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TOMOYO Linux Cross Reference
Linux/fs/gfs2/quota.c

Version: ~ [ linux-5.9 ] ~ [ linux-5.8.14 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.70 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.150 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.200 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.238 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.238 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
  3  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
  4  *
  5  * This copyrighted material is made available to anyone wishing to use,
  6  * modify, copy, or redistribute it subject to the terms and conditions
  7  * of the GNU General Public License version 2.
  8  */
  9 
 10 /*
 11  * Quota change tags are associated with each transaction that allocates or
 12  * deallocates space.  Those changes are accumulated locally to each node (in a
 13  * per-node file) and then are periodically synced to the quota file.  This
 14  * avoids the bottleneck of constantly touching the quota file, but introduces
 15  * fuzziness in the current usage value of IDs that are being used on different
 16  * nodes in the cluster simultaneously.  So, it is possible for a user on
 17  * multiple nodes to overrun their quota, but that overrun is controlable.
 18  * Since quota tags are part of transactions, there is no need for a quota check
 19  * program to be run on node crashes or anything like that.
 20  *
 21  * There are couple of knobs that let the administrator manage the quota
 22  * fuzziness.  "quota_quantum" sets the maximum time a quota change can be
 23  * sitting on one node before being synced to the quota file.  (The default is
 24  * 60 seconds.)  Another knob, "quota_scale" controls how quickly the frequency
 25  * of quota file syncs increases as the user moves closer to their limit.  The
 26  * more frequent the syncs, the more accurate the quota enforcement, but that
 27  * means that there is more contention between the nodes for the quota file.
 28  * The default value is one.  This sets the maximum theoretical quota overrun
 29  * (with infinite node with infinite bandwidth) to twice the user's limit.  (In
 30  * practice, the maximum overrun you see should be much less.)  A "quota_scale"
 31  * number greater than one makes quota syncs more frequent and reduces the
 32  * maximum overrun.  Numbers less than one (but greater than zero) make quota
 33  * syncs less frequent.
 34  *
 35  * GFS quotas also use per-ID Lock Value Blocks (LVBs) to cache the contents of
 36  * the quota file, so it is not being constantly read.
 37  */
 38 
 39 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 40 
 41 #include <linux/sched.h>
 42 #include <linux/slab.h>
 43 #include <linux/mm.h>
 44 #include <linux/spinlock.h>
 45 #include <linux/completion.h>
 46 #include <linux/buffer_head.h>
 47 #include <linux/sort.h>
 48 #include <linux/fs.h>
 49 #include <linux/bio.h>
 50 #include <linux/gfs2_ondisk.h>
 51 #include <linux/kthread.h>
 52 #include <linux/freezer.h>
 53 #include <linux/quota.h>
 54 #include <linux/dqblk_xfs.h>
 55 #include <linux/lockref.h>
 56 #include <linux/list_lru.h>
 57 #include <linux/rcupdate.h>
 58 #include <linux/rculist_bl.h>
 59 #include <linux/bit_spinlock.h>
 60 #include <linux/jhash.h>
 61 #include <linux/vmalloc.h>
 62 
 63 #include "gfs2.h"
 64 #include "incore.h"
 65 #include "bmap.h"
 66 #include "glock.h"
 67 #include "glops.h"
 68 #include "log.h"
 69 #include "meta_io.h"
 70 #include "quota.h"
 71 #include "rgrp.h"
 72 #include "super.h"
 73 #include "trans.h"
 74 #include "inode.h"
 75 #include "util.h"
 76 
 77 #define GFS2_QD_HASH_SHIFT      12
 78 #define GFS2_QD_HASH_SIZE       (1 << GFS2_QD_HASH_SHIFT)
 79 #define GFS2_QD_HASH_MASK       (GFS2_QD_HASH_SIZE - 1)
 80 
 81 /* Lock order: qd_lock -> bucket lock -> qd->lockref.lock -> lru lock */
 82 /*                     -> sd_bitmap_lock                              */
 83 static DEFINE_SPINLOCK(qd_lock);
 84 struct list_lru gfs2_qd_lru;
 85 
 86 static struct hlist_bl_head qd_hash_table[GFS2_QD_HASH_SIZE];
 87 
 88 static unsigned int gfs2_qd_hash(const struct gfs2_sbd *sdp,
 89                                  const struct kqid qid)
 90 {
 91         unsigned int h;
 92 
 93         h = jhash(&sdp, sizeof(struct gfs2_sbd *), 0);
 94         h = jhash(&qid, sizeof(struct kqid), h);
 95 
 96         return h & GFS2_QD_HASH_MASK;
 97 }
 98 
 99 static inline void spin_lock_bucket(unsigned int hash)
100 {
101         hlist_bl_lock(&qd_hash_table[hash]);
102 }
103 
104 static inline void spin_unlock_bucket(unsigned int hash)
105 {
106         hlist_bl_unlock(&qd_hash_table[hash]);
107 }
108 
109 static void gfs2_qd_dealloc(struct rcu_head *rcu)
110 {
111         struct gfs2_quota_data *qd = container_of(rcu, struct gfs2_quota_data, qd_rcu);
112         kmem_cache_free(gfs2_quotad_cachep, qd);
113 }
114 
115 static void gfs2_qd_dispose(struct list_head *list)
116 {
117         struct gfs2_quota_data *qd;
118         struct gfs2_sbd *sdp;
119 
120         while (!list_empty(list)) {
121                 qd = list_entry(list->next, struct gfs2_quota_data, qd_lru);
122                 sdp = qd->qd_gl->gl_sbd;
123 
124                 list_del(&qd->qd_lru);
125 
126                 /* Free from the filesystem-specific list */
127                 spin_lock(&qd_lock);
128                 list_del(&qd->qd_list);
129                 spin_unlock(&qd_lock);
130 
131                 spin_lock_bucket(qd->qd_hash);
132                 hlist_bl_del_rcu(&qd->qd_hlist);
133                 spin_unlock_bucket(qd->qd_hash);
134 
135                 gfs2_assert_warn(sdp, !qd->qd_change);
136                 gfs2_assert_warn(sdp, !qd->qd_slot_count);
137                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
138 
139                 gfs2_glock_put(qd->qd_gl);
140                 atomic_dec(&sdp->sd_quota_count);
141 
142                 /* Delete it from the common reclaim list */
143                 call_rcu(&qd->qd_rcu, gfs2_qd_dealloc);
144         }
145 }
146 
147 
148 static enum lru_status gfs2_qd_isolate(struct list_head *item, spinlock_t *lock, void *arg)
149 {
150         struct list_head *dispose = arg;
151         struct gfs2_quota_data *qd = list_entry(item, struct gfs2_quota_data, qd_lru);
152 
153         if (!spin_trylock(&qd->qd_lockref.lock))
154                 return LRU_SKIP;
155 
156         if (qd->qd_lockref.count == 0) {
157                 lockref_mark_dead(&qd->qd_lockref);
158                 list_move(&qd->qd_lru, dispose);
159         }
160 
161         spin_unlock(&qd->qd_lockref.lock);
162         return LRU_REMOVED;
163 }
164 
165 static unsigned long gfs2_qd_shrink_scan(struct shrinker *shrink,
166                                          struct shrink_control *sc)
167 {
168         LIST_HEAD(dispose);
169         unsigned long freed;
170 
171         if (!(sc->gfp_mask & __GFP_FS))
172                 return SHRINK_STOP;
173 
174         freed = list_lru_walk_node(&gfs2_qd_lru, sc->nid, gfs2_qd_isolate,
175                                    &dispose, &sc->nr_to_scan);
176 
177         gfs2_qd_dispose(&dispose);
178 
179         return freed;
180 }
181 
182 static unsigned long gfs2_qd_shrink_count(struct shrinker *shrink,
183                                           struct shrink_control *sc)
184 {
185         return vfs_pressure_ratio(list_lru_count_node(&gfs2_qd_lru, sc->nid));
186 }
187 
188 struct shrinker gfs2_qd_shrinker = {
189         .count_objects = gfs2_qd_shrink_count,
190         .scan_objects = gfs2_qd_shrink_scan,
191         .seeks = DEFAULT_SEEKS,
192         .flags = SHRINKER_NUMA_AWARE,
193 };
194 
195 
196 static u64 qd2index(struct gfs2_quota_data *qd)
197 {
198         struct kqid qid = qd->qd_id;
199         return (2 * (u64)from_kqid(&init_user_ns, qid)) +
200                 ((qid.type == USRQUOTA) ? 0 : 1);
201 }
202 
203 static u64 qd2offset(struct gfs2_quota_data *qd)
204 {
205         u64 offset;
206 
207         offset = qd2index(qd);
208         offset *= sizeof(struct gfs2_quota);
209 
210         return offset;
211 }
212 
213 static struct gfs2_quota_data *qd_alloc(unsigned hash, struct gfs2_sbd *sdp, struct kqid qid)
214 {
215         struct gfs2_quota_data *qd;
216         int error;
217 
218         qd = kmem_cache_zalloc(gfs2_quotad_cachep, GFP_NOFS);
219         if (!qd)
220                 return NULL;
221 
222         qd->qd_sbd = sdp;
223         qd->qd_lockref.count = 1;
224         spin_lock_init(&qd->qd_lockref.lock);
225         qd->qd_id = qid;
226         qd->qd_slot = -1;
227         INIT_LIST_HEAD(&qd->qd_lru);
228         qd->qd_hash = hash;
229 
230         error = gfs2_glock_get(sdp, qd2index(qd),
231                               &gfs2_quota_glops, CREATE, &qd->qd_gl);
232         if (error)
233                 goto fail;
234 
235         return qd;
236 
237 fail:
238         kmem_cache_free(gfs2_quotad_cachep, qd);
239         return NULL;
240 }
241 
242 static struct gfs2_quota_data *gfs2_qd_search_bucket(unsigned int hash,
243                                                      const struct gfs2_sbd *sdp,
244                                                      struct kqid qid)
245 {
246         struct gfs2_quota_data *qd;
247         struct hlist_bl_node *h;
248 
249         hlist_bl_for_each_entry_rcu(qd, h, &qd_hash_table[hash], qd_hlist) {
250                 if (!qid_eq(qd->qd_id, qid))
251                         continue;
252                 if (qd->qd_sbd != sdp)
253                         continue;
254                 if (lockref_get_not_dead(&qd->qd_lockref)) {
255                         list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
256                         return qd;
257                 }
258         }
259 
260         return NULL;
261 }
262 
263 
264 static int qd_get(struct gfs2_sbd *sdp, struct kqid qid,
265                   struct gfs2_quota_data **qdp)
266 {
267         struct gfs2_quota_data *qd, *new_qd;
268         unsigned int hash = gfs2_qd_hash(sdp, qid);
269 
270         rcu_read_lock();
271         *qdp = qd = gfs2_qd_search_bucket(hash, sdp, qid);
272         rcu_read_unlock();
273 
274         if (qd)
275                 return 0;
276 
277         new_qd = qd_alloc(hash, sdp, qid);
278         if (!new_qd)
279                 return -ENOMEM;
280 
281         spin_lock(&qd_lock);
282         spin_lock_bucket(hash);
283         *qdp = qd = gfs2_qd_search_bucket(hash, sdp, qid);
284         if (qd == NULL) {
285                 *qdp = new_qd;
286                 list_add(&new_qd->qd_list, &sdp->sd_quota_list);
287                 hlist_bl_add_head_rcu(&new_qd->qd_hlist, &qd_hash_table[hash]);
288                 atomic_inc(&sdp->sd_quota_count);
289         }
290         spin_unlock_bucket(hash);
291         spin_unlock(&qd_lock);
292 
293         if (qd) {
294                 gfs2_glock_put(new_qd->qd_gl);
295                 kmem_cache_free(gfs2_quotad_cachep, new_qd);
296         }
297 
298         return 0;
299 }
300 
301 
302 static void qd_hold(struct gfs2_quota_data *qd)
303 {
304         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
305         gfs2_assert(sdp, !__lockref_is_dead(&qd->qd_lockref));
306         lockref_get(&qd->qd_lockref);
307 }
308 
309 static void qd_put(struct gfs2_quota_data *qd)
310 {
311         if (lockref_put_or_lock(&qd->qd_lockref))
312                 return;
313 
314         qd->qd_lockref.count = 0;
315         list_lru_add(&gfs2_qd_lru, &qd->qd_lru);
316         spin_unlock(&qd->qd_lockref.lock);
317 
318 }
319 
320 static int slot_get(struct gfs2_quota_data *qd)
321 {
322         struct gfs2_sbd *sdp = qd->qd_sbd;
323         unsigned int bit;
324         int error = 0;
325 
326         spin_lock(&sdp->sd_bitmap_lock);
327         if (qd->qd_slot_count != 0)
328                 goto out;
329 
330         error = -ENOSPC;
331         bit = find_first_zero_bit(sdp->sd_quota_bitmap, sdp->sd_quota_slots);
332         if (bit < sdp->sd_quota_slots) {
333                 set_bit(bit, sdp->sd_quota_bitmap);
334                 qd->qd_slot = bit;
335                 error = 0;
336 out:
337                 qd->qd_slot_count++;
338         }
339         spin_unlock(&sdp->sd_bitmap_lock);
340 
341         return error;
342 }
343 
344 static void slot_hold(struct gfs2_quota_data *qd)
345 {
346         struct gfs2_sbd *sdp = qd->qd_sbd;
347 
348         spin_lock(&sdp->sd_bitmap_lock);
349         gfs2_assert(sdp, qd->qd_slot_count);
350         qd->qd_slot_count++;
351         spin_unlock(&sdp->sd_bitmap_lock);
352 }
353 
354 static void slot_put(struct gfs2_quota_data *qd)
355 {
356         struct gfs2_sbd *sdp = qd->qd_sbd;
357 
358         spin_lock(&sdp->sd_bitmap_lock);
359         gfs2_assert(sdp, qd->qd_slot_count);
360         if (!--qd->qd_slot_count) {
361                 BUG_ON(!test_and_clear_bit(qd->qd_slot, sdp->sd_quota_bitmap));
362                 qd->qd_slot = -1;
363         }
364         spin_unlock(&sdp->sd_bitmap_lock);
365 }
366 
367 static int bh_get(struct gfs2_quota_data *qd)
368 {
369         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
370         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
371         unsigned int block, offset;
372         struct buffer_head *bh;
373         int error;
374         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
375 
376         mutex_lock(&sdp->sd_quota_mutex);
377 
378         if (qd->qd_bh_count++) {
379                 mutex_unlock(&sdp->sd_quota_mutex);
380                 return 0;
381         }
382 
383         block = qd->qd_slot / sdp->sd_qc_per_block;
384         offset = qd->qd_slot % sdp->sd_qc_per_block;
385 
386         bh_map.b_size = 1 << ip->i_inode.i_blkbits;
387         error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
388         if (error)
389                 goto fail;
390         error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
391         if (error)
392                 goto fail;
393         error = -EIO;
394         if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
395                 goto fail_brelse;
396 
397         qd->qd_bh = bh;
398         qd->qd_bh_qc = (struct gfs2_quota_change *)
399                 (bh->b_data + sizeof(struct gfs2_meta_header) +
400                  offset * sizeof(struct gfs2_quota_change));
401 
402         mutex_unlock(&sdp->sd_quota_mutex);
403 
404         return 0;
405 
406 fail_brelse:
407         brelse(bh);
408 fail:
409         qd->qd_bh_count--;
410         mutex_unlock(&sdp->sd_quota_mutex);
411         return error;
412 }
413 
414 static void bh_put(struct gfs2_quota_data *qd)
415 {
416         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
417 
418         mutex_lock(&sdp->sd_quota_mutex);
419         gfs2_assert(sdp, qd->qd_bh_count);
420         if (!--qd->qd_bh_count) {
421                 brelse(qd->qd_bh);
422                 qd->qd_bh = NULL;
423                 qd->qd_bh_qc = NULL;
424         }
425         mutex_unlock(&sdp->sd_quota_mutex);
426 }
427 
428 static int qd_check_sync(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd,
429                          u64 *sync_gen)
430 {
431         if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
432             !test_bit(QDF_CHANGE, &qd->qd_flags) ||
433             (sync_gen && (qd->qd_sync_gen >= *sync_gen)))
434                 return 0;
435 
436         if (!lockref_get_not_dead(&qd->qd_lockref))
437                 return 0;
438 
439         list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
440         set_bit(QDF_LOCKED, &qd->qd_flags);
441         qd->qd_change_sync = qd->qd_change;
442         slot_hold(qd);
443         return 1;
444 }
445 
446 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
447 {
448         struct gfs2_quota_data *qd = NULL;
449         int error;
450         int found = 0;
451 
452         *qdp = NULL;
453 
454         if (sdp->sd_vfs->s_flags & MS_RDONLY)
455                 return 0;
456 
457         spin_lock(&qd_lock);
458 
459         list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
460                 found = qd_check_sync(sdp, qd, &sdp->sd_quota_sync_gen);
461                 if (found)
462                         break;
463         }
464 
465         if (!found)
466                 qd = NULL;
467 
468         spin_unlock(&qd_lock);
469 
470         if (qd) {
471                 gfs2_assert_warn(sdp, qd->qd_change_sync);
472                 error = bh_get(qd);
473                 if (error) {
474                         clear_bit(QDF_LOCKED, &qd->qd_flags);
475                         slot_put(qd);
476                         qd_put(qd);
477                         return error;
478                 }
479         }
480 
481         *qdp = qd;
482 
483         return 0;
484 }
485 
486 static void qd_unlock(struct gfs2_quota_data *qd)
487 {
488         gfs2_assert_warn(qd->qd_gl->gl_sbd,
489                          test_bit(QDF_LOCKED, &qd->qd_flags));
490         clear_bit(QDF_LOCKED, &qd->qd_flags);
491         bh_put(qd);
492         slot_put(qd);
493         qd_put(qd);
494 }
495 
496 static int qdsb_get(struct gfs2_sbd *sdp, struct kqid qid,
497                     struct gfs2_quota_data **qdp)
498 {
499         int error;
500 
501         error = qd_get(sdp, qid, qdp);
502         if (error)
503                 return error;
504 
505         error = slot_get(*qdp);
506         if (error)
507                 goto fail;
508 
509         error = bh_get(*qdp);
510         if (error)
511                 goto fail_slot;
512 
513         return 0;
514 
515 fail_slot:
516         slot_put(*qdp);
517 fail:
518         qd_put(*qdp);
519         return error;
520 }
521 
522 static void qdsb_put(struct gfs2_quota_data *qd)
523 {
524         bh_put(qd);
525         slot_put(qd);
526         qd_put(qd);
527 }
528 
529 int gfs2_quota_hold(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
530 {
531         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
532         struct gfs2_quota_data **qd;
533         int error;
534 
535         if (ip->i_res == NULL) {
536                 error = gfs2_rs_alloc(ip);
537                 if (error)
538                         return error;
539         }
540 
541         qd = ip->i_res->rs_qa_qd;
542 
543         if (gfs2_assert_warn(sdp, !ip->i_res->rs_qa_qd_num) ||
544             gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
545                 return -EIO;
546 
547         if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
548                 return 0;
549 
550         error = qdsb_get(sdp, make_kqid_uid(ip->i_inode.i_uid), qd);
551         if (error)
552                 goto out;
553         ip->i_res->rs_qa_qd_num++;
554         qd++;
555 
556         error = qdsb_get(sdp, make_kqid_gid(ip->i_inode.i_gid), qd);
557         if (error)
558                 goto out;
559         ip->i_res->rs_qa_qd_num++;
560         qd++;
561 
562         if (!uid_eq(uid, NO_UID_QUOTA_CHANGE) &&
563             !uid_eq(uid, ip->i_inode.i_uid)) {
564                 error = qdsb_get(sdp, make_kqid_uid(uid), qd);
565                 if (error)
566                         goto out;
567                 ip->i_res->rs_qa_qd_num++;
568                 qd++;
569         }
570 
571         if (!gid_eq(gid, NO_GID_QUOTA_CHANGE) &&
572             !gid_eq(gid, ip->i_inode.i_gid)) {
573                 error = qdsb_get(sdp, make_kqid_gid(gid), qd);
574                 if (error)
575                         goto out;
576                 ip->i_res->rs_qa_qd_num++;
577                 qd++;
578         }
579 
580 out:
581         if (error)
582                 gfs2_quota_unhold(ip);
583         return error;
584 }
585 
586 void gfs2_quota_unhold(struct gfs2_inode *ip)
587 {
588         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
589         unsigned int x;
590 
591         if (ip->i_res == NULL)
592                 return;
593         gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
594 
595         for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
596                 qdsb_put(ip->i_res->rs_qa_qd[x]);
597                 ip->i_res->rs_qa_qd[x] = NULL;
598         }
599         ip->i_res->rs_qa_qd_num = 0;
600 }
601 
602 static int sort_qd(const void *a, const void *b)
603 {
604         const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
605         const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
606 
607         if (qid_lt(qd_a->qd_id, qd_b->qd_id))
608                 return -1;
609         if (qid_lt(qd_b->qd_id, qd_a->qd_id))
610                 return 1;
611         return 0;
612 }
613 
614 static void do_qc(struct gfs2_quota_data *qd, s64 change)
615 {
616         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
617         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
618         struct gfs2_quota_change *qc = qd->qd_bh_qc;
619         s64 x;
620 
621         mutex_lock(&sdp->sd_quota_mutex);
622         gfs2_trans_add_meta(ip->i_gl, qd->qd_bh);
623 
624         if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
625                 qc->qc_change = 0;
626                 qc->qc_flags = 0;
627                 if (qd->qd_id.type == USRQUOTA)
628                         qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
629                 qc->qc_id = cpu_to_be32(from_kqid(&init_user_ns, qd->qd_id));
630         }
631 
632         x = be64_to_cpu(qc->qc_change) + change;
633         qc->qc_change = cpu_to_be64(x);
634 
635         spin_lock(&qd_lock);
636         qd->qd_change = x;
637         spin_unlock(&qd_lock);
638 
639         if (!x) {
640                 gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
641                 clear_bit(QDF_CHANGE, &qd->qd_flags);
642                 qc->qc_flags = 0;
643                 qc->qc_id = 0;
644                 slot_put(qd);
645                 qd_put(qd);
646         } else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
647                 qd_hold(qd);
648                 slot_hold(qd);
649         }
650 
651         mutex_unlock(&sdp->sd_quota_mutex);
652 }
653 
654 /**
655  * gfs2_adjust_quota - adjust record of current block usage
656  * @ip: The quota inode
657  * @loc: Offset of the entry in the quota file
658  * @change: The amount of usage change to record
659  * @qd: The quota data
660  * @fdq: The updated limits to record
661  *
662  * This function was mostly borrowed from gfs2_block_truncate_page which was
663  * in turn mostly borrowed from ext3
664  *
665  * Returns: 0 or -ve on error
666  */
667 
668 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
669                              s64 change, struct gfs2_quota_data *qd,
670                              struct fs_disk_quota *fdq)
671 {
672         struct inode *inode = &ip->i_inode;
673         struct gfs2_sbd *sdp = GFS2_SB(inode);
674         struct address_space *mapping = inode->i_mapping;
675         unsigned long index = loc >> PAGE_CACHE_SHIFT;
676         unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
677         unsigned blocksize, iblock, pos;
678         struct buffer_head *bh;
679         struct page *page;
680         void *kaddr, *ptr;
681         struct gfs2_quota q;
682         int err, nbytes;
683         u64 size;
684 
685         if (gfs2_is_stuffed(ip)) {
686                 err = gfs2_unstuff_dinode(ip, NULL);
687                 if (err)
688                         return err;
689         }
690 
691         memset(&q, 0, sizeof(struct gfs2_quota));
692         err = gfs2_internal_read(ip, (char *)&q, &loc, sizeof(q));
693         if (err < 0)
694                 return err;
695 
696         err = -EIO;
697         be64_add_cpu(&q.qu_value, change);
698         qd->qd_qb.qb_value = q.qu_value;
699         if (fdq) {
700                 if (fdq->d_fieldmask & FS_DQ_BSOFT) {
701                         q.qu_warn = cpu_to_be64(fdq->d_blk_softlimit >> sdp->sd_fsb2bb_shift);
702                         qd->qd_qb.qb_warn = q.qu_warn;
703                 }
704                 if (fdq->d_fieldmask & FS_DQ_BHARD) {
705                         q.qu_limit = cpu_to_be64(fdq->d_blk_hardlimit >> sdp->sd_fsb2bb_shift);
706                         qd->qd_qb.qb_limit = q.qu_limit;
707                 }
708                 if (fdq->d_fieldmask & FS_DQ_BCOUNT) {
709                         q.qu_value = cpu_to_be64(fdq->d_bcount >> sdp->sd_fsb2bb_shift);
710                         qd->qd_qb.qb_value = q.qu_value;
711                 }
712         }
713 
714         /* Write the quota into the quota file on disk */
715         ptr = &q;
716         nbytes = sizeof(struct gfs2_quota);
717 get_a_page:
718         page = find_or_create_page(mapping, index, GFP_NOFS);
719         if (!page)
720                 return -ENOMEM;
721 
722         blocksize = inode->i_sb->s_blocksize;
723         iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
724 
725         if (!page_has_buffers(page))
726                 create_empty_buffers(page, blocksize, 0);
727 
728         bh = page_buffers(page);
729         pos = blocksize;
730         while (offset >= pos) {
731                 bh = bh->b_this_page;
732                 iblock++;
733                 pos += blocksize;
734         }
735 
736         if (!buffer_mapped(bh)) {
737                 gfs2_block_map(inode, iblock, bh, 1);
738                 if (!buffer_mapped(bh))
739                         goto unlock_out;
740                 /* If it's a newly allocated disk block for quota, zero it */
741                 if (buffer_new(bh))
742                         zero_user(page, pos - blocksize, bh->b_size);
743         }
744 
745         if (PageUptodate(page))
746                 set_buffer_uptodate(bh);
747 
748         if (!buffer_uptodate(bh)) {
749                 ll_rw_block(READ | REQ_META, 1, &bh);
750                 wait_on_buffer(bh);
751                 if (!buffer_uptodate(bh))
752                         goto unlock_out;
753         }
754 
755         gfs2_trans_add_data(ip->i_gl, bh);
756 
757         kaddr = kmap_atomic(page);
758         if (offset + sizeof(struct gfs2_quota) > PAGE_CACHE_SIZE)
759                 nbytes = PAGE_CACHE_SIZE - offset;
760         memcpy(kaddr + offset, ptr, nbytes);
761         flush_dcache_page(page);
762         kunmap_atomic(kaddr);
763         unlock_page(page);
764         page_cache_release(page);
765 
766         /* If quota straddles page boundary, we need to update the rest of the
767          * quota at the beginning of the next page */
768         if ((offset + sizeof(struct gfs2_quota)) > PAGE_CACHE_SIZE) {
769                 ptr = ptr + nbytes;
770                 nbytes = sizeof(struct gfs2_quota) - nbytes;
771                 offset = 0;
772                 index++;
773                 goto get_a_page;
774         }
775 
776         size = loc + sizeof(struct gfs2_quota);
777         if (size > inode->i_size)
778                 i_size_write(inode, size);
779         inode->i_mtime = inode->i_atime = CURRENT_TIME;
780         mark_inode_dirty(inode);
781         return 0;
782 
783 unlock_out:
784         unlock_page(page);
785         page_cache_release(page);
786         return err;
787 }
788 
789 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
790 {
791         struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
792         struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
793         struct gfs2_alloc_parms ap = { .aflags = 0, };
794         unsigned int data_blocks, ind_blocks;
795         struct gfs2_holder *ghs, i_gh;
796         unsigned int qx, x;
797         struct gfs2_quota_data *qd;
798         unsigned reserved;
799         loff_t offset;
800         unsigned int nalloc = 0, blocks;
801         int error;
802 
803         error = gfs2_rs_alloc(ip);
804         if (error)
805                 return error;
806 
807         gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
808                               &data_blocks, &ind_blocks);
809 
810         ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
811         if (!ghs)
812                 return -ENOMEM;
813 
814         sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
815         mutex_lock(&ip->i_inode.i_mutex);
816         for (qx = 0; qx < num_qd; qx++) {
817                 error = gfs2_glock_nq_init(qda[qx]->qd_gl, LM_ST_EXCLUSIVE,
818                                            GL_NOCACHE, &ghs[qx]);
819                 if (error)
820                         goto out;
821         }
822 
823         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
824         if (error)
825                 goto out;
826 
827         for (x = 0; x < num_qd; x++) {
828                 offset = qd2offset(qda[x]);
829                 if (gfs2_write_alloc_required(ip, offset,
830                                               sizeof(struct gfs2_quota)))
831                         nalloc++;
832         }
833 
834         /* 
835          * 1 blk for unstuffing inode if stuffed. We add this extra
836          * block to the reservation unconditionally. If the inode
837          * doesn't need unstuffing, the block will be released to the 
838          * rgrp since it won't be allocated during the transaction
839          */
840         /* +3 in the end for unstuffing block, inode size update block
841          * and another block in case quota straddles page boundary and 
842          * two blocks need to be updated instead of 1 */
843         blocks = num_qd * data_blocks + RES_DINODE + num_qd + 3;
844 
845         reserved = 1 + (nalloc * (data_blocks + ind_blocks));
846         ap.target = reserved;
847         error = gfs2_inplace_reserve(ip, &ap);
848         if (error)
849                 goto out_alloc;
850 
851         if (nalloc)
852                 blocks += gfs2_rg_blocks(ip, reserved) + nalloc * ind_blocks + RES_STATFS;
853 
854         error = gfs2_trans_begin(sdp, blocks, 0);
855         if (error)
856                 goto out_ipres;
857 
858         for (x = 0; x < num_qd; x++) {
859                 qd = qda[x];
860                 offset = qd2offset(qd);
861                 error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync, qd, NULL);
862                 if (error)
863                         goto out_end_trans;
864 
865                 do_qc(qd, -qd->qd_change_sync);
866                 set_bit(QDF_REFRESH, &qd->qd_flags);
867         }
868 
869         error = 0;
870 
871 out_end_trans:
872         gfs2_trans_end(sdp);
873 out_ipres:
874         gfs2_inplace_release(ip);
875 out_alloc:
876         gfs2_glock_dq_uninit(&i_gh);
877 out:
878         while (qx--)
879                 gfs2_glock_dq_uninit(&ghs[qx]);
880         mutex_unlock(&ip->i_inode.i_mutex);
881         kfree(ghs);
882         gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
883         return error;
884 }
885 
886 static int update_qd(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd)
887 {
888         struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
889         struct gfs2_quota q;
890         struct gfs2_quota_lvb *qlvb;
891         loff_t pos;
892         int error;
893 
894         memset(&q, 0, sizeof(struct gfs2_quota));
895         pos = qd2offset(qd);
896         error = gfs2_internal_read(ip, (char *)&q, &pos, sizeof(q));
897         if (error < 0)
898                 return error;
899 
900         qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
901         qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
902         qlvb->__pad = 0;
903         qlvb->qb_limit = q.qu_limit;
904         qlvb->qb_warn = q.qu_warn;
905         qlvb->qb_value = q.qu_value;
906         qd->qd_qb = *qlvb;
907 
908         return 0;
909 }
910 
911 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
912                     struct gfs2_holder *q_gh)
913 {
914         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
915         struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
916         struct gfs2_holder i_gh;
917         int error;
918 
919 restart:
920         error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
921         if (error)
922                 return error;
923 
924         qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
925 
926         if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
927                 gfs2_glock_dq_uninit(q_gh);
928                 error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE,
929                                            GL_NOCACHE, q_gh);
930                 if (error)
931                         return error;
932 
933                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
934                 if (error)
935                         goto fail;
936 
937                 error = update_qd(sdp, qd);
938                 if (error)
939                         goto fail_gunlock;
940 
941                 gfs2_glock_dq_uninit(&i_gh);
942                 gfs2_glock_dq_uninit(q_gh);
943                 force_refresh = 0;
944                 goto restart;
945         }
946 
947         return 0;
948 
949 fail_gunlock:
950         gfs2_glock_dq_uninit(&i_gh);
951 fail:
952         gfs2_glock_dq_uninit(q_gh);
953         return error;
954 }
955 
956 int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
957 {
958         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
959         struct gfs2_quota_data *qd;
960         unsigned int x;
961         int error = 0;
962 
963         error = gfs2_quota_hold(ip, uid, gid);
964         if (error)
965                 return error;
966 
967         if (capable(CAP_SYS_RESOURCE) ||
968             sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
969                 return 0;
970 
971         sort(ip->i_res->rs_qa_qd, ip->i_res->rs_qa_qd_num,
972              sizeof(struct gfs2_quota_data *), sort_qd, NULL);
973 
974         for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
975                 int force = NO_FORCE;
976                 qd = ip->i_res->rs_qa_qd[x];
977                 if (test_and_clear_bit(QDF_REFRESH, &qd->qd_flags))
978                         force = FORCE;
979                 error = do_glock(qd, force, &ip->i_res->rs_qa_qd_ghs[x]);
980                 if (error)
981                         break;
982         }
983 
984         if (!error)
985                 set_bit(GIF_QD_LOCKED, &ip->i_flags);
986         else {
987                 while (x--)
988                         gfs2_glock_dq_uninit(&ip->i_res->rs_qa_qd_ghs[x]);
989                 gfs2_quota_unhold(ip);
990         }
991 
992         return error;
993 }
994 
995 static int need_sync(struct gfs2_quota_data *qd)
996 {
997         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
998         struct gfs2_tune *gt = &sdp->sd_tune;
999         s64 value;
1000         unsigned int num, den;
1001         int do_sync = 1;
1002 
1003         if (!qd->qd_qb.qb_limit)
1004                 return 0;
1005 
1006         spin_lock(&qd_lock);
1007         value = qd->qd_change;
1008         spin_unlock(&qd_lock);
1009 
1010         spin_lock(&gt->gt_spin);
1011         num = gt->gt_quota_scale_num;
1012         den = gt->gt_quota_scale_den;
1013         spin_unlock(&gt->gt_spin);
1014 
1015         if (value < 0)
1016                 do_sync = 0;
1017         else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
1018                  (s64)be64_to_cpu(qd->qd_qb.qb_limit))
1019                 do_sync = 0;
1020         else {
1021                 value *= gfs2_jindex_size(sdp) * num;
1022                 value = div_s64(value, den);
1023                 value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
1024                 if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
1025                         do_sync = 0;
1026         }
1027 
1028         return do_sync;
1029 }
1030 
1031 void gfs2_quota_unlock(struct gfs2_inode *ip)
1032 {
1033         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1034         struct gfs2_quota_data *qda[4];
1035         unsigned int count = 0;
1036         unsigned int x;
1037         int found;
1038 
1039         if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
1040                 goto out;
1041 
1042         for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1043                 struct gfs2_quota_data *qd;
1044                 int sync;
1045 
1046                 qd = ip->i_res->rs_qa_qd[x];
1047                 sync = need_sync(qd);
1048 
1049                 gfs2_glock_dq_uninit(&ip->i_res->rs_qa_qd_ghs[x]);
1050                 if (!sync)
1051                         continue;
1052 
1053                 spin_lock(&qd_lock);
1054                 found = qd_check_sync(sdp, qd, NULL);
1055                 spin_unlock(&qd_lock);
1056 
1057                 if (!found)
1058                         continue;
1059 
1060                 gfs2_assert_warn(sdp, qd->qd_change_sync);
1061                 if (bh_get(qd)) {
1062                         clear_bit(QDF_LOCKED, &qd->qd_flags);
1063                         slot_put(qd);
1064                         qd_put(qd);
1065                         continue;
1066                 }
1067 
1068                 qda[count++] = qd;
1069         }
1070 
1071         if (count) {
1072                 do_sync(count, qda);
1073                 for (x = 0; x < count; x++)
1074                         qd_unlock(qda[x]);
1075         }
1076 
1077 out:
1078         gfs2_quota_unhold(ip);
1079 }
1080 
1081 #define MAX_LINE 256
1082 
1083 static int print_message(struct gfs2_quota_data *qd, char *type)
1084 {
1085         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
1086 
1087         fs_info(sdp, "quota %s for %s %u\n",
1088                 type,
1089                 (qd->qd_id.type == USRQUOTA) ? "user" : "group",
1090                 from_kqid(&init_user_ns, qd->qd_id));
1091 
1092         return 0;
1093 }
1094 
1095 int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
1096 {
1097         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1098         struct gfs2_quota_data *qd;
1099         s64 value;
1100         unsigned int x;
1101         int error = 0;
1102 
1103         if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
1104                 return 0;
1105 
1106         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
1107                 return 0;
1108 
1109         for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1110                 qd = ip->i_res->rs_qa_qd[x];
1111 
1112                 if (!(qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
1113                       qid_eq(qd->qd_id, make_kqid_gid(gid))))
1114                         continue;
1115 
1116                 value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
1117                 spin_lock(&qd_lock);
1118                 value += qd->qd_change;
1119                 spin_unlock(&qd_lock);
1120 
1121                 if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
1122                         print_message(qd, "exceeded");
1123                         quota_send_warning(qd->qd_id,
1124                                            sdp->sd_vfs->s_dev, QUOTA_NL_BHARDWARN);
1125 
1126                         error = -EDQUOT;
1127                         break;
1128                 } else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
1129                            (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
1130                            time_after_eq(jiffies, qd->qd_last_warn +
1131                                          gfs2_tune_get(sdp,
1132                                                 gt_quota_warn_period) * HZ)) {
1133                         quota_send_warning(qd->qd_id,
1134                                            sdp->sd_vfs->s_dev, QUOTA_NL_BSOFTWARN);
1135                         error = print_message(qd, "warning");
1136                         qd->qd_last_warn = jiffies;
1137                 }
1138         }
1139 
1140         return error;
1141 }
1142 
1143 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1144                        kuid_t uid, kgid_t gid)
1145 {
1146         struct gfs2_quota_data *qd;
1147         unsigned int x;
1148 
1149         if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1150                 return;
1151         if (ip->i_diskflags & GFS2_DIF_SYSTEM)
1152                 return;
1153 
1154         for (x = 0; x < ip->i_res->rs_qa_qd_num; x++) {
1155                 qd = ip->i_res->rs_qa_qd[x];
1156 
1157                 if (qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
1158                     qid_eq(qd->qd_id, make_kqid_gid(gid))) {
1159                         do_qc(qd, change);
1160                 }
1161         }
1162 }
1163 
1164 int gfs2_quota_sync(struct super_block *sb, int type)
1165 {
1166         struct gfs2_sbd *sdp = sb->s_fs_info;
1167         struct gfs2_quota_data **qda;
1168         unsigned int max_qd = PAGE_SIZE/sizeof(struct gfs2_holder);
1169         unsigned int num_qd;
1170         unsigned int x;
1171         int error = 0;
1172 
1173         qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1174         if (!qda)
1175                 return -ENOMEM;
1176 
1177         mutex_lock(&sdp->sd_quota_sync_mutex);
1178         sdp->sd_quota_sync_gen++;
1179 
1180         do {
1181                 num_qd = 0;
1182 
1183                 for (;;) {
1184                         error = qd_fish(sdp, qda + num_qd);
1185                         if (error || !qda[num_qd])
1186                                 break;
1187                         if (++num_qd == max_qd)
1188                                 break;
1189                 }
1190 
1191                 if (num_qd) {
1192                         if (!error)
1193                                 error = do_sync(num_qd, qda);
1194                         if (!error)
1195                                 for (x = 0; x < num_qd; x++)
1196                                         qda[x]->qd_sync_gen =
1197                                                 sdp->sd_quota_sync_gen;
1198 
1199                         for (x = 0; x < num_qd; x++)
1200                                 qd_unlock(qda[x]);
1201                 }
1202         } while (!error && num_qd == max_qd);
1203 
1204         mutex_unlock(&sdp->sd_quota_sync_mutex);
1205         kfree(qda);
1206 
1207         return error;
1208 }
1209 
1210 int gfs2_quota_refresh(struct gfs2_sbd *sdp, struct kqid qid)
1211 {
1212         struct gfs2_quota_data *qd;
1213         struct gfs2_holder q_gh;
1214         int error;
1215 
1216         error = qd_get(sdp, qid, &qd);
1217         if (error)
1218                 return error;
1219 
1220         error = do_glock(qd, FORCE, &q_gh);
1221         if (!error)
1222                 gfs2_glock_dq_uninit(&q_gh);
1223 
1224         qd_put(qd);
1225         return error;
1226 }
1227 
1228 int gfs2_quota_init(struct gfs2_sbd *sdp)
1229 {
1230         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1231         u64 size = i_size_read(sdp->sd_qc_inode);
1232         unsigned int blocks = size >> sdp->sd_sb.sb_bsize_shift;
1233         unsigned int x, slot = 0;
1234         unsigned int found = 0;
1235         unsigned int hash;
1236         unsigned int bm_size;
1237         u64 dblock;
1238         u32 extlen = 0;
1239         int error;
1240 
1241         if (gfs2_check_internal_file_size(sdp->sd_qc_inode, 1, 64 << 20))
1242                 return -EIO;
1243 
1244         sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1245         bm_size = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * sizeof(unsigned long));
1246         bm_size *= sizeof(unsigned long);
1247         error = -ENOMEM;
1248         sdp->sd_quota_bitmap = kzalloc(bm_size, GFP_NOFS | __GFP_NOWARN);
1249         if (sdp->sd_quota_bitmap == NULL)
1250                 sdp->sd_quota_bitmap = __vmalloc(bm_size, GFP_NOFS |
1251                                                  __GFP_ZERO, PAGE_KERNEL);
1252         if (!sdp->sd_quota_bitmap)
1253                 return error;
1254 
1255         for (x = 0; x < blocks; x++) {
1256                 struct buffer_head *bh;
1257                 const struct gfs2_quota_change *qc;
1258                 unsigned int y;
1259 
1260                 if (!extlen) {
1261                         int new = 0;
1262                         error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1263                         if (error)
1264                                 goto fail;
1265                 }
1266                 error = -EIO;
1267                 bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1268                 if (!bh)
1269                         goto fail;
1270                 if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1271                         brelse(bh);
1272                         goto fail;
1273                 }
1274 
1275                 qc = (const struct gfs2_quota_change *)(bh->b_data + sizeof(struct gfs2_meta_header));
1276                 for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1277                      y++, slot++) {
1278                         struct gfs2_quota_data *qd;
1279                         s64 qc_change = be64_to_cpu(qc->qc_change);
1280                         u32 qc_flags = be32_to_cpu(qc->qc_flags);
1281                         enum quota_type qtype = (qc_flags & GFS2_QCF_USER) ?
1282                                                 USRQUOTA : GRPQUOTA;
1283                         struct kqid qc_id = make_kqid(&init_user_ns, qtype,
1284                                                       be32_to_cpu(qc->qc_id));
1285                         qc++;
1286                         if (!qc_change)
1287                                 continue;
1288 
1289                         hash = gfs2_qd_hash(sdp, qc_id);
1290                         qd = qd_alloc(hash, sdp, qc_id);
1291                         if (qd == NULL) {
1292                                 brelse(bh);
1293                                 goto fail;
1294                         }
1295 
1296                         set_bit(QDF_CHANGE, &qd->qd_flags);
1297                         qd->qd_change = qc_change;
1298                         qd->qd_slot = slot;
1299                         qd->qd_slot_count = 1;
1300 
1301                         spin_lock(&qd_lock);
1302                         BUG_ON(test_and_set_bit(slot, sdp->sd_quota_bitmap));
1303                         list_add(&qd->qd_list, &sdp->sd_quota_list);
1304                         atomic_inc(&sdp->sd_quota_count);
1305                         spin_unlock(&qd_lock);
1306 
1307                         spin_lock_bucket(hash);
1308                         hlist_bl_add_head_rcu(&qd->qd_hlist, &qd_hash_table[hash]);
1309                         spin_unlock_bucket(hash);
1310 
1311                         found++;
1312                 }
1313 
1314                 brelse(bh);
1315                 dblock++;
1316                 extlen--;
1317         }
1318 
1319         if (found)
1320                 fs_info(sdp, "found %u quota changes\n", found);
1321 
1322         return 0;
1323 
1324 fail:
1325         gfs2_quota_cleanup(sdp);
1326         return error;
1327 }
1328 
1329 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1330 {
1331         struct list_head *head = &sdp->sd_quota_list;
1332         struct gfs2_quota_data *qd;
1333 
1334         spin_lock(&qd_lock);
1335         while (!list_empty(head)) {
1336                 qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1337 
1338                 list_del(&qd->qd_list);
1339 
1340                 /* Also remove if this qd exists in the reclaim list */
1341                 list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
1342                 atomic_dec(&sdp->sd_quota_count);
1343                 spin_unlock(&qd_lock);
1344 
1345                 spin_lock_bucket(qd->qd_hash);
1346                 hlist_bl_del_rcu(&qd->qd_hlist);
1347                 spin_unlock_bucket(qd->qd_hash);
1348 
1349                 gfs2_assert_warn(sdp, !qd->qd_change);
1350                 gfs2_assert_warn(sdp, !qd->qd_slot_count);
1351                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
1352 
1353                 gfs2_glock_put(qd->qd_gl);
1354                 call_rcu(&qd->qd_rcu, gfs2_qd_dealloc);
1355 
1356                 spin_lock(&qd_lock);
1357         }
1358         spin_unlock(&qd_lock);
1359 
1360         gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1361 
1362         if (sdp->sd_quota_bitmap) {
1363                 if (is_vmalloc_addr(sdp->sd_quota_bitmap))
1364                         vfree(sdp->sd_quota_bitmap);
1365                 else
1366                         kfree(sdp->sd_quota_bitmap);
1367                 sdp->sd_quota_bitmap = NULL;
1368         }
1369 }
1370 
1371 static void quotad_error(struct gfs2_sbd *sdp, const char *msg, int error)
1372 {
1373         if (error == 0 || error == -EROFS)
1374                 return;
1375         if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
1376                 fs_err(sdp, "gfs2_quotad: %s error %d\n", msg, error);
1377 }
1378 
1379 static void quotad_check_timeo(struct gfs2_sbd *sdp, const char *msg,
1380                                int (*fxn)(struct super_block *sb, int type),
1381                                unsigned long t, unsigned long *timeo,
1382                                unsigned int *new_timeo)
1383 {
1384         if (t >= *timeo) {
1385                 int error = fxn(sdp->sd_vfs, 0);
1386                 quotad_error(sdp, msg, error);
1387                 *timeo = gfs2_tune_get_i(&sdp->sd_tune, new_timeo) * HZ;
1388         } else {
1389                 *timeo -= t;
1390         }
1391 }
1392 
1393 static void quotad_check_trunc_list(struct gfs2_sbd *sdp)
1394 {
1395         struct gfs2_inode *ip;
1396 
1397         while(1) {
1398                 ip = NULL;
1399                 spin_lock(&sdp->sd_trunc_lock);
1400                 if (!list_empty(&sdp->sd_trunc_list)) {
1401                         ip = list_entry(sdp->sd_trunc_list.next,
1402                                         struct gfs2_inode, i_trunc_list);
1403                         list_del_init(&ip->i_trunc_list);
1404                 }
1405                 spin_unlock(&sdp->sd_trunc_lock);
1406                 if (ip == NULL)
1407                         return;
1408                 gfs2_glock_finish_truncate(ip);
1409         }
1410 }
1411 
1412 void gfs2_wake_up_statfs(struct gfs2_sbd *sdp) {
1413         if (!sdp->sd_statfs_force_sync) {
1414                 sdp->sd_statfs_force_sync = 1;
1415                 wake_up(&sdp->sd_quota_wait);
1416         }
1417 }
1418 
1419 
1420 /**
1421  * gfs2_quotad - Write cached quota changes into the quota file
1422  * @sdp: Pointer to GFS2 superblock
1423  *
1424  */
1425 
1426 int gfs2_quotad(void *data)
1427 {
1428         struct gfs2_sbd *sdp = data;
1429         struct gfs2_tune *tune = &sdp->sd_tune;
1430         unsigned long statfs_timeo = 0;
1431         unsigned long quotad_timeo = 0;
1432         unsigned long t = 0;
1433         DEFINE_WAIT(wait);
1434         int empty;
1435 
1436         while (!kthread_should_stop()) {
1437 
1438                 /* Update the master statfs file */
1439                 if (sdp->sd_statfs_force_sync) {
1440                         int error = gfs2_statfs_sync(sdp->sd_vfs, 0);
1441                         quotad_error(sdp, "statfs", error);
1442                         statfs_timeo = gfs2_tune_get(sdp, gt_statfs_quantum) * HZ;
1443                 }
1444                 else
1445                         quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
1446                                            &statfs_timeo,
1447                                            &tune->gt_statfs_quantum);
1448 
1449                 /* Update quota file */
1450                 quotad_check_timeo(sdp, "sync", gfs2_quota_sync, t,
1451                                    &quotad_timeo, &tune->gt_quota_quantum);
1452 
1453                 /* Check for & recover partially truncated inodes */
1454                 quotad_check_trunc_list(sdp);
1455 
1456                 try_to_freeze();
1457 
1458                 t = min(quotad_timeo, statfs_timeo);
1459 
1460                 prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);
1461                 spin_lock(&sdp->sd_trunc_lock);
1462                 empty = list_empty(&sdp->sd_trunc_list);
1463                 spin_unlock(&sdp->sd_trunc_lock);
1464                 if (empty && !sdp->sd_statfs_force_sync)
1465                         t -= schedule_timeout(t);
1466                 else
1467                         t = 0;
1468                 finish_wait(&sdp->sd_quota_wait, &wait);
1469         }
1470 
1471         return 0;
1472 }
1473 
1474 static int gfs2_quota_get_xstate(struct super_block *sb,
1475                                  struct fs_quota_stat *fqs)
1476 {
1477         struct gfs2_sbd *sdp = sb->s_fs_info;
1478 
1479         memset(fqs, 0, sizeof(struct fs_quota_stat));
1480         fqs->qs_version = FS_QSTAT_VERSION;
1481 
1482         switch (sdp->sd_args.ar_quota) {
1483         case GFS2_QUOTA_ON:
1484                 fqs->qs_flags |= (FS_QUOTA_UDQ_ENFD | FS_QUOTA_GDQ_ENFD);
1485                 /*FALLTHRU*/
1486         case GFS2_QUOTA_ACCOUNT:
1487                 fqs->qs_flags |= (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT);
1488                 break;
1489         case GFS2_QUOTA_OFF:
1490                 break;
1491         }
1492 
1493         if (sdp->sd_quota_inode) {
1494                 fqs->qs_uquota.qfs_ino = GFS2_I(sdp->sd_quota_inode)->i_no_addr;
1495                 fqs->qs_uquota.qfs_nblks = sdp->sd_quota_inode->i_blocks;
1496         }
1497         fqs->qs_uquota.qfs_nextents = 1; /* unsupported */
1498         fqs->qs_gquota = fqs->qs_uquota; /* its the same inode in both cases */
1499         fqs->qs_incoredqs = list_lru_count(&gfs2_qd_lru);
1500         return 0;
1501 }
1502 
1503 static int gfs2_get_dqblk(struct super_block *sb, struct kqid qid,
1504                           struct fs_disk_quota *fdq)
1505 {
1506         struct gfs2_sbd *sdp = sb->s_fs_info;
1507         struct gfs2_quota_lvb *qlvb;
1508         struct gfs2_quota_data *qd;
1509         struct gfs2_holder q_gh;
1510         int error;
1511 
1512         memset(fdq, 0, sizeof(struct fs_disk_quota));
1513 
1514         if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1515                 return -ESRCH; /* Crazy XFS error code */
1516 
1517         if ((qid.type != USRQUOTA) &&
1518             (qid.type != GRPQUOTA))
1519                 return -EINVAL;
1520 
1521         error = qd_get(sdp, qid, &qd);
1522         if (error)
1523                 return error;
1524         error = do_glock(qd, FORCE, &q_gh);
1525         if (error)
1526                 goto out;
1527 
1528         qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
1529         fdq->d_version = FS_DQUOT_VERSION;
1530         fdq->d_flags = (qid.type == USRQUOTA) ? FS_USER_QUOTA : FS_GROUP_QUOTA;
1531         fdq->d_id = from_kqid_munged(current_user_ns(), qid);
1532         fdq->d_blk_hardlimit = be64_to_cpu(qlvb->qb_limit) << sdp->sd_fsb2bb_shift;
1533         fdq->d_blk_softlimit = be64_to_cpu(qlvb->qb_warn) << sdp->sd_fsb2bb_shift;
1534         fdq->d_bcount = be64_to_cpu(qlvb->qb_value) << sdp->sd_fsb2bb_shift;
1535 
1536         gfs2_glock_dq_uninit(&q_gh);
1537 out:
1538         qd_put(qd);
1539         return error;
1540 }
1541 
1542 /* GFS2 only supports a subset of the XFS fields */
1543 #define GFS2_FIELDMASK (FS_DQ_BSOFT|FS_DQ_BHARD|FS_DQ_BCOUNT)
1544 
1545 static int gfs2_set_dqblk(struct super_block *sb, struct kqid qid,
1546                           struct fs_disk_quota *fdq)
1547 {
1548         struct gfs2_sbd *sdp = sb->s_fs_info;
1549         struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
1550         struct gfs2_quota_data *qd;
1551         struct gfs2_holder q_gh, i_gh;
1552         unsigned int data_blocks, ind_blocks;
1553         unsigned int blocks = 0;
1554         int alloc_required;
1555         loff_t offset;
1556         int error;
1557 
1558         if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
1559                 return -ESRCH; /* Crazy XFS error code */
1560 
1561         if ((qid.type != USRQUOTA) &&
1562             (qid.type != GRPQUOTA))
1563                 return -EINVAL;
1564 
1565         if (fdq->d_fieldmask & ~GFS2_FIELDMASK)
1566                 return -EINVAL;
1567 
1568         error = qd_get(sdp, qid, &qd);
1569         if (error)
1570                 return error;
1571 
1572         error = gfs2_rs_alloc(ip);
1573         if (error)
1574                 goto out_put;
1575 
1576         mutex_lock(&ip->i_inode.i_mutex);
1577         error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE, 0, &q_gh);
1578         if (error)
1579                 goto out_unlockput;
1580         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
1581         if (error)
1582                 goto out_q;
1583 
1584         /* Check for existing entry, if none then alloc new blocks */
1585         error = update_qd(sdp, qd);
1586         if (error)
1587                 goto out_i;
1588 
1589         /* If nothing has changed, this is a no-op */
1590         if ((fdq->d_fieldmask & FS_DQ_BSOFT) &&
1591             ((fdq->d_blk_softlimit >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_warn)))
1592                 fdq->d_fieldmask ^= FS_DQ_BSOFT;
1593 
1594         if ((fdq->d_fieldmask & FS_DQ_BHARD) &&
1595             ((fdq->d_blk_hardlimit >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_limit)))
1596                 fdq->d_fieldmask ^= FS_DQ_BHARD;
1597 
1598         if ((fdq->d_fieldmask & FS_DQ_BCOUNT) &&
1599             ((fdq->d_bcount >> sdp->sd_fsb2bb_shift) == be64_to_cpu(qd->qd_qb.qb_value)))
1600                 fdq->d_fieldmask ^= FS_DQ_BCOUNT;
1601 
1602         if (fdq->d_fieldmask == 0)
1603                 goto out_i;
1604 
1605         offset = qd2offset(qd);
1606         alloc_required = gfs2_write_alloc_required(ip, offset, sizeof(struct gfs2_quota));
1607         if (gfs2_is_stuffed(ip))
1608                 alloc_required = 1;
1609         if (alloc_required) {
1610                 struct gfs2_alloc_parms ap = { .aflags = 0, };
1611                 gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
1612                                        &data_blocks, &ind_blocks);
1613                 blocks = 1 + data_blocks + ind_blocks;
1614                 ap.target = blocks;
1615                 error = gfs2_inplace_reserve(ip, &ap);
1616                 if (error)
1617                         goto out_i;
1618                 blocks += gfs2_rg_blocks(ip, blocks);
1619         }
1620 
1621         /* Some quotas span block boundaries and can update two blocks,
1622            adding an extra block to the transaction to handle such quotas */
1623         error = gfs2_trans_begin(sdp, blocks + RES_DINODE + 2, 0);
1624         if (error)
1625                 goto out_release;
1626 
1627         /* Apply changes */
1628         error = gfs2_adjust_quota(ip, offset, 0, qd, fdq);
1629 
1630         gfs2_trans_end(sdp);
1631 out_release:
1632         if (alloc_required)
1633                 gfs2_inplace_release(ip);
1634 out_i:
1635         gfs2_glock_dq_uninit(&i_gh);
1636 out_q:
1637         gfs2_glock_dq_uninit(&q_gh);
1638 out_unlockput:
1639         mutex_unlock(&ip->i_inode.i_mutex);
1640 out_put:
1641         qd_put(qd);
1642         return error;
1643 }
1644 
1645 const struct quotactl_ops gfs2_quotactl_ops = {
1646         .quota_sync     = gfs2_quota_sync,
1647         .get_xstate     = gfs2_quota_get_xstate,
1648         .get_dqblk      = gfs2_get_dqblk,
1649         .set_dqblk      = gfs2_set_dqblk,
1650 };
1651 
1652 void __init gfs2_quota_hash_init(void)
1653 {
1654         unsigned i;
1655 
1656         for(i = 0; i < GFS2_QD_HASH_SIZE; i++)
1657                 INIT_HLIST_BL_HEAD(&qd_hash_table[i]);
1658 }
1659 

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