xref: /openbmc/linux/fs/gfs2/quota.c (revision b595076a)
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/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 #include <linux/quota.h>
51 #include <linux/dqblk_xfs.h>
52 
53 #include "gfs2.h"
54 #include "incore.h"
55 #include "bmap.h"
56 #include "glock.h"
57 #include "glops.h"
58 #include "log.h"
59 #include "meta_io.h"
60 #include "quota.h"
61 #include "rgrp.h"
62 #include "super.h"
63 #include "trans.h"
64 #include "inode.h"
65 #include "util.h"
66 
67 #define QUOTA_USER 1
68 #define QUOTA_GROUP 0
69 
70 struct gfs2_quota_change_host {
71 	u64 qc_change;
72 	u32 qc_flags; /* GFS2_QCF_... */
73 	u32 qc_id;
74 };
75 
76 static LIST_HEAD(qd_lru_list);
77 static atomic_t qd_lru_count = ATOMIC_INIT(0);
78 static DEFINE_SPINLOCK(qd_lru_lock);
79 
80 int gfs2_shrink_qd_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
81 {
82 	struct gfs2_quota_data *qd;
83 	struct gfs2_sbd *sdp;
84 
85 	if (nr == 0)
86 		goto out;
87 
88 	if (!(gfp_mask & __GFP_FS))
89 		return -1;
90 
91 	spin_lock(&qd_lru_lock);
92 	while (nr && !list_empty(&qd_lru_list)) {
93 		qd = list_entry(qd_lru_list.next,
94 				struct gfs2_quota_data, qd_reclaim);
95 		sdp = qd->qd_gl->gl_sbd;
96 
97 		/* Free from the filesystem-specific list */
98 		list_del(&qd->qd_list);
99 
100 		gfs2_assert_warn(sdp, !qd->qd_change);
101 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
102 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
103 
104 		gfs2_glock_put(qd->qd_gl);
105 		atomic_dec(&sdp->sd_quota_count);
106 
107 		/* Delete it from the common reclaim list */
108 		list_del_init(&qd->qd_reclaim);
109 		atomic_dec(&qd_lru_count);
110 		spin_unlock(&qd_lru_lock);
111 		kmem_cache_free(gfs2_quotad_cachep, qd);
112 		spin_lock(&qd_lru_lock);
113 		nr--;
114 	}
115 	spin_unlock(&qd_lru_lock);
116 
117 out:
118 	return (atomic_read(&qd_lru_count) * sysctl_vfs_cache_pressure) / 100;
119 }
120 
121 static u64 qd2offset(struct gfs2_quota_data *qd)
122 {
123 	u64 offset;
124 
125 	offset = 2 * (u64)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
126 	offset *= sizeof(struct gfs2_quota);
127 
128 	return offset;
129 }
130 
131 static int qd_alloc(struct gfs2_sbd *sdp, int user, u32 id,
132 		    struct gfs2_quota_data **qdp)
133 {
134 	struct gfs2_quota_data *qd;
135 	int error;
136 
137 	qd = kmem_cache_zalloc(gfs2_quotad_cachep, GFP_NOFS);
138 	if (!qd)
139 		return -ENOMEM;
140 
141 	atomic_set(&qd->qd_count, 1);
142 	qd->qd_id = id;
143 	if (user)
144 		set_bit(QDF_USER, &qd->qd_flags);
145 	qd->qd_slot = -1;
146 	INIT_LIST_HEAD(&qd->qd_reclaim);
147 
148 	error = gfs2_glock_get(sdp, 2 * (u64)id + !user,
149 			      &gfs2_quota_glops, CREATE, &qd->qd_gl);
150 	if (error)
151 		goto fail;
152 
153 	*qdp = qd;
154 
155 	return 0;
156 
157 fail:
158 	kmem_cache_free(gfs2_quotad_cachep, qd);
159 	return error;
160 }
161 
162 static int qd_get(struct gfs2_sbd *sdp, int user, u32 id,
163 		  struct gfs2_quota_data **qdp)
164 {
165 	struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
166 	int error, found;
167 
168 	*qdp = NULL;
169 
170 	for (;;) {
171 		found = 0;
172 		spin_lock(&qd_lru_lock);
173 		list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
174 			if (qd->qd_id == id &&
175 			    !test_bit(QDF_USER, &qd->qd_flags) == !user) {
176 				if (!atomic_read(&qd->qd_count) &&
177 				    !list_empty(&qd->qd_reclaim)) {
178 					/* Remove it from reclaim list */
179 					list_del_init(&qd->qd_reclaim);
180 					atomic_dec(&qd_lru_count);
181 				}
182 				atomic_inc(&qd->qd_count);
183 				found = 1;
184 				break;
185 			}
186 		}
187 
188 		if (!found)
189 			qd = NULL;
190 
191 		if (!qd && new_qd) {
192 			qd = new_qd;
193 			list_add(&qd->qd_list, &sdp->sd_quota_list);
194 			atomic_inc(&sdp->sd_quota_count);
195 			new_qd = NULL;
196 		}
197 
198 		spin_unlock(&qd_lru_lock);
199 
200 		if (qd) {
201 			if (new_qd) {
202 				gfs2_glock_put(new_qd->qd_gl);
203 				kmem_cache_free(gfs2_quotad_cachep, new_qd);
204 			}
205 			*qdp = qd;
206 			return 0;
207 		}
208 
209 		error = qd_alloc(sdp, user, id, &new_qd);
210 		if (error)
211 			return error;
212 	}
213 }
214 
215 static void qd_hold(struct gfs2_quota_data *qd)
216 {
217 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
218 	gfs2_assert(sdp, atomic_read(&qd->qd_count));
219 	atomic_inc(&qd->qd_count);
220 }
221 
222 static void qd_put(struct gfs2_quota_data *qd)
223 {
224 	if (atomic_dec_and_lock(&qd->qd_count, &qd_lru_lock)) {
225 		/* Add to the reclaim list */
226 		list_add_tail(&qd->qd_reclaim, &qd_lru_list);
227 		atomic_inc(&qd_lru_count);
228 		spin_unlock(&qd_lru_lock);
229 	}
230 }
231 
232 static int slot_get(struct gfs2_quota_data *qd)
233 {
234 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
235 	unsigned int c, o = 0, b;
236 	unsigned char byte = 0;
237 
238 	spin_lock(&qd_lru_lock);
239 
240 	if (qd->qd_slot_count++) {
241 		spin_unlock(&qd_lru_lock);
242 		return 0;
243 	}
244 
245 	for (c = 0; c < sdp->sd_quota_chunks; c++)
246 		for (o = 0; o < PAGE_SIZE; o++) {
247 			byte = sdp->sd_quota_bitmap[c][o];
248 			if (byte != 0xFF)
249 				goto found;
250 		}
251 
252 	goto fail;
253 
254 found:
255 	for (b = 0; b < 8; b++)
256 		if (!(byte & (1 << b)))
257 			break;
258 	qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
259 
260 	if (qd->qd_slot >= sdp->sd_quota_slots)
261 		goto fail;
262 
263 	sdp->sd_quota_bitmap[c][o] |= 1 << b;
264 
265 	spin_unlock(&qd_lru_lock);
266 
267 	return 0;
268 
269 fail:
270 	qd->qd_slot_count--;
271 	spin_unlock(&qd_lru_lock);
272 	return -ENOSPC;
273 }
274 
275 static void slot_hold(struct gfs2_quota_data *qd)
276 {
277 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
278 
279 	spin_lock(&qd_lru_lock);
280 	gfs2_assert(sdp, qd->qd_slot_count);
281 	qd->qd_slot_count++;
282 	spin_unlock(&qd_lru_lock);
283 }
284 
285 static void slot_put(struct gfs2_quota_data *qd)
286 {
287 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
288 
289 	spin_lock(&qd_lru_lock);
290 	gfs2_assert(sdp, qd->qd_slot_count);
291 	if (!--qd->qd_slot_count) {
292 		gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
293 		qd->qd_slot = -1;
294 	}
295 	spin_unlock(&qd_lru_lock);
296 }
297 
298 static int bh_get(struct gfs2_quota_data *qd)
299 {
300 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
301 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
302 	unsigned int block, offset;
303 	struct buffer_head *bh;
304 	int error;
305 	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
306 
307 	mutex_lock(&sdp->sd_quota_mutex);
308 
309 	if (qd->qd_bh_count++) {
310 		mutex_unlock(&sdp->sd_quota_mutex);
311 		return 0;
312 	}
313 
314 	block = qd->qd_slot / sdp->sd_qc_per_block;
315 	offset = qd->qd_slot % sdp->sd_qc_per_block;
316 
317 	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
318 	error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
319 	if (error)
320 		goto fail;
321 	error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
322 	if (error)
323 		goto fail;
324 	error = -EIO;
325 	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
326 		goto fail_brelse;
327 
328 	qd->qd_bh = bh;
329 	qd->qd_bh_qc = (struct gfs2_quota_change *)
330 		(bh->b_data + sizeof(struct gfs2_meta_header) +
331 		 offset * sizeof(struct gfs2_quota_change));
332 
333 	mutex_unlock(&sdp->sd_quota_mutex);
334 
335 	return 0;
336 
337 fail_brelse:
338 	brelse(bh);
339 fail:
340 	qd->qd_bh_count--;
341 	mutex_unlock(&sdp->sd_quota_mutex);
342 	return error;
343 }
344 
345 static void bh_put(struct gfs2_quota_data *qd)
346 {
347 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
348 
349 	mutex_lock(&sdp->sd_quota_mutex);
350 	gfs2_assert(sdp, qd->qd_bh_count);
351 	if (!--qd->qd_bh_count) {
352 		brelse(qd->qd_bh);
353 		qd->qd_bh = NULL;
354 		qd->qd_bh_qc = NULL;
355 	}
356 	mutex_unlock(&sdp->sd_quota_mutex);
357 }
358 
359 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
360 {
361 	struct gfs2_quota_data *qd = NULL;
362 	int error;
363 	int found = 0;
364 
365 	*qdp = NULL;
366 
367 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
368 		return 0;
369 
370 	spin_lock(&qd_lru_lock);
371 
372 	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
373 		if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
374 		    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
375 		    qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
376 			continue;
377 
378 		list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
379 
380 		set_bit(QDF_LOCKED, &qd->qd_flags);
381 		gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
382 		atomic_inc(&qd->qd_count);
383 		qd->qd_change_sync = qd->qd_change;
384 		gfs2_assert_warn(sdp, qd->qd_slot_count);
385 		qd->qd_slot_count++;
386 		found = 1;
387 
388 		break;
389 	}
390 
391 	if (!found)
392 		qd = NULL;
393 
394 	spin_unlock(&qd_lru_lock);
395 
396 	if (qd) {
397 		gfs2_assert_warn(sdp, qd->qd_change_sync);
398 		error = bh_get(qd);
399 		if (error) {
400 			clear_bit(QDF_LOCKED, &qd->qd_flags);
401 			slot_put(qd);
402 			qd_put(qd);
403 			return error;
404 		}
405 	}
406 
407 	*qdp = qd;
408 
409 	return 0;
410 }
411 
412 static int qd_trylock(struct gfs2_quota_data *qd)
413 {
414 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
415 
416 	if (sdp->sd_vfs->s_flags & MS_RDONLY)
417 		return 0;
418 
419 	spin_lock(&qd_lru_lock);
420 
421 	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
422 	    !test_bit(QDF_CHANGE, &qd->qd_flags)) {
423 		spin_unlock(&qd_lru_lock);
424 		return 0;
425 	}
426 
427 	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
428 
429 	set_bit(QDF_LOCKED, &qd->qd_flags);
430 	gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
431 	atomic_inc(&qd->qd_count);
432 	qd->qd_change_sync = qd->qd_change;
433 	gfs2_assert_warn(sdp, qd->qd_slot_count);
434 	qd->qd_slot_count++;
435 
436 	spin_unlock(&qd_lru_lock);
437 
438 	gfs2_assert_warn(sdp, qd->qd_change_sync);
439 	if (bh_get(qd)) {
440 		clear_bit(QDF_LOCKED, &qd->qd_flags);
441 		slot_put(qd);
442 		qd_put(qd);
443 		return 0;
444 	}
445 
446 	return 1;
447 }
448 
449 static void qd_unlock(struct gfs2_quota_data *qd)
450 {
451 	gfs2_assert_warn(qd->qd_gl->gl_sbd,
452 			 test_bit(QDF_LOCKED, &qd->qd_flags));
453 	clear_bit(QDF_LOCKED, &qd->qd_flags);
454 	bh_put(qd);
455 	slot_put(qd);
456 	qd_put(qd);
457 }
458 
459 static int qdsb_get(struct gfs2_sbd *sdp, int user, u32 id,
460 		    struct gfs2_quota_data **qdp)
461 {
462 	int error;
463 
464 	error = qd_get(sdp, user, id, qdp);
465 	if (error)
466 		return error;
467 
468 	error = slot_get(*qdp);
469 	if (error)
470 		goto fail;
471 
472 	error = bh_get(*qdp);
473 	if (error)
474 		goto fail_slot;
475 
476 	return 0;
477 
478 fail_slot:
479 	slot_put(*qdp);
480 fail:
481 	qd_put(*qdp);
482 	return error;
483 }
484 
485 static void qdsb_put(struct gfs2_quota_data *qd)
486 {
487 	bh_put(qd);
488 	slot_put(qd);
489 	qd_put(qd);
490 }
491 
492 int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
493 {
494 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
495 	struct gfs2_alloc *al = ip->i_alloc;
496 	struct gfs2_quota_data **qd = al->al_qd;
497 	int error;
498 
499 	if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
500 	    gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
501 		return -EIO;
502 
503 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
504 		return 0;
505 
506 	error = qdsb_get(sdp, QUOTA_USER, ip->i_inode.i_uid, qd);
507 	if (error)
508 		goto out;
509 	al->al_qd_num++;
510 	qd++;
511 
512 	error = qdsb_get(sdp, QUOTA_GROUP, ip->i_inode.i_gid, qd);
513 	if (error)
514 		goto out;
515 	al->al_qd_num++;
516 	qd++;
517 
518 	if (uid != NO_QUOTA_CHANGE && uid != ip->i_inode.i_uid) {
519 		error = qdsb_get(sdp, QUOTA_USER, uid, qd);
520 		if (error)
521 			goto out;
522 		al->al_qd_num++;
523 		qd++;
524 	}
525 
526 	if (gid != NO_QUOTA_CHANGE && gid != ip->i_inode.i_gid) {
527 		error = qdsb_get(sdp, QUOTA_GROUP, gid, qd);
528 		if (error)
529 			goto out;
530 		al->al_qd_num++;
531 		qd++;
532 	}
533 
534 out:
535 	if (error)
536 		gfs2_quota_unhold(ip);
537 	return error;
538 }
539 
540 void gfs2_quota_unhold(struct gfs2_inode *ip)
541 {
542 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
543 	struct gfs2_alloc *al = ip->i_alloc;
544 	unsigned int x;
545 
546 	gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
547 
548 	for (x = 0; x < al->al_qd_num; x++) {
549 		qdsb_put(al->al_qd[x]);
550 		al->al_qd[x] = NULL;
551 	}
552 	al->al_qd_num = 0;
553 }
554 
555 static int sort_qd(const void *a, const void *b)
556 {
557 	const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
558 	const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
559 
560 	if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
561 	    !test_bit(QDF_USER, &qd_b->qd_flags)) {
562 		if (test_bit(QDF_USER, &qd_a->qd_flags))
563 			return -1;
564 		else
565 			return 1;
566 	}
567 	if (qd_a->qd_id < qd_b->qd_id)
568 		return -1;
569 	if (qd_a->qd_id > qd_b->qd_id)
570 		return 1;
571 
572 	return 0;
573 }
574 
575 static void do_qc(struct gfs2_quota_data *qd, s64 change)
576 {
577 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
578 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
579 	struct gfs2_quota_change *qc = qd->qd_bh_qc;
580 	s64 x;
581 
582 	mutex_lock(&sdp->sd_quota_mutex);
583 	gfs2_trans_add_bh(ip->i_gl, qd->qd_bh, 1);
584 
585 	if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
586 		qc->qc_change = 0;
587 		qc->qc_flags = 0;
588 		if (test_bit(QDF_USER, &qd->qd_flags))
589 			qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
590 		qc->qc_id = cpu_to_be32(qd->qd_id);
591 	}
592 
593 	x = be64_to_cpu(qc->qc_change) + change;
594 	qc->qc_change = cpu_to_be64(x);
595 
596 	spin_lock(&qd_lru_lock);
597 	qd->qd_change = x;
598 	spin_unlock(&qd_lru_lock);
599 
600 	if (!x) {
601 		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
602 		clear_bit(QDF_CHANGE, &qd->qd_flags);
603 		qc->qc_flags = 0;
604 		qc->qc_id = 0;
605 		slot_put(qd);
606 		qd_put(qd);
607 	} else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
608 		qd_hold(qd);
609 		slot_hold(qd);
610 	}
611 
612 	mutex_unlock(&sdp->sd_quota_mutex);
613 }
614 
615 /**
616  * gfs2_adjust_quota - adjust record of current block usage
617  * @ip: The quota inode
618  * @loc: Offset of the entry in the quota file
619  * @change: The amount of usage change to record
620  * @qd: The quota data
621  * @fdq: The updated limits to record
622  *
623  * This function was mostly borrowed from gfs2_block_truncate_page which was
624  * in turn mostly borrowed from ext3
625  *
626  * Returns: 0 or -ve on error
627  */
628 
629 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
630 			     s64 change, struct gfs2_quota_data *qd,
631 			     struct fs_disk_quota *fdq)
632 {
633 	struct inode *inode = &ip->i_inode;
634 	struct address_space *mapping = inode->i_mapping;
635 	unsigned long index = loc >> PAGE_CACHE_SHIFT;
636 	unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
637 	unsigned blocksize, iblock, pos;
638 	struct buffer_head *bh, *dibh;
639 	struct page *page;
640 	void *kaddr, *ptr;
641 	struct gfs2_quota q, *qp;
642 	int err, nbytes;
643 	u64 size;
644 
645 	if (gfs2_is_stuffed(ip))
646 		gfs2_unstuff_dinode(ip, NULL);
647 
648 	memset(&q, 0, sizeof(struct gfs2_quota));
649 	err = gfs2_internal_read(ip, NULL, (char *)&q, &loc, sizeof(q));
650 	if (err < 0)
651 		return err;
652 
653 	err = -EIO;
654 	qp = &q;
655 	qp->qu_value = be64_to_cpu(qp->qu_value);
656 	qp->qu_value += change;
657 	qp->qu_value = cpu_to_be64(qp->qu_value);
658 	qd->qd_qb.qb_value = qp->qu_value;
659 	if (fdq) {
660 		if (fdq->d_fieldmask & FS_DQ_BSOFT) {
661 			qp->qu_warn = cpu_to_be64(fdq->d_blk_softlimit);
662 			qd->qd_qb.qb_warn = qp->qu_warn;
663 		}
664 		if (fdq->d_fieldmask & FS_DQ_BHARD) {
665 			qp->qu_limit = cpu_to_be64(fdq->d_blk_hardlimit);
666 			qd->qd_qb.qb_limit = qp->qu_limit;
667 		}
668 	}
669 
670 	/* Write the quota into the quota file on disk */
671 	ptr = qp;
672 	nbytes = sizeof(struct gfs2_quota);
673 get_a_page:
674 	page = grab_cache_page(mapping, index);
675 	if (!page)
676 		return -ENOMEM;
677 
678 	blocksize = inode->i_sb->s_blocksize;
679 	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
680 
681 	if (!page_has_buffers(page))
682 		create_empty_buffers(page, blocksize, 0);
683 
684 	bh = page_buffers(page);
685 	pos = blocksize;
686 	while (offset >= pos) {
687 		bh = bh->b_this_page;
688 		iblock++;
689 		pos += blocksize;
690 	}
691 
692 	if (!buffer_mapped(bh)) {
693 		gfs2_block_map(inode, iblock, bh, 1);
694 		if (!buffer_mapped(bh))
695 			goto unlock_out;
696 		/* If it's a newly allocated disk block for quota, zero it */
697 		if (buffer_new(bh))
698 			zero_user(page, pos - blocksize, bh->b_size);
699 	}
700 
701 	if (PageUptodate(page))
702 		set_buffer_uptodate(bh);
703 
704 	if (!buffer_uptodate(bh)) {
705 		ll_rw_block(READ_META, 1, &bh);
706 		wait_on_buffer(bh);
707 		if (!buffer_uptodate(bh))
708 			goto unlock_out;
709 	}
710 
711 	gfs2_trans_add_bh(ip->i_gl, bh, 0);
712 
713 	kaddr = kmap_atomic(page, KM_USER0);
714 	if (offset + sizeof(struct gfs2_quota) > PAGE_CACHE_SIZE)
715 		nbytes = PAGE_CACHE_SIZE - offset;
716 	memcpy(kaddr + offset, ptr, nbytes);
717 	flush_dcache_page(page);
718 	kunmap_atomic(kaddr, KM_USER0);
719 	unlock_page(page);
720 	page_cache_release(page);
721 
722 	/* If quota straddles page boundary, we need to update the rest of the
723 	 * quota at the beginning of the next page */
724 	if ((offset + sizeof(struct gfs2_quota)) > PAGE_CACHE_SIZE) {
725 		ptr = ptr + nbytes;
726 		nbytes = sizeof(struct gfs2_quota) - nbytes;
727 		offset = 0;
728 		index++;
729 		goto get_a_page;
730 	}
731 
732 	/* Update the disk inode timestamp and size (if extended) */
733 	err = gfs2_meta_inode_buffer(ip, &dibh);
734 	if (err)
735 		goto out;
736 
737 	size = loc + sizeof(struct gfs2_quota);
738 	if (size > inode->i_size)
739 		i_size_write(inode, size);
740 	inode->i_mtime = inode->i_atime = CURRENT_TIME;
741 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
742 	gfs2_dinode_out(ip, dibh->b_data);
743 	brelse(dibh);
744 	mark_inode_dirty(inode);
745 
746 out:
747 	return err;
748 unlock_out:
749 	unlock_page(page);
750 	page_cache_release(page);
751 	return err;
752 }
753 
754 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
755 {
756 	struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
757 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
758 	unsigned int data_blocks, ind_blocks;
759 	struct gfs2_holder *ghs, i_gh;
760 	unsigned int qx, x;
761 	struct gfs2_quota_data *qd;
762 	loff_t offset;
763 	unsigned int nalloc = 0, blocks;
764 	struct gfs2_alloc *al = NULL;
765 	int error;
766 
767 	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
768 			      &data_blocks, &ind_blocks);
769 
770 	ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
771 	if (!ghs)
772 		return -ENOMEM;
773 
774 	sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
775 	mutex_lock_nested(&ip->i_inode.i_mutex, I_MUTEX_QUOTA);
776 	for (qx = 0; qx < num_qd; qx++) {
777 		error = gfs2_glock_nq_init(qda[qx]->qd_gl, LM_ST_EXCLUSIVE,
778 					   GL_NOCACHE, &ghs[qx]);
779 		if (error)
780 			goto out;
781 	}
782 
783 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
784 	if (error)
785 		goto out;
786 
787 	for (x = 0; x < num_qd; x++) {
788 		offset = qd2offset(qda[x]);
789 		if (gfs2_write_alloc_required(ip, offset,
790 					      sizeof(struct gfs2_quota)))
791 			nalloc++;
792 	}
793 
794 	al = gfs2_alloc_get(ip);
795 	if (!al) {
796 		error = -ENOMEM;
797 		goto out_gunlock;
798 	}
799 	/*
800 	 * 1 blk for unstuffing inode if stuffed. We add this extra
801 	 * block to the reservation unconditionally. If the inode
802 	 * doesn't need unstuffing, the block will be released to the
803 	 * rgrp since it won't be allocated during the transaction
804 	 */
805 	al->al_requested = 1;
806 	/* +3 in the end for unstuffing block, inode size update block
807 	 * and another block in case quota straddles page boundary and
808 	 * two blocks need to be updated instead of 1 */
809 	blocks = num_qd * data_blocks + RES_DINODE + num_qd + 3;
810 
811 	if (nalloc)
812 		al->al_requested += nalloc * (data_blocks + ind_blocks);
813 	error = gfs2_inplace_reserve(ip);
814 	if (error)
815 		goto out_alloc;
816 
817 	if (nalloc)
818 		blocks += gfs2_rg_blocks(al) + nalloc * ind_blocks + RES_STATFS;
819 
820 	error = gfs2_trans_begin(sdp, blocks, 0);
821 	if (error)
822 		goto out_ipres;
823 
824 	for (x = 0; x < num_qd; x++) {
825 		qd = qda[x];
826 		offset = qd2offset(qd);
827 		error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync, qd, NULL);
828 		if (error)
829 			goto out_end_trans;
830 
831 		do_qc(qd, -qd->qd_change_sync);
832 	}
833 
834 	error = 0;
835 
836 out_end_trans:
837 	gfs2_trans_end(sdp);
838 out_ipres:
839 	gfs2_inplace_release(ip);
840 out_alloc:
841 	gfs2_alloc_put(ip);
842 out_gunlock:
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, NULL, (char *)&q, &pos, sizeof(q));
864 	if (error < 0)
865 		return error;
866 
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 = 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_lvb;
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, u32 uid, u32 gid)
924 {
925 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
926 	struct gfs2_alloc *al = ip->i_alloc;
927 	unsigned int x;
928 	int error = 0;
929 
930 	gfs2_quota_hold(ip, uid, gid);
931 
932 	if (capable(CAP_SYS_RESOURCE) ||
933 	    sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
934 		return 0;
935 
936 	sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
937 	     sort_qd, NULL);
938 
939 	for (x = 0; x < al->al_qd_num; x++) {
940 		error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
941 		if (error)
942 			break;
943 	}
944 
945 	if (!error)
946 		set_bit(GIF_QD_LOCKED, &ip->i_flags);
947 	else {
948 		while (x--)
949 			gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
950 		gfs2_quota_unhold(ip);
951 	}
952 
953 	return error;
954 }
955 
956 static int need_sync(struct gfs2_quota_data *qd)
957 {
958 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
959 	struct gfs2_tune *gt = &sdp->sd_tune;
960 	s64 value;
961 	unsigned int num, den;
962 	int do_sync = 1;
963 
964 	if (!qd->qd_qb.qb_limit)
965 		return 0;
966 
967 	spin_lock(&qd_lru_lock);
968 	value = qd->qd_change;
969 	spin_unlock(&qd_lru_lock);
970 
971 	spin_lock(&gt->gt_spin);
972 	num = gt->gt_quota_scale_num;
973 	den = gt->gt_quota_scale_den;
974 	spin_unlock(&gt->gt_spin);
975 
976 	if (value < 0)
977 		do_sync = 0;
978 	else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
979 		 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
980 		do_sync = 0;
981 	else {
982 		value *= gfs2_jindex_size(sdp) * num;
983 		value = div_s64(value, den);
984 		value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
985 		if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
986 			do_sync = 0;
987 	}
988 
989 	return do_sync;
990 }
991 
992 void gfs2_quota_unlock(struct gfs2_inode *ip)
993 {
994 	struct gfs2_alloc *al = ip->i_alloc;
995 	struct gfs2_quota_data *qda[4];
996 	unsigned int count = 0;
997 	unsigned int x;
998 
999 	if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
1000 		goto out;
1001 
1002 	for (x = 0; x < al->al_qd_num; x++) {
1003 		struct gfs2_quota_data *qd;
1004 		int sync;
1005 
1006 		qd = al->al_qd[x];
1007 		sync = need_sync(qd);
1008 
1009 		gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
1010 
1011 		if (sync && qd_trylock(qd))
1012 			qda[count++] = qd;
1013 	}
1014 
1015 	if (count) {
1016 		do_sync(count, qda);
1017 		for (x = 0; x < count; x++)
1018 			qd_unlock(qda[x]);
1019 	}
1020 
1021 out:
1022 	gfs2_quota_unhold(ip);
1023 }
1024 
1025 #define MAX_LINE 256
1026 
1027 static int print_message(struct gfs2_quota_data *qd, char *type)
1028 {
1029 	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
1030 
1031 	printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\n",
1032 	       sdp->sd_fsname, type,
1033 	       (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
1034 	       qd->qd_id);
1035 
1036 	return 0;
1037 }
1038 
1039 int gfs2_quota_check(struct gfs2_inode *ip, u32 uid, u32 gid)
1040 {
1041 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1042 	struct gfs2_alloc *al = ip->i_alloc;
1043 	struct gfs2_quota_data *qd;
1044 	s64 value;
1045 	unsigned int x;
1046 	int error = 0;
1047 
1048 	if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
1049 		return 0;
1050 
1051         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
1052                 return 0;
1053 
1054 	for (x = 0; x < al->al_qd_num; x++) {
1055 		qd = al->al_qd[x];
1056 
1057 		if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1058 		      (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
1059 			continue;
1060 
1061 		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
1062 		spin_lock(&qd_lru_lock);
1063 		value += qd->qd_change;
1064 		spin_unlock(&qd_lru_lock);
1065 
1066 		if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
1067 			print_message(qd, "exceeded");
1068 			quota_send_warning(test_bit(QDF_USER, &qd->qd_flags) ?
1069 					   USRQUOTA : GRPQUOTA, qd->qd_id,
1070 					   sdp->sd_vfs->s_dev, QUOTA_NL_BHARDWARN);
1071 
1072 			error = -EDQUOT;
1073 			break;
1074 		} else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
1075 			   (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
1076 			   time_after_eq(jiffies, qd->qd_last_warn +
1077 					 gfs2_tune_get(sdp,
1078 						gt_quota_warn_period) * HZ)) {
1079 			quota_send_warning(test_bit(QDF_USER, &qd->qd_flags) ?
1080 					   USRQUOTA : GRPQUOTA, qd->qd_id,
1081 					   sdp->sd_vfs->s_dev, QUOTA_NL_BSOFTWARN);
1082 			error = print_message(qd, "warning");
1083 			qd->qd_last_warn = jiffies;
1084 		}
1085 	}
1086 
1087 	return error;
1088 }
1089 
1090 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1091 		       u32 uid, u32 gid)
1092 {
1093 	struct gfs2_alloc *al = ip->i_alloc;
1094 	struct gfs2_quota_data *qd;
1095 	unsigned int x;
1096 
1097 	if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1098 		return;
1099 	if (ip->i_diskflags & GFS2_DIF_SYSTEM)
1100 		return;
1101 
1102 	for (x = 0; x < al->al_qd_num; x++) {
1103 		qd = al->al_qd[x];
1104 
1105 		if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1106 		    (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
1107 			do_qc(qd, change);
1108 		}
1109 	}
1110 }
1111 
1112 int gfs2_quota_sync(struct super_block *sb, int type, int wait)
1113 {
1114 	struct gfs2_sbd *sdp = sb->s_fs_info;
1115 	struct gfs2_quota_data **qda;
1116 	unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
1117 	unsigned int num_qd;
1118 	unsigned int x;
1119 	int error = 0;
1120 
1121 	sdp->sd_quota_sync_gen++;
1122 
1123 	qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1124 	if (!qda)
1125 		return -ENOMEM;
1126 
1127 	do {
1128 		num_qd = 0;
1129 
1130 		for (;;) {
1131 			error = qd_fish(sdp, qda + num_qd);
1132 			if (error || !qda[num_qd])
1133 				break;
1134 			if (++num_qd == max_qd)
1135 				break;
1136 		}
1137 
1138 		if (num_qd) {
1139 			if (!error)
1140 				error = do_sync(num_qd, qda);
1141 			if (!error)
1142 				for (x = 0; x < num_qd; x++)
1143 					qda[x]->qd_sync_gen =
1144 						sdp->sd_quota_sync_gen;
1145 
1146 			for (x = 0; x < num_qd; x++)
1147 				qd_unlock(qda[x]);
1148 		}
1149 	} while (!error && num_qd == max_qd);
1150 
1151 	kfree(qda);
1152 
1153 	return error;
1154 }
1155 
1156 static int gfs2_quota_sync_timeo(struct super_block *sb, int type)
1157 {
1158 	return gfs2_quota_sync(sb, type, 0);
1159 }
1160 
1161 int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, u32 id)
1162 {
1163 	struct gfs2_quota_data *qd;
1164 	struct gfs2_holder q_gh;
1165 	int error;
1166 
1167 	error = qd_get(sdp, user, id, &qd);
1168 	if (error)
1169 		return error;
1170 
1171 	error = do_glock(qd, FORCE, &q_gh);
1172 	if (!error)
1173 		gfs2_glock_dq_uninit(&q_gh);
1174 
1175 	qd_put(qd);
1176 	return error;
1177 }
1178 
1179 static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
1180 {
1181 	const struct gfs2_quota_change *str = buf;
1182 
1183 	qc->qc_change = be64_to_cpu(str->qc_change);
1184 	qc->qc_flags = be32_to_cpu(str->qc_flags);
1185 	qc->qc_id = be32_to_cpu(str->qc_id);
1186 }
1187 
1188 int gfs2_quota_init(struct gfs2_sbd *sdp)
1189 {
1190 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1191 	u64 size = i_size_read(sdp->sd_qc_inode);
1192 	unsigned int blocks = size >> sdp->sd_sb.sb_bsize_shift;
1193 	unsigned int x, slot = 0;
1194 	unsigned int found = 0;
1195 	u64 dblock;
1196 	u32 extlen = 0;
1197 	int error;
1198 
1199 	if (gfs2_check_internal_file_size(sdp->sd_qc_inode, 1, 64 << 20))
1200 		return -EIO;
1201 
1202 	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1203 	sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1204 
1205 	error = -ENOMEM;
1206 
1207 	sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1208 				       sizeof(unsigned char *), GFP_NOFS);
1209 	if (!sdp->sd_quota_bitmap)
1210 		return error;
1211 
1212 	for (x = 0; x < sdp->sd_quota_chunks; x++) {
1213 		sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_NOFS);
1214 		if (!sdp->sd_quota_bitmap[x])
1215 			goto fail;
1216 	}
1217 
1218 	for (x = 0; x < blocks; x++) {
1219 		struct buffer_head *bh;
1220 		unsigned int y;
1221 
1222 		if (!extlen) {
1223 			int new = 0;
1224 			error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1225 			if (error)
1226 				goto fail;
1227 		}
1228 		error = -EIO;
1229 		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1230 		if (!bh)
1231 			goto fail;
1232 		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1233 			brelse(bh);
1234 			goto fail;
1235 		}
1236 
1237 		for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1238 		     y++, slot++) {
1239 			struct gfs2_quota_change_host qc;
1240 			struct gfs2_quota_data *qd;
1241 
1242 			gfs2_quota_change_in(&qc, bh->b_data +
1243 					  sizeof(struct gfs2_meta_header) +
1244 					  y * sizeof(struct gfs2_quota_change));
1245 			if (!qc.qc_change)
1246 				continue;
1247 
1248 			error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1249 					 qc.qc_id, &qd);
1250 			if (error) {
1251 				brelse(bh);
1252 				goto fail;
1253 			}
1254 
1255 			set_bit(QDF_CHANGE, &qd->qd_flags);
1256 			qd->qd_change = qc.qc_change;
1257 			qd->qd_slot = slot;
1258 			qd->qd_slot_count = 1;
1259 
1260 			spin_lock(&qd_lru_lock);
1261 			gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1262 			list_add(&qd->qd_list, &sdp->sd_quota_list);
1263 			atomic_inc(&sdp->sd_quota_count);
1264 			spin_unlock(&qd_lru_lock);
1265 
1266 			found++;
1267 		}
1268 
1269 		brelse(bh);
1270 		dblock++;
1271 		extlen--;
1272 	}
1273 
1274 	if (found)
1275 		fs_info(sdp, "found %u quota changes\n", found);
1276 
1277 	return 0;
1278 
1279 fail:
1280 	gfs2_quota_cleanup(sdp);
1281 	return error;
1282 }
1283 
1284 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1285 {
1286 	struct list_head *head = &sdp->sd_quota_list;
1287 	struct gfs2_quota_data *qd;
1288 	unsigned int x;
1289 
1290 	spin_lock(&qd_lru_lock);
1291 	while (!list_empty(head)) {
1292 		qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1293 
1294 		if (atomic_read(&qd->qd_count) > 1 ||
1295 		    (atomic_read(&qd->qd_count) &&
1296 		     !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1297 			list_move(&qd->qd_list, head);
1298 			spin_unlock(&qd_lru_lock);
1299 			schedule();
1300 			spin_lock(&qd_lru_lock);
1301 			continue;
1302 		}
1303 
1304 		list_del(&qd->qd_list);
1305 		/* Also remove if this qd exists in the reclaim list */
1306 		if (!list_empty(&qd->qd_reclaim)) {
1307 			list_del_init(&qd->qd_reclaim);
1308 			atomic_dec(&qd_lru_count);
1309 		}
1310 		atomic_dec(&sdp->sd_quota_count);
1311 		spin_unlock(&qd_lru_lock);
1312 
1313 		if (!atomic_read(&qd->qd_count)) {
1314 			gfs2_assert_warn(sdp, !qd->qd_change);
1315 			gfs2_assert_warn(sdp, !qd->qd_slot_count);
1316 		} else
1317 			gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1318 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1319 
1320 		gfs2_glock_put(qd->qd_gl);
1321 		kmem_cache_free(gfs2_quotad_cachep, qd);
1322 
1323 		spin_lock(&qd_lru_lock);
1324 	}
1325 	spin_unlock(&qd_lru_lock);
1326 
1327 	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1328 
1329 	if (sdp->sd_quota_bitmap) {
1330 		for (x = 0; x < sdp->sd_quota_chunks; x++)
1331 			kfree(sdp->sd_quota_bitmap[x]);
1332 		kfree(sdp->sd_quota_bitmap);
1333 	}
1334 }
1335 
1336 static void quotad_error(struct gfs2_sbd *sdp, const char *msg, int error)
1337 {
1338 	if (error == 0 || error == -EROFS)
1339 		return;
1340 	if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
1341 		fs_err(sdp, "gfs2_quotad: %s error %d\n", msg, error);
1342 }
1343 
1344 static void quotad_check_timeo(struct gfs2_sbd *sdp, const char *msg,
1345 			       int (*fxn)(struct super_block *sb, int type),
1346 			       unsigned long t, unsigned long *timeo,
1347 			       unsigned int *new_timeo)
1348 {
1349 	if (t >= *timeo) {
1350 		int error = fxn(sdp->sd_vfs, 0);
1351 		quotad_error(sdp, msg, error);
1352 		*timeo = gfs2_tune_get_i(&sdp->sd_tune, new_timeo) * HZ;
1353 	} else {
1354 		*timeo -= t;
1355 	}
1356 }
1357 
1358 static void quotad_check_trunc_list(struct gfs2_sbd *sdp)
1359 {
1360 	struct gfs2_inode *ip;
1361 
1362 	while(1) {
1363 		ip = NULL;
1364 		spin_lock(&sdp->sd_trunc_lock);
1365 		if (!list_empty(&sdp->sd_trunc_list)) {
1366 			ip = list_entry(sdp->sd_trunc_list.next,
1367 					struct gfs2_inode, i_trunc_list);
1368 			list_del_init(&ip->i_trunc_list);
1369 		}
1370 		spin_unlock(&sdp->sd_trunc_lock);
1371 		if (ip == NULL)
1372 			return;
1373 		gfs2_glock_finish_truncate(ip);
1374 	}
1375 }
1376 
1377 void gfs2_wake_up_statfs(struct gfs2_sbd *sdp) {
1378 	if (!sdp->sd_statfs_force_sync) {
1379 		sdp->sd_statfs_force_sync = 1;
1380 		wake_up(&sdp->sd_quota_wait);
1381 	}
1382 }
1383 
1384 
1385 /**
1386  * gfs2_quotad - Write cached quota changes into the quota file
1387  * @sdp: Pointer to GFS2 superblock
1388  *
1389  */
1390 
1391 int gfs2_quotad(void *data)
1392 {
1393 	struct gfs2_sbd *sdp = data;
1394 	struct gfs2_tune *tune = &sdp->sd_tune;
1395 	unsigned long statfs_timeo = 0;
1396 	unsigned long quotad_timeo = 0;
1397 	unsigned long t = 0;
1398 	DEFINE_WAIT(wait);
1399 	int empty;
1400 
1401 	while (!kthread_should_stop()) {
1402 
1403 		/* Update the master statfs file */
1404 		if (sdp->sd_statfs_force_sync) {
1405 			int error = gfs2_statfs_sync(sdp->sd_vfs, 0);
1406 			quotad_error(sdp, "statfs", error);
1407 			statfs_timeo = gfs2_tune_get(sdp, gt_statfs_quantum) * HZ;
1408 		}
1409 		else
1410 			quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
1411 				   	   &statfs_timeo,
1412 					   &tune->gt_statfs_quantum);
1413 
1414 		/* Update quota file */
1415 		quotad_check_timeo(sdp, "sync", gfs2_quota_sync_timeo, t,
1416 				   &quotad_timeo, &tune->gt_quota_quantum);
1417 
1418 		/* Check for & recover partially truncated inodes */
1419 		quotad_check_trunc_list(sdp);
1420 
1421 		if (freezing(current))
1422 			refrigerator();
1423 		t = min(quotad_timeo, statfs_timeo);
1424 
1425 		prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);
1426 		spin_lock(&sdp->sd_trunc_lock);
1427 		empty = list_empty(&sdp->sd_trunc_list);
1428 		spin_unlock(&sdp->sd_trunc_lock);
1429 		if (empty && !sdp->sd_statfs_force_sync)
1430 			t -= schedule_timeout(t);
1431 		else
1432 			t = 0;
1433 		finish_wait(&sdp->sd_quota_wait, &wait);
1434 	}
1435 
1436 	return 0;
1437 }
1438 
1439 static int gfs2_quota_get_xstate(struct super_block *sb,
1440 				 struct fs_quota_stat *fqs)
1441 {
1442 	struct gfs2_sbd *sdp = sb->s_fs_info;
1443 
1444 	memset(fqs, 0, sizeof(struct fs_quota_stat));
1445 	fqs->qs_version = FS_QSTAT_VERSION;
1446 
1447 	switch (sdp->sd_args.ar_quota) {
1448 	case GFS2_QUOTA_ON:
1449 		fqs->qs_flags |= (FS_QUOTA_UDQ_ENFD | FS_QUOTA_GDQ_ENFD);
1450 		/*FALLTHRU*/
1451 	case GFS2_QUOTA_ACCOUNT:
1452 		fqs->qs_flags |= (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT);
1453 		break;
1454 	case GFS2_QUOTA_OFF:
1455 		break;
1456 	}
1457 
1458 	if (sdp->sd_quota_inode) {
1459 		fqs->qs_uquota.qfs_ino = GFS2_I(sdp->sd_quota_inode)->i_no_addr;
1460 		fqs->qs_uquota.qfs_nblks = sdp->sd_quota_inode->i_blocks;
1461 	}
1462 	fqs->qs_uquota.qfs_nextents = 1; /* unsupported */
1463 	fqs->qs_gquota = fqs->qs_uquota; /* its the same inode in both cases */
1464 	fqs->qs_incoredqs = atomic_read(&qd_lru_count);
1465 	return 0;
1466 }
1467 
1468 static int gfs2_get_dqblk(struct super_block *sb, int type, qid_t id,
1469 			  struct fs_disk_quota *fdq)
1470 {
1471 	struct gfs2_sbd *sdp = sb->s_fs_info;
1472 	struct gfs2_quota_lvb *qlvb;
1473 	struct gfs2_quota_data *qd;
1474 	struct gfs2_holder q_gh;
1475 	int error;
1476 
1477 	memset(fdq, 0, sizeof(struct fs_disk_quota));
1478 
1479 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1480 		return -ESRCH; /* Crazy XFS error code */
1481 
1482 	if (type == USRQUOTA)
1483 		type = QUOTA_USER;
1484 	else if (type == GRPQUOTA)
1485 		type = QUOTA_GROUP;
1486 	else
1487 		return -EINVAL;
1488 
1489 	error = qd_get(sdp, type, id, &qd);
1490 	if (error)
1491 		return error;
1492 	error = do_glock(qd, FORCE, &q_gh);
1493 	if (error)
1494 		goto out;
1495 
1496 	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
1497 	fdq->d_version = FS_DQUOT_VERSION;
1498 	fdq->d_flags = (type == QUOTA_USER) ? FS_USER_QUOTA : FS_GROUP_QUOTA;
1499 	fdq->d_id = id;
1500 	fdq->d_blk_hardlimit = be64_to_cpu(qlvb->qb_limit);
1501 	fdq->d_blk_softlimit = be64_to_cpu(qlvb->qb_warn);
1502 	fdq->d_bcount = be64_to_cpu(qlvb->qb_value);
1503 
1504 	gfs2_glock_dq_uninit(&q_gh);
1505 out:
1506 	qd_put(qd);
1507 	return error;
1508 }
1509 
1510 /* GFS2 only supports a subset of the XFS fields */
1511 #define GFS2_FIELDMASK (FS_DQ_BSOFT|FS_DQ_BHARD)
1512 
1513 static int gfs2_set_dqblk(struct super_block *sb, int type, qid_t id,
1514 			  struct fs_disk_quota *fdq)
1515 {
1516 	struct gfs2_sbd *sdp = sb->s_fs_info;
1517 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
1518 	struct gfs2_quota_data *qd;
1519 	struct gfs2_holder q_gh, i_gh;
1520 	unsigned int data_blocks, ind_blocks;
1521 	unsigned int blocks = 0;
1522 	int alloc_required;
1523 	struct gfs2_alloc *al;
1524 	loff_t offset;
1525 	int error;
1526 
1527 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1528 		return -ESRCH; /* Crazy XFS error code */
1529 
1530 	switch(type) {
1531 	case USRQUOTA:
1532 		type = QUOTA_USER;
1533 		if (fdq->d_flags != FS_USER_QUOTA)
1534 			return -EINVAL;
1535 		break;
1536 	case GRPQUOTA:
1537 		type = QUOTA_GROUP;
1538 		if (fdq->d_flags != FS_GROUP_QUOTA)
1539 			return -EINVAL;
1540 		break;
1541 	default:
1542 		return -EINVAL;
1543 	}
1544 
1545 	if (fdq->d_fieldmask & ~GFS2_FIELDMASK)
1546 		return -EINVAL;
1547 	if (fdq->d_id != id)
1548 		return -EINVAL;
1549 
1550 	error = qd_get(sdp, type, id, &qd);
1551 	if (error)
1552 		return error;
1553 
1554 	mutex_lock(&ip->i_inode.i_mutex);
1555 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE, 0, &q_gh);
1556 	if (error)
1557 		goto out_put;
1558 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
1559 	if (error)
1560 		goto out_q;
1561 
1562 	/* Check for existing entry, if none then alloc new blocks */
1563 	error = update_qd(sdp, qd);
1564 	if (error)
1565 		goto out_i;
1566 
1567 	/* If nothing has changed, this is a no-op */
1568 	if ((fdq->d_fieldmask & FS_DQ_BSOFT) &&
1569 	    (fdq->d_blk_softlimit == be64_to_cpu(qd->qd_qb.qb_warn)))
1570 		fdq->d_fieldmask ^= FS_DQ_BSOFT;
1571 	if ((fdq->d_fieldmask & FS_DQ_BHARD) &&
1572 	    (fdq->d_blk_hardlimit == be64_to_cpu(qd->qd_qb.qb_limit)))
1573 		fdq->d_fieldmask ^= FS_DQ_BHARD;
1574 	if (fdq->d_fieldmask == 0)
1575 		goto out_i;
1576 
1577 	offset = qd2offset(qd);
1578 	alloc_required = gfs2_write_alloc_required(ip, offset, sizeof(struct gfs2_quota));
1579 	if (alloc_required) {
1580 		al = gfs2_alloc_get(ip);
1581 		if (al == NULL)
1582 			goto out_i;
1583 		gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
1584 				       &data_blocks, &ind_blocks);
1585 		blocks = al->al_requested = 1 + data_blocks + ind_blocks;
1586 		error = gfs2_inplace_reserve(ip);
1587 		if (error)
1588 			goto out_alloc;
1589 		blocks += gfs2_rg_blocks(al);
1590 	}
1591 
1592 	error = gfs2_trans_begin(sdp, blocks + RES_DINODE + 1, 0);
1593 	if (error)
1594 		goto out_release;
1595 
1596 	/* Apply changes */
1597 	error = gfs2_adjust_quota(ip, offset, 0, qd, fdq);
1598 
1599 	gfs2_trans_end(sdp);
1600 out_release:
1601 	if (alloc_required) {
1602 		gfs2_inplace_release(ip);
1603 out_alloc:
1604 		gfs2_alloc_put(ip);
1605 	}
1606 out_i:
1607 	gfs2_glock_dq_uninit(&i_gh);
1608 out_q:
1609 	gfs2_glock_dq_uninit(&q_gh);
1610 out_put:
1611 	mutex_unlock(&ip->i_inode.i_mutex);
1612 	qd_put(qd);
1613 	return error;
1614 }
1615 
1616 const struct quotactl_ops gfs2_quotactl_ops = {
1617 	.quota_sync     = gfs2_quota_sync,
1618 	.get_xstate     = gfs2_quota_get_xstate,
1619 	.get_dqblk	= gfs2_get_dqblk,
1620 	.set_dqblk	= gfs2_set_dqblk,
1621 };
1622 
1623