	mutex_unlock(&sdp->sd_quota_mutex);
360 }
361 
362 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
363 {
364 	struct gfs2_quota_data *qd = NULL;
365 	int error;
366 	int found = 0;
367 
368 	*qdp = NULL;
369 
370 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
371 		return 0;
372 
373 	spin_lock(&qd_lru_lock);
374 
375 	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
376 		if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
377 		    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
378 		    qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
379 			continue;
380 
381 		list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
382 
383 		set_bit(QDF_LOCKED, &qd->qd_flags);
384 		gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
385 		atomic_inc(&qd->qd_count);
386 		qd->qd_change_sync = qd->qd_change;
387 		gfs2_assert_warn(sdp, qd->qd_slot_count);
388 		qd->qd_slot_count++;
389 		found = 1;
390 
391 		break;
392 	}
393 
394 	if (!found)
395 		qd = NULL;
396 
397 	spin_unlock(&qd_lru_lock);
398 
399 	if (qd) {
400 		gfs2_assert_warn(sdp, qd->qd_change_sync);
401 		error = bh_get(qd);
402 		if (error) {
403 			clear_bit(QDF_LOCKED, &qd->qd_flags);
404 			slot_put(qd);
405 			qd_put(qd);
406 			return error;
407 		}
408 	}
409 
410 	*qdp = qd;
411 
412 	return 0;
413 }
414 
415 static int qd_trylock(struct gfs2_quota_data *qd)
416 {
417 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
418 
419 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
420 		return 0;
421 
422 	spin_lock(&qd_lru_lock);
423 
424 	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
425 	    !test_bit(QDF_CHANGE, &qd->qd_flags)) {
426 		spin_unlock(&qd_lru_lock);
427 		return 0;
428 	}
429 
430 	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
431 
432 	set_bit(QDF_LOCKED, &qd->qd_flags);
433 	gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
434 	atomic_inc(&qd->qd_count);
435 	qd->qd_change_sync = qd->qd_change;
436 	gfs2_assert_warn(sdp, qd->qd_slot_count);
437 	qd->qd_slot_count++;
438 
439 	spin_unlock(&qd_lru_lock);
440 
441 	gfs2_assert_warn(sdp, qd->qd_change_sync);
442 	if (bh_get(qd)) {
443 		clear_bit(QDF_LOCKED, &qd->qd_flags);
444 		slot_put(qd);
445 		qd_put(qd);
446 		return 0;
447 	}
448 
449 	return 1;
450 }
451 
452 static void qd_unlock(struct gfs2_quota_data *qd)
453 {
454 	gfs2_assert_warn(qd->qd_gl->gl_sbd,
455 			 test_bit(QDF_LOCKED, &qd->qd_flags));
456 	clear_bit(QDF_LOCKED, &qd->qd_flags);
457 	bh_put(qd);
458 	slot_put(qd);
459 	qd_put(qd);
460 }
461 
462 static int qdsb_get(struct gfs2_sbd *sdp, struct kqid qid,
463 		    struct gfs2_quota_data **qdp)
464 {
465 	int error;
466 
467 	error = qd_get(sdp, qid, qdp);
468 	if (error)
469 		return error;
470 
471 	error = slot_get(*qdp);
472 	if (error)
473 		goto fail;
474 
475 	error = bh_get(*qdp);
476 	if (error)
477 		goto fail_slot;
478 
479 	return 0;
480 
481 fail_slot:
482 	slot_put(*qdp);
483 fail:
484 	qd_put(*qdp);
485 	return error;
486 }
487 
488 static void qdsb_put(struct gfs2_quota_data *qd)
489 {
490 	bh_put(qd);
491 	slot_put(qd);
492 	qd_put(qd);
493 }
494 
495 int gfs2_quota_hold(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
496 {
497 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
498 	struct gfs2_quota_data **qd;
499 	int error;
500 
501 	if (ip->i_res == NULL) {
502 		error = gfs2_rs_alloc(ip);
503 		if (error)
504 			return error;
505 	}
506 
507 	qd = ip->i_res->rs_qa_qd;
508 
509 	if (gfs2_assert_warn(sdp, !ip->i_res->rs_qa_qd_num) ||
510 	    gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
511 		return -EIO;
512 
513 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
514 		return 0;
515 
516 	error = qdsb_get(sdp, make_kqid_uid(ip->i_inode.i_uid), qd);
517 	if (error)
518 		goto out;
519 	ip->i_res->rs_qa_qd_num++;
520 	qd++;
521 
522 	error = qdsb_get(sdp, make_kqid_gid(ip->i_inode.i_gid), qd);
523 	if (error)
524 		goto out;
525 	ip->i_res->rs_qa_qd_num++;
526 	qd++;
527 
528 	if (!uid_eq(uid, NO_UID_QUOTA_CHANGE) &&
529 	    !uid_eq(uid, ip->i_inode.i_uid)) {
530 		error = qdsb_get(sdp, make_kqid_uid(uid), qd);
531 		if (error)
532 			goto out;
533 		ip->i_res->rs_qa_qd_num++;
534 		qd++;
535 	}
536 
537 	if (!gid_eq(gid, NO_GID_QUOTA_CHANGE) &&
538 	    !gid_eq(gid, ip->i_inode.i_gid)) {
539 		error = qdsb_get(sdp, make_kqid_gid(gid), qd);
540 		if (error)
541 			goto out;
542 		ip->i_res->rs_qa_qd_num++;
543 		qd++;
544 	}
545 
546 out:
547 	if (error)
548 		gfs2_quota_unhold(ip);
549 	return error;
550 }
551 
552 void gfs2_quota_unhold(struct gfs2_inode *ip)
553 {
554 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
555 	unsigned int x;
556 
557 	if (ip->i_res == NULL)
558 		return;
559 	gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
560 
561 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
562 		qdsb_put(ip->i_res->rs_qa_qd[x]);
563 		ip->i_res->rs_qa_qd[x] = NULL;
564 	}
565 	ip->i_res->rs_qa_qd_num = 0;
566 }
567 
568 static int sort_qd(const void *a, const void *b)
569 {
570 	const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
571 	const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
572 
573 	if (qid_lt(qd_a->qd_id, qd_b->qd_id))
574 		return -1;
575 	if (qid_lt(qd_b->qd_id, qd_a->qd_id))
576 		return 1;
577 	return 0;
578 }
579 
580 static void do_qc(struct gfs2_quota_data *qd, s64 change)
581 {
582 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
583 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
584 	struct gfs2_quota_change *qc = qd->qd_bh_qc;
585 	s64 x;
586 
587 	mutex_lock(&sdp->sd_quota_mutex);
588 	gfs2_trans_add_meta(ip->i_gl, qd->qd_bh);
589 
590 	if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
591 		qc->qc_change = 0;
592 		qc->qc_flags = 0;
593 		if (qd->qd_id.type == USRQUOTA)
594 			qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
595 		qc->qc_id = cpu_to_be32(from_kqid(&init_user_ns, qd->qd_id));
596 	}
597 
598 	x = be64_to_cpu(qc->qc_change) + change;
599 	qc->qc_change = cpu_to_be64(x);
600 
601 	spin_lock(&qd_lru_lock);
602 	qd->qd_change = x;
603 	spin_unlock(&qd_lru_lock);
604 
605 	if (!x) {
606 		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
607 		clear_bit(QDF_CHANGE, &qd->qd_flags);
608 		qc->qc_flags = 0;
609 		qc->qc_id = 0;
610 		slot_put(qd);
611 		qd_put(qd);
612 	} else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
613 		qd_hold(qd);
614 		slot_hold(qd);
615 	}
616 
617 	mutex_unlock(&sdp->sd_quota_mutex);
618 }
619 
620 /**
621  * gfs2_adjust_quota - adjust record of current block usage
622  * @ip: The quota inode
623  * @loc: Offset of the entry in the quota file
624  * @change: The amount of usage change to record
625  * @qd: The quota data
626  * @fdq: The updated limits to record
627  *
628  * This function was mostly borrowed from gfs2_block_truncate_page which was
629  * in turn mostly borrowed from ext3
630  *
631  * Returns: 0 or -ve on error
632  */
633 
634 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
635 			     s64 change, struct gfs2_quota_data *qd,
636 			     struct fs_disk_quota *fdq)
637 {
638 	struct inode *inode = &ip->i_inode;
639 	struct gfs2_sbd *sdp = GFS2_SB(inode);
640 	struct address_space *mapping = inode->i_mapping;
641 	unsigned long index = loc >> PAGE_CACHE_SHIFT;
642 	unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
643 	unsigned blocksize, iblock, pos;
644 	struct buffer_head *bh;
645 	struct page *page;
646 	void *kaddr, *ptr;
647 	struct gfs2_quota q, *qp;
648 	int err, nbytes;
649 	u64 size;
650 
651 	if (gfs2_is_stuffed(ip)) {
652 		err = gfs2_unstuff_dinode(ip, NULL);
653 		if (err)
654 			return err;
655 	}
656 
657 	memset(&q, 0, sizeof(struct gfs2_quota));
658 	err = gfs2_internal_read(ip, (char *)&q, &loc, sizeof(q));
659 	if (err < 0)
660 		return err;
661 
662 	err = -EIO;
663 	qp = &q;
664 	qp->qu_value = be64_to_cpu(qp->qu_value);
665 	qp->qu_value += change;
666 	qp->qu_value = cpu_to_be64(qp->qu_value);
667 	qd->qd_qb.qb_value = qp->qu_value;
668 	if (fdq) {
669 		if (fdq->d_fieldmask & FS_DQ_BSOFT) {
670 			qp->qu_warn = cpu_to_be64(fdq->d_blk_softlimit >> sdp->sd_fsb2bb_shift);
671 			qd->qd_qb.qb_warn = qp->qu_warn;
672 		}
673 		if (fdq->d_fieldmask & FS_DQ_BHARD) {
674 			qp->qu_limit = cpu_to_be64(fdq->d_blk_hardlimit >> sdp->sd_fsb2bb_shift);
675 			qd->qd_qb.qb_limit = qp->qu_limit;
676 		}
677 		if (fdq->d_fieldmask & FS_DQ_BCOUNT) {
678 			qp->qu_value = cpu_to_be64(fdq->d_bcount >> sdp->sd_fsb2bb_shift);
679 			qd->qd_qb.qb_value = qp->qu_value;
680 		}
681 	}
682 
683 	/* Write the quota into the quota file on disk */
684 	ptr = qp;
685 	nbytes = sizeof(struct gfs2_quota);
686 get_a_page:
687 	page = find_or_create_page(mapping, index, GFP_NOFS);
688 	if (!page)
689 		return -ENOMEM;
690 
691 	blocksize = inode->i_sb->s_blocksize;
692 	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
693 
694 	if (!page_has_buffers(page))
695 		create_empty_buffers(page, blocksize, 0);
696 
697 	bh = page_buffers(page);
698 	pos = blocksize;
699 	while (offset >= pos) {
700 		bh = bh->b_this_page;
701 		iblock++;
702 		pos += blocksize;
703 	}
704 
705 	if (!buffer_mapped(bh)) {
706 		gfs2_block_map(inode, iblock, bh, 1);
707 		if (!buffer_mapped(bh))
708 			goto unlock_out;
709 		/* If it's a newly allocated disk block for quota, zero it */
710 		if (buffer_new(bh))
711 			zero_user(page, pos - blocksize, bh->b_size);
712 	}
713 
714 	if (PageUptodate(page))
715 		set_buffer_uptodate(bh);
716 
717 	if (!buffer_uptodate(bh)) {
718 		ll_rw_block(READ | REQ_META, 1, &bh);
719 		wait_on_buffer(bh);
720 		if (!buffer_uptodate(bh))
721 			goto unlock_out;
722 	}
723 
724 	gfs2_trans_add_data(ip->i_gl, bh);
725 
726 	kaddr = kmap_atomic(page);
727 	if (offset + sizeof(struct gfs2_quota) > PAGE_CACHE_SIZE)
728 		nbytes = PAGE_CACHE_SIZE - offset;
729 	memcpy(kaddr + offset, ptr, nbytes);
730 	flush_dcache_page(page);
731 	kunmap_atomic(kaddr);
732 	unlock_page(page);
733 	page_cache_release(page);
734 
735 	/* If quota straddles page boundary, we need to update the rest of the
736 	 * quota at the beginning of the next page */
737 	if ((offset + sizeof(struct gfs2_quota)) > PAGE_CACHE_SIZE) {
738 		ptr = ptr + nbytes;
739 		nbytes = sizeof(struct gfs2_quota) - nbytes;
740 		offset = 0;
741 		index++;
742 		goto get_a_page;
743 	}
744 
745 	size = loc + sizeof(struct gfs2_quota);
746 	if (size > inode->i_size)
747 		i_size_write(inode, size);
748 	inode->i_mtime = inode->i_atime = CURRENT_TIME;
749 	mark_inode_dirty(inode);
750 	return 0;
751 
752 unlock_out:
753 	unlock_page(page);
754 	page_cache_release(page);
755 	return err;
756 }
757 
758 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
759 {
760 	struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
761 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
762 	unsigned int data_blocks, ind_blocks;
763 	struct gfs2_holder *ghs, i_gh;
764 	unsigned int qx, x;
765 	struct gfs2_quota_data *qd;
766 	unsigned reserved;
767 	loff_t offset;
768 	unsigned int nalloc = 0, blocks;
769 	int error;
770 
771 	error = gfs2_rs_alloc(ip);
772 	if (error)
773 		return error;
774 
775 	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
776 			      &data_blocks, &ind_blocks);
777 
778 	ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
779 	if (!ghs)
780 		return -ENOMEM;
781 
782 	sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
783 	mutex_lock(&ip->i_inode.i_mutex);
784 	for (qx = 0; qx < num_qd; qx++) {
785 		error = gfs2_glock_nq_init(qda[qx]->qd_gl, LM_ST_EXCLUSIVE,
786 					   GL_NOCACHE, &ghs[qx]);
787 		if (error)
788 			goto out;
789 	}
790 
791 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
792 	if (error)
793 		goto out;
794 
795 	for (x = 0; x < num_qd; x++) {
796 		offset = qd2offset(qda[x]);
797 		if (gfs2_write_alloc_required(ip, offset,
798 					      sizeof(struct gfs2_quota)))
799 			nalloc++;
800 	}
801 
802 	/*
803 	 * 1 blk for unstuffing inode if stuffed. We add this extra
804 	 * block to the reservation unconditionally. If the inode
805 	 * doesn't need unstuffing, the block will be released to the
806 	 * rgrp since it won't be allocated during the transaction
807 	 */
808 	/* +3 in the end for unstuffing block, inode size update block
809 	 * and another block in case quota straddles page boundary and
810 	 * two blocks need to be updated instead of 1 */
811 	blocks = num_qd * data_blocks + RES_DINODE + num_qd + 3;
812 
813 	reserved = 1 + (nalloc * (data_blocks + ind_blocks));
814 	error = gfs2_inplace_reserve(ip, reserved, 0);
815 	if (error)
816 		goto out_alloc;
817 
818 	if (nalloc)
819 		blocks += gfs2_rg_blocks(ip, reserved) + nalloc * ind_blocks + RES_STATFS;
820 
821 	error = gfs2_trans_begin(sdp, blocks, 0);
822 	if (error)
823 		goto out_ipres;
824 
825 	for (x = 0; x < num_qd; x++) {
826 		qd = qda[x];
827 		offset = qd2offset(qd);
828 		error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync, qd, NULL);
829 		if (error)
830 			goto out_end_trans;
831 
832 		do_qc(qd, -qd->qd_change_sync);
833 		set_bit(QDF_REFRESH, &qd->qd_flags);
834 	}
835 
836 	error = 0;
837 
838 out_end_trans:
839 	gfs2_trans_end(sdp);
840 out_ipres:
841 	gfs2_inplace_release(ip);
842 out_alloc:
843 	gfs2_glock_dq_uninit(&i_gh);
844 out:
845 	while (qx--)
846 		gfs2_glock_dq_uninit(&ghs[qx]);
847 	mutex_unlock(&ip->i_inode.i_mutex);
848 	kfree(ghs);
849 	gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
850 	return error;
851 }
852 
853 static int update_qd(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd)
854 {
855 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
856 	struct gfs2_quota q;
857 	struct gfs2_quota_lvb *qlvb;
858 	loff_t pos;
859 	int error;
860 
861 	memset(&q, 0, sizeof(struct gfs2_quota));
862 	pos = qd2offset(qd);
863 	error = gfs2_internal_read(ip, (char *)&q, &pos, sizeof(q));
864 	if (error < 0)
865 		return error;
866 
867 	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
868 	qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
869 	qlvb->__pad = 0;
870 	qlvb->qb_limit = q.qu_limit;
871 	qlvb->qb_warn = q.qu_warn;
872 	qlvb->qb_value = q.qu_value;
873 	qd->qd_qb = *qlvb;
874 
875 	return 0;
876 }
877 
878 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
879 		    struct gfs2_holder *q_gh)
880 {
881 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
882 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
883 	struct gfs2_holder i_gh;
884 	int error;
885 
886 restart:
887 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
888 	if (error)
889 		return error;
890 
891 	qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
892 
893 	if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
894 		gfs2_glock_dq_uninit(q_gh);
895 		error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE,
896 					   GL_NOCACHE, q_gh);
897 		if (error)
898 			return error;
899 
900 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
901 		if (error)
902 			goto fail;
903 
904 		error = update_qd(sdp, qd);
905 		if (error)
906 			goto fail_gunlock;
907 
908 		gfs2_glock_dq_uninit(&i_gh);
909 		gfs2_glock_dq_uninit(q_gh);
910 		force_refresh = 0;
911 		goto restart;
912 	}
913 
914 	return 0;
915 
916 fail_gunlock:
917 	gfs2_glock_dq_uninit(&i_gh);
918 fail:
919 	gfs2_glock_dq_uninit(q_gh);
920 	return error;
921 }
922 
923 int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
924 {
925 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
926 	struct gfs2_quota_data *qd;
927 	unsigned int x;
928 	int error = 0;
929 
930 	error = gfs2_quota_hold(ip, uid, gid);
931 	if (error)
932 		return error;
933 
934 	if (capable(CAP_SYS_RESOURCE) ||
935 	    sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
936 		return 0;
937 
938 	sort(ip->i_res->rs_qa_qd, ip->i_res->rs_qa_qd_num,
939 	     sizeof(struct gfs2_quota_data *), sort_qd, NULL);
940 
941 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
942 		int force = NO_FORCE;
943 		qd = ip->i_res->rs_qa_qd[x];
944 		if (test_and_clear_bit(QDF_REFRESH, &qd->qd_flags))
945 			force = FORCE;
946 		error = do_glock(qd, force, &ip->i_res->rs_qa_qd_ghs[x]);
947 		if (error)
948 			break;
949 	}
950 
951 	if (!error)
952 		set_bit(GIF_QD_LOCKED, &ip->i_flags);
953 	else {
954 		while (x--)
955 			gfs2_glock_dq_uninit(&ip->i_res->rs_qa_qd_ghs[x]);
956 		gfs2_quota_unhold(ip);
957 	}
958 
959 	return error;
960 }
961 
962 static int need_sync(struct gfs2_quota_data *qd)
963 {
964 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
965 	struct gfs2_tune *gt = &sdp->sd_tune;
966 	s64 value;
967 	unsigned int num, den;
968 	int do_sync = 1;
969 
970 	if (!qd->qd_qb.qb_limit)
971 		return 0;
972 
973 	spin_lock(&qd_lru_lock);
974 	value = qd->qd_change;
975 	spin_unlock(&qd_lru_lock);
976 
977 	spin_lock(&gt->gt_spin);
978 	num = gt->gt_quota_scale_num;
979 	den = gt->gt_quota_scale_den;
980 	spin_unlock(&gt->gt_spin);
981 
982 	if (value < 0)
983 		do_sync = 0;
984 	else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
985 		 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
986 		do_sync = 0;
987 	else {
988 		value *= gfs2_jindex_size(sdp) * num;
989 		value = div_s64(value, den);
990 		value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
991 		if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
992 			do_sync = 0;
993 	}
994 
995 	return do_sync;
996 }
997 
998 void gfs2_quota_unlock(struct gfs2_inode *ip)
999 {
1000 	struct gfs2_quota_data *qda[4];
1001 	unsigned int count = 0;
1002 	unsigned int x;
1003 
1004 	if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
1005 		goto out;
1006 
1007 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1008 		struct gfs2_quota_data *qd;
1009 		int sync;
1010 
1011 		qd = ip->i_res->rs_qa_qd[x];
1012 		sync = need_sync(qd);
1013 
1014 		gfs2_glock_dq_uninit(&ip->i_res->rs_qa_qd_ghs[x]);
1015 
1016 		if (sync && qd_trylock(qd))
1017 			qda[count++] = qd;
1018 	}
1019 
1020 	if (count) {
1021 		do_sync(count, qda);
1022 		for (x = 0; x < count; x++)
1023 			qd_unlock(qda[x]);
1024 	}
1025 
1026 out:
1027 	gfs2_quota_unhold(ip);
1028 }
1029 
1030 #define MAX_LINE 256
1031 
1032 static int print_message(struct gfs2_quota_data *qd, char *type)
1033 {
1034 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
1035 
1036 	printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\n",
1037 	       sdp->sd_fsname, type,
1038 	       (qd->qd_id.type == USRQUOTA) ? "user" : "group",
1039 	       from_kqid(&init_user_ns, qd->qd_id));
1040 
1041 	return 0;
1042 }
1043 
1044 int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
1045 {
1046 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1047 	struct gfs2_quota_data *qd;
1048 	s64 value;
1049 	unsigned int x;
1050 	int error = 0;
1051 
1052 	if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
1053 		return 0;
1054 
1055         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
1056                 return 0;
1057 
1058 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1059 		qd = ip->i_res->rs_qa_qd[x];
1060 
1061 		if (!(qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
1062 		      qid_eq(qd->qd_id, make_kqid_gid(gid))))
1063 			continue;
1064 
1065 		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
1066 		spin_lock(&qd_lru_lock);
1067 		value += qd->qd_change;
1068 		spin_unlock(&qd_lru_lock);
1069 
1070 		if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
1071 			print_message(qd, "exceeded");
1072 			quota_send_warning(qd->qd_id,
1073 					   sdp->sd_vfs->s_dev, QUOTA_NL_BHARDWARN);
1074 
1075 			error = -EDQUOT;
1076 			break;
1077 		} else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
1078 			   (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
1079 			   time_after_eq(jiffies, qd->qd_last_warn +
1080 					 gfs2_tune_get(sdp,
1081 						gt_quota_warn_period) * HZ)) {
1082 			quota_send_warning(qd->qd_id,
1083 					   sdp->sd_vfs->s_dev, QUOTA_NL_BSOFTWARN);
1084 			error = print_message(qd, "warning");
1085 			qd->qd_last_warn = jiffies;
1086 		}
1087 	}
1088 
1089 	return error;
1090 }
1091 
1092 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1093 		       kuid_t uid, kgid_t gid)
1094 {
1095 	struct gfs2_quota_data *qd;
1096 	unsigned int x;
1097 
1098 	if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1099 		return;
1100 	if (ip->i_diskflags & GFS2_DIF_SYSTEM)
1101 		return;
1102 
1103 	for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1104 		qd = ip->i_res->rs_qa_qd[x];
1105 
1106 		if (qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
1107 		    qid_eq(qd->qd_id, make_kqid_gid(gid))) {
1108 			do_qc(qd, change);
1109 		}
1110 	}
1111 }
1112 
1113 int gfs2_quota_sync(struct super_block *sb, int type)
1114 {
1115 	struct gfs2_sbd *sdp = sb->s_fs_info;
1116 	struct gfs2_quota_data **qda;
1117 	unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
1118 	unsigned int num_qd;
1119 	unsigned int x;
1120 	int error = 0;
1121 
1122 	sdp->sd_quota_sync_gen++;
1123 
1124 	qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1125 	if (!qda)
1126 		return -ENOMEM;
1127 
1128 	do {
1129 		num_qd = 0;
1130 
1131 		for (;;) {
1132 			error = qd_fish(sdp, qda + num_qd);
1133 			if (error || !qda[num_qd])
1134 				break;
1135 			if (++num_qd == max_qd)
1136 				break;
1137 		}
1138 
1139 		if (num_qd) {
1140 			if (!error)
1141 				error = do_sync(num_qd, qda);
1142 			if (!error)
1143 				for (x = 0; x < num_qd; x++)
1144 					qda[x]->qd_sync_gen =
1145 						sdp->sd_quota_sync_gen;
1146 
1147 			for (x = 0; x < num_qd; x++)
1148 				qd_unlock(qda[x]);
1149 		}
1150 	} while (!error && num_qd == max_qd);
1151 
1152 	kfree(qda);
1153 
1154 	return error;
1155 }
1156 
1157 static int gfs2_quota_sync_timeo(struct super_block *sb, int type)
1158 {
1159 	return gfs2_quota_sync(sb, type);
1160 }
1161 
1162 int gfs2_quota_refresh(struct gfs2_sbd *sdp, struct kqid qid)
1163 {
1164 	struct gfs2_quota_data *qd;
1165 	struct gfs2_holder q_gh;
1166 	int error;
1167 
1168 	error = qd_get(sdp, qid, &qd);
1169 	if (error)
1170 		return error;
1171 
1172 	error = do_glock(qd, FORCE, &q_gh);
1173 	if (!error)
1174 		gfs2_glock_dq_uninit(&q_gh);
1175 
1176 	qd_put(qd);
1177 	return error;
1178 }
1179 
1180 static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
1181 {
1182 	const struct gfs2_quota_change *str = buf;
1183 
1184 	qc->qc_change = be64_to_cpu(str->qc_change);
1185 	qc->qc_flags = be32_to_cpu(str->qc_flags);
1186 	qc->qc_id = make_kqid(&init_user_ns,
1187 			      (qc->qc_flags & GFS2_QCF_USER)?USRQUOTA:GRPQUOTA,
1188 			      be32_to_cpu(str->qc_id));
1189 }
1190 
1191 int gfs2_quota_init(struct gfs2_sbd *sdp)
1192 {
1193 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1194 	u64 size = i_size_read(sdp->sd_qc_inode);
1195 	unsigned int blocks = size >> sdp->sd_sb.sb_bsize_shift;
1196 	unsigned int x, slot = 0;
1197 	unsigned int found = 0;
1198 	u64 dblock;
1199 	u32 extlen = 0;
1200 	int error;
1201 
1202 	if (gfs2_check_internal_file_size(sdp->sd_qc_inode, 1, 64 << 20))
1203 		return -EIO;
1204 
1205 	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1206 	sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1207 
1208 	error = -ENOMEM;
1209 
1210 	sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1211 				       sizeof(unsigned char *), GFP_NOFS);
1212 	if (!sdp->sd_quota_bitmap)
1213 		return error;
1214 
1215 	for (x = 0; x < sdp->sd_quota_chunks; x++) {
1216 		sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_NOFS);
1217 		if (!sdp->sd_quota_bitmap[x])
1218 			goto fail;
1219 	}
1220 
1221 	for (x = 0; x < blocks; x++) {
1222 		struct buffer_head *bh;
1223 		unsigned int y;
1224 
1225 		if (!extlen) {
1226 			int new = 0;
1227 			error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1228 			if (error)
1229 				goto fail;
1230 		}
1231 		error = -EIO;
1232 		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1233 		if (!bh)
1234 			goto fail;
1235 		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1236 			brelse(bh);
1237 			goto fail;
1238 		}
1239 
1240 		for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1241 		     y++, slot++) {
1242 			struct gfs2_quota_change_host qc;
1243 			struct gfs2_quota_data *qd;
1244 
1245 			gfs2_quota_change_in(&qc, bh->b_data +
1246 					  sizeof(struct gfs2_meta_header) +
1247 					  y * sizeof(struct gfs2_quota_change));
1248 			if (!qc.qc_change)
1249 				continue;
1250 
1251 			error = qd_alloc(sdp, qc.qc_id, &qd);
1252 			if (error) {
1253 				brelse(bh);
1254 				goto fail;
1255 			}
1256 
1257 			set_bit(QDF_CHANGE, &qd->qd_flags);
1258 			qd->qd_change = qc.qc_change;
1259 			qd->qd_slot = slot;
1260 			qd->qd_slot_count = 1;
1261 
1262 			spin_lock(&qd_lru_lock);
1263 			gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1264 			list_add(&qd->qd_list, &sdp->sd_quota_list);
1265 			atomic_inc(&sdp->sd_quota_count);
1266 			spin_unlock(&qd_lru_lock);
1267 
1268 			found++;
1269 		}
1270 
1271 		brelse(bh);
1272 		dblock++;
1273 		extlen--;
1274 	}
1275 
1276 	if (found)
1277 		fs_info(sdp, "found %u quota changes\n", found);
1278 
1279 	return 0;
1280 
1281 fail:
1282 	gfs2_quota_cleanup(sdp);
1283 	return error;
1284 }
1285 
1286 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1287 {
1288 	struct list_head *head = &sdp->sd_quota_list;
1289 	struct gfs2_quota_data *qd;
1290 	unsigned int x;
1291 
1292 	spin_lock(&qd_lru_lock);
1293 	while (!list_empty(head)) {
1294 		qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1295 
1296 		if (atomic_read(&qd->qd_count) > 1 ||
1297 		    (atomic_read(&qd->qd_count) &&
1298 		     !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1299 			list_move(&qd->qd_list, head);
1300 			spin_unlock(&qd_lru_lock);
1301 			schedule();
1302 			spin_lock(&qd_lru_lock);
1303 			continue;
1304 		}
1305 
1306 		list_del(&qd->qd_list);
1307 		/* Also remove if this qd exists in the reclaim list */
1308 		if (!list_empty(&qd->qd_reclaim)) {
1309 			list_del_init(&qd->qd_reclaim);
1310 			atomic_dec(&qd_lru_count);
1311 		}
1312 		atomic_dec(&sdp->sd_quota_count);
1313 		spin_unlock(&qd_lru_lock);
1314 
1315 		if (!atomic_read(&qd->qd_count)) {
1316 			gfs2_assert_warn(sdp, !qd->qd_change);
1317 			gfs2_assert_warn(sdp, !qd->qd_slot_count);
1318 		} else
1319 			gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1320 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1321 
1322 		gfs2_glock_put(qd->qd_gl);
1323 		kmem_cache_free(gfs2_quotad_cachep, qd);
1324 
1325 		spin_lock(&qd_lru_lock);
1326 	}
1327 	spin_unlock(&qd_lru_lock);
1328 
1329 	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1330 
1331 	if (sdp->sd_quota_bitmap) {
1332 		for (x = 0; x < sdp->sd_quota_chunks; x++)
1333 			kfree(sdp->sd_quota_bitmap[x]);
1334 		kfree(sdp->sd_quota_bitmap);
1335 	}
1336 }
1337 
1338 static void quotad_error(struct gfs2_sbd *sdp, const char *msg, int error)
1339 {
1340 	if (error == 0 || error == -EROFS)
1341 		return;
1342 	if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
1343 		fs_err(sdp, "gfs2_quotad: %s error %d\n", msg, error);
1344 }
1345 
1346 static void quotad_check_timeo(struct gfs2_sbd *sdp, const char *msg,
1347 			       int (*fxn)(struct super_block *sb, int type),
1348 			       unsigned long t, unsigned long *timeo,
1349 			       unsigned int *new_timeo)
1350 {
1351 	if (t >= *timeo) {
1352 		int error = fxn(sdp->sd_vfs, 0);
1353 		quotad_error(sdp, msg, error);
1354 		*timeo = gfs2_tune_get_i(&sdp->sd_tune, new_timeo) * HZ;
1355 	} else {
1356 		*timeo -= t;
1357 	}
1358 }
1359 
1360 static void quotad_check_trunc_list(struct gfs2_sbd *sdp)
1361 {
1362 	struct gfs2_inode *ip;
1363 
1364 	while(1) {
1365 		ip = NULL;
1366 		spin_lock(&sdp->sd_trunc_lock);
1367 		if (!list_empty(&sdp->sd_trunc_list)) {
1368 			ip = list_entry(sdp->sd_trunc_list.next,
1369 					struct gfs2_inode, i_trunc_list);
1370 			list_del_init(&ip->i_trunc_list);
1371 		}
1372 		spin_unlock(&sdp->sd_trunc_lock);
1373 		if (ip == NULL)
1374 			return;
1375 		gfs2_glock_finish_truncate(ip);
1376 	}
1377 }
1378 
1379 void gfs2_wake_up_statfs(struct gfs2_sbd *sdp) {
1380 	if (!sdp->sd_statfs_force_sync) {
1381 		sdp->sd_statfs_force_sync = 1;
1382 		wake_up(&sdp->sd_quota_wait);
1383 	}
1384 }
1385 
1386 
1387 /**
1388  * gfs2_quotad - Write cached quota changes into the quota file
1389  * @sdp: Pointer to GFS2 superblock
1390  *
1391  */
1392 
1393 int gfs2_quotad(void *data)
1394 {
1395 	struct gfs2_sbd *sdp = data;
1396 	struct gfs2_tune *tune = &sdp->sd_tune;
1397 	unsigned long statfs_timeo = 0;
1398 	unsigned long quotad_timeo = 0;
1399 	unsigned long t = 0;
1400 	DEFINE_WAIT(wait);
1401 	int empty;
1402 
1403 	while (!kthread_should_stop()) {
1404 
1405 		/* Update the master statfs file */
1406 		if (sdp->sd_statfs_force_sync) {
1407 			int error = gfs2_statfs_sync(sdp->sd_vfs, 0);
1408 			quotad_error(sdp, "statfs", error);
1409 			statfs_timeo = gfs2_tune_get(sdp, gt_statfs_quantum) * HZ;
1410 		}
1411 		else
1412 			quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
1413 				   	   &statfs_timeo,
1414 					   &tune->gt_statfs_quantum);
1415 
1416 		/* Update quota file */
1417 		quotad_check_timeo(sdp, "sync", gfs2_quota_sync_timeo, t,
1418 				   &quotad_timeo, &tune->gt_quota_quantum);
1419 
1420 		/* Check for & recover partially truncated inodes */
1421 		quotad_check_trunc_list(sdp);
1422 
1423 		try_to_freeze();
1424 
1425 		t = min(quotad_timeo, statfs_timeo);
1426 
1427 		prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);
1428 		spin_lock(&sdp->sd_trunc_lock);
1429 		empty = list_empty(&sdp->sd_trunc_list);
1430 		spin_unlock(&sdp->sd_trunc_lock);
1431 		if (empty && !sdp->sd_statfs_force_sync)
1432 			t -= schedule_timeout(t);
1433 		else
1434 			t = 0;
1435 		finish_wait(&sdp->sd_quota_wait, &wait);
1436 	}
1437 
1438 	return 0;
1439 }
1440 
1441 static int gfs2_quota_get_xstate(struct super_block *sb,
1442 				 struct fs_quota_stat *fqs)
1443 {
1444 	struct gfs2_sbd *sdp = sb->s_fs_info;
1445 
1446 	memset(fqs, 0, sizeof(struct fs_quota_stat));
1447 	fqs->qs_version = FS_QSTAT_VERSION;
1448 
1449 	switch (sdp->sd_args.ar_quota) {
1450 	case GFS2_QUOTA_ON:
1451 		fqs->qs_flags |= (FS_QUOTA_UDQ_ENFD | FS_QUOTA_GDQ_ENFD);
1452 		/*FALLTHRU*/
1453 	case GFS2_QUOTA_ACCOUNT:
1454 		fqs->qs_flags |= (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT);
1455 		break;
1456 	case GFS2_QUOTA_OFF:
1457 		break;
1458 	}
1459 
1460 	if (sdp->sd_quota_inode) {
1461 		fqs->qs_uquota.qfs_ino = GFS2_I(sdp->sd_quota_inode)->i_no_addr;
1462 		fqs->qs_uquota.qfs_nblks = sdp->sd_quota_inode->i_blocks;
1463 	}
1464 	fqs->qs_uquota.qfs_nextents = 1; /* unsupported */
1465 	fqs->qs_gquota = fqs->qs_uquota; /* its the same inode in both cases */
1466 	fqs->qs_incoredqs = atomic_read(&qd_lru_count);
1467 	return 0;
1468 }
1469 
1470 static int gfs2_get_dqblk(struct super_block *sb, struct kqid qid,
1471 			  struct fs_disk_quota *fdq)
1472 {
1473 	struct gfs2_sbd *sdp = sb->s_fs_info;
1474 	struct gfs2_quota_lvb *qlvb;
1475 	struct gfs2_quota_data *qd;
1476 	struct gfs2_holder q_gh;
1477 	int error;
1478 
1479 	memset(fdq, 0, sizeof(struct fs_disk_quota));
1480 
1481 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1482 		return -ESRCH; /* Crazy XFS error code */
1483 
1484 	if ((qid.type != USRQUOTA) &&
1485 	    (qid.type != GRPQUOTA))
1486 		return -EINVAL;
1487 
1488 	error = qd_get(sdp, qid, &qd);
1489 	if (error)
1490 		return error;
1491 	error = do_glock(qd, FORCE, &q_gh);
1492 	if (error)
1493 		goto out;
1494 
1495 	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
1496 	fdq->d_version = FS_DQUOT_VERSION;
1497 	fdq->d_flags = (qid.type == USRQUOTA) ? FS_USER_QUOTA : FS_GROUP_QUOTA;
1498 	fdq->d_id = from_kqid_munged(current_user_ns(), qid);
1499 	fdq->d_blk_hardlimit = be64_to_cpu(qlvb->qb_limit) << sdp->sd_fsb2bb_shift;
1500 	fdq->d_blk_softlimit = be64_to_cpu(qlvb->qb_warn) << sdp->sd_fsb2bb_shift;
1501 	fdq->d_bcount = be64_to_cpu(qlvb->qb_value) << sdp->sd_fsb2bb_shift;
1502 
1503 	gfs2_glock_dq_uninit(&q_gh);
1504 out:
1505 	qd_put(qd);
1506 	return error;
1507 }
1508 
1509 /* GFS2 only supports a subset of the XFS fields */
1510 #define GFS2_FIELDMASK (FS_DQ_BSOFT|FS_DQ_BHARD|FS_DQ_BCOUNT)
1511 
1512 static int gfs2_set_dqblk(struct super_block *sb, struct kqid qid,
1513 			  struct fs_disk_quota *fdq)
1514 {
1515 	struct gfs2_sbd *sdp = sb->s_fs_info;
1516 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
1517 	struct gfs2_quota_data *qd;
1518 	struct gfs2_holder q_gh, i_gh;
1519 	unsigned int data_blocks, ind_blocks;
1520 	unsigned int blocks = 0;
1521 	int alloc_required;
1522 	loff_t offset;
1523 	int error;
1524 
1525 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1526 		return -ESRCH; /* Crazy XFS error code */
1527 
1528 	if ((qid.type != USRQUOTA) &&
1529 	    (qid.type != GRPQUOTA))
1530 		return -EINVAL;
1531 
1532 	if (fdq->d_fieldmask & ~GFS2_FIELDMASK)
1533 		return -EINVAL;
1534 
1535 	error = qd_get(sdp, qid, &qd);
1536 	if (error)
1537 		return error;
1538 
1539 	error = gfs2_rs_alloc(ip);
1540 	if (error)
1541 		goto out_put;
1542 
1543 	mutex_lock(&ip->i_inode.i_mutex);
1544 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE, 0, &q_gh);
1545 	if (error)
1546 		goto out_unlockput;
1547 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
1548 	if (error)
1549 		goto out_q;
1550 
1551 	/* Check for existing entry, if none then alloc new blocks */
1552 	error = update_qd(sdp, qd);
1553 	if (error)
1554 		goto out_i;
1555 
1556 	/* If nothing has changed, this is a no-op */
1557 	if ((fdq->d_fieldmask & FS_DQ_BSOFT) &&
1558 	    ((fdq->d_blk_softlimit >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_warn)))
1559 		fdq->d_fieldmask ^= FS_DQ_BSOFT;
1560 
1561 	if ((fdq->d_fieldmask & FS_DQ_BHARD) &&
1562 	    ((fdq->d_blk_hardlimit >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_limit)))
1563 		fdq->d_fieldmask ^= FS_DQ_BHARD;
1564 
1565 	if ((fdq->d_fieldmask & FS_DQ_BCOUNT) &&
1566 	    ((fdq->d_bcount >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_value)))
1567 		fdq->d_fieldmask ^= FS_DQ_BCOUNT;
1568 
1569 	if (fdq->d_fieldmask == 0)
1570 		goto out_i;
1571 
1572 	offset = qd2offset(qd);
1573 	alloc_required = gfs2_write_alloc_required(ip, offset, sizeof(struct gfs2_quota));
1574 	if (gfs2_is_stuffed(ip))
1575 		alloc_required = 1;
1576 	if (alloc_required) {
1577 		gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
1578 				       &data_blocks, &ind_blocks);
1579 		blocks = 1 + data_blocks + ind_blocks;
1580 		error = gfs2_inplace_reserve(ip, blocks, 0);
1581 		if (error)
1582 			goto out_i;
1583 		blocks += gfs2_rg_blocks(ip, blocks);
1584 	}
1585 
1586 	/* Some quotas span block boundaries and can update two blocks,
1587 	   adding an extra block to the transaction to handle such quotas */
1588 	error = gfs2_trans_begin(sdp, blocks + RES_DINODE + 2, 0);
1589 	if (error)
1590 		goto out_release;
1591 
1592 	/* Apply changes */
1593 	error = gfs2_adjust_quota(ip, offset, 0, qd, fdq);
1594 
1595 	gfs2_trans_end(sdp);
1596 out_release:
1597 	if (alloc_required)
1598 		gfs2_inplace_release(ip);
1599 out_i:
1600 	gfs2_glock_dq_uninit(&i_gh);
1601 out_q:
1602 	gfs2_glock_dq_uninit(&q_gh);
1603 out_unlockput:
1604 	mutex_unlock(&ip->i_inode.i_mutex);
1605 out_put:
1606 	qd_put(qd);
1607 	return error;
1608 }
1609 
1610 const struct quotactl_ops gfs2_quotactl_ops = {
1611 	.quota_sync     = gfs2_quota_sync,
1612 	.get_xstate     = gfs2_quota_get_xstate,
1613 	.get_dqblk	= gfs2_get_dqblk,
1614 	.set_dqblk	= gfs2_set_dqblk,
1615 };
1616