xref: /openbmc/linux/fs/gfs2/quota.c (revision e15a5365)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
5  */
6 
7 /*
8  * Quota change tags are associated with each transaction that allocates or
9  * deallocates space.  Those changes are accumulated locally to each node (in a
10  * per-node file) and then are periodically synced to the quota file.  This
11  * avoids the bottleneck of constantly touching the quota file, but introduces
12  * fuzziness in the current usage value of IDs that are being used on different
13  * nodes in the cluster simultaneously.  So, it is possible for a user on
14  * multiple nodes to overrun their quota, but that overrun is controlable.
15  * Since quota tags are part of transactions, there is no need for a quota check
16  * program to be run on node crashes or anything like that.
17  *
18  * There are couple of knobs that let the administrator manage the quota
19  * fuzziness.  "quota_quantum" sets the maximum time a quota change can be
20  * sitting on one node before being synced to the quota file.  (The default is
21  * 60 seconds.)  Another knob, "quota_scale" controls how quickly the frequency
22  * of quota file syncs increases as the user moves closer to their limit.  The
23  * more frequent the syncs, the more accurate the quota enforcement, but that
24  * means that there is more contention between the nodes for the quota file.
25  * The default value is one.  This sets the maximum theoretical quota overrun
26  * (with infinite node with infinite bandwidth) to twice the user's limit.  (In
27  * practice, the maximum overrun you see should be much less.)  A "quota_scale"
28  * number greater than one makes quota syncs more frequent and reduces the
29  * maximum overrun.  Numbers less than one (but greater than zero) make quota
30  * syncs less frequent.
31  *
32  * GFS quotas also use per-ID Lock Value Blocks (LVBs) to cache the contents of
33  * the quota file, so it is not being constantly read.
34  */
35 
36 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
37 
38 #include <linux/sched.h>
39 #include <linux/slab.h>
40 #include <linux/mm.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 #include <linux/lockref.h>
53 #include <linux/list_lru.h>
54 #include <linux/rcupdate.h>
55 #include <linux/rculist_bl.h>
56 #include <linux/bit_spinlock.h>
57 #include <linux/jhash.h>
58 #include <linux/vmalloc.h>
59 
60 #include "gfs2.h"
61 #include "incore.h"
62 #include "bmap.h"
63 #include "glock.h"
64 #include "glops.h"
65 #include "log.h"
66 #include "meta_io.h"
67 #include "quota.h"
68 #include "rgrp.h"
69 #include "super.h"
70 #include "trans.h"
71 #include "inode.h"
72 #include "util.h"
73 
74 #define GFS2_QD_HASH_SHIFT      12
75 #define GFS2_QD_HASH_SIZE       BIT(GFS2_QD_HASH_SHIFT)
76 #define GFS2_QD_HASH_MASK       (GFS2_QD_HASH_SIZE - 1)
77 
78 /* Lock order: qd_lock -> bucket lock -> qd->lockref.lock -> lru lock */
79 /*                     -> sd_bitmap_lock                              */
80 static DEFINE_SPINLOCK(qd_lock);
81 struct list_lru gfs2_qd_lru;
82 
83 static struct hlist_bl_head qd_hash_table[GFS2_QD_HASH_SIZE];
84 
85 static unsigned int gfs2_qd_hash(const struct gfs2_sbd *sdp,
86 				 const struct kqid qid)
87 {
88 	unsigned int h;
89 
90 	h = jhash(&sdp, sizeof(struct gfs2_sbd *), 0);
91 	h = jhash(&qid, sizeof(struct kqid), h);
92 
93 	return h & GFS2_QD_HASH_MASK;
94 }
95 
96 static inline void spin_lock_bucket(unsigned int hash)
97 {
98         hlist_bl_lock(&qd_hash_table[hash]);
99 }
100 
101 static inline void spin_unlock_bucket(unsigned int hash)
102 {
103         hlist_bl_unlock(&qd_hash_table[hash]);
104 }
105 
106 static void gfs2_qd_dealloc(struct rcu_head *rcu)
107 {
108 	struct gfs2_quota_data *qd = container_of(rcu, struct gfs2_quota_data, qd_rcu);
109 	kmem_cache_free(gfs2_quotad_cachep, qd);
110 }
111 
112 static void gfs2_qd_dispose(struct list_head *list)
113 {
114 	struct gfs2_quota_data *qd;
115 	struct gfs2_sbd *sdp;
116 
117 	while (!list_empty(list)) {
118 		qd = list_first_entry(list, struct gfs2_quota_data, qd_lru);
119 		sdp = qd->qd_gl->gl_name.ln_sbd;
120 
121 		list_del(&qd->qd_lru);
122 
123 		/* Free from the filesystem-specific list */
124 		spin_lock(&qd_lock);
125 		list_del(&qd->qd_list);
126 		spin_unlock(&qd_lock);
127 
128 		spin_lock_bucket(qd->qd_hash);
129 		hlist_bl_del_rcu(&qd->qd_hlist);
130 		spin_unlock_bucket(qd->qd_hash);
131 
132 		gfs2_assert_warn(sdp, !qd->qd_change);
133 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
134 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
135 
136 		gfs2_glock_put(qd->qd_gl);
137 		atomic_dec(&sdp->sd_quota_count);
138 
139 		/* Delete it from the common reclaim list */
140 		call_rcu(&qd->qd_rcu, gfs2_qd_dealloc);
141 	}
142 }
143 
144 
145 static enum lru_status gfs2_qd_isolate(struct list_head *item,
146 		struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
147 {
148 	struct list_head *dispose = arg;
149 	struct gfs2_quota_data *qd = list_entry(item, struct gfs2_quota_data, qd_lru);
150 
151 	if (!spin_trylock(&qd->qd_lockref.lock))
152 		return LRU_SKIP;
153 
154 	if (qd->qd_lockref.count == 0) {
155 		lockref_mark_dead(&qd->qd_lockref);
156 		list_lru_isolate_move(lru, &qd->qd_lru, dispose);
157 	}
158 
159 	spin_unlock(&qd->qd_lockref.lock);
160 	return LRU_REMOVED;
161 }
162 
163 static unsigned long gfs2_qd_shrink_scan(struct shrinker *shrink,
164 					 struct shrink_control *sc)
165 {
166 	LIST_HEAD(dispose);
167 	unsigned long freed;
168 
169 	if (!(sc->gfp_mask & __GFP_FS))
170 		return SHRINK_STOP;
171 
172 	freed = list_lru_shrink_walk(&gfs2_qd_lru, sc,
173 				     gfs2_qd_isolate, &dispose);
174 
175 	gfs2_qd_dispose(&dispose);
176 
177 	return freed;
178 }
179 
180 static unsigned long gfs2_qd_shrink_count(struct shrinker *shrink,
181 					  struct shrink_control *sc)
182 {
183 	return vfs_pressure_ratio(list_lru_shrink_count(&gfs2_qd_lru, sc));
184 }
185 
186 struct shrinker gfs2_qd_shrinker = {
187 	.count_objects = gfs2_qd_shrink_count,
188 	.scan_objects = gfs2_qd_shrink_scan,
189 	.seeks = DEFAULT_SEEKS,
190 	.flags = SHRINKER_NUMA_AWARE,
191 };
192 
193 
194 static u64 qd2index(struct gfs2_quota_data *qd)
195 {
196 	struct kqid qid = qd->qd_id;
197 	return (2 * (u64)from_kqid(&init_user_ns, qid)) +
198 		((qid.type == USRQUOTA) ? 0 : 1);
199 }
200 
201 static u64 qd2offset(struct gfs2_quota_data *qd)
202 {
203 	u64 offset;
204 
205 	offset = qd2index(qd);
206 	offset *= sizeof(struct gfs2_quota);
207 
208 	return offset;
209 }
210 
211 static struct gfs2_quota_data *qd_alloc(unsigned hash, struct gfs2_sbd *sdp, struct kqid qid)
212 {
213 	struct gfs2_quota_data *qd;
214 	int error;
215 
216 	qd = kmem_cache_zalloc(gfs2_quotad_cachep, GFP_NOFS);
217 	if (!qd)
218 		return NULL;
219 
220 	qd->qd_sbd = sdp;
221 	qd->qd_lockref.count = 1;
222 	spin_lock_init(&qd->qd_lockref.lock);
223 	qd->qd_id = qid;
224 	qd->qd_slot = -1;
225 	INIT_LIST_HEAD(&qd->qd_lru);
226 	qd->qd_hash = hash;
227 
228 	error = gfs2_glock_get(sdp, qd2index(qd),
229 			      &gfs2_quota_glops, CREATE, &qd->qd_gl);
230 	if (error)
231 		goto fail;
232 
233 	return qd;
234 
235 fail:
236 	kmem_cache_free(gfs2_quotad_cachep, qd);
237 	return NULL;
238 }
239 
240 static struct gfs2_quota_data *gfs2_qd_search_bucket(unsigned int hash,
241 						     const struct gfs2_sbd *sdp,
242 						     struct kqid qid)
243 {
244 	struct gfs2_quota_data *qd;
245 	struct hlist_bl_node *h;
246 
247 	hlist_bl_for_each_entry_rcu(qd, h, &qd_hash_table[hash], qd_hlist) {
248 		if (!qid_eq(qd->qd_id, qid))
249 			continue;
250 		if (qd->qd_sbd != sdp)
251 			continue;
252 		if (lockref_get_not_dead(&qd->qd_lockref)) {
253 			list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
254 			return qd;
255 		}
256 	}
257 
258 	return NULL;
259 }
260 
261 
262 static int qd_get(struct gfs2_sbd *sdp, struct kqid qid,
263 		  struct gfs2_quota_data **qdp)
264 {
265 	struct gfs2_quota_data *qd, *new_qd;
266 	unsigned int hash = gfs2_qd_hash(sdp, qid);
267 
268 	rcu_read_lock();
269 	*qdp = qd = gfs2_qd_search_bucket(hash, sdp, qid);
270 	rcu_read_unlock();
271 
272 	if (qd)
273 		return 0;
274 
275 	new_qd = qd_alloc(hash, sdp, qid);
276 	if (!new_qd)
277 		return -ENOMEM;
278 
279 	spin_lock(&qd_lock);
280 	spin_lock_bucket(hash);
281 	*qdp = qd = gfs2_qd_search_bucket(hash, sdp, qid);
282 	if (qd == NULL) {
283 		*qdp = new_qd;
284 		list_add(&new_qd->qd_list, &sdp->sd_quota_list);
285 		hlist_bl_add_head_rcu(&new_qd->qd_hlist, &qd_hash_table[hash]);
286 		atomic_inc(&sdp->sd_quota_count);
287 	}
288 	spin_unlock_bucket(hash);
289 	spin_unlock(&qd_lock);
290 
291 	if (qd) {
292 		gfs2_glock_put(new_qd->qd_gl);
293 		kmem_cache_free(gfs2_quotad_cachep, new_qd);
294 	}
295 
296 	return 0;
297 }
298 
299 
300 static void qd_hold(struct gfs2_quota_data *qd)
301 {
302 	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
303 	gfs2_assert(sdp, !__lockref_is_dead(&qd->qd_lockref));
304 	lockref_get(&qd->qd_lockref);
305 }
306 
307 static void qd_put(struct gfs2_quota_data *qd)
308 {
309 	if (lockref_put_or_lock(&qd->qd_lockref))
310 		return;
311 
312 	qd->qd_lockref.count = 0;
313 	list_lru_add(&gfs2_qd_lru, &qd->qd_lru);
314 	spin_unlock(&qd->qd_lockref.lock);
315 
316 }
317 
318 static int slot_get(struct gfs2_quota_data *qd)
319 {
320 	struct gfs2_sbd *sdp = qd->qd_sbd;
321 	unsigned int bit;
322 	int error = 0;
323 
324 	spin_lock(&sdp->sd_bitmap_lock);
325 	if (qd->qd_slot_count != 0)
326 		goto out;
327 
328 	error = -ENOSPC;
329 	bit = find_first_zero_bit(sdp->sd_quota_bitmap, sdp->sd_quota_slots);
330 	if (bit < sdp->sd_quota_slots) {
331 		set_bit(bit, sdp->sd_quota_bitmap);
332 		qd->qd_slot = bit;
333 		error = 0;
334 out:
335 		qd->qd_slot_count++;
336 	}
337 	spin_unlock(&sdp->sd_bitmap_lock);
338 
339 	return error;
340 }
341 
342 static void slot_hold(struct gfs2_quota_data *qd)
343 {
344 	struct gfs2_sbd *sdp = qd->qd_sbd;
345 
346 	spin_lock(&sdp->sd_bitmap_lock);
347 	gfs2_assert(sdp, qd->qd_slot_count);
348 	qd->qd_slot_count++;
349 	spin_unlock(&sdp->sd_bitmap_lock);
350 }
351 
352 static void slot_put(struct gfs2_quota_data *qd)
353 {
354 	struct gfs2_sbd *sdp = qd->qd_sbd;
355 
356 	spin_lock(&sdp->sd_bitmap_lock);
357 	gfs2_assert(sdp, qd->qd_slot_count);
358 	if (!--qd->qd_slot_count) {
359 		BUG_ON(!test_and_clear_bit(qd->qd_slot, sdp->sd_quota_bitmap));
360 		qd->qd_slot = -1;
361 	}
362 	spin_unlock(&sdp->sd_bitmap_lock);
363 }
364 
365 static int bh_get(struct gfs2_quota_data *qd)
366 {
367 	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
368 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
369 	unsigned int block, offset;
370 	struct buffer_head *bh;
371 	int error;
372 	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
373 
374 	mutex_lock(&sdp->sd_quota_mutex);
375 
376 	if (qd->qd_bh_count++) {
377 		mutex_unlock(&sdp->sd_quota_mutex);
378 		return 0;
379 	}
380 
381 	block = qd->qd_slot / sdp->sd_qc_per_block;
382 	offset = qd->qd_slot % sdp->sd_qc_per_block;
383 
384 	bh_map.b_size = BIT(ip->i_inode.i_blkbits);
385 	error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
386 	if (error)
387 		goto fail;
388 	error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, 0, &bh);
389 	if (error)
390 		goto fail;
391 	error = -EIO;
392 	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
393 		goto fail_brelse;
394 
395 	qd->qd_bh = bh;
396 	qd->qd_bh_qc = (struct gfs2_quota_change *)
397 		(bh->b_data + sizeof(struct gfs2_meta_header) +
398 		 offset * sizeof(struct gfs2_quota_change));
399 
400 	mutex_unlock(&sdp->sd_quota_mutex);
401 
402 	return 0;
403 
404 fail_brelse:
405 	brelse(bh);
406 fail:
407 	qd->qd_bh_count--;
408 	mutex_unlock(&sdp->sd_quota_mutex);
409 	return error;
410 }
411 
412 static void bh_put(struct gfs2_quota_data *qd)
413 {
414 	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
415 
416 	mutex_lock(&sdp->sd_quota_mutex);
417 	gfs2_assert(sdp, qd->qd_bh_count);
418 	if (!--qd->qd_bh_count) {
419 		brelse(qd->qd_bh);
420 		qd->qd_bh = NULL;
421 		qd->qd_bh_qc = NULL;
422 	}
423 	mutex_unlock(&sdp->sd_quota_mutex);
424 }
425 
426 static int qd_check_sync(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd,
427 			 u64 *sync_gen)
428 {
429 	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
430 	    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
431 	    (sync_gen && (qd->qd_sync_gen >= *sync_gen)))
432 		return 0;
433 
434 	if (!lockref_get_not_dead(&qd->qd_lockref))
435 		return 0;
436 
437 	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
438 	set_bit(QDF_LOCKED, &qd->qd_flags);
439 	qd->qd_change_sync = qd->qd_change;
440 	slot_hold(qd);
441 	return 1;
442 }
443 
444 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
445 {
446 	struct gfs2_quota_data *qd = NULL;
447 	int error;
448 	int found = 0;
449 
450 	*qdp = NULL;
451 
452 	if (sb_rdonly(sdp->sd_vfs))
453 		return 0;
454 
455 	spin_lock(&qd_lock);
456 
457 	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
458 		found = qd_check_sync(sdp, qd, &sdp->sd_quota_sync_gen);
459 		if (found)
460 			break;
461 	}
462 
463 	if (!found)
464 		qd = NULL;
465 
466 	spin_unlock(&qd_lock);
467 
468 	if (qd) {
469 		gfs2_assert_warn(sdp, qd->qd_change_sync);
470 		error = bh_get(qd);
471 		if (error) {
472 			clear_bit(QDF_LOCKED, &qd->qd_flags);
473 			slot_put(qd);
474 			qd_put(qd);
475 			return error;
476 		}
477 	}
478 
479 	*qdp = qd;
480 
481 	return 0;
482 }
483 
484 static void qd_unlock(struct gfs2_quota_data *qd)
485 {
486 	gfs2_assert_warn(qd->qd_gl->gl_name.ln_sbd,
487 			 test_bit(QDF_LOCKED, &qd->qd_flags));
488 	clear_bit(QDF_LOCKED, &qd->qd_flags);
489 	bh_put(qd);
490 	slot_put(qd);
491 	qd_put(qd);
492 }
493 
494 static int qdsb_get(struct gfs2_sbd *sdp, struct kqid qid,
495 		    struct gfs2_quota_data **qdp)
496 {
497 	int error;
498 
499 	error = qd_get(sdp, qid, qdp);
500 	if (error)
501 		return error;
502 
503 	error = slot_get(*qdp);
504 	if (error)
505 		goto fail;
506 
507 	error = bh_get(*qdp);
508 	if (error)
509 		goto fail_slot;
510 
511 	return 0;
512 
513 fail_slot:
514 	slot_put(*qdp);
515 fail:
516 	qd_put(*qdp);
517 	return error;
518 }
519 
520 static void qdsb_put(struct gfs2_quota_data *qd)
521 {
522 	bh_put(qd);
523 	slot_put(qd);
524 	qd_put(qd);
525 }
526 
527 /**
528  * gfs2_qa_get - make sure we have a quota allocations data structure,
529  *               if necessary
530  * @ip: the inode for this reservation
531  */
532 int gfs2_qa_get(struct gfs2_inode *ip)
533 {
534 	int error = 0;
535 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
536 
537 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
538 		return 0;
539 
540 	down_write(&ip->i_rw_mutex);
541 	if (ip->i_qadata == NULL) {
542 		ip->i_qadata = kmem_cache_zalloc(gfs2_qadata_cachep, GFP_NOFS);
543 		if (!ip->i_qadata) {
544 			error = -ENOMEM;
545 			goto out;
546 		}
547 	}
548 	ip->i_qadata->qa_ref++;
549 out:
550 	up_write(&ip->i_rw_mutex);
551 	return error;
552 }
553 
554 void gfs2_qa_put(struct gfs2_inode *ip)
555 {
556 	down_write(&ip->i_rw_mutex);
557 	if (ip->i_qadata && --ip->i_qadata->qa_ref == 0) {
558 		kmem_cache_free(gfs2_qadata_cachep, ip->i_qadata);
559 		ip->i_qadata = NULL;
560 	}
561 	up_write(&ip->i_rw_mutex);
562 }
563 
564 int gfs2_quota_hold(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
565 {
566 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
567 	struct gfs2_quota_data **qd;
568 	int error;
569 
570 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
571 		return 0;
572 
573 	error = gfs2_qa_get(ip);
574 	if (error)
575 		return error;
576 
577 	qd = ip->i_qadata->qa_qd;
578 
579 	if (gfs2_assert_warn(sdp, !ip->i_qadata->qa_qd_num) ||
580 	    gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags))) {
581 		error = -EIO;
582 		goto out;
583 	}
584 
585 	error = qdsb_get(sdp, make_kqid_uid(ip->i_inode.i_uid), qd);
586 	if (error)
587 		goto out_unhold;
588 	ip->i_qadata->qa_qd_num++;
589 	qd++;
590 
591 	error = qdsb_get(sdp, make_kqid_gid(ip->i_inode.i_gid), qd);
592 	if (error)
593 		goto out_unhold;
594 	ip->i_qadata->qa_qd_num++;
595 	qd++;
596 
597 	if (!uid_eq(uid, NO_UID_QUOTA_CHANGE) &&
598 	    !uid_eq(uid, ip->i_inode.i_uid)) {
599 		error = qdsb_get(sdp, make_kqid_uid(uid), qd);
600 		if (error)
601 			goto out_unhold;
602 		ip->i_qadata->qa_qd_num++;
603 		qd++;
604 	}
605 
606 	if (!gid_eq(gid, NO_GID_QUOTA_CHANGE) &&
607 	    !gid_eq(gid, ip->i_inode.i_gid)) {
608 		error = qdsb_get(sdp, make_kqid_gid(gid), qd);
609 		if (error)
610 			goto out_unhold;
611 		ip->i_qadata->qa_qd_num++;
612 		qd++;
613 	}
614 
615 out_unhold:
616 	if (error)
617 		gfs2_quota_unhold(ip);
618 out:
619 	return error;
620 }
621 
622 void gfs2_quota_unhold(struct gfs2_inode *ip)
623 {
624 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
625 	u32 x;
626 
627 	if (ip->i_qadata == NULL)
628 		return;
629 
630 	gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
631 
632 	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
633 		qdsb_put(ip->i_qadata->qa_qd[x]);
634 		ip->i_qadata->qa_qd[x] = NULL;
635 	}
636 	ip->i_qadata->qa_qd_num = 0;
637 	gfs2_qa_put(ip);
638 }
639 
640 static int sort_qd(const void *a, const void *b)
641 {
642 	const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
643 	const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
644 
645 	if (qid_lt(qd_a->qd_id, qd_b->qd_id))
646 		return -1;
647 	if (qid_lt(qd_b->qd_id, qd_a->qd_id))
648 		return 1;
649 	return 0;
650 }
651 
652 static void do_qc(struct gfs2_quota_data *qd, s64 change)
653 {
654 	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
655 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
656 	struct gfs2_quota_change *qc = qd->qd_bh_qc;
657 	s64 x;
658 
659 	mutex_lock(&sdp->sd_quota_mutex);
660 	gfs2_trans_add_meta(ip->i_gl, qd->qd_bh);
661 
662 	if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
663 		qc->qc_change = 0;
664 		qc->qc_flags = 0;
665 		if (qd->qd_id.type == USRQUOTA)
666 			qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
667 		qc->qc_id = cpu_to_be32(from_kqid(&init_user_ns, qd->qd_id));
668 	}
669 
670 	x = be64_to_cpu(qc->qc_change) + change;
671 	qc->qc_change = cpu_to_be64(x);
672 
673 	spin_lock(&qd_lock);
674 	qd->qd_change = x;
675 	spin_unlock(&qd_lock);
676 
677 	if (!x) {
678 		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
679 		clear_bit(QDF_CHANGE, &qd->qd_flags);
680 		qc->qc_flags = 0;
681 		qc->qc_id = 0;
682 		slot_put(qd);
683 		qd_put(qd);
684 	} else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
685 		qd_hold(qd);
686 		slot_hold(qd);
687 	}
688 
689 	if (change < 0) /* Reset quiet flag if we freed some blocks */
690 		clear_bit(QDF_QMSG_QUIET, &qd->qd_flags);
691 	mutex_unlock(&sdp->sd_quota_mutex);
692 }
693 
694 static int gfs2_write_buf_to_page(struct gfs2_inode *ip, unsigned long index,
695 				  unsigned off, void *buf, unsigned bytes)
696 {
697 	struct inode *inode = &ip->i_inode;
698 	struct gfs2_sbd *sdp = GFS2_SB(inode);
699 	struct address_space *mapping = inode->i_mapping;
700 	struct page *page;
701 	struct buffer_head *bh;
702 	void *kaddr;
703 	u64 blk;
704 	unsigned bsize = sdp->sd_sb.sb_bsize, bnum = 0, boff = 0;
705 	unsigned to_write = bytes, pg_off = off;
706 	int done = 0;
707 
708 	blk = index << (PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift);
709 	boff = off % bsize;
710 
711 	page = find_or_create_page(mapping, index, GFP_NOFS);
712 	if (!page)
713 		return -ENOMEM;
714 	if (!page_has_buffers(page))
715 		create_empty_buffers(page, bsize, 0);
716 
717 	bh = page_buffers(page);
718 	while (!done) {
719 		/* Find the beginning block within the page */
720 		if (pg_off >= ((bnum * bsize) + bsize)) {
721 			bh = bh->b_this_page;
722 			bnum++;
723 			blk++;
724 			continue;
725 		}
726 		if (!buffer_mapped(bh)) {
727 			gfs2_block_map(inode, blk, bh, 1);
728 			if (!buffer_mapped(bh))
729 				goto unlock_out;
730 			/* If it's a newly allocated disk block, zero it */
731 			if (buffer_new(bh))
732 				zero_user(page, bnum * bsize, bh->b_size);
733 		}
734 		if (PageUptodate(page))
735 			set_buffer_uptodate(bh);
736 		if (!buffer_uptodate(bh)) {
737 			ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh);
738 			wait_on_buffer(bh);
739 			if (!buffer_uptodate(bh))
740 				goto unlock_out;
741 		}
742 		if (gfs2_is_jdata(ip))
743 			gfs2_trans_add_data(ip->i_gl, bh);
744 		else
745 			gfs2_ordered_add_inode(ip);
746 
747 		/* If we need to write to the next block as well */
748 		if (to_write > (bsize - boff)) {
749 			pg_off += (bsize - boff);
750 			to_write -= (bsize - boff);
751 			boff = pg_off % bsize;
752 			continue;
753 		}
754 		done = 1;
755 	}
756 
757 	/* Write to the page, now that we have setup the buffer(s) */
758 	kaddr = kmap_atomic(page);
759 	memcpy(kaddr + off, buf, bytes);
760 	flush_dcache_page(page);
761 	kunmap_atomic(kaddr);
762 	unlock_page(page);
763 	put_page(page);
764 
765 	return 0;
766 
767 unlock_out:
768 	unlock_page(page);
769 	put_page(page);
770 	return -EIO;
771 }
772 
773 static int gfs2_write_disk_quota(struct gfs2_inode *ip, struct gfs2_quota *qp,
774 				 loff_t loc)
775 {
776 	unsigned long pg_beg;
777 	unsigned pg_off, nbytes, overflow = 0;
778 	int pg_oflow = 0, error;
779 	void *ptr;
780 
781 	nbytes = sizeof(struct gfs2_quota);
782 
783 	pg_beg = loc >> PAGE_SHIFT;
784 	pg_off = offset_in_page(loc);
785 
786 	/* If the quota straddles a page boundary, split the write in two */
787 	if ((pg_off + nbytes) > PAGE_SIZE) {
788 		pg_oflow = 1;
789 		overflow = (pg_off + nbytes) - PAGE_SIZE;
790 	}
791 
792 	ptr = qp;
793 	error = gfs2_write_buf_to_page(ip, pg_beg, pg_off, ptr,
794 				       nbytes - overflow);
795 	/* If there's an overflow, write the remaining bytes to the next page */
796 	if (!error && pg_oflow)
797 		error = gfs2_write_buf_to_page(ip, pg_beg + 1, 0,
798 					       ptr + nbytes - overflow,
799 					       overflow);
800 	return error;
801 }
802 
803 /**
804  * gfs2_adjust_quota - adjust record of current block usage
805  * @ip: The quota inode
806  * @loc: Offset of the entry in the quota file
807  * @change: The amount of usage change to record
808  * @qd: The quota data
809  * @fdq: The updated limits to record
810  *
811  * This function was mostly borrowed from gfs2_block_truncate_page which was
812  * in turn mostly borrowed from ext3
813  *
814  * Returns: 0 or -ve on error
815  */
816 
817 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
818 			     s64 change, struct gfs2_quota_data *qd,
819 			     struct qc_dqblk *fdq)
820 {
821 	struct inode *inode = &ip->i_inode;
822 	struct gfs2_sbd *sdp = GFS2_SB(inode);
823 	struct gfs2_quota q;
824 	int err;
825 	u64 size;
826 
827 	if (gfs2_is_stuffed(ip)) {
828 		err = gfs2_unstuff_dinode(ip, NULL);
829 		if (err)
830 			return err;
831 	}
832 
833 	memset(&q, 0, sizeof(struct gfs2_quota));
834 	err = gfs2_internal_read(ip, (char *)&q, &loc, sizeof(q));
835 	if (err < 0)
836 		return err;
837 
838 	loc -= sizeof(q); /* gfs2_internal_read would've advanced the loc ptr */
839 	err = -EIO;
840 	be64_add_cpu(&q.qu_value, change);
841 	if (((s64)be64_to_cpu(q.qu_value)) < 0)
842 		q.qu_value = 0; /* Never go negative on quota usage */
843 	qd->qd_qb.qb_value = q.qu_value;
844 	if (fdq) {
845 		if (fdq->d_fieldmask & QC_SPC_SOFT) {
846 			q.qu_warn = cpu_to_be64(fdq->d_spc_softlimit >> sdp->sd_sb.sb_bsize_shift);
847 			qd->qd_qb.qb_warn = q.qu_warn;
848 		}
849 		if (fdq->d_fieldmask & QC_SPC_HARD) {
850 			q.qu_limit = cpu_to_be64(fdq->d_spc_hardlimit >> sdp->sd_sb.sb_bsize_shift);
851 			qd->qd_qb.qb_limit = q.qu_limit;
852 		}
853 		if (fdq->d_fieldmask & QC_SPACE) {
854 			q.qu_value = cpu_to_be64(fdq->d_space >> sdp->sd_sb.sb_bsize_shift);
855 			qd->qd_qb.qb_value = q.qu_value;
856 		}
857 	}
858 
859 	err = gfs2_write_disk_quota(ip, &q, loc);
860 	if (!err) {
861 		size = loc + sizeof(struct gfs2_quota);
862 		if (size > inode->i_size)
863 			i_size_write(inode, size);
864 		inode->i_mtime = inode->i_atime = current_time(inode);
865 		mark_inode_dirty(inode);
866 		set_bit(QDF_REFRESH, &qd->qd_flags);
867 	}
868 
869 	return err;
870 }
871 
872 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
873 {
874 	struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_name.ln_sbd;
875 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
876 	struct gfs2_alloc_parms ap = { .aflags = 0, };
877 	unsigned int data_blocks, ind_blocks;
878 	struct gfs2_holder *ghs, i_gh;
879 	unsigned int qx, x;
880 	struct gfs2_quota_data *qd;
881 	unsigned reserved;
882 	loff_t offset;
883 	unsigned int nalloc = 0, blocks;
884 	int error;
885 
886 	error = gfs2_qa_get(ip);
887 	if (error)
888 		return error;
889 
890 	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
891 			      &data_blocks, &ind_blocks);
892 
893 	ghs = kmalloc_array(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
894 	if (!ghs) {
895 		error = -ENOMEM;
896 		goto out;
897 	}
898 
899 	sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
900 	inode_lock(&ip->i_inode);
901 	for (qx = 0; qx < num_qd; qx++) {
902 		error = gfs2_glock_nq_init(qda[qx]->qd_gl, LM_ST_EXCLUSIVE,
903 					   GL_NOCACHE, &ghs[qx]);
904 		if (error)
905 			goto out_dq;
906 	}
907 
908 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
909 	if (error)
910 		goto out_dq;
911 
912 	for (x = 0; x < num_qd; x++) {
913 		offset = qd2offset(qda[x]);
914 		if (gfs2_write_alloc_required(ip, offset,
915 					      sizeof(struct gfs2_quota)))
916 			nalloc++;
917 	}
918 
919 	/*
920 	 * 1 blk for unstuffing inode if stuffed. We add this extra
921 	 * block to the reservation unconditionally. If the inode
922 	 * doesn't need unstuffing, the block will be released to the
923 	 * rgrp since it won't be allocated during the transaction
924 	 */
925 	/* +3 in the end for unstuffing block, inode size update block
926 	 * and another block in case quota straddles page boundary and
927 	 * two blocks need to be updated instead of 1 */
928 	blocks = num_qd * data_blocks + RES_DINODE + num_qd + 3;
929 
930 	reserved = 1 + (nalloc * (data_blocks + ind_blocks));
931 	ap.target = reserved;
932 	error = gfs2_inplace_reserve(ip, &ap);
933 	if (error)
934 		goto out_alloc;
935 
936 	if (nalloc)
937 		blocks += gfs2_rg_blocks(ip, reserved) + nalloc * ind_blocks + RES_STATFS;
938 
939 	error = gfs2_trans_begin(sdp, blocks, 0);
940 	if (error)
941 		goto out_ipres;
942 
943 	for (x = 0; x < num_qd; x++) {
944 		qd = qda[x];
945 		offset = qd2offset(qd);
946 		error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync, qd, NULL);
947 		if (error)
948 			goto out_end_trans;
949 
950 		do_qc(qd, -qd->qd_change_sync);
951 		set_bit(QDF_REFRESH, &qd->qd_flags);
952 	}
953 
954 	error = 0;
955 
956 out_end_trans:
957 	gfs2_trans_end(sdp);
958 out_ipres:
959 	gfs2_inplace_release(ip);
960 out_alloc:
961 	gfs2_glock_dq_uninit(&i_gh);
962 out_dq:
963 	while (qx--)
964 		gfs2_glock_dq_uninit(&ghs[qx]);
965 	inode_unlock(&ip->i_inode);
966 	kfree(ghs);
967 	gfs2_log_flush(ip->i_gl->gl_name.ln_sbd, ip->i_gl,
968 		       GFS2_LOG_HEAD_FLUSH_NORMAL | GFS2_LFC_DO_SYNC);
969 out:
970 	gfs2_qa_put(ip);
971 	return error;
972 }
973 
974 static int update_qd(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd)
975 {
976 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
977 	struct gfs2_quota q;
978 	struct gfs2_quota_lvb *qlvb;
979 	loff_t pos;
980 	int error;
981 
982 	memset(&q, 0, sizeof(struct gfs2_quota));
983 	pos = qd2offset(qd);
984 	error = gfs2_internal_read(ip, (char *)&q, &pos, sizeof(q));
985 	if (error < 0)
986 		return error;
987 
988 	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
989 	qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
990 	qlvb->__pad = 0;
991 	qlvb->qb_limit = q.qu_limit;
992 	qlvb->qb_warn = q.qu_warn;
993 	qlvb->qb_value = q.qu_value;
994 	qd->qd_qb = *qlvb;
995 
996 	return 0;
997 }
998 
999 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
1000 		    struct gfs2_holder *q_gh)
1001 {
1002 	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
1003 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
1004 	struct gfs2_holder i_gh;
1005 	int error;
1006 
1007 restart:
1008 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
1009 	if (error)
1010 		return error;
1011 
1012 	if (test_and_clear_bit(QDF_REFRESH, &qd->qd_flags))
1013 		force_refresh = FORCE;
1014 
1015 	qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
1016 
1017 	if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
1018 		gfs2_glock_dq_uninit(q_gh);
1019 		error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE,
1020 					   GL_NOCACHE, q_gh);
1021 		if (error)
1022 			return error;
1023 
1024 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
1025 		if (error)
1026 			goto fail;
1027 
1028 		error = update_qd(sdp, qd);
1029 		if (error)
1030 			goto fail_gunlock;
1031 
1032 		gfs2_glock_dq_uninit(&i_gh);
1033 		gfs2_glock_dq_uninit(q_gh);
1034 		force_refresh = 0;
1035 		goto restart;
1036 	}
1037 
1038 	return 0;
1039 
1040 fail_gunlock:
1041 	gfs2_glock_dq_uninit(&i_gh);
1042 fail:
1043 	gfs2_glock_dq_uninit(q_gh);
1044 	return error;
1045 }
1046 
1047 int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
1048 {
1049 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1050 	struct gfs2_quota_data *qd;
1051 	u32 x;
1052 	int error = 0;
1053 
1054 	if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
1055 		return 0;
1056 
1057 	error = gfs2_quota_hold(ip, uid, gid);
1058 	if (error)
1059 		return error;
1060 
1061 	sort(ip->i_qadata->qa_qd, ip->i_qadata->qa_qd_num,
1062 	     sizeof(struct gfs2_quota_data *), sort_qd, NULL);
1063 
1064 	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
1065 		qd = ip->i_qadata->qa_qd[x];
1066 		error = do_glock(qd, NO_FORCE, &ip->i_qadata->qa_qd_ghs[x]);
1067 		if (error)
1068 			break;
1069 	}
1070 
1071 	if (!error)
1072 		set_bit(GIF_QD_LOCKED, &ip->i_flags);
1073 	else {
1074 		while (x--)
1075 			gfs2_glock_dq_uninit(&ip->i_qadata->qa_qd_ghs[x]);
1076 		gfs2_quota_unhold(ip);
1077 	}
1078 
1079 	return error;
1080 }
1081 
1082 static int need_sync(struct gfs2_quota_data *qd)
1083 {
1084 	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
1085 	struct gfs2_tune *gt = &sdp->sd_tune;
1086 	s64 value;
1087 	unsigned int num, den;
1088 	int do_sync = 1;
1089 
1090 	if (!qd->qd_qb.qb_limit)
1091 		return 0;
1092 
1093 	spin_lock(&qd_lock);
1094 	value = qd->qd_change;
1095 	spin_unlock(&qd_lock);
1096 
1097 	spin_lock(&gt->gt_spin);
1098 	num = gt->gt_quota_scale_num;
1099 	den = gt->gt_quota_scale_den;
1100 	spin_unlock(&gt->gt_spin);
1101 
1102 	if (value < 0)
1103 		do_sync = 0;
1104 	else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
1105 		 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
1106 		do_sync = 0;
1107 	else {
1108 		value *= gfs2_jindex_size(sdp) * num;
1109 		value = div_s64(value, den);
1110 		value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
1111 		if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
1112 			do_sync = 0;
1113 	}
1114 
1115 	return do_sync;
1116 }
1117 
1118 void gfs2_quota_unlock(struct gfs2_inode *ip)
1119 {
1120 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1121 	struct gfs2_quota_data *qda[4];
1122 	unsigned int count = 0;
1123 	u32 x;
1124 	int found;
1125 
1126 	if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
1127 		return;
1128 
1129 	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
1130 		struct gfs2_quota_data *qd;
1131 		int sync;
1132 
1133 		qd = ip->i_qadata->qa_qd[x];
1134 		sync = need_sync(qd);
1135 
1136 		gfs2_glock_dq_uninit(&ip->i_qadata->qa_qd_ghs[x]);
1137 		if (!sync)
1138 			continue;
1139 
1140 		spin_lock(&qd_lock);
1141 		found = qd_check_sync(sdp, qd, NULL);
1142 		spin_unlock(&qd_lock);
1143 
1144 		if (!found)
1145 			continue;
1146 
1147 		gfs2_assert_warn(sdp, qd->qd_change_sync);
1148 		if (bh_get(qd)) {
1149 			clear_bit(QDF_LOCKED, &qd->qd_flags);
1150 			slot_put(qd);
1151 			qd_put(qd);
1152 			continue;
1153 		}
1154 
1155 		qda[count++] = qd;
1156 	}
1157 
1158 	if (count) {
1159 		do_sync(count, qda);
1160 		for (x = 0; x < count; x++)
1161 			qd_unlock(qda[x]);
1162 	}
1163 
1164 	gfs2_quota_unhold(ip);
1165 }
1166 
1167 #define MAX_LINE 256
1168 
1169 static int print_message(struct gfs2_quota_data *qd, char *type)
1170 {
1171 	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
1172 
1173 	fs_info(sdp, "quota %s for %s %u\n",
1174 		type,
1175 		(qd->qd_id.type == USRQUOTA) ? "user" : "group",
1176 		from_kqid(&init_user_ns, qd->qd_id));
1177 
1178 	return 0;
1179 }
1180 
1181 /**
1182  * gfs2_quota_check - check if allocating new blocks will exceed quota
1183  * @ip:  The inode for which this check is being performed
1184  * @uid: The uid to check against
1185  * @gid: The gid to check against
1186  * @ap:  The allocation parameters. ap->target contains the requested
1187  *       blocks. ap->min_target, if set, contains the minimum blks
1188  *       requested.
1189  *
1190  * Returns: 0 on success.
1191  *                  min_req = ap->min_target ? ap->min_target : ap->target;
1192  *                  quota must allow at least min_req blks for success and
1193  *                  ap->allowed is set to the number of blocks allowed
1194  *
1195  *          -EDQUOT otherwise, quota violation. ap->allowed is set to number
1196  *                  of blocks available.
1197  */
1198 int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid,
1199 		     struct gfs2_alloc_parms *ap)
1200 {
1201 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1202 	struct gfs2_quota_data *qd;
1203 	s64 value, warn, limit;
1204 	u32 x;
1205 	int error = 0;
1206 
1207 	ap->allowed = UINT_MAX; /* Assume we are permitted a whole lot */
1208 	if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
1209 		return 0;
1210 
1211 	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
1212 		qd = ip->i_qadata->qa_qd[x];
1213 
1214 		if (!(qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
1215 		      qid_eq(qd->qd_id, make_kqid_gid(gid))))
1216 			continue;
1217 
1218 		warn = (s64)be64_to_cpu(qd->qd_qb.qb_warn);
1219 		limit = (s64)be64_to_cpu(qd->qd_qb.qb_limit);
1220 		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
1221 		spin_lock(&qd_lock);
1222 		value += qd->qd_change;
1223 		spin_unlock(&qd_lock);
1224 
1225 		if (limit > 0 && (limit - value) < ap->allowed)
1226 			ap->allowed = limit - value;
1227 		/* If we can't meet the target */
1228 		if (limit && limit < (value + (s64)ap->target)) {
1229 			/* If no min_target specified or we don't meet
1230 			 * min_target, return -EDQUOT */
1231 			if (!ap->min_target || ap->min_target > ap->allowed) {
1232 				if (!test_and_set_bit(QDF_QMSG_QUIET,
1233 						      &qd->qd_flags)) {
1234 					print_message(qd, "exceeded");
1235 					quota_send_warning(qd->qd_id,
1236 							   sdp->sd_vfs->s_dev,
1237 							   QUOTA_NL_BHARDWARN);
1238 				}
1239 				error = -EDQUOT;
1240 				break;
1241 			}
1242 		} else if (warn && warn < value &&
1243 			   time_after_eq(jiffies, qd->qd_last_warn +
1244 					 gfs2_tune_get(sdp, gt_quota_warn_period)
1245 					 * HZ)) {
1246 			quota_send_warning(qd->qd_id,
1247 					   sdp->sd_vfs->s_dev, QUOTA_NL_BSOFTWARN);
1248 			error = print_message(qd, "warning");
1249 			qd->qd_last_warn = jiffies;
1250 		}
1251 	}
1252 	return error;
1253 }
1254 
1255 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1256 		       kuid_t uid, kgid_t gid)
1257 {
1258 	struct gfs2_quota_data *qd;
1259 	u32 x;
1260 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1261 
1262 	if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON ||
1263 	    gfs2_assert_warn(sdp, change))
1264 		return;
1265 	if (ip->i_diskflags & GFS2_DIF_SYSTEM)
1266 		return;
1267 
1268 	if (gfs2_assert_withdraw(sdp, ip->i_qadata &&
1269 				 ip->i_qadata->qa_ref > 0))
1270 		return;
1271 	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
1272 		qd = ip->i_qadata->qa_qd[x];
1273 
1274 		if (qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
1275 		    qid_eq(qd->qd_id, make_kqid_gid(gid))) {
1276 			do_qc(qd, change);
1277 		}
1278 	}
1279 }
1280 
1281 int gfs2_quota_sync(struct super_block *sb, int type)
1282 {
1283 	struct gfs2_sbd *sdp = sb->s_fs_info;
1284 	struct gfs2_quota_data **qda;
1285 	unsigned int max_qd = PAGE_SIZE / sizeof(struct gfs2_holder);
1286 	unsigned int num_qd;
1287 	unsigned int x;
1288 	int error = 0;
1289 
1290 	qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1291 	if (!qda)
1292 		return -ENOMEM;
1293 
1294 	mutex_lock(&sdp->sd_quota_sync_mutex);
1295 	sdp->sd_quota_sync_gen++;
1296 
1297 	do {
1298 		num_qd = 0;
1299 
1300 		for (;;) {
1301 			error = qd_fish(sdp, qda + num_qd);
1302 			if (error || !qda[num_qd])
1303 				break;
1304 			if (++num_qd == max_qd)
1305 				break;
1306 		}
1307 
1308 		if (num_qd) {
1309 			if (!error)
1310 				error = do_sync(num_qd, qda);
1311 			if (!error)
1312 				for (x = 0; x < num_qd; x++)
1313 					qda[x]->qd_sync_gen =
1314 						sdp->sd_quota_sync_gen;
1315 
1316 			for (x = 0; x < num_qd; x++)
1317 				qd_unlock(qda[x]);
1318 		}
1319 	} while (!error && num_qd == max_qd);
1320 
1321 	mutex_unlock(&sdp->sd_quota_sync_mutex);
1322 	kfree(qda);
1323 
1324 	return error;
1325 }
1326 
1327 int gfs2_quota_refresh(struct gfs2_sbd *sdp, struct kqid qid)
1328 {
1329 	struct gfs2_quota_data *qd;
1330 	struct gfs2_holder q_gh;
1331 	int error;
1332 
1333 	error = qd_get(sdp, qid, &qd);
1334 	if (error)
1335 		return error;
1336 
1337 	error = do_glock(qd, FORCE, &q_gh);
1338 	if (!error)
1339 		gfs2_glock_dq_uninit(&q_gh);
1340 
1341 	qd_put(qd);
1342 	return error;
1343 }
1344 
1345 int gfs2_quota_init(struct gfs2_sbd *sdp)
1346 {
1347 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1348 	u64 size = i_size_read(sdp->sd_qc_inode);
1349 	unsigned int blocks = size >> sdp->sd_sb.sb_bsize_shift;
1350 	unsigned int x, slot = 0;
1351 	unsigned int found = 0;
1352 	unsigned int hash;
1353 	unsigned int bm_size;
1354 	u64 dblock;
1355 	u32 extlen = 0;
1356 	int error;
1357 
1358 	if (gfs2_check_internal_file_size(sdp->sd_qc_inode, 1, 64 << 20))
1359 		return -EIO;
1360 
1361 	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1362 	bm_size = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * sizeof(unsigned long));
1363 	bm_size *= sizeof(unsigned long);
1364 	error = -ENOMEM;
1365 	sdp->sd_quota_bitmap = kzalloc(bm_size, GFP_NOFS | __GFP_NOWARN);
1366 	if (sdp->sd_quota_bitmap == NULL)
1367 		sdp->sd_quota_bitmap = __vmalloc(bm_size, GFP_NOFS |
1368 						 __GFP_ZERO);
1369 	if (!sdp->sd_quota_bitmap)
1370 		return error;
1371 
1372 	for (x = 0; x < blocks; x++) {
1373 		struct buffer_head *bh;
1374 		const struct gfs2_quota_change *qc;
1375 		unsigned int y;
1376 
1377 		if (!extlen) {
1378 			int new = 0;
1379 			error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1380 			if (error)
1381 				goto fail;
1382 		}
1383 		error = -EIO;
1384 		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1385 		if (!bh)
1386 			goto fail;
1387 		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1388 			brelse(bh);
1389 			goto fail;
1390 		}
1391 
1392 		qc = (const struct gfs2_quota_change *)(bh->b_data + sizeof(struct gfs2_meta_header));
1393 		for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1394 		     y++, slot++) {
1395 			struct gfs2_quota_data *qd;
1396 			s64 qc_change = be64_to_cpu(qc->qc_change);
1397 			u32 qc_flags = be32_to_cpu(qc->qc_flags);
1398 			enum quota_type qtype = (qc_flags & GFS2_QCF_USER) ?
1399 						USRQUOTA : GRPQUOTA;
1400 			struct kqid qc_id = make_kqid(&init_user_ns, qtype,
1401 						      be32_to_cpu(qc->qc_id));
1402 			qc++;
1403 			if (!qc_change)
1404 				continue;
1405 
1406 			hash = gfs2_qd_hash(sdp, qc_id);
1407 			qd = qd_alloc(hash, sdp, qc_id);
1408 			if (qd == NULL) {
1409 				brelse(bh);
1410 				goto fail;
1411 			}
1412 
1413 			set_bit(QDF_CHANGE, &qd->qd_flags);
1414 			qd->qd_change = qc_change;
1415 			qd->qd_slot = slot;
1416 			qd->qd_slot_count = 1;
1417 
1418 			spin_lock(&qd_lock);
1419 			BUG_ON(test_and_set_bit(slot, sdp->sd_quota_bitmap));
1420 			list_add(&qd->qd_list, &sdp->sd_quota_list);
1421 			atomic_inc(&sdp->sd_quota_count);
1422 			spin_unlock(&qd_lock);
1423 
1424 			spin_lock_bucket(hash);
1425 			hlist_bl_add_head_rcu(&qd->qd_hlist, &qd_hash_table[hash]);
1426 			spin_unlock_bucket(hash);
1427 
1428 			found++;
1429 		}
1430 
1431 		brelse(bh);
1432 		dblock++;
1433 		extlen--;
1434 	}
1435 
1436 	if (found)
1437 		fs_info(sdp, "found %u quota changes\n", found);
1438 
1439 	return 0;
1440 
1441 fail:
1442 	gfs2_quota_cleanup(sdp);
1443 	return error;
1444 }
1445 
1446 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1447 {
1448 	struct list_head *head = &sdp->sd_quota_list;
1449 	struct gfs2_quota_data *qd;
1450 
1451 	spin_lock(&qd_lock);
1452 	while (!list_empty(head)) {
1453 		qd = list_last_entry(head, struct gfs2_quota_data, qd_list);
1454 
1455 		list_del(&qd->qd_list);
1456 
1457 		/* Also remove if this qd exists in the reclaim list */
1458 		list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
1459 		atomic_dec(&sdp->sd_quota_count);
1460 		spin_unlock(&qd_lock);
1461 
1462 		spin_lock_bucket(qd->qd_hash);
1463 		hlist_bl_del_rcu(&qd->qd_hlist);
1464 		spin_unlock_bucket(qd->qd_hash);
1465 
1466 		gfs2_assert_warn(sdp, !qd->qd_change);
1467 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
1468 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
1469 
1470 		gfs2_glock_put(qd->qd_gl);
1471 		call_rcu(&qd->qd_rcu, gfs2_qd_dealloc);
1472 
1473 		spin_lock(&qd_lock);
1474 	}
1475 	spin_unlock(&qd_lock);
1476 
1477 	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1478 
1479 	kvfree(sdp->sd_quota_bitmap);
1480 	sdp->sd_quota_bitmap = NULL;
1481 }
1482 
1483 static void quotad_error(struct gfs2_sbd *sdp, const char *msg, int error)
1484 {
1485 	if (error == 0 || error == -EROFS)
1486 		return;
1487 	if (!gfs2_withdrawn(sdp)) {
1488 		if (!cmpxchg(&sdp->sd_log_error, 0, error))
1489 			fs_err(sdp, "gfs2_quotad: %s error %d\n", msg, error);
1490 		wake_up(&sdp->sd_logd_waitq);
1491 	}
1492 }
1493 
1494 static void quotad_check_timeo(struct gfs2_sbd *sdp, const char *msg,
1495 			       int (*fxn)(struct super_block *sb, int type),
1496 			       unsigned long t, unsigned long *timeo,
1497 			       unsigned int *new_timeo)
1498 {
1499 	if (t >= *timeo) {
1500 		int error = fxn(sdp->sd_vfs, 0);
1501 		quotad_error(sdp, msg, error);
1502 		*timeo = gfs2_tune_get_i(&sdp->sd_tune, new_timeo) * HZ;
1503 	} else {
1504 		*timeo -= t;
1505 	}
1506 }
1507 
1508 static void quotad_check_trunc_list(struct gfs2_sbd *sdp)
1509 {
1510 	struct gfs2_inode *ip;
1511 
1512 	while(1) {
1513 		ip = NULL;
1514 		spin_lock(&sdp->sd_trunc_lock);
1515 		if (!list_empty(&sdp->sd_trunc_list)) {
1516 			ip = list_first_entry(&sdp->sd_trunc_list,
1517 					struct gfs2_inode, i_trunc_list);
1518 			list_del_init(&ip->i_trunc_list);
1519 		}
1520 		spin_unlock(&sdp->sd_trunc_lock);
1521 		if (ip == NULL)
1522 			return;
1523 		gfs2_glock_finish_truncate(ip);
1524 	}
1525 }
1526 
1527 void gfs2_wake_up_statfs(struct gfs2_sbd *sdp) {
1528 	if (!sdp->sd_statfs_force_sync) {
1529 		sdp->sd_statfs_force_sync = 1;
1530 		wake_up(&sdp->sd_quota_wait);
1531 	}
1532 }
1533 
1534 
1535 /**
1536  * gfs2_quotad - Write cached quota changes into the quota file
1537  * @sdp: Pointer to GFS2 superblock
1538  *
1539  */
1540 
1541 int gfs2_quotad(void *data)
1542 {
1543 	struct gfs2_sbd *sdp = data;
1544 	struct gfs2_tune *tune = &sdp->sd_tune;
1545 	unsigned long statfs_timeo = 0;
1546 	unsigned long quotad_timeo = 0;
1547 	unsigned long t = 0;
1548 	DEFINE_WAIT(wait);
1549 	int empty;
1550 
1551 	while (!kthread_should_stop()) {
1552 
1553 		if (gfs2_withdrawn(sdp))
1554 			goto bypass;
1555 		/* Update the master statfs file */
1556 		if (sdp->sd_statfs_force_sync) {
1557 			int error = gfs2_statfs_sync(sdp->sd_vfs, 0);
1558 			quotad_error(sdp, "statfs", error);
1559 			statfs_timeo = gfs2_tune_get(sdp, gt_statfs_quantum) * HZ;
1560 		}
1561 		else
1562 			quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
1563 				   	   &statfs_timeo,
1564 					   &tune->gt_statfs_quantum);
1565 
1566 		/* Update quota file */
1567 		quotad_check_timeo(sdp, "sync", gfs2_quota_sync, t,
1568 				   &quotad_timeo, &tune->gt_quota_quantum);
1569 
1570 		/* Check for & recover partially truncated inodes */
1571 		quotad_check_trunc_list(sdp);
1572 
1573 		try_to_freeze();
1574 
1575 bypass:
1576 		t = min(quotad_timeo, statfs_timeo);
1577 
1578 		prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);
1579 		spin_lock(&sdp->sd_trunc_lock);
1580 		empty = list_empty(&sdp->sd_trunc_list);
1581 		spin_unlock(&sdp->sd_trunc_lock);
1582 		if (empty && !sdp->sd_statfs_force_sync)
1583 			t -= schedule_timeout(t);
1584 		else
1585 			t = 0;
1586 		finish_wait(&sdp->sd_quota_wait, &wait);
1587 	}
1588 
1589 	return 0;
1590 }
1591 
1592 static int gfs2_quota_get_state(struct super_block *sb, struct qc_state *state)
1593 {
1594 	struct gfs2_sbd *sdp = sb->s_fs_info;
1595 
1596 	memset(state, 0, sizeof(*state));
1597 
1598 	switch (sdp->sd_args.ar_quota) {
1599 	case GFS2_QUOTA_ON:
1600 		state->s_state[USRQUOTA].flags |= QCI_LIMITS_ENFORCED;
1601 		state->s_state[GRPQUOTA].flags |= QCI_LIMITS_ENFORCED;
1602 		fallthrough;
1603 	case GFS2_QUOTA_ACCOUNT:
1604 		state->s_state[USRQUOTA].flags |= QCI_ACCT_ENABLED |
1605 						  QCI_SYSFILE;
1606 		state->s_state[GRPQUOTA].flags |= QCI_ACCT_ENABLED |
1607 						  QCI_SYSFILE;
1608 		break;
1609 	case GFS2_QUOTA_OFF:
1610 		break;
1611 	}
1612 	if (sdp->sd_quota_inode) {
1613 		state->s_state[USRQUOTA].ino =
1614 					GFS2_I(sdp->sd_quota_inode)->i_no_addr;
1615 		state->s_state[USRQUOTA].blocks = sdp->sd_quota_inode->i_blocks;
1616 	}
1617 	state->s_state[USRQUOTA].nextents = 1;	/* unsupported */
1618 	state->s_state[GRPQUOTA] = state->s_state[USRQUOTA];
1619 	state->s_incoredqs = list_lru_count(&gfs2_qd_lru);
1620 	return 0;
1621 }
1622 
1623 static int gfs2_get_dqblk(struct super_block *sb, struct kqid qid,
1624 			  struct qc_dqblk *fdq)
1625 {
1626 	struct gfs2_sbd *sdp = sb->s_fs_info;
1627 	struct gfs2_quota_lvb *qlvb;
1628 	struct gfs2_quota_data *qd;
1629 	struct gfs2_holder q_gh;
1630 	int error;
1631 
1632 	memset(fdq, 0, sizeof(*fdq));
1633 
1634 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1635 		return -ESRCH; /* Crazy XFS error code */
1636 
1637 	if ((qid.type != USRQUOTA) &&
1638 	    (qid.type != GRPQUOTA))
1639 		return -EINVAL;
1640 
1641 	error = qd_get(sdp, qid, &qd);
1642 	if (error)
1643 		return error;
1644 	error = do_glock(qd, FORCE, &q_gh);
1645 	if (error)
1646 		goto out;
1647 
1648 	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
1649 	fdq->d_spc_hardlimit = be64_to_cpu(qlvb->qb_limit) << sdp->sd_sb.sb_bsize_shift;
1650 	fdq->d_spc_softlimit = be64_to_cpu(qlvb->qb_warn) << sdp->sd_sb.sb_bsize_shift;
1651 	fdq->d_space = be64_to_cpu(qlvb->qb_value) << sdp->sd_sb.sb_bsize_shift;
1652 
1653 	gfs2_glock_dq_uninit(&q_gh);
1654 out:
1655 	qd_put(qd);
1656 	return error;
1657 }
1658 
1659 /* GFS2 only supports a subset of the XFS fields */
1660 #define GFS2_FIELDMASK (QC_SPC_SOFT|QC_SPC_HARD|QC_SPACE)
1661 
1662 static int gfs2_set_dqblk(struct super_block *sb, struct kqid qid,
1663 			  struct qc_dqblk *fdq)
1664 {
1665 	struct gfs2_sbd *sdp = sb->s_fs_info;
1666 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
1667 	struct gfs2_quota_data *qd;
1668 	struct gfs2_holder q_gh, i_gh;
1669 	unsigned int data_blocks, ind_blocks;
1670 	unsigned int blocks = 0;
1671 	int alloc_required;
1672 	loff_t offset;
1673 	int error;
1674 
1675 	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1676 		return -ESRCH; /* Crazy XFS error code */
1677 
1678 	if ((qid.type != USRQUOTA) &&
1679 	    (qid.type != GRPQUOTA))
1680 		return -EINVAL;
1681 
1682 	if (fdq->d_fieldmask & ~GFS2_FIELDMASK)
1683 		return -EINVAL;
1684 
1685 	error = qd_get(sdp, qid, &qd);
1686 	if (error)
1687 		return error;
1688 
1689 	error = gfs2_qa_get(ip);
1690 	if (error)
1691 		goto out_put;
1692 
1693 	inode_lock(&ip->i_inode);
1694 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE, 0, &q_gh);
1695 	if (error)
1696 		goto out_unlockput;
1697 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
1698 	if (error)
1699 		goto out_q;
1700 
1701 	/* Check for existing entry, if none then alloc new blocks */
1702 	error = update_qd(sdp, qd);
1703 	if (error)
1704 		goto out_i;
1705 
1706 	/* If nothing has changed, this is a no-op */
1707 	if ((fdq->d_fieldmask & QC_SPC_SOFT) &&
1708 	    ((fdq->d_spc_softlimit >> sdp->sd_sb.sb_bsize_shift) == be64_to_cpu(qd->qd_qb.qb_warn)))
1709 		fdq->d_fieldmask ^= QC_SPC_SOFT;
1710 
1711 	if ((fdq->d_fieldmask & QC_SPC_HARD) &&
1712 	    ((fdq->d_spc_hardlimit >> sdp->sd_sb.sb_bsize_shift) == be64_to_cpu(qd->qd_qb.qb_limit)))
1713 		fdq->d_fieldmask ^= QC_SPC_HARD;
1714 
1715 	if ((fdq->d_fieldmask & QC_SPACE) &&
1716 	    ((fdq->d_space >> sdp->sd_sb.sb_bsize_shift) == be64_to_cpu(qd->qd_qb.qb_value)))
1717 		fdq->d_fieldmask ^= QC_SPACE;
1718 
1719 	if (fdq->d_fieldmask == 0)
1720 		goto out_i;
1721 
1722 	offset = qd2offset(qd);
1723 	alloc_required = gfs2_write_alloc_required(ip, offset, sizeof(struct gfs2_quota));
1724 	if (gfs2_is_stuffed(ip))
1725 		alloc_required = 1;
1726 	if (alloc_required) {
1727 		struct gfs2_alloc_parms ap = { .aflags = 0, };
1728 		gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
1729 				       &data_blocks, &ind_blocks);
1730 		blocks = 1 + data_blocks + ind_blocks;
1731 		ap.target = blocks;
1732 		error = gfs2_inplace_reserve(ip, &ap);
1733 		if (error)
1734 			goto out_i;
1735 		blocks += gfs2_rg_blocks(ip, blocks);
1736 	}
1737 
1738 	/* Some quotas span block boundaries and can update two blocks,
1739 	   adding an extra block to the transaction to handle such quotas */
1740 	error = gfs2_trans_begin(sdp, blocks + RES_DINODE + 2, 0);
1741 	if (error)
1742 		goto out_release;
1743 
1744 	/* Apply changes */
1745 	error = gfs2_adjust_quota(ip, offset, 0, qd, fdq);
1746 	if (!error)
1747 		clear_bit(QDF_QMSG_QUIET, &qd->qd_flags);
1748 
1749 	gfs2_trans_end(sdp);
1750 out_release:
1751 	if (alloc_required)
1752 		gfs2_inplace_release(ip);
1753 out_i:
1754 	gfs2_glock_dq_uninit(&i_gh);
1755 out_q:
1756 	gfs2_glock_dq_uninit(&q_gh);
1757 out_unlockput:
1758 	gfs2_qa_put(ip);
1759 	inode_unlock(&ip->i_inode);
1760 out_put:
1761 	qd_put(qd);
1762 	return error;
1763 }
1764 
1765 const struct quotactl_ops gfs2_quotactl_ops = {
1766 	.quota_sync     = gfs2_quota_sync,
1767 	.get_state	= gfs2_quota_get_state,
1768 	.get_dqblk	= gfs2_get_dqblk,
1769 	.set_dqblk	= gfs2_set_dqblk,
1770 };
1771 
1772 void __init gfs2_quota_hash_init(void)
1773 {
1774 	unsigned i;
1775 
1776 	for(i = 0; i < GFS2_QD_HASH_SIZE; i++)
1777 		INIT_HLIST_BL_HEAD(&qd_hash_table[i]);
1778 }
1779