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   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 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/bio.h>
  47 #include <linux/gfs2_ondisk.h>
  48 #include <linux/kthread.h>
  49 #include <linux/freezer.h>
  50
  51 #include "gfs2.h"
  52 #include "incore.h"
  53 #include "bmap.h"
  54 #include "glock.h"
  55 #include "glops.h"
  56 #include "log.h"
  57 #include "meta_io.h"
  58 #include "quota.h"
  59 #include "rgrp.h"
  60 #include "super.h"
  61 #include "trans.h"
  62 #include "inode.h"
  63 #include "ops_address.h"
  64 #include "util.h"
  65
  66 #define QUOTA_USER 1
  67 #define QUOTA_GROUP 0
  68
  69 struct gfs2_quota_host {
  70         u64 qu_limit;
  71         u64 qu_warn;
  72         s64 qu_value;
  73         u32 qu_ll_next;
  74 };
  75
  76 struct gfs2_quota_change_host {
  77         u64 qc_change;
  78         u32 qc_flags; /* GFS2_QCF_... */
  79         u32 qc_id;
  80 };
  81
  82 static LIST_HEAD(qd_lru_list);
  83 static atomic_t qd_lru_count = ATOMIC_INIT(0);
  84 static DEFINE_SPINLOCK(qd_lru_lock);
  85
  86 int gfs2_shrink_qd_memory(int nr, gfp_t gfp_mask)
  87 {
  88         struct gfs2_quota_data *qd;
  89         struct gfs2_sbd *sdp;
  90
  91         if (nr == 0)
  92                 goto out;
  93
  94         if (!(gfp_mask & __GFP_FS))
  95                 return -1;
  96
  97         spin_lock(&qd_lru_lock);
  98         while (nr && !list_empty(&qd_lru_list)) {
  99                 qd = list_entry(qd_lru_list.next,
 100                                 struct gfs2_quota_data, qd_reclaim);
 101                 sdp = qd->qd_gl->gl_sbd;
 102
 103                 /* Free from the filesystem-specific list */
 104                 list_del(&qd->qd_list);
 105
 106                 gfs2_assert_warn(sdp, !qd->qd_change);
 107                 gfs2_assert_warn(sdp, !qd->qd_slot_count);
 108                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
 109
 110                 gfs2_glock_put(qd->qd_gl);
 111                 atomic_dec(&sdp->sd_quota_count);
 112
 113                 /* Delete it from the common reclaim list */
 114                 list_del_init(&qd->qd_reclaim);
 115                 atomic_dec(&qd_lru_count);
 116                 spin_unlock(&qd_lru_lock);
 117                 kmem_cache_free(gfs2_quotad_cachep, qd);
 118                 spin_lock(&qd_lru_lock);
 119                 nr--;
 120         }
 121         spin_unlock(&qd_lru_lock);
 122
 123 out:
 124         return (atomic_read(&qd_lru_count) * sysctl_vfs_cache_pressure) / 100;
 125 }
 126
 127 static u64 qd2offset(struct gfs2_quota_data *qd)
 128 {
 129         u64 offset;
 130
 131         offset = 2 * (u64)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
 132         offset *= sizeof(struct gfs2_quota);
 133
 134         return offset;
 135 }
 136
 137 static int qd_alloc(struct gfs2_sbd *sdp, int user, u32 id,
 138                     struct gfs2_quota_data **qdp)
 139 {
 140         struct gfs2_quota_data *qd;
 141         int error;
 142
 143         qd = kmem_cache_zalloc(gfs2_quotad_cachep, GFP_NOFS);
 144         if (!qd)
 145                 return -ENOMEM;
 146
 147         atomic_set(&qd->qd_count, 1);
 148         qd->qd_id = id;
 149         if (user)
 150                 set_bit(QDF_USER, &qd->qd_flags);
 151         qd->qd_slot = -1;
 152         INIT_LIST_HEAD(&qd->qd_reclaim);
 153
 154         error = gfs2_glock_get(sdp, 2 * (u64)id + !user,
 155                               &gfs2_quota_glops, CREATE, &qd->qd_gl);
 156         if (error)
 157                 goto fail;
 158
 159         *qdp = qd;
 160
 161         return 0;
 162
 163 fail:
 164         kmem_cache_free(gfs2_quotad_cachep, qd);
 165         return error;
 166 }
 167
 168 static int qd_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
 169                   struct gfs2_quota_data **qdp)
 170 {
 171         struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
 172         int error, found;
 173
 174         *qdp = NULL;
 175
 176         for (;;) {
 177                 found = 0;
 178                 spin_lock(&qd_lru_lock);
 179                 list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
 180                         if (qd->qd_id == id &&
 181                             !test_bit(QDF_USER, &qd->qd_flags) == !user) {
 182                                 if (!atomic_read(&qd->qd_count) &&
 183                                     !list_empty(&qd->qd_reclaim)) {
 184                                         /* Remove it from reclaim list */
 185                                         list_del_init(&qd->qd_reclaim);
 186                                         atomic_dec(&qd_lru_count);
 187                                 }
 188                                 atomic_inc(&qd->qd_count);
 189                                 found = 1;
 190                                 break;
 191                         }
 192                 }
 193
 194                 if (!found)
 195                         qd = NULL;
 196
 197                 if (!qd && new_qd) {
 198                         qd = new_qd;
 199                         list_add(&qd->qd_list, &sdp->sd_quota_list);
 200                         atomic_inc(&sdp->sd_quota_count);
 201                         new_qd = NULL;
 202                 }
 203
 204                 spin_unlock(&qd_lru_lock);
 205
 206                 if (qd || !create) {
 207                         if (new_qd) {
 208                                 gfs2_glock_put(new_qd->qd_gl);
 209                                 kmem_cache_free(gfs2_quotad_cachep, new_qd);
 210                         }
 211                         *qdp = qd;
 212                         return 0;
 213                 }
 214
 215                 error = qd_alloc(sdp, user, id, &new_qd);
 216                 if (error)
 217                         return error;
 218         }
 219 }
 220
 221 static void qd_hold(struct gfs2_quota_data *qd)
 222 {
 223         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 224         gfs2_assert(sdp, atomic_read(&qd->qd_count));
 225         atomic_inc(&qd->qd_count);
 226 }
 227
 228 static void qd_put(struct gfs2_quota_data *qd)
 229 {
 230         if (atomic_dec_and_lock(&qd->qd_count, &qd_lru_lock)) {
 231                 /* Add to the reclaim list */
 232                 list_add_tail(&qd->qd_reclaim, &qd_lru_list);
 233                 atomic_inc(&qd_lru_count);
 234                 spin_unlock(&qd_lru_lock);
 235         }
 236 }
 237
 238 static int slot_get(struct gfs2_quota_data *qd)
 239 {
 240         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 241         unsigned int c, o = 0, b;
 242         unsigned char byte = 0;
 243
 244         spin_lock(&qd_lru_lock);
 245
 246         if (qd->qd_slot_count++) {
 247                 spin_unlock(&qd_lru_lock);
 248                 return 0;
 249         }
 250
 251         for (c = 0; c < sdp->sd_quota_chunks; c++)
 252                 for (o = 0; o < PAGE_SIZE; o++) {
 253                         byte = sdp->sd_quota_bitmap[c][o];
 254                         if (byte != 0xFF)
 255                                 goto found;
 256                 }
 257
 258         goto fail;
 259
 260 found:
 261         for (b = 0; b < 8; b++)
 262                 if (!(byte & (1 << b)))
 263                         break;
 264         qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
 265
 266         if (qd->qd_slot >= sdp->sd_quota_slots)
 267                 goto fail;
 268
 269         sdp->sd_quota_bitmap[c][o] |= 1 << b;
 270
 271         spin_unlock(&qd_lru_lock);
 272
 273         return 0;
 274
 275 fail:
 276         qd->qd_slot_count--;
 277         spin_unlock(&qd_lru_lock);
 278         return -ENOSPC;
 279 }
 280
 281 static void slot_hold(struct gfs2_quota_data *qd)
 282 {
 283         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 284
 285         spin_lock(&qd_lru_lock);
 286         gfs2_assert(sdp, qd->qd_slot_count);
 287         qd->qd_slot_count++;
 288         spin_unlock(&qd_lru_lock);
 289 }
 290
 291 static void slot_put(struct gfs2_quota_data *qd)
 292 {
 293         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 294
 295         spin_lock(&qd_lru_lock);
 296         gfs2_assert(sdp, qd->qd_slot_count);
 297         if (!--qd->qd_slot_count) {
 298                 gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
 299                 qd->qd_slot = -1;
 300         }
 301         spin_unlock(&qd_lru_lock);
 302 }
 303
 304 static int bh_get(struct gfs2_quota_data *qd)
 305 {
 306         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 307         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
 308         unsigned int block, offset;
 309         struct buffer_head *bh;
 310         int error;
 311         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 312
 313         mutex_lock(&sdp->sd_quota_mutex);
 314
 315         if (qd->qd_bh_count++) {
 316                 mutex_unlock(&sdp->sd_quota_mutex);
 317                 return 0;
 318         }
 319
 320         block = qd->qd_slot / sdp->sd_qc_per_block;
 321         offset = qd->qd_slot % sdp->sd_qc_per_block;
 322
 323         bh_map.b_size = 1 << ip->i_inode.i_blkbits;
 324         error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
 325         if (error)
 326                 goto fail;
 327         error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
 328         if (error)
 329                 goto fail;
 330         error = -EIO;
 331         if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
 332                 goto fail_brelse;
 333
 334         qd->qd_bh = bh;
 335         qd->qd_bh_qc = (struct gfs2_quota_change *)
 336                 (bh->b_data + sizeof(struct gfs2_meta_header) +
 337                  offset * sizeof(struct gfs2_quota_change));
 338
 339         mutex_unlock(&sdp->sd_quota_mutex);
 340
 341         return 0;
 342
 343 fail_brelse:
 344         brelse(bh);
 345 fail:
 346         qd->qd_bh_count--;
 347         mutex_unlock(&sdp->sd_quota_mutex);
 348         return error;
 349 }
 350
 351 static void bh_put(struct gfs2_quota_data *qd)
 352 {
 353         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 354
 355         mutex_lock(&sdp->sd_quota_mutex);
 356         gfs2_assert(sdp, qd->qd_bh_count);
 357         if (!--qd->qd_bh_count) {
 358                 brelse(qd->qd_bh);
 359                 qd->qd_bh = NULL;
 360                 qd->qd_bh_qc = NULL;
 361         }
 362         mutex_unlock(&sdp->sd_quota_mutex);
 363 }
 364
 365 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
 366 {
 367         struct gfs2_quota_data *qd = NULL;
 368         int error;
 369         int found = 0;
 370
 371         *qdp = NULL;
 372
 373         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 374                 return 0;
 375
 376         spin_lock(&qd_lru_lock);
 377
 378         list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
 379                 if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
 380                     !test_bit(QDF_CHANGE, &qd->qd_flags) ||
 381                     qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
 382                         continue;
 383
 384                 list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 385
 386                 set_bit(QDF_LOCKED, &qd->qd_flags);
 387                 gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
 388                 atomic_inc(&qd->qd_count);
 389                 qd->qd_change_sync = qd->qd_change;
 390                 gfs2_assert_warn(sdp, qd->qd_slot_count);
 391                 qd->qd_slot_count++;
 392                 found = 1;
 393
 394                 break;
 395         }
 396
 397         if (!found)
 398                 qd = NULL;
 399
 400         spin_unlock(&qd_lru_lock);
 401
 402         if (qd) {
 403                 gfs2_assert_warn(sdp, qd->qd_change_sync);
 404                 error = bh_get(qd);
 405                 if (error) {
 406                         clear_bit(QDF_LOCKED, &qd->qd_flags);
 407                         slot_put(qd);
 408                         qd_put(qd);
 409                         return error;
 410                 }
 411         }
 412
 413         *qdp = qd;
 414
 415         return 0;
 416 }
 417
 418 static int qd_trylock(struct gfs2_quota_data *qd)
 419 {
 420         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 421
 422         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 423                 return 0;
 424
 425         spin_lock(&qd_lru_lock);
 426
 427         if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
 428             !test_bit(QDF_CHANGE, &qd->qd_flags)) {
 429                 spin_unlock(&qd_lru_lock);
 430                 return 0;
 431         }
 432
 433         list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 434
 435         set_bit(QDF_LOCKED, &qd->qd_flags);
 436         gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
 437         atomic_inc(&qd->qd_count);
 438         qd->qd_change_sync = qd->qd_change;
 439         gfs2_assert_warn(sdp, qd->qd_slot_count);
 440         qd->qd_slot_count++;
 441
 442         spin_unlock(&qd_lru_lock);
 443
 444         gfs2_assert_warn(sdp, qd->qd_change_sync);
 445         if (bh_get(qd)) {
 446                 clear_bit(QDF_LOCKED, &qd->qd_flags);
 447                 slot_put(qd);
 448                 qd_put(qd);
 449                 return 0;
 450         }
 451
 452         return 1;
 453 }
 454
 455 static void qd_unlock(struct gfs2_quota_data *qd)
 456 {
 457         gfs2_assert_warn(qd->qd_gl->gl_sbd,
 458                          test_bit(QDF_LOCKED, &qd->qd_flags));
 459         clear_bit(QDF_LOCKED, &qd->qd_flags);
 460         bh_put(qd);
 461         slot_put(qd);
 462         qd_put(qd);
 463 }
 464
 465 static int qdsb_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
 466                     struct gfs2_quota_data **qdp)
 467 {
 468         int error;
 469
 470         error = qd_get(sdp, user, id, create, qdp);
 471         if (error)
 472                 return error;
 473
 474         error = slot_get(*qdp);
 475         if (error)
 476                 goto fail;
 477
 478         error = bh_get(*qdp);
 479         if (error)
 480                 goto fail_slot;
 481
 482         return 0;
 483
 484 fail_slot:
 485         slot_put(*qdp);
 486 fail:
 487         qd_put(*qdp);
 488         return error;
 489 }
 490
 491 static void qdsb_put(struct gfs2_quota_data *qd)
 492 {
 493         bh_put(qd);
 494         slot_put(qd);
 495         qd_put(qd);
 496 }
 497
 498 int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
 499 {
 500         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 501         struct gfs2_alloc *al = ip->i_alloc;
 502         struct gfs2_quota_data **qd = al->al_qd;
 503         int error;
 504
 505         if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
 506             gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
 507                 return -EIO;
 508
 509         if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
 510                 return 0;
 511
 512         error = qdsb_get(sdp, QUOTA_USER, ip->i_inode.i_uid, CREATE, qd);
 513         if (error)
 514                 goto out;
 515         al->al_qd_num++;
 516         qd++;
 517
 518         error = qdsb_get(sdp, QUOTA_GROUP, ip->i_inode.i_gid, CREATE, qd);
 519         if (error)
 520                 goto out;
 521         al->al_qd_num++;
 522         qd++;
 523
 524         if (uid != NO_QUOTA_CHANGE && uid != ip->i_inode.i_uid) {
 525                 error = qdsb_get(sdp, QUOTA_USER, uid, CREATE, qd);
 526                 if (error)
 527                         goto out;
 528                 al->al_qd_num++;
 529                 qd++;
 530         }
 531
 532         if (gid != NO_QUOTA_CHANGE && gid != ip->i_inode.i_gid) {
 533                 error = qdsb_get(sdp, QUOTA_GROUP, gid, CREATE, qd);
 534                 if (error)
 535                         goto out;
 536                 al->al_qd_num++;
 537                 qd++;
 538         }
 539
 540 out:
 541         if (error)
 542                 gfs2_quota_unhold(ip);
 543         return error;
 544 }
 545
 546 void gfs2_quota_unhold(struct gfs2_inode *ip)
 547 {
 548         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 549         struct gfs2_alloc *al = ip->i_alloc;
 550         unsigned int x;
 551
 552         gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
 553
 554         for (x = 0; x < al->al_qd_num; x++) {
 555                 qdsb_put(al->al_qd[x]);
 556                 al->al_qd[x] = NULL;
 557         }
 558         al->al_qd_num = 0;
 559 }
 560
 561 static int sort_qd(const void *a, const void *b)
 562 {
 563         const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
 564         const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
 565
 566         if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
 567             !test_bit(QDF_USER, &qd_b->qd_flags)) {
 568                 if (test_bit(QDF_USER, &qd_a->qd_flags))
 569                         return -1;
 570                 else
 571                         return 1;
 572         }
 573         if (qd_a->qd_id < qd_b->qd_id)
 574                 return -1;
 575         if (qd_a->qd_id > qd_b->qd_id)
 576                 return 1;
 577
 578         return 0;
 579 }
 580
 581 static void do_qc(struct gfs2_quota_data *qd, s64 change)
 582 {
 583         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 584         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
 585         struct gfs2_quota_change *qc = qd->qd_bh_qc;
 586         s64 x;
 587
 588         mutex_lock(&sdp->sd_quota_mutex);
 589         gfs2_trans_add_bh(ip->i_gl, qd->qd_bh, 1);
 590
 591         if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
 592                 qc->qc_change = 0;
 593                 qc->qc_flags = 0;
 594                 if (test_bit(QDF_USER, &qd->qd_flags))
 595                         qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
 596                 qc->qc_id = cpu_to_be32(qd->qd_id);
 597         }
 598
 599         x = be64_to_cpu(qc->qc_change) + change;
 600         qc->qc_change = cpu_to_be64(x);
 601
 602         spin_lock(&qd_lru_lock);
 603         qd->qd_change = x;
 604         spin_unlock(&qd_lru_lock);
 605
 606         if (!x) {
 607                 gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
 608                 clear_bit(QDF_CHANGE, &qd->qd_flags);
 609                 qc->qc_flags = 0;
 610                 qc->qc_id = 0;
 611                 slot_put(qd);
 612                 qd_put(qd);
 613         } else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
 614                 qd_hold(qd);
 615                 slot_hold(qd);
 616         }
 617
 618         mutex_unlock(&sdp->sd_quota_mutex);
 619 }
 620
 621 static void gfs2_quota_in(struct gfs2_quota_host *qu, const void *buf)
 622 {
 623         const struct gfs2_quota *str = buf;
 624
 625         qu->qu_limit = be64_to_cpu(str->qu_limit);
 626         qu->qu_warn = be64_to_cpu(str->qu_warn);
 627         qu->qu_value = be64_to_cpu(str->qu_value);
 628         qu->qu_ll_next = be32_to_cpu(str->qu_ll_next);
 629 }
 630
 631 static void gfs2_quota_out(const struct gfs2_quota_host *qu, void *buf)
 632 {
 633         struct gfs2_quota *str = buf;
 634
 635         str->qu_limit = cpu_to_be64(qu->qu_limit);
 636         str->qu_warn = cpu_to_be64(qu->qu_warn);
 637         str->qu_value = cpu_to_be64(qu->qu_value);
 638         str->qu_ll_next = cpu_to_be32(qu->qu_ll_next);
 639         memset(&str->qu_reserved, 0, sizeof(str->qu_reserved));
 640 }
 641
 642 /**
 643  * gfs2_adjust_quota
 644  *
 645  * This function was mostly borrowed from gfs2_block_truncate_page which was
 646  * in turn mostly borrowed from ext3
 647  */
 648 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
 649                              s64 change, struct gfs2_quota_data *qd)
 650 {
 651         struct inode *inode = &ip->i_inode;
 652         struct address_space *mapping = inode->i_mapping;
 653         unsigned long index = loc >> PAGE_CACHE_SHIFT;
 654         unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
 655         unsigned blocksize, iblock, pos;
 656         struct buffer_head *bh;
 657         struct page *page;
 658         void *kaddr;
 659         char *ptr;
 660         struct gfs2_quota_host qp;
 661         s64 value;
 662         int err = -EIO;
 663
 664         if (gfs2_is_stuffed(ip))
 665                 gfs2_unstuff_dinode(ip, NULL);
 666
 667         page = grab_cache_page(mapping, index);
 668         if (!page)
 669                 return -ENOMEM;
 670
 671         blocksize = inode->i_sb->s_blocksize;
 672         iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
 673
 674         if (!page_has_buffers(page))
 675                 create_empty_buffers(page, blocksize, 0);
 676
 677         bh = page_buffers(page);
 678         pos = blocksize;
 679         while (offset >= pos) {
 680                 bh = bh->b_this_page;
 681                 iblock++;
 682                 pos += blocksize;
 683         }
 684
 685         if (!buffer_mapped(bh)) {
 686                 gfs2_block_map(inode, iblock, bh, 1);
 687                 if (!buffer_mapped(bh))
 688                         goto unlock;
 689         }
 690
 691         if (PageUptodate(page))
 692                 set_buffer_uptodate(bh);
 693
 694         if (!buffer_uptodate(bh)) {
 695                 ll_rw_block(READ_META, 1, &bh);
 696                 wait_on_buffer(bh);
 697                 if (!buffer_uptodate(bh))
 698                         goto unlock;
 699         }
 700
 701         gfs2_trans_add_bh(ip->i_gl, bh, 0);
 702
 703         kaddr = kmap_atomic(page, KM_USER0);
 704         ptr = kaddr + offset;
 705         gfs2_quota_in(&qp, ptr);
 706         qp.qu_value += change;
 707         value = qp.qu_value;
 708         gfs2_quota_out(&qp, ptr);
 709         flush_dcache_page(page);
 710         kunmap_atomic(kaddr, KM_USER0);
 711         err = 0;
 712         qd->qd_qb.qb_magic = cpu_to_be32(GFS2_MAGIC);
 713         qd->qd_qb.qb_value = cpu_to_be64(value);
 714         ((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_magic = cpu_to_be32(GFS2_MAGIC);
 715         ((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_value = cpu_to_be64(value);
 716 unlock:
 717         unlock_page(page);
 718         page_cache_release(page);
 719         return err;
 720 }
 721
 722 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 723 {
 724         struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
 725         struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
 726         unsigned int data_blocks, ind_blocks;
 727         struct gfs2_holder *ghs, i_gh;
 728         unsigned int qx, x;
 729         struct gfs2_quota_data *qd;
 730         loff_t offset;
 731         unsigned int nalloc = 0, blocks;
 732         struct gfs2_alloc *al = NULL;
 733         int error;
 734
 735         gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
 736                               &data_blocks, &ind_blocks);
 737
 738         ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
 739         if (!ghs)
 740                 return -ENOMEM;
 741
 742         sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
 743         for (qx = 0; qx < num_qd; qx++) {
 744                 error = gfs2_glock_nq_init(qda[qx]->qd_gl,
 745                                            LM_ST_EXCLUSIVE,
 746                                            GL_NOCACHE, &ghs[qx]);
 747                 if (error)
 748                         goto out;
 749         }
 750
 751         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 752         if (error)
 753                 goto out;
 754
 755         for (x = 0; x < num_qd; x++) {
 756                 int alloc_required;
 757
 758                 offset = qd2offset(qda[x]);
 759                 error = gfs2_write_alloc_required(ip, offset,
 760                                                   sizeof(struct gfs2_quota),
 761                                                   &alloc_required);
 762                 if (error)
 763                         goto out_gunlock;
 764                 if (alloc_required)
 765                         nalloc++;
 766         }
 767
 768         al = gfs2_alloc_get(ip);
 769         if (!al) {
 770                 error = -ENOMEM;
 771                 goto out_gunlock;
 772         }
 773         /*
 774          * 1 blk for unstuffing inode if stuffed. We add this extra
 775          * block to the reservation unconditionally. If the inode
 776          * doesn't need unstuffing, the block will be released to the
 777          * rgrp since it won't be allocated during the transaction
 778          */
 779         al->al_requested = 1;
 780         /* +1 in the end for block requested above for unstuffing */
 781         blocks = num_qd * data_blocks + RES_DINODE + num_qd + 1;
 782
 783         if (nalloc)
 784                 al->al_requested += nalloc * (data_blocks + ind_blocks);
 785         error = gfs2_inplace_reserve(ip);
 786         if (error)
 787                 goto out_alloc;
 788
 789         if (nalloc)
 790                 blocks += al->al_rgd->rd_length + nalloc * ind_blocks + RES_STATFS;
 791
 792         error = gfs2_trans_begin(sdp, blocks, 0);
 793         if (error)
 794                 goto out_ipres;
 795
 796         for (x = 0; x < num_qd; x++) {
 797                 qd = qda[x];
 798                 offset = qd2offset(qd);
 799                 error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync,
 800                                           (struct gfs2_quota_data *)
 801                                           qd);
 802                 if (error)
 803                         goto out_end_trans;
 804
 805                 do_qc(qd, -qd->qd_change_sync);
 806         }
 807
 808         error = 0;
 809
 810 out_end_trans:
 811         gfs2_trans_end(sdp);
 812 out_ipres:
 813         gfs2_inplace_release(ip);
 814 out_alloc:
 815         gfs2_alloc_put(ip);
 816 out_gunlock:
 817         gfs2_glock_dq_uninit(&i_gh);
 818 out:
 819         while (qx--)
 820                 gfs2_glock_dq_uninit(&ghs[qx]);
 821         kfree(ghs);
 822         gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
 823         return error;
 824 }
 825
 826 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
 827                     struct gfs2_holder *q_gh)
 828 {
 829         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 830         struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
 831         struct gfs2_holder i_gh;
 832         struct gfs2_quota_host q;
 833         char buf[sizeof(struct gfs2_quota)];
 834         int error;
 835         struct gfs2_quota_lvb *qlvb;
 836
 837 restart:
 838         error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
 839         if (error)
 840                 return error;
 841
 842         qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
 843
 844         if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
 845                 loff_t pos;
 846                 gfs2_glock_dq_uninit(q_gh);
 847                 error = gfs2_glock_nq_init(qd->qd_gl,
 848                                            LM_ST_EXCLUSIVE, GL_NOCACHE,
 849                                            q_gh);
 850                 if (error)
 851                         return error;
 852
 853                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
 854                 if (error)
 855                         goto fail;
 856
 857                 memset(buf, 0, sizeof(struct gfs2_quota));
 858                 pos = qd2offset(qd);
 859                 error = gfs2_internal_read(ip, NULL, buf, &pos,
 860                                            sizeof(struct gfs2_quota));
 861                 if (error < 0)
 862                         goto fail_gunlock;
 863
 864                 gfs2_glock_dq_uninit(&i_gh);
 865
 866                 gfs2_quota_in(&q, buf);
 867                 qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
 868                 qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
 869                 qlvb->__pad = 0;
 870                 qlvb->qb_limit = cpu_to_be64(q.qu_limit);
 871                 qlvb->qb_warn = cpu_to_be64(q.qu_warn);
 872                 qlvb->qb_value = cpu_to_be64(q.qu_value);
 873                 qd->qd_qb = *qlvb;
 874
 875                 if (gfs2_glock_is_blocking(qd->qd_gl)) {
 876                         gfs2_glock_dq_uninit(q_gh);
 877                         force_refresh = 0;
 878                         goto restart;
 879                 }
 880         }
 881
 882         return 0;
 883
 884 fail_gunlock:
 885         gfs2_glock_dq_uninit(&i_gh);
 886 fail:
 887         gfs2_glock_dq_uninit(q_gh);
 888         return error;
 889 }
 890
 891 int gfs2_quota_lock(struct gfs2_inode *ip, u32 uid, u32 gid)
 892 {
 893         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 894         struct gfs2_alloc *al = ip->i_alloc;
 895         unsigned int x;
 896         int error = 0;
 897
 898         gfs2_quota_hold(ip, uid, gid);
 899
 900         if (capable(CAP_SYS_RESOURCE) ||
 901             sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
 902                 return 0;
 903
 904         sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
 905              sort_qd, NULL);
 906
 907         for (x = 0; x < al->al_qd_num; x++) {
 908                 error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
 909                 if (error)
 910                         break;
 911         }
 912
 913         if (!error)
 914                 set_bit(GIF_QD_LOCKED, &ip->i_flags);
 915         else {
 916                 while (x--)
 917                         gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
 918                 gfs2_quota_unhold(ip);
 919         }
 920
 921         return error;
 922 }
 923
 924 static int need_sync(struct gfs2_quota_data *qd)
 925 {
 926         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 927         struct gfs2_tune *gt = &sdp->sd_tune;
 928         s64 value;
 929         unsigned int num, den;
 930         int do_sync = 1;
 931
 932         if (!qd->qd_qb.qb_limit)
 933                 return 0;
 934
 935         spin_lock(&qd_lru_lock);
 936         value = qd->qd_change;
 937         spin_unlock(&qd_lru_lock);
 938
 939         spin_lock(&gt->gt_spin);
 940         num = gt->gt_quota_scale_num;
 941         den = gt->gt_quota_scale_den;
 942         spin_unlock(&gt->gt_spin);
 943
 944         if (value < 0)
 945                 do_sync = 0;
 946         else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
 947                  (s64)be64_to_cpu(qd->qd_qb.qb_limit))
 948                 do_sync = 0;
 949         else {
 950                 value *= gfs2_jindex_size(sdp) * num;
 951                 value = div_s64(value, den);
 952                 value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
 953                 if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
 954                         do_sync = 0;
 955         }
 956
 957         return do_sync;
 958 }
 959
 960 void gfs2_quota_unlock(struct gfs2_inode *ip)
 961 {
 962         struct gfs2_alloc *al = ip->i_alloc;
 963         struct gfs2_quota_data *qda[4];
 964         unsigned int count = 0;
 965         unsigned int x;
 966
 967         if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
 968                 goto out;
 969
 970         for (x = 0; x < al->al_qd_num; x++) {
 971                 struct gfs2_quota_data *qd;
 972                 int sync;
 973
 974                 qd = al->al_qd[x];
 975                 sync = need_sync(qd);
 976
 977                 gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
 978
 979                 if (sync && qd_trylock(qd))
 980                         qda[count++] = qd;
 981         }
 982
 983         if (count) {
 984                 do_sync(count, qda);
 985                 for (x = 0; x < count; x++)
 986                         qd_unlock(qda[x]);
 987         }
 988
 989 out:
 990         gfs2_quota_unhold(ip);
 991 }
 992
 993 #define MAX_LINE 256
 994
 995 static int print_message(struct gfs2_quota_data *qd, char *type)
 996 {
 997         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 998
 999         printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\r\n",
1000                sdp->sd_fsname, type,
1001                (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
1002                qd->qd_id);
1003
1004         return 0;
1005 }
1006
1007 int gfs2_quota_check(struct gfs2_inode *ip, u32 uid, u32 gid)
1008 {
1009         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1010         struct gfs2_alloc *al = ip->i_alloc;
1011         struct gfs2_quota_data *qd;
1012         s64 value;
1013         unsigned int x;
1014         int error = 0;
1015
1016         if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
1017                 return 0;
1018
1019         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
1020                 return 0;
1021
1022         for (x = 0; x < al->al_qd_num; x++) {
1023                 qd = al->al_qd[x];
1024
1025                 if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1026                       (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
1027                         continue;
1028
1029                 value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
1030                 spin_lock(&qd_lru_lock);
1031                 value += qd->qd_change;
1032                 spin_unlock(&qd_lru_lock);
1033
1034                 if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
1035                         print_message(qd, "exceeded");
1036                         error = -EDQUOT;
1037                         break;
1038                 } else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
1039                            (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
1040                            time_after_eq(jiffies, qd->qd_last_warn +
1041                                          gfs2_tune_get(sdp,
1042                                                 gt_quota_warn_period) * HZ)) {
1043                         error = print_message(qd, "warning");
1044                         qd->qd_last_warn = jiffies;
1045                 }
1046         }
1047
1048         return error;
1049 }
1050
1051 void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1052                        u32 uid, u32 gid)
1053 {
1054         struct gfs2_alloc *al = ip->i_alloc;
1055         struct gfs2_quota_data *qd;
1056         unsigned int x;
1057
1058         if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1059                 return;
1060         if (ip->i_diskflags & GFS2_DIF_SYSTEM)
1061                 return;
1062
1063         for (x = 0; x < al->al_qd_num; x++) {
1064                 qd = al->al_qd[x];
1065
1066                 if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1067                     (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
1068                         do_qc(qd, change);
1069                 }
1070         }
1071 }
1072
1073 int gfs2_quota_sync(struct gfs2_sbd *sdp)
1074 {
1075         struct gfs2_quota_data **qda;
1076         unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
1077         unsigned int num_qd;
1078         unsigned int x;
1079         int error = 0;
1080
1081         sdp->sd_quota_sync_gen++;
1082
1083         qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1084         if (!qda)
1085                 return -ENOMEM;
1086
1087         do {
1088                 num_qd = 0;
1089
1090                 for (;;) {
1091                         error = qd_fish(sdp, qda + num_qd);
1092                         if (error || !qda[num_qd])
1093                                 break;
1094                         if (++num_qd == max_qd)
1095                                 break;
1096                 }
1097
1098                 if (num_qd) {
1099                         if (!error)
1100                                 error = do_sync(num_qd, qda);
1101                         if (!error)
1102                                 for (x = 0; x < num_qd; x++)
1103                                         qda[x]->qd_sync_gen =
1104                                                 sdp->sd_quota_sync_gen;
1105
1106                         for (x = 0; x < num_qd; x++)
1107                                 qd_unlock(qda[x]);
1108                 }
1109         } while (!error && num_qd == max_qd);
1110
1111         kfree(qda);
1112
1113         return error;
1114 }
1115
1116 int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, u32 id)
1117 {
1118         struct gfs2_quota_data *qd;
1119         struct gfs2_holder q_gh;
1120         int error;
1121
1122         error = qd_get(sdp, user, id, CREATE, &qd);
1123         if (error)
1124                 return error;
1125
1126         error = do_glock(qd, FORCE, &q_gh);
1127         if (!error)
1128                 gfs2_glock_dq_uninit(&q_gh);
1129
1130         qd_put(qd);
1131
1132         return error;
1133 }
1134
1135 static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
1136 {
1137         const struct gfs2_quota_change *str = buf;
1138
1139         qc->qc_change = be64_to_cpu(str->qc_change);
1140         qc->qc_flags = be32_to_cpu(str->qc_flags);
1141         qc->qc_id = be32_to_cpu(str->qc_id);
1142 }
1143
1144 int gfs2_quota_init(struct gfs2_sbd *sdp)
1145 {
1146         struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1147         unsigned int blocks = ip->i_disksize >> sdp->sd_sb.sb_bsize_shift;
1148         unsigned int x, slot = 0;
1149         unsigned int found = 0;
1150         u64 dblock;
1151         u32 extlen = 0;
1152         int error;
1153
1154         if (!ip->i_disksize || ip->i_disksize > (64 << 20) ||
1155             ip->i_disksize & (sdp->sd_sb.sb_bsize - 1)) {
1156                 gfs2_consist_inode(ip);
1157                 return -EIO;
1158         }
1159         sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1160         sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1161
1162         error = -ENOMEM;
1163
1164         sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1165                                        sizeof(unsigned char *), GFP_NOFS);
1166         if (!sdp->sd_quota_bitmap)
1167                 return error;
1168
1169         for (x = 0; x < sdp->sd_quota_chunks; x++) {
1170                 sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_NOFS);
1171                 if (!sdp->sd_quota_bitmap[x])
1172                         goto fail;
1173         }
1174
1175         for (x = 0; x < blocks; x++) {
1176                 struct buffer_head *bh;
1177                 unsigned int y;
1178
1179                 if (!extlen) {
1180                         int new = 0;
1181                         error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1182                         if (error)
1183                                 goto fail;
1184                 }
1185                 error = -EIO;
1186                 bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1187                 if (!bh)
1188                         goto fail;
1189                 if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1190                         brelse(bh);
1191                         goto fail;
1192                 }
1193
1194                 for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1195                      y++, slot++) {
1196                         struct gfs2_quota_change_host qc;
1197                         struct gfs2_quota_data *qd;
1198
1199                         gfs2_quota_change_in(&qc, bh->b_data +
1200                                           sizeof(struct gfs2_meta_header) +
1201                                           y * sizeof(struct gfs2_quota_change));
1202                         if (!qc.qc_change)
1203                                 continue;
1204
1205                         error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1206                                          qc.qc_id, &qd);
1207                         if (error) {
1208                                 brelse(bh);
1209                                 goto fail;
1210                         }
1211
1212                         set_bit(QDF_CHANGE, &qd->qd_flags);
1213                         qd->qd_change = qc.qc_change;
1214                         qd->qd_slot = slot;
1215                         qd->qd_slot_count = 1;
1216
1217                         spin_lock(&qd_lru_lock);
1218                         gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1219                         list_add(&qd->qd_list, &sdp->sd_quota_list);
1220                         atomic_inc(&sdp->sd_quota_count);
1221                         spin_unlock(&qd_lru_lock);
1222
1223                         found++;
1224                 }
1225
1226                 brelse(bh);
1227                 dblock++;
1228                 extlen--;
1229         }
1230
1231         if (found)
1232                 fs_info(sdp, "found %u quota changes\n", found);
1233
1234         return 0;
1235
1236 fail:
1237         gfs2_quota_cleanup(sdp);
1238         return error;
1239 }
1240
1241 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1242 {
1243         struct list_head *head = &sdp->sd_quota_list;
1244         struct gfs2_quota_data *qd;
1245         unsigned int x;
1246
1247         spin_lock(&qd_lru_lock);
1248         while (!list_empty(head)) {
1249                 qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1250
1251                 if (atomic_read(&qd->qd_count) > 1 ||
1252                     (atomic_read(&qd->qd_count) &&
1253                      !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1254                         list_move(&qd->qd_list, head);
1255                         spin_unlock(&qd_lru_lock);
1256                         schedule();
1257                         spin_lock(&qd_lru_lock);
1258                         continue;
1259                 }
1260
1261                 list_del(&qd->qd_list);
1262                 /* Also remove if this qd exists in the reclaim list */
1263                 if (!list_empty(&qd->qd_reclaim)) {
1264                         list_del_init(&qd->qd_reclaim);
1265                         atomic_dec(&qd_lru_count);
1266                 }
1267                 atomic_dec(&sdp->sd_quota_count);
1268                 spin_unlock(&qd_lru_lock);
1269
1270                 if (!atomic_read(&qd->qd_count)) {
1271                         gfs2_assert_warn(sdp, !qd->qd_change);
1272                         gfs2_assert_warn(sdp, !qd->qd_slot_count);
1273                 } else
1274                         gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1275                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
1276
1277                 gfs2_glock_put(qd->qd_gl);
1278                 kmem_cache_free(gfs2_quotad_cachep, qd);
1279
1280                 spin_lock(&qd_lru_lock);
1281         }
1282         spin_unlock(&qd_lru_lock);
1283
1284         gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1285
1286         if (sdp->sd_quota_bitmap) {
1287                 for (x = 0; x < sdp->sd_quota_chunks; x++)
1288                         kfree(sdp->sd_quota_bitmap[x]);
1289                 kfree(sdp->sd_quota_bitmap);
1290         }
1291 }
1292
1293 static void quotad_error(struct gfs2_sbd *sdp, const char *msg, int error)
1294 {
1295         if (error == 0 || error == -EROFS)
1296                 return;
1297         if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
1298                 fs_err(sdp, "gfs2_quotad: %s error %d\n", msg, error);
1299 }
1300
1301 static void quotad_check_timeo(struct gfs2_sbd *sdp, const char *msg,
1302                                int (*fxn)(struct gfs2_sbd *sdp),
1303                                unsigned long t, unsigned long *timeo,
1304                                unsigned int *new_timeo)
1305 {
1306         if (t >= *timeo) {
1307                 int error = fxn(sdp);
1308                 quotad_error(sdp, msg, error);
1309                 *timeo = gfs2_tune_get_i(&sdp->sd_tune, new_timeo) * HZ;
1310         } else {
1311                 *timeo -= t;
1312         }
1313 }
1314
1315 static void quotad_check_trunc_list(struct gfs2_sbd *sdp)
1316 {
1317         struct gfs2_inode *ip;
1318
1319         while(1) {
1320                 ip = NULL;
1321                 spin_lock(&sdp->sd_trunc_lock);
1322                 if (!list_empty(&sdp->sd_trunc_list)) {
1323                         ip = list_entry(sdp->sd_trunc_list.next,
1324                                         struct gfs2_inode, i_trunc_list);
1325                         list_del_init(&ip->i_trunc_list);
1326                 }
1327                 spin_unlock(&sdp->sd_trunc_lock);
1328                 if (ip == NULL)
1329                         return;
1330                 gfs2_glock_finish_truncate(ip);
1331         }
1332 }
1333
1334 /**
1335  * gfs2_quotad - Write cached quota changes into the quota file
1336  * @sdp: Pointer to GFS2 superblock
1337  *
1338  */
1339
1340 int gfs2_quotad(void *data)
1341 {
1342         struct gfs2_sbd *sdp = data;
1343         struct gfs2_tune *tune = &sdp->sd_tune;
1344         unsigned long statfs_timeo = 0;
1345         unsigned long quotad_timeo = 0;
1346         unsigned long t = 0;
1347         DEFINE_WAIT(wait);
1348         int empty;
1349
1350         while (!kthread_should_stop()) {
1351
1352                 /* Update the master statfs file */
1353                 quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
1354                                    &statfs_timeo, &tune->gt_statfs_quantum);
1355
1356                 /* Update quota file */
1357                 quotad_check_timeo(sdp, "sync", gfs2_quota_sync, t,
1358                                    &quotad_timeo, &tune->gt_quota_quantum);
1359
1360                 /* Check for & recover partially truncated inodes */
1361                 quotad_check_trunc_list(sdp);
1362
1363                 if (freezing(current))
1364                         refrigerator();
1365                 t = min(quotad_timeo, statfs_timeo);
1366
1367                 prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);
1368                 spin_lock(&sdp->sd_trunc_lock);
1369                 empty = list_empty(&sdp->sd_trunc_list);
1370                 spin_unlock(&sdp->sd_trunc_lock);
1371                 if (empty)
1372                         t -= schedule_timeout(t);
1373                 else
1374                         t = 0;
1375                 finish_wait(&sdp->sd_quota_wait, &wait);
1376         }
1377
1378         return 0;
1379 }
1380