[GFS2] Export lm_interface to kernel headers
[linux-2.6.git] / fs / gfs2 / quota.c
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9
10 /*
11  * Quota change tags are associated with each transaction that allocates or
12  * deallocates space.  Those changes are accumulated locally to each node (in a
13  * per-node file) and then are periodically synced to the quota file.  This
14  * avoids the bottleneck of constantly touching the quota file, but introduces
15  * fuzziness in the current usage value of IDs that are being used on different
16  * nodes in the cluster simultaneously.  So, it is possible for a user on
17  * multiple nodes to overrun their quota, but that overrun is controlable.
18  * Since quota tags are part of transactions, there is no need to a quota check
19  * program to be run on node crashes or anything like that.
20  *
21  * There are couple of knobs that let the administrator manage the quota
22  * fuzziness.  "quota_quantum" sets the maximum time a quota change can be
23  * sitting on one node before being synced to the quota file.  (The default is
24  * 60 seconds.)  Another knob, "quota_scale" controls how quickly the frequency
25  * of quota file syncs increases as the user moves closer to their limit.  The
26  * more frequent the syncs, the more accurate the quota enforcement, but that
27  * means that there is more contention between the nodes for the quota file.
28  * The default value is one.  This sets the maximum theoretical quota overrun
29  * (with infinite node with infinite bandwidth) to twice the user's limit.  (In
30  * practice, the maximum overrun you see should be much less.)  A "quota_scale"
31  * number greater than one makes quota syncs more frequent and reduces the
32  * maximum overrun.  Numbers less than one (but greater than zero) make quota
33  * syncs less frequent.
34  *
35  * GFS quotas also use per-ID Lock Value Blocks (LVBs) to cache the contents of
36  * the quota file, so it is not being constantly read.
37  */
38
39 #include <linux/sched.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/completion.h>
43 #include <linux/buffer_head.h>
44 #include <linux/sort.h>
45 #include <linux/fs.h>
46 #include <linux/gfs2_ondisk.h>
47 #include <linux/lm_interface.h>
48
49 #include "gfs2.h"
50 #include "incore.h"
51 #include "bmap.h"
52 #include "glock.h"
53 #include "glops.h"
54 #include "log.h"
55 #include "meta_io.h"
56 #include "quota.h"
57 #include "rgrp.h"
58 #include "super.h"
59 #include "trans.h"
60 #include "inode.h"
61 #include "ops_file.h"
62 #include "ops_address.h"
63 #include "util.h"
64
65 #define QUOTA_USER 1
66 #define QUOTA_GROUP 0
67
68 static u64 qd2offset(struct gfs2_quota_data *qd)
69 {
70         u64 offset;
71
72         offset = 2 * (u64)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
73         offset *= sizeof(struct gfs2_quota);
74
75         return offset;
76 }
77
78 static int qd_alloc(struct gfs2_sbd *sdp, int user, u32 id,
79                     struct gfs2_quota_data **qdp)
80 {
81         struct gfs2_quota_data *qd;
82         int error;
83
84         qd = kzalloc(sizeof(struct gfs2_quota_data), GFP_KERNEL);
85         if (!qd)
86                 return -ENOMEM;
87
88         qd->qd_count = 1;
89         qd->qd_id = id;
90         if (user)
91                 set_bit(QDF_USER, &qd->qd_flags);
92         qd->qd_slot = -1;
93
94         error = gfs2_glock_get(sdp, 2 * (u64)id + !user,
95                               &gfs2_quota_glops, CREATE, &qd->qd_gl);
96         if (error)
97                 goto fail;
98
99         error = gfs2_lvb_hold(qd->qd_gl);
100         gfs2_glock_put(qd->qd_gl);
101         if (error)
102                 goto fail;
103
104         *qdp = qd;
105
106         return 0;
107
108 fail:
109         kfree(qd);
110         return error;
111 }
112
113 static int qd_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
114                   struct gfs2_quota_data **qdp)
115 {
116         struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
117         int error, found;
118
119         *qdp = NULL;
120
121         for (;;) {
122                 found = 0;
123                 spin_lock(&sdp->sd_quota_spin);
124                 list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
125                         if (qd->qd_id == id &&
126                             !test_bit(QDF_USER, &qd->qd_flags) == !user) {
127                                 qd->qd_count++;
128                                 found = 1;
129                                 break;
130                         }
131                 }
132
133                 if (!found)
134                         qd = NULL;
135
136                 if (!qd && new_qd) {
137                         qd = new_qd;
138                         list_add(&qd->qd_list, &sdp->sd_quota_list);
139                         atomic_inc(&sdp->sd_quota_count);
140                         new_qd = NULL;
141                 }
142
143                 spin_unlock(&sdp->sd_quota_spin);
144
145                 if (qd || !create) {
146                         if (new_qd) {
147                                 gfs2_lvb_unhold(new_qd->qd_gl);
148                                 kfree(new_qd);
149                         }
150                         *qdp = qd;
151                         return 0;
152                 }
153
154                 error = qd_alloc(sdp, user, id, &new_qd);
155                 if (error)
156                         return error;
157         }
158 }
159
160 static void qd_hold(struct gfs2_quota_data *qd)
161 {
162         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
163
164         spin_lock(&sdp->sd_quota_spin);
165         gfs2_assert(sdp, qd->qd_count);
166         qd->qd_count++;
167         spin_unlock(&sdp->sd_quota_spin);
168 }
169
170 static void qd_put(struct gfs2_quota_data *qd)
171 {
172         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
173         spin_lock(&sdp->sd_quota_spin);
174         gfs2_assert(sdp, qd->qd_count);
175         if (!--qd->qd_count)
176                 qd->qd_last_touched = jiffies;
177         spin_unlock(&sdp->sd_quota_spin);
178 }
179
180 static int slot_get(struct gfs2_quota_data *qd)
181 {
182         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
183         unsigned int c, o = 0, b;
184         unsigned char byte = 0;
185
186         spin_lock(&sdp->sd_quota_spin);
187
188         if (qd->qd_slot_count++) {
189                 spin_unlock(&sdp->sd_quota_spin);
190                 return 0;
191         }
192
193         for (c = 0; c < sdp->sd_quota_chunks; c++)
194                 for (o = 0; o < PAGE_SIZE; o++) {
195                         byte = sdp->sd_quota_bitmap[c][o];
196                         if (byte != 0xFF)
197                                 goto found;
198                 }
199
200         goto fail;
201
202 found:
203         for (b = 0; b < 8; b++)
204                 if (!(byte & (1 << b)))
205                         break;
206         qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
207
208         if (qd->qd_slot >= sdp->sd_quota_slots)
209                 goto fail;
210
211         sdp->sd_quota_bitmap[c][o] |= 1 << b;
212
213         spin_unlock(&sdp->sd_quota_spin);
214
215         return 0;
216
217 fail:
218         qd->qd_slot_count--;
219         spin_unlock(&sdp->sd_quota_spin);
220         return -ENOSPC;
221 }
222
223 static void slot_hold(struct gfs2_quota_data *qd)
224 {
225         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
226
227         spin_lock(&sdp->sd_quota_spin);
228         gfs2_assert(sdp, qd->qd_slot_count);
229         qd->qd_slot_count++;
230         spin_unlock(&sdp->sd_quota_spin);
231 }
232
233 static void slot_put(struct gfs2_quota_data *qd)
234 {
235         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
236
237         spin_lock(&sdp->sd_quota_spin);
238         gfs2_assert(sdp, qd->qd_slot_count);
239         if (!--qd->qd_slot_count) {
240                 gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
241                 qd->qd_slot = -1;
242         }
243         spin_unlock(&sdp->sd_quota_spin);
244 }
245
246 static int bh_get(struct gfs2_quota_data *qd)
247 {
248         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
249         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
250         unsigned int block, offset;
251         struct buffer_head *bh;
252         int error;
253         struct buffer_head bh_map;
254
255         mutex_lock(&sdp->sd_quota_mutex);
256
257         if (qd->qd_bh_count++) {
258                 mutex_unlock(&sdp->sd_quota_mutex);
259                 return 0;
260         }
261
262         block = qd->qd_slot / sdp->sd_qc_per_block;
263         offset = qd->qd_slot % sdp->sd_qc_per_block;;
264
265         error = gfs2_block_map(&ip->i_inode, block, 0, &bh_map, 1);
266         if (error)
267                 goto fail;
268         error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_START | DIO_WAIT, &bh);
269         if (error)
270                 goto fail;
271         error = -EIO;
272         if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
273                 goto fail_brelse;
274
275         qd->qd_bh = bh;
276         qd->qd_bh_qc = (struct gfs2_quota_change *)
277                 (bh->b_data + sizeof(struct gfs2_meta_header) +
278                  offset * sizeof(struct gfs2_quota_change));
279
280         mutex_lock(&sdp->sd_quota_mutex);
281
282         return 0;
283
284 fail_brelse:
285         brelse(bh);
286 fail:
287         qd->qd_bh_count--;
288         mutex_unlock(&sdp->sd_quota_mutex);
289         return error;
290 }
291
292 static void bh_put(struct gfs2_quota_data *qd)
293 {
294         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
295
296         mutex_lock(&sdp->sd_quota_mutex);
297         gfs2_assert(sdp, qd->qd_bh_count);
298         if (!--qd->qd_bh_count) {
299                 brelse(qd->qd_bh);
300                 qd->qd_bh = NULL;
301                 qd->qd_bh_qc = NULL;
302         }
303         mutex_unlock(&sdp->sd_quota_mutex);
304 }
305
306 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
307 {
308         struct gfs2_quota_data *qd = NULL;
309         int error;
310         int found = 0;
311
312         *qdp = NULL;
313
314         if (sdp->sd_vfs->s_flags & MS_RDONLY)
315                 return 0;
316
317         spin_lock(&sdp->sd_quota_spin);
318
319         list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
320                 if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
321                     !test_bit(QDF_CHANGE, &qd->qd_flags) ||
322                     qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
323                         continue;
324
325                 list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
326
327                 set_bit(QDF_LOCKED, &qd->qd_flags);
328                 gfs2_assert_warn(sdp, qd->qd_count);
329                 qd->qd_count++;
330                 qd->qd_change_sync = qd->qd_change;
331                 gfs2_assert_warn(sdp, qd->qd_slot_count);
332                 qd->qd_slot_count++;
333                 found = 1;
334
335                 break;
336         }
337
338         if (!found)
339                 qd = NULL;
340
341         spin_unlock(&sdp->sd_quota_spin);
342
343         if (qd) {
344                 gfs2_assert_warn(sdp, qd->qd_change_sync);
345                 error = bh_get(qd);
346                 if (error) {
347                         clear_bit(QDF_LOCKED, &qd->qd_flags);
348                         slot_put(qd);
349                         qd_put(qd);
350                         return error;
351                 }
352         }
353
354         *qdp = qd;
355
356         return 0;
357 }
358
359 static int qd_trylock(struct gfs2_quota_data *qd)
360 {
361         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
362
363         if (sdp->sd_vfs->s_flags & MS_RDONLY)
364                 return 0;
365
366         spin_lock(&sdp->sd_quota_spin);
367
368         if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
369             !test_bit(QDF_CHANGE, &qd->qd_flags)) {
370                 spin_unlock(&sdp->sd_quota_spin);
371                 return 0;
372         }
373
374         list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
375
376         set_bit(QDF_LOCKED, &qd->qd_flags);
377         gfs2_assert_warn(sdp, qd->qd_count);
378         qd->qd_count++;
379         qd->qd_change_sync = qd->qd_change;
380         gfs2_assert_warn(sdp, qd->qd_slot_count);
381         qd->qd_slot_count++;
382
383         spin_unlock(&sdp->sd_quota_spin);
384
385         gfs2_assert_warn(sdp, qd->qd_change_sync);
386         if (bh_get(qd)) {
387                 clear_bit(QDF_LOCKED, &qd->qd_flags);
388                 slot_put(qd);
389                 qd_put(qd);
390                 return 0;
391         }
392
393         return 1;
394 }
395
396 static void qd_unlock(struct gfs2_quota_data *qd)
397 {
398         gfs2_assert_warn(qd->qd_gl->gl_sbd,
399                          test_bit(QDF_LOCKED, &qd->qd_flags));
400         clear_bit(QDF_LOCKED, &qd->qd_flags);
401         bh_put(qd);
402         slot_put(qd);
403         qd_put(qd);
404 }
405
406 static int qdsb_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
407                     struct gfs2_quota_data **qdp)
408 {
409         int error;
410
411         error = qd_get(sdp, user, id, create, qdp);
412         if (error)
413                 return error;
414
415         error = slot_get(*qdp);
416         if (error)
417                 goto fail;
418
419         error = bh_get(*qdp);
420         if (error)
421                 goto fail_slot;
422
423         return 0;
424
425 fail_slot:
426         slot_put(*qdp);
427 fail:
428         qd_put(*qdp);
429         return error;
430 }
431
432 static void qdsb_put(struct gfs2_quota_data *qd)
433 {
434         bh_put(qd);
435         slot_put(qd);
436         qd_put(qd);
437 }
438
439 int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
440 {
441         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
442         struct gfs2_alloc *al = &ip->i_alloc;
443         struct gfs2_quota_data **qd = al->al_qd;
444         int error;
445
446         if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
447             gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
448                 return -EIO;
449
450         if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
451                 return 0;
452
453         error = qdsb_get(sdp, QUOTA_USER, ip->i_di.di_uid, CREATE, qd);
454         if (error)
455                 goto out;
456         al->al_qd_num++;
457         qd++;
458
459         error = qdsb_get(sdp, QUOTA_GROUP, ip->i_di.di_gid, CREATE, qd);
460         if (error)
461                 goto out;
462         al->al_qd_num++;
463         qd++;
464
465         if (uid != NO_QUOTA_CHANGE && uid != ip->i_di.di_uid) {
466                 error = qdsb_get(sdp, QUOTA_USER, uid, CREATE, qd);
467                 if (error)
468                         goto out;
469                 al->al_qd_num++;
470                 qd++;
471         }
472
473         if (gid != NO_QUOTA_CHANGE && gid != ip->i_di.di_gid) {
474                 error = qdsb_get(sdp, QUOTA_GROUP, gid, CREATE, qd);
475                 if (error)
476                         goto out;
477                 al->al_qd_num++;
478                 qd++;
479         }
480
481 out:
482         if (error)
483                 gfs2_quota_unhold(ip);
484         return error;
485 }
486
487 void gfs2_quota_unhold(struct gfs2_inode *ip)
488 {
489         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
490         struct gfs2_alloc *al = &ip->i_alloc;
491         unsigned int x;
492
493         gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
494
495         for (x = 0; x < al->al_qd_num; x++) {
496                 qdsb_put(al->al_qd[x]);
497                 al->al_qd[x] = NULL;
498         }
499         al->al_qd_num = 0;
500 }
501
502 static int sort_qd(const void *a, const void *b)
503 {
504         const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
505         const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
506
507         if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
508             !test_bit(QDF_USER, &qd_b->qd_flags)) {
509                 if (test_bit(QDF_USER, &qd_a->qd_flags))
510                         return -1;
511                 else
512                         return 1;
513         }
514         if (qd_a->qd_id < qd_b->qd_id)
515                 return -1;
516         if (qd_a->qd_id > qd_b->qd_id)
517                 return 1;
518
519         return 0;
520 }
521
522 static void do_qc(struct gfs2_quota_data *qd, s64 change)
523 {
524         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
525         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
526         struct gfs2_quota_change *qc = qd->qd_bh_qc;
527         s64 x;
528
529         mutex_lock(&sdp->sd_quota_mutex);
530         gfs2_trans_add_bh(ip->i_gl, qd->qd_bh, 1);
531
532         if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
533                 qc->qc_change = 0;
534                 qc->qc_flags = 0;
535                 if (test_bit(QDF_USER, &qd->qd_flags))
536                         qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
537                 qc->qc_id = cpu_to_be32(qd->qd_id);
538         }
539
540         x = qc->qc_change;
541         x = be64_to_cpu(x) + change;
542         qc->qc_change = cpu_to_be64(x);
543
544         spin_lock(&sdp->sd_quota_spin);
545         qd->qd_change = x;
546         spin_unlock(&sdp->sd_quota_spin);
547
548         if (!x) {
549                 gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
550                 clear_bit(QDF_CHANGE, &qd->qd_flags);
551                 qc->qc_flags = 0;
552                 qc->qc_id = 0;
553                 slot_put(qd);
554                 qd_put(qd);
555         } else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
556                 qd_hold(qd);
557                 slot_hold(qd);
558         }
559                         
560         mutex_unlock(&sdp->sd_quota_mutex);
561 }
562
563 /**
564  * gfs2_adjust_quota
565  *
566  * This function was mostly borrowed from gfs2_block_truncate_page which was
567  * in turn mostly borrowed from ext3
568  */
569 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
570                              s64 change, struct gfs2_quota_data *qd)
571 {
572         struct inode *inode = &ip->i_inode;
573         struct address_space *mapping = inode->i_mapping;
574         unsigned long index = loc >> PAGE_CACHE_SHIFT;
575         unsigned offset = loc & (PAGE_CACHE_SHIFT - 1);
576         unsigned blocksize, iblock, pos;
577         struct buffer_head *bh;
578         struct page *page;
579         void *kaddr;
580         __be64 *ptr;
581         s64 value;
582         int err = -EIO;
583
584         page = grab_cache_page(mapping, index);
585         if (!page)
586                 return -ENOMEM;
587
588         blocksize = inode->i_sb->s_blocksize;
589         iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
590
591         if (!page_has_buffers(page))
592                 create_empty_buffers(page, blocksize, 0);
593
594         bh = page_buffers(page);
595         pos = blocksize;
596         while (offset >= pos) {
597                 bh = bh->b_this_page;
598                 iblock++;
599                 pos += blocksize;
600         }
601
602         if (!buffer_mapped(bh)) {
603                 gfs2_get_block(inode, iblock, bh, 1);
604                 if (!buffer_mapped(bh))
605                         goto unlock;
606         }
607
608         if (PageUptodate(page))
609                 set_buffer_uptodate(bh);
610
611         if (!buffer_uptodate(bh)) {
612                 ll_rw_block(READ, 1, &bh);
613                 wait_on_buffer(bh);
614                 if (!buffer_uptodate(bh))
615                         goto unlock;
616         }
617
618         gfs2_trans_add_bh(ip->i_gl, bh, 0);
619
620         kaddr = kmap_atomic(page, KM_USER0);
621         ptr = kaddr + offset;
622         value = (s64)be64_to_cpu(*ptr) + change;
623         *ptr = cpu_to_be64(value);
624         flush_dcache_page(page);
625         kunmap_atomic(kaddr, KM_USER0);
626         err = 0;
627         qd->qd_qb.qb_magic = cpu_to_be32(GFS2_MAGIC);
628         qd->qd_qb.qb_value = cpu_to_be64(value);
629 unlock:
630         unlock_page(page);
631         page_cache_release(page);
632         return err;
633 }
634
635 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
636 {
637         struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
638         struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
639         unsigned int data_blocks, ind_blocks;
640         struct gfs2_holder *ghs, i_gh;
641         unsigned int qx, x;
642         struct gfs2_quota_data *qd;
643         loff_t offset;
644         unsigned int nalloc = 0;
645         struct gfs2_alloc *al = NULL;
646         int error;
647
648         gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
649                               &data_blocks, &ind_blocks);
650
651         ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_KERNEL);
652         if (!ghs)
653                 return -ENOMEM;
654
655         sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
656         for (qx = 0; qx < num_qd; qx++) {
657                 error = gfs2_glock_nq_init(qda[qx]->qd_gl,
658                                            LM_ST_EXCLUSIVE,
659                                            GL_NOCACHE, &ghs[qx]);
660                 if (error)
661                         goto out;
662         }
663
664         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
665         if (error)
666                 goto out;
667
668         for (x = 0; x < num_qd; x++) {
669                 int alloc_required;
670
671                 offset = qd2offset(qda[x]);
672                 error = gfs2_write_alloc_required(ip, offset,
673                                                   sizeof(struct gfs2_quota),
674                                                   &alloc_required);
675                 if (error)
676                         goto out_gunlock;
677                 if (alloc_required)
678                         nalloc++;
679         }
680
681         if (nalloc) {
682                 al = gfs2_alloc_get(ip);
683
684                 al->al_requested = nalloc * (data_blocks + ind_blocks);
685
686                 error = gfs2_inplace_reserve(ip);
687                 if (error)
688                         goto out_alloc;
689
690                 error = gfs2_trans_begin(sdp,
691                                          al->al_rgd->rd_ri.ri_length +
692                                          num_qd * data_blocks +
693                                          nalloc * ind_blocks +
694                                          RES_DINODE + num_qd +
695                                          RES_STATFS, 0);
696                 if (error)
697                         goto out_ipres;
698         } else {
699                 error = gfs2_trans_begin(sdp,
700                                          num_qd * data_blocks +
701                                          RES_DINODE + num_qd, 0);
702                 if (error)
703                         goto out_gunlock;
704         }
705
706         for (x = 0; x < num_qd; x++) {
707                 qd = qda[x];
708                 offset = qd2offset(qd);
709                 error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync,
710                                           (struct gfs2_quota_data *)
711                                           qd->qd_gl->gl_lvb);
712                 if (error)
713                         goto out_end_trans;
714
715                 do_qc(qd, -qd->qd_change_sync);
716         }
717
718         error = 0;
719
720 out_end_trans:
721         gfs2_trans_end(sdp);
722 out_ipres:
723         if (nalloc)
724                 gfs2_inplace_release(ip);
725 out_alloc:
726         if (nalloc)
727                 gfs2_alloc_put(ip);
728 out_gunlock:
729         gfs2_glock_dq_uninit(&i_gh);
730 out:
731         while (qx--)
732                 gfs2_glock_dq_uninit(&ghs[qx]);
733         kfree(ghs);
734         gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
735         return error;
736 }
737
738 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
739                     struct gfs2_holder *q_gh)
740 {
741         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
742         struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
743         struct gfs2_holder i_gh;
744         struct gfs2_quota q;
745         char buf[sizeof(struct gfs2_quota)];
746         struct file_ra_state ra_state;
747         int error;
748         struct gfs2_quota_lvb *qlvb;
749
750         file_ra_state_init(&ra_state, sdp->sd_quota_inode->i_mapping);
751 restart:
752         error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
753         if (error)
754                 return error;
755
756         qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
757
758         if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
759                 loff_t pos;
760                 gfs2_glock_dq_uninit(q_gh);
761                 error = gfs2_glock_nq_init(qd->qd_gl,
762                                           LM_ST_EXCLUSIVE, GL_NOCACHE,
763                                           q_gh);
764                 if (error)
765                         return error;
766
767                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
768                 if (error)
769                         goto fail;
770
771                 memset(buf, 0, sizeof(struct gfs2_quota));
772                 pos = qd2offset(qd);
773                 error = gfs2_internal_read(ip, &ra_state, buf,
774                                            &pos, sizeof(struct gfs2_quota));
775                 if (error < 0)
776                         goto fail_gunlock;
777
778                 gfs2_glock_dq_uninit(&i_gh);
779
780                 
781                 gfs2_quota_in(&q, buf);
782                 qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
783                 qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
784                 qlvb->__pad = 0;
785                 qlvb->qb_limit = cpu_to_be64(q.qu_limit);
786                 qlvb->qb_warn = cpu_to_be64(q.qu_warn);
787                 qlvb->qb_value = cpu_to_be64(q.qu_value);
788                 qd->qd_qb = *qlvb;
789
790                 if (gfs2_glock_is_blocking(qd->qd_gl)) {
791                         gfs2_glock_dq_uninit(q_gh);
792                         force_refresh = 0;
793                         goto restart;
794                 }
795         }
796
797         return 0;
798
799 fail_gunlock:
800         gfs2_glock_dq_uninit(&i_gh);
801 fail:
802         gfs2_glock_dq_uninit(q_gh);
803         return error;
804 }
805
806 int gfs2_quota_lock(struct gfs2_inode *ip, u32 uid, u32 gid)
807 {
808         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
809         struct gfs2_alloc *al = &ip->i_alloc;
810         unsigned int x;
811         int error = 0;
812
813         gfs2_quota_hold(ip, uid, gid);
814
815         if (capable(CAP_SYS_RESOURCE) ||
816             sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
817                 return 0;
818
819         sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
820              sort_qd, NULL);
821
822         for (x = 0; x < al->al_qd_num; x++) {
823                 error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
824                 if (error)
825                         break;
826         }
827
828         if (!error)
829                 set_bit(GIF_QD_LOCKED, &ip->i_flags);
830         else {
831                 while (x--)
832                         gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
833                 gfs2_quota_unhold(ip);
834         }
835
836         return error;
837 }
838
839 static int need_sync(struct gfs2_quota_data *qd)
840 {
841         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
842         struct gfs2_tune *gt = &sdp->sd_tune;
843         s64 value;
844         unsigned int num, den;
845         int do_sync = 1;
846
847         if (!qd->qd_qb.qb_limit)
848                 return 0;
849
850         spin_lock(&sdp->sd_quota_spin);
851         value = qd->qd_change;
852         spin_unlock(&sdp->sd_quota_spin);
853
854         spin_lock(&gt->gt_spin);
855         num = gt->gt_quota_scale_num;
856         den = gt->gt_quota_scale_den;
857         spin_unlock(&gt->gt_spin);
858
859         if (value < 0)
860                 do_sync = 0;
861         else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
862                  (s64)be64_to_cpu(qd->qd_qb.qb_limit))
863                 do_sync = 0;
864         else {
865                 value *= gfs2_jindex_size(sdp) * num;
866                 do_div(value, den);
867                 value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
868                 if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
869                         do_sync = 0;
870         }
871
872         return do_sync;
873 }
874
875 void gfs2_quota_unlock(struct gfs2_inode *ip)
876 {
877         struct gfs2_alloc *al = &ip->i_alloc;
878         struct gfs2_quota_data *qda[4];
879         unsigned int count = 0;
880         unsigned int x;
881
882         if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
883                 goto out;
884
885         for (x = 0; x < al->al_qd_num; x++) {
886                 struct gfs2_quota_data *qd;
887                 int sync;
888
889                 qd = al->al_qd[x];
890                 sync = need_sync(qd);
891
892                 gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
893
894                 if (sync && qd_trylock(qd))
895                         qda[count++] = qd;
896         }
897
898         if (count) {
899                 do_sync(count, qda);
900                 for (x = 0; x < count; x++)
901                         qd_unlock(qda[x]);
902         }
903
904 out:
905         gfs2_quota_unhold(ip);
906 }
907
908 #define MAX_LINE 256
909
910 static int print_message(struct gfs2_quota_data *qd, char *type)
911 {
912         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
913
914         printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\r\n",
915                sdp->sd_fsname, type,
916                (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
917                qd->qd_id);
918
919         return 0;
920 }
921
922 int gfs2_quota_check(struct gfs2_inode *ip, u32 uid, u32 gid)
923 {
924         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
925         struct gfs2_alloc *al = &ip->i_alloc;
926         struct gfs2_quota_data *qd;
927         s64 value;
928         unsigned int x;
929         int error = 0;
930
931         if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
932                 return 0;
933
934         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
935                 return 0;
936
937         for (x = 0; x < al->al_qd_num; x++) {
938                 qd = al->al_qd[x];
939
940                 if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
941                       (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
942                         continue;
943
944                 value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
945                 spin_lock(&sdp->sd_quota_spin);
946                 value += qd->qd_change;
947                 spin_unlock(&sdp->sd_quota_spin);
948
949                 if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
950                         print_message(qd, "exceeded");
951                         error = -EDQUOT;
952                         break;
953                 } else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
954                            (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
955                            time_after_eq(jiffies, qd->qd_last_warn +
956                                          gfs2_tune_get(sdp,
957                                                 gt_quota_warn_period) * HZ)) {
958                         error = print_message(qd, "warning");
959                         qd->qd_last_warn = jiffies;
960                 }
961         }
962
963         return error;
964 }
965
966 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
967                        u32 uid, u32 gid)
968 {
969         struct gfs2_alloc *al = &ip->i_alloc;
970         struct gfs2_quota_data *qd;
971         unsigned int x;
972         unsigned int found = 0;
973
974         if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
975                 return;
976         if (ip->i_di.di_flags & GFS2_DIF_SYSTEM)
977                 return;
978
979         for (x = 0; x < al->al_qd_num; x++) {
980                 qd = al->al_qd[x];
981
982                 if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
983                     (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
984                         do_qc(qd, change);
985                         found++;
986                 }
987         }
988 }
989
990 int gfs2_quota_sync(struct gfs2_sbd *sdp)
991 {
992         struct gfs2_quota_data **qda;
993         unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
994         unsigned int num_qd;
995         unsigned int x;
996         int error = 0;
997
998         sdp->sd_quota_sync_gen++;
999
1000         qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1001         if (!qda)
1002                 return -ENOMEM;
1003
1004         do {
1005                 num_qd = 0;
1006
1007                 for (;;) {
1008                         error = qd_fish(sdp, qda + num_qd);
1009                         if (error || !qda[num_qd])
1010                                 break;
1011                         if (++num_qd == max_qd)
1012                                 break;
1013                 }
1014
1015                 if (num_qd) {
1016                         if (!error)
1017                                 error = do_sync(num_qd, qda);
1018                         if (!error)
1019                                 for (x = 0; x < num_qd; x++)
1020                                         qda[x]->qd_sync_gen =
1021                                                 sdp->sd_quota_sync_gen;
1022
1023                         for (x = 0; x < num_qd; x++)
1024                                 qd_unlock(qda[x]);
1025                 }
1026         } while (!error && num_qd == max_qd);
1027
1028         kfree(qda);
1029
1030         return error;
1031 }
1032
1033 int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, u32 id)
1034 {
1035         struct gfs2_quota_data *qd;
1036         struct gfs2_holder q_gh;
1037         int error;
1038
1039         error = qd_get(sdp, user, id, CREATE, &qd);
1040         if (error)
1041                 return error;
1042
1043         error = do_glock(qd, FORCE, &q_gh);
1044         if (!error)
1045                 gfs2_glock_dq_uninit(&q_gh);
1046
1047         qd_put(qd);
1048
1049         return error;
1050 }
1051
1052 int gfs2_quota_init(struct gfs2_sbd *sdp)
1053 {
1054         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1055         unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
1056         unsigned int x, slot = 0;
1057         unsigned int found = 0;
1058         u64 dblock;
1059         u32 extlen = 0;
1060         int error;
1061
1062         if (!ip->i_di.di_size ||
1063             ip->i_di.di_size > (64 << 20) ||
1064             ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
1065                 gfs2_consist_inode(ip);
1066                 return -EIO;            
1067         }
1068         sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1069         sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1070
1071         error = -ENOMEM;
1072
1073         sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1074                                        sizeof(unsigned char *), GFP_KERNEL);
1075         if (!sdp->sd_quota_bitmap)
1076                 return error;
1077
1078         for (x = 0; x < sdp->sd_quota_chunks; x++) {
1079                 sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL);
1080                 if (!sdp->sd_quota_bitmap[x])
1081                         goto fail;
1082         }
1083
1084         for (x = 0; x < blocks; x++) {
1085                 struct buffer_head *bh;
1086                 unsigned int y;
1087
1088                 if (!extlen) {
1089                         int new = 0;
1090                         error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1091                         if (error)
1092                                 goto fail;
1093                 }
1094                 gfs2_meta_ra(ip->i_gl,  dblock, extlen);
1095                 error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT,
1096                                        &bh);
1097                 if (error)
1098                         goto fail;
1099                 error = -EIO;
1100                 if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1101                         brelse(bh);
1102                         goto fail;
1103                 }
1104
1105                 for (y = 0;
1106                      y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1107                      y++, slot++) {
1108                         struct gfs2_quota_change qc;
1109                         struct gfs2_quota_data *qd;
1110
1111                         gfs2_quota_change_in(&qc, bh->b_data +
1112                                           sizeof(struct gfs2_meta_header) +
1113                                           y * sizeof(struct gfs2_quota_change));
1114                         if (!qc.qc_change)
1115                                 continue;
1116
1117                         error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1118                                          qc.qc_id, &qd);
1119                         if (error) {
1120                                 brelse(bh);
1121                                 goto fail;
1122                         }
1123
1124                         set_bit(QDF_CHANGE, &qd->qd_flags);
1125                         qd->qd_change = qc.qc_change;
1126                         qd->qd_slot = slot;
1127                         qd->qd_slot_count = 1;
1128                         qd->qd_last_touched = jiffies;
1129
1130                         spin_lock(&sdp->sd_quota_spin);
1131                         gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1132                         list_add(&qd->qd_list, &sdp->sd_quota_list);
1133                         atomic_inc(&sdp->sd_quota_count);
1134                         spin_unlock(&sdp->sd_quota_spin);
1135
1136                         found++;
1137                 }
1138
1139                 brelse(bh);
1140                 dblock++;
1141                 extlen--;
1142         }
1143
1144         if (found)
1145                 fs_info(sdp, "found %u quota changes\n", found);
1146
1147         return 0;
1148
1149 fail:
1150         gfs2_quota_cleanup(sdp);
1151         return error;
1152 }
1153
1154 void gfs2_quota_scan(struct gfs2_sbd *sdp)
1155 {
1156         struct gfs2_quota_data *qd, *safe;
1157         LIST_HEAD(dead);
1158
1159         spin_lock(&sdp->sd_quota_spin);
1160         list_for_each_entry_safe(qd, safe, &sdp->sd_quota_list, qd_list) {
1161                 if (!qd->qd_count &&
1162                     time_after_eq(jiffies, qd->qd_last_touched +
1163                                 gfs2_tune_get(sdp, gt_quota_cache_secs) * HZ)) {
1164                         list_move(&qd->qd_list, &dead);
1165                         gfs2_assert_warn(sdp,
1166                                          atomic_read(&sdp->sd_quota_count) > 0);
1167                         atomic_dec(&sdp->sd_quota_count);
1168                 }
1169         }
1170         spin_unlock(&sdp->sd_quota_spin);
1171
1172         while (!list_empty(&dead)) {
1173                 qd = list_entry(dead.next, struct gfs2_quota_data, qd_list);
1174                 list_del(&qd->qd_list);
1175
1176                 gfs2_assert_warn(sdp, !qd->qd_change);
1177                 gfs2_assert_warn(sdp, !qd->qd_slot_count);
1178                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
1179
1180                 gfs2_lvb_unhold(qd->qd_gl);
1181                 kfree(qd);
1182         }
1183 }
1184
1185 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1186 {
1187         struct list_head *head = &sdp->sd_quota_list;
1188         struct gfs2_quota_data *qd;
1189         unsigned int x;
1190
1191         spin_lock(&sdp->sd_quota_spin);
1192         while (!list_empty(head)) {
1193                 qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1194
1195                 if (qd->qd_count > 1 ||
1196                     (qd->qd_count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1197                         list_move(&qd->qd_list, head);
1198                         spin_unlock(&sdp->sd_quota_spin);
1199                         schedule();
1200                         spin_lock(&sdp->sd_quota_spin);
1201                         continue;
1202                 }
1203
1204                 list_del(&qd->qd_list);
1205                 atomic_dec(&sdp->sd_quota_count);
1206                 spin_unlock(&sdp->sd_quota_spin);
1207
1208                 if (!qd->qd_count) {
1209                         gfs2_assert_warn(sdp, !qd->qd_change);
1210                         gfs2_assert_warn(sdp, !qd->qd_slot_count);
1211                 } else
1212                         gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1213                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
1214
1215                 gfs2_lvb_unhold(qd->qd_gl);
1216                 kfree(qd);
1217
1218                 spin_lock(&sdp->sd_quota_spin);
1219         }
1220         spin_unlock(&sdp->sd_quota_spin);
1221
1222         gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1223
1224         if (sdp->sd_quota_bitmap) {
1225                 for (x = 0; x < sdp->sd_quota_chunks; x++)
1226                         kfree(sdp->sd_quota_bitmap[x]);
1227                 kfree(sdp->sd_quota_bitmap);
1228         }
1229 }
1230