fs/gfs2/quota.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 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 v.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/tty.h>
  45 #include <linux/sort.h>
  46 #include <asm/semaphore.h>
  47
  48 #include "gfs2.h"
  49 #include "bmap.h"
  50 #include "glock.h"
  51 #include "glops.h"
  52 #include "jdata.h"
  53 #include "log.h"
  54 #include "meta_io.h"
  55 #include "quota.h"
  56 #include "rgrp.h"
  57 #include "super.h"
  58 #include "trans.h"
  59
  60 #define QUOTA_USER 1
  61 #define QUOTA_GROUP 0
  62
  63 static uint64_t qd2offset(struct gfs2_quota_data *qd)
  64 {
  65         uint64_t offset;
  66
  67         offset = 2 * (uint64_t)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
  68         offset *= sizeof(struct gfs2_quota);
  69
  70         return offset;
  71 }
  72
  73 static int qd_alloc(struct gfs2_sbd *sdp, int user, uint32_t id,
  74                     struct gfs2_quota_data **qdp)
  75 {
  76         struct gfs2_quota_data *qd;
  77         int error;
  78
  79         qd = kzalloc(sizeof(struct gfs2_quota_data), GFP_KERNEL);
  80         if (!qd)
  81                 return -ENOMEM;
  82
  83         qd->qd_count = 1;
  84         qd->qd_id = id;
  85         if (user)
  86                 set_bit(QDF_USER, &qd->qd_flags);
  87         qd->qd_slot = -1;
  88
  89         error = gfs2_glock_get(sdp, 2 * (uint64_t)id + !user,
  90                               &gfs2_quota_glops, CREATE, &qd->qd_gl);
  91         if (error)
  92                 goto fail;
  93
  94         error = gfs2_lvb_hold(qd->qd_gl);
  95         gfs2_glock_put(qd->qd_gl);
  96         if (error)
  97                 goto fail;
  98
  99         *qdp = qd;
 100
 101         return 0;
 102
 103  fail:
 104         kfree(qd);
 105         return error;
 106 }
 107
 108 static int qd_get(struct gfs2_sbd *sdp, int user, uint32_t id, int create,
 109                   struct gfs2_quota_data **qdp)
 110 {
 111         struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
 112         int error, found;
 113
 114         *qdp = NULL;
 115
 116         for (;;) {
 117                 found = 0;
 118                 spin_lock(&sdp->sd_quota_spin);
 119                 list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
 120                         if (qd->qd_id == id &&
 121                             !test_bit(QDF_USER, &qd->qd_flags) == !user) {
 122                                 qd->qd_count++;
 123                                 found = 1;
 124                                 break;
 125                         }
 126                 }
 127
 128                 if (!found)
 129                         qd = NULL;
 130
 131                 if (!qd && new_qd) {
 132                         qd = new_qd;
 133                         list_add(&qd->qd_list, &sdp->sd_quota_list);
 134                         atomic_inc(&sdp->sd_quota_count);
 135                         new_qd = NULL;
 136                 }
 137
 138                 spin_unlock(&sdp->sd_quota_spin);
 139
 140                 if (qd || !create) {
 141                         if (new_qd) {
 142                                 gfs2_lvb_unhold(new_qd->qd_gl);
 143                                 kfree(new_qd);
 144                         }
 145                         *qdp = qd;
 146                         return 0;
 147                 }
 148
 149                 error = qd_alloc(sdp, user, id, &new_qd);
 150                 if (error)
 151                         return error;
 152         }
 153 }
 154
 155 static void qd_hold(struct gfs2_quota_data *qd)
 156 {
 157         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 158
 159         spin_lock(&sdp->sd_quota_spin);
 160         gfs2_assert(sdp, qd->qd_count);
 161         qd->qd_count++;
 162         spin_unlock(&sdp->sd_quota_spin);
 163 }
 164
 165 static void qd_put(struct gfs2_quota_data *qd)
 166 {
 167         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 168         spin_lock(&sdp->sd_quota_spin);
 169         gfs2_assert(sdp, qd->qd_count);
 170         if (!--qd->qd_count)
 171                 qd->qd_last_touched = jiffies;
 172         spin_unlock(&sdp->sd_quota_spin);
 173 }
 174
 175 static int slot_get(struct gfs2_quota_data *qd)
 176 {
 177         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 178         unsigned int c, o = 0, b;
 179         unsigned char byte = 0;
 180
 181         spin_lock(&sdp->sd_quota_spin);
 182
 183         if (qd->qd_slot_count++) {
 184                 spin_unlock(&sdp->sd_quota_spin);
 185                 return 0;
 186         }
 187
 188         for (c = 0; c < sdp->sd_quota_chunks; c++)
 189                 for (o = 0; o < PAGE_SIZE; o++) {
 190                         byte = sdp->sd_quota_bitmap[c][o];
 191                         if (byte != 0xFF)
 192                                 goto found;
 193                 }
 194
 195         goto fail;
 196
 197  found:
 198         for (b = 0; b < 8; b++)
 199                 if (!(byte & (1 << b)))
 200                         break;
 201         qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
 202
 203         if (qd->qd_slot >= sdp->sd_quota_slots)
 204                 goto fail;
 205
 206         sdp->sd_quota_bitmap[c][o] |= 1 << b;
 207
 208         spin_unlock(&sdp->sd_quota_spin);
 209
 210         return 0;
 211
 212  fail:
 213         qd->qd_slot_count--;
 214         spin_unlock(&sdp->sd_quota_spin);
 215         return -ENOSPC;
 216 }
 217
 218 static void slot_hold(struct gfs2_quota_data *qd)
 219 {
 220         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 221
 222         spin_lock(&sdp->sd_quota_spin);
 223         gfs2_assert(sdp, qd->qd_slot_count);
 224         qd->qd_slot_count++;
 225         spin_unlock(&sdp->sd_quota_spin);
 226 }
 227
 228 static void slot_put(struct gfs2_quota_data *qd)
 229 {
 230         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 231
 232         spin_lock(&sdp->sd_quota_spin);
 233         gfs2_assert(sdp, qd->qd_slot_count);
 234         if (!--qd->qd_slot_count) {
 235                 gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
 236                 qd->qd_slot = -1;
 237         }
 238         spin_unlock(&sdp->sd_quota_spin);
 239 }
 240
 241 static int bh_get(struct gfs2_quota_data *qd)
 242 {
 243         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 244         struct gfs2_inode *ip = sdp->sd_qc_inode;
 245         unsigned int block, offset;
 246         uint64_t dblock;
 247         int new = 0;
 248         struct buffer_head *bh;
 249         int error;
 250
 251         down(&sdp->sd_quota_mutex);
 252
 253         if (qd->qd_bh_count++) {
 254                 up(&sdp->sd_quota_mutex);
 255                 return 0;
 256         }
 257
 258         block = qd->qd_slot / sdp->sd_qc_per_block;
 259         offset = qd->qd_slot % sdp->sd_qc_per_block;;
 260
 261         error = gfs2_block_map(ip, block, &new, &dblock, NULL);
 262         if (error)
 263                 goto fail;
 264         error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT, &bh);
 265         if (error)
 266                 goto fail;
 267         error = -EIO;
 268         if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
 269                 goto fail_brelse;
 270
 271         qd->qd_bh = bh;
 272         qd->qd_bh_qc = (struct gfs2_quota_change *)
 273                 (bh->b_data + sizeof(struct gfs2_meta_header) +
 274                  offset * sizeof(struct gfs2_quota_change));
 275
 276         up(&sdp->sd_quota_mutex);
 277
 278         return 0;
 279
 280  fail_brelse:
 281         brelse(bh);
 282
 283  fail:
 284         qd->qd_bh_count--;
 285         up(&sdp->sd_quota_mutex);
 286         return error;
 287 }
 288
 289 static void bh_put(struct gfs2_quota_data *qd)
 290 {
 291         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 292
 293         down(&sdp->sd_quota_mutex);
 294         gfs2_assert(sdp, qd->qd_bh_count);
 295         if (!--qd->qd_bh_count) {
 296                 brelse(qd->qd_bh);
 297                 qd->qd_bh = NULL;
 298                 qd->qd_bh_qc = NULL;
 299         }
 300         up(&sdp->sd_quota_mutex);
 301 }
 302
 303 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
 304 {
 305         struct gfs2_quota_data *qd = NULL;
 306         int error;
 307         int found = 0;
 308
 309         *qdp = NULL;
 310
 311         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 312                 return 0;
 313
 314         spin_lock(&sdp->sd_quota_spin);
 315
 316         list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
 317                 if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
 318                     !test_bit(QDF_CHANGE, &qd->qd_flags) ||
 319                     qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
 320                         continue;
 321
 322                 list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 323
 324                 set_bit(QDF_LOCKED, &qd->qd_flags);
 325                 gfs2_assert_warn(sdp, qd->qd_count);
 326                 qd->qd_count++;
 327                 qd->qd_change_sync = qd->qd_change;
 328                 gfs2_assert_warn(sdp, qd->qd_slot_count);
 329                 qd->qd_slot_count++;
 330                 found = 1;
 331
 332                 break;
 333         }
 334
 335         if (!found)
 336                 qd = NULL;
 337
 338         spin_unlock(&sdp->sd_quota_spin);
 339
 340         if (qd) {
 341                 gfs2_assert_warn(sdp, qd->qd_change_sync);
 342                 error = bh_get(qd);
 343                 if (error) {
 344                         clear_bit(QDF_LOCKED, &qd->qd_flags);
 345                         slot_put(qd);
 346                         qd_put(qd);
 347                         return error;
 348                 }
 349         }
 350
 351         *qdp = qd;
 352
 353         return 0;
 354 }
 355
 356 static int qd_trylock(struct gfs2_quota_data *qd)
 357 {
 358         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 359
 360         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 361                 return 0;
 362
 363         spin_lock(&sdp->sd_quota_spin);
 364
 365         if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
 366             !test_bit(QDF_CHANGE, &qd->qd_flags)) {
 367                 spin_unlock(&sdp->sd_quota_spin);
 368                 return 0;
 369         }
 370
 371         list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 372
 373         set_bit(QDF_LOCKED, &qd->qd_flags);
 374         gfs2_assert_warn(sdp, qd->qd_count);
 375         qd->qd_count++;
 376         qd->qd_change_sync = qd->qd_change;
 377         gfs2_assert_warn(sdp, qd->qd_slot_count);
 378         qd->qd_slot_count++;
 379
 380         spin_unlock(&sdp->sd_quota_spin);
 381
 382         gfs2_assert_warn(sdp, qd->qd_change_sync);
 383         if (bh_get(qd)) {
 384                 clear_bit(QDF_LOCKED, &qd->qd_flags);
 385                 slot_put(qd);
 386                 qd_put(qd);
 387                 return 0;
 388         }
 389
 390         return 1;
 391 }
 392
 393 static void qd_unlock(struct gfs2_quota_data *qd)
 394 {
 395         gfs2_assert_warn(qd->qd_gl->gl_sbd, test_bit(QDF_LOCKED, &qd->qd_flags));
 396         clear_bit(QDF_LOCKED, &qd->qd_flags);
 397         bh_put(qd);
 398         slot_put(qd);
 399         qd_put(qd);
 400 }
 401
 402 static int qdsb_get(struct gfs2_sbd *sdp, int user, uint32_t id, int create,
 403                     struct gfs2_quota_data **qdp)
 404 {
 405         int error;
 406
 407         error = qd_get(sdp, user, id, create, qdp);
 408         if (error)
 409                 return error;
 410
 411         error = slot_get(*qdp);
 412         if (error)
 413                 goto fail;
 414
 415         error = bh_get(*qdp);
 416         if (error)
 417                 goto fail_slot;
 418
 419         return 0;
 420
 421  fail_slot:
 422         slot_put(*qdp);
 423
 424  fail:
 425         qd_put(*qdp);
 426         return error;
 427 }
 428
 429 static void qdsb_put(struct gfs2_quota_data *qd)
 430 {
 431         bh_put(qd);
 432         slot_put(qd);
 433         qd_put(qd);
 434 }
 435
 436 int gfs2_quota_hold(struct gfs2_inode *ip, uint32_t uid, uint32_t gid)
 437 {
 438         struct gfs2_sbd *sdp = ip->i_sbd;
 439         struct gfs2_alloc *al = &ip->i_alloc;
 440         struct gfs2_quota_data **qd = al->al_qd;
 441         int error;
 442
 443         if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
 444             gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
 445                 return -EIO;
 446
 447         if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
 448                 return 0;
 449
 450         error = qdsb_get(sdp, QUOTA_USER, ip->i_di.di_uid, CREATE, qd);
 451         if (error)
 452                 goto out;
 453         al->al_qd_num++;
 454         qd++;
 455
 456         error = qdsb_get(sdp, QUOTA_GROUP, ip->i_di.di_gid, CREATE, qd);
 457         if (error)
 458                 goto out;
 459         al->al_qd_num++;
 460         qd++;
 461
 462         if (uid != NO_QUOTA_CHANGE && uid != ip->i_di.di_uid) {
 463                 error = qdsb_get(sdp, QUOTA_USER, uid, CREATE, qd);
 464                 if (error)
 465                         goto out;
 466                 al->al_qd_num++;
 467                 qd++;
 468         }
 469
 470         if (gid != NO_QUOTA_CHANGE && gid != ip->i_di.di_gid) {
 471                 error = qdsb_get(sdp, QUOTA_GROUP, gid, CREATE, qd);
 472                 if (error)
 473                         goto out;
 474                 al->al_qd_num++;
 475                 qd++;
 476         }
 477
 478  out:
 479         if (error)
 480                 gfs2_quota_unhold(ip);
 481
 482         return error;
 483 }
 484
 485 void gfs2_quota_unhold(struct gfs2_inode *ip)
 486 {
 487         struct gfs2_sbd *sdp = ip->i_sbd;
 488         struct gfs2_alloc *al = &ip->i_alloc;
 489         unsigned int x;
 490
 491         gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
 492
 493         for (x = 0; x < al->al_qd_num; x++) {
 494                 qdsb_put(al->al_qd[x]);
 495                 al->al_qd[x] = NULL;
 496         }
 497         al->al_qd_num = 0;
 498 }
 499
 500 static int sort_qd(const void *a, const void *b)
 501 {
 502         struct gfs2_quota_data *qd_a = *(struct gfs2_quota_data **)a;
 503         struct gfs2_quota_data *qd_b = *(struct gfs2_quota_data **)b;
 504         int ret = 0;
 505
 506         if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
 507             !test_bit(QDF_USER, &qd_b->qd_flags)) {
 508                 if (test_bit(QDF_USER, &qd_a->qd_flags))
 509                         ret = -1;
 510                 else
 511                         ret = 1;
 512         } else {
 513                 if (qd_a->qd_id < qd_b->qd_id)
 514                         ret = -1;
 515                 else if (qd_a->qd_id > qd_b->qd_id)
 516                         ret = 1;
 517         }
 518
 519         return ret;
 520 }
 521
 522 static void do_qc(struct gfs2_quota_data *qd, int64_t change)
 523 {
 524         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 525         struct gfs2_inode *ip = sdp->sd_qc_inode;
 526         struct gfs2_quota_change *qc = qd->qd_bh_qc;
 527         int64_t x;
 528
 529         down(&sdp->sd_quota_mutex);
 530         gfs2_trans_add_bh(ip->i_gl, qd->qd_bh);
 531
 532         if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
 533                 qc->qc_change = 0;
 534                 qc->qc_flags = 0;
 535                 if (test_bit(QDF_USER, &qd->qd_flags))
 536                         qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
 537                 qc->qc_id = cpu_to_be32(qd->qd_id);
 538         }
 539
 540         x = qc->qc_change;
 541         x = be64_to_cpu(x) + change;
 542         qc->qc_change = cpu_to_be64(x);
 543
 544         spin_lock(&sdp->sd_quota_spin);
 545         qd->qd_change = x;
 546         spin_unlock(&sdp->sd_quota_spin);
 547
 548         if (!x) {
 549                 gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
 550                 clear_bit(QDF_CHANGE, &qd->qd_flags);
 551                 qc->qc_flags = 0;
 552                 qc->qc_id = 0;
 553                 slot_put(qd);
 554                 qd_put(qd);
 555         } else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
 556                 qd_hold(qd);
 557                 slot_hold(qd);
 558         }
 559
 560         up(&sdp->sd_quota_mutex);
 561 }
 562
 563 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 564 {
 565         struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
 566         struct gfs2_inode *ip = sdp->sd_quota_inode;
 567         unsigned int data_blocks, ind_blocks;
 568         struct gfs2_holder *ghs, i_gh;
 569         unsigned int qx, x;
 570         struct gfs2_quota_data *qd;
 571         uint64_t offset;
 572         unsigned int nalloc = 0;
 573         struct gfs2_alloc *al = NULL;
 574         int error;
 575
 576         gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
 577                               &data_blocks, &ind_blocks);
 578
 579         ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_KERNEL);
 580         if (!ghs)
 581                 return -ENOMEM;
 582
 583         sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
 584         for (qx = 0; qx < num_qd; qx++) {
 585                 error = gfs2_glock_nq_init(qda[qx]->qd_gl,
 586                                            LM_ST_EXCLUSIVE,
 587                                            GL_NOCACHE, &ghs[qx]);
 588                 if (error)
 589                         goto out;
 590         }
 591
 592         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 593         if (error)
 594                 goto out;
 595
 596         for (x = 0; x < num_qd; x++) {
 597                 int alloc_required;
 598
 599                 offset = qd2offset(qda[x]);
 600                 error = gfs2_write_alloc_required(ip, offset,
 601                                                   sizeof(struct gfs2_quota),
 602                                                   &alloc_required);
 603                 if (error)
 604                         goto out_gunlock;
 605                 if (alloc_required)
 606                         nalloc++;
 607         }
 608
 609         if (nalloc) {
 610                 al = gfs2_alloc_get(ip);
 611
 612                 al->al_requested = nalloc * (data_blocks + ind_blocks);
 613
 614                 error = gfs2_inplace_reserve(ip);
 615                 if (error)
 616                         goto out_alloc;
 617
 618                 error = gfs2_trans_begin(sdp,
 619                                          al->al_rgd->rd_ri.ri_length +
 620                                          num_qd * data_blocks +
 621                                          nalloc * ind_blocks +
 622                                          RES_DINODE + num_qd +
 623                                          RES_STATFS, 0);
 624                 if (error)
 625                         goto out_ipres;
 626         } else {
 627                 error = gfs2_trans_begin(sdp,
 628                                          num_qd * data_blocks +
 629                                          RES_DINODE + num_qd, 0);
 630                 if (error)
 631                         goto out_gunlock;
 632         }
 633
 634         for (x = 0; x < num_qd; x++) {
 635                 char buf[sizeof(struct gfs2_quota)];
 636                 struct gfs2_quota q;
 637
 638                 qd = qda[x];
 639                 offset = qd2offset(qd);
 640
 641                 /* The quota file may not be a multiple of
 642                    sizeof(struct gfs2_quota) bytes. */
 643                 memset(buf, 0, sizeof(struct gfs2_quota));
 644
 645                 error = gfs2_jdata_read_mem(ip, buf, offset,
 646                                             sizeof(struct gfs2_quota));
 647                 if (error < 0)
 648                         goto out_end_trans;
 649
 650                 gfs2_quota_in(&q, buf);
 651                 q.qu_value += qda[x]->qd_change_sync;
 652                 gfs2_quota_out(&q, buf);
 653
 654                 error = gfs2_jdata_write_mem(ip, buf, offset,
 655                                              sizeof(struct gfs2_quota));
 656                 if (error < 0)
 657                         goto out_end_trans;
 658                 else if (error != sizeof(struct gfs2_quota)) {
 659                         error = -EIO;
 660                         goto out_end_trans;
 661                 }
 662
 663                 do_qc(qd, -qd->qd_change_sync);
 664
 665                 memset(&qd->qd_qb, 0, sizeof(struct gfs2_quota_lvb));
 666                 qd->qd_qb.qb_magic = GFS2_MAGIC;
 667                 qd->qd_qb.qb_limit = q.qu_limit;
 668                 qd->qd_qb.qb_warn = q.qu_warn;
 669                 qd->qd_qb.qb_value = q.qu_value;
 670
 671                 gfs2_quota_lvb_out(&qd->qd_qb, qd->qd_gl->gl_lvb);
 672         }
 673
 674         error = 0;
 675
 676  out_end_trans:
 677         gfs2_trans_end(sdp);
 678
 679  out_ipres:
 680         if (nalloc)
 681                 gfs2_inplace_release(ip);
 682
 683  out_alloc:
 684         if (nalloc)
 685                 gfs2_alloc_put(ip);
 686
 687  out_gunlock:
 688         gfs2_glock_dq_uninit(&i_gh);
 689
 690  out:
 691         while (qx--)
 692                 gfs2_glock_dq_uninit(&ghs[qx]);
 693         kfree(ghs);
 694         gfs2_log_flush_glock(ip->i_gl);
 695
 696         return error;
 697 }
 698
 699 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
 700                     struct gfs2_holder *q_gh)
 701 {
 702         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 703         struct gfs2_holder i_gh;
 704         struct gfs2_quota q;
 705         char buf[sizeof(struct gfs2_quota)];
 706         int error;
 707
 708  restart:
 709         error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
 710         if (error)
 711                 return error;
 712
 713         gfs2_quota_lvb_in(&qd->qd_qb, qd->qd_gl->gl_lvb);
 714
 715         if (force_refresh || qd->qd_qb.qb_magic != GFS2_MAGIC) {
 716                 gfs2_glock_dq_uninit(q_gh);
 717                 error = gfs2_glock_nq_init(qd->qd_gl,
 718                                           LM_ST_EXCLUSIVE, GL_NOCACHE,
 719                                           q_gh);
 720                 if (error)
 721                         return error;
 722
 723                 error = gfs2_glock_nq_init(sdp->sd_quota_inode->i_gl,
 724                                           LM_ST_SHARED, 0,
 725                                           &i_gh);
 726                 if (error)
 727                         goto fail;
 728
 729                 memset(buf, 0, sizeof(struct gfs2_quota));
 730
 731                 error = gfs2_jdata_read_mem(sdp->sd_quota_inode, buf,
 732                                             qd2offset(qd),
 733                                             sizeof(struct gfs2_quota));
 734                 if (error < 0)
 735                         goto fail_gunlock;
 736
 737                 gfs2_glock_dq_uninit(&i_gh);
 738
 739                 gfs2_quota_in(&q, buf);
 740
 741                 memset(&qd->qd_qb, 0, sizeof(struct gfs2_quota_lvb));
 742                 qd->qd_qb.qb_magic = GFS2_MAGIC;
 743                 qd->qd_qb.qb_limit = q.qu_limit;
 744                 qd->qd_qb.qb_warn = q.qu_warn;
 745                 qd->qd_qb.qb_value = q.qu_value;
 746
 747                 gfs2_quota_lvb_out(&qd->qd_qb, qd->qd_gl->gl_lvb);
 748
 749                 if (gfs2_glock_is_blocking(qd->qd_gl)) {
 750                         gfs2_glock_dq_uninit(q_gh);
 751                         force_refresh = 0;
 752                         goto restart;
 753                 }
 754         }
 755
 756         return 0;
 757
 758  fail_gunlock:
 759         gfs2_glock_dq_uninit(&i_gh);
 760
 761  fail:
 762         gfs2_glock_dq_uninit(q_gh);
 763
 764         return error;
 765 }
 766
 767 int gfs2_quota_lock(struct gfs2_inode *ip, uint32_t uid, uint32_t gid)
 768 {
 769         struct gfs2_sbd *sdp = ip->i_sbd;
 770         struct gfs2_alloc *al = &ip->i_alloc;
 771         unsigned int x;
 772         int error = 0;
 773
 774         gfs2_quota_hold(ip, uid, gid);
 775
 776         if (capable(CAP_SYS_RESOURCE) ||
 777             sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
 778                 return 0;
 779
 780         sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
 781              sort_qd, NULL);
 782
 783         for (x = 0; x < al->al_qd_num; x++) {
 784                 error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
 785                 if (error)
 786                         break;
 787         }
 788
 789         if (!error)
 790                 set_bit(GIF_QD_LOCKED, &ip->i_flags);
 791         else {
 792                 while (x--)
 793                         gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
 794                 gfs2_quota_unhold(ip);
 795         }
 796
 797         return error;
 798 }
 799
 800 static int need_sync(struct gfs2_quota_data *qd)
 801 {
 802         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 803         struct gfs2_tune *gt = &sdp->sd_tune;
 804         int64_t value;
 805         unsigned int num, den;
 806         int do_sync = 1;
 807
 808         if (!qd->qd_qb.qb_limit)
 809                 return 0;
 810
 811         spin_lock(&sdp->sd_quota_spin);
 812         value = qd->qd_change;
 813         spin_unlock(&sdp->sd_quota_spin);
 814
 815         spin_lock(&gt->gt_spin);
 816         num = gt->gt_quota_scale_num;
 817         den = gt->gt_quota_scale_den;
 818         spin_unlock(&gt->gt_spin);
 819
 820         if (value < 0)
 821                 do_sync = 0;
 822         else if (qd->qd_qb.qb_value >= (int64_t)qd->qd_qb.qb_limit)
 823                 do_sync = 0;
 824         else {
 825                 value *= gfs2_jindex_size(sdp) * num;
 826                 do_div(value, den);
 827                 value += qd->qd_qb.qb_value;
 828                 if (value < (int64_t)qd->qd_qb.qb_limit)
 829                         do_sync = 0;
 830         }
 831
 832         return do_sync;
 833 }
 834
 835 void gfs2_quota_unlock(struct gfs2_inode *ip)
 836 {
 837         struct gfs2_alloc *al = &ip->i_alloc;
 838         struct gfs2_quota_data *qda[4];
 839         unsigned int count = 0;
 840         unsigned int x;
 841
 842         if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
 843                 goto out;
 844
 845         for (x = 0; x < al->al_qd_num; x++) {
 846                 struct gfs2_quota_data *qd;
 847                 int sync;
 848
 849                 qd = al->al_qd[x];
 850                 sync = need_sync(qd);
 851
 852                 gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
 853
 854                 if (sync && qd_trylock(qd))
 855                         qda[count++] = qd;
 856         }
 857
 858         if (count) {
 859                 do_sync(count, qda);
 860                 for (x = 0; x < count; x++)
 861                         qd_unlock(qda[x]);
 862         }
 863
 864  out:
 865         gfs2_quota_unhold(ip);
 866 }
 867
 868 #define MAX_LINE 256
 869
 870 static int print_message(struct gfs2_quota_data *qd, char *type)
 871 {
 872         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 873         char *line;
 874         int len;
 875
 876         line = kmalloc(MAX_LINE, GFP_KERNEL);
 877         if (!line)
 878                 return -ENOMEM;
 879
 880         len = snprintf(line, MAX_LINE-1, "GFS2: fsid=%s: quota %s for %s %u\r\n",
 881                        sdp->sd_fsname, type,
 882                        (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
 883                        qd->qd_id);
 884         line[MAX_LINE-1] = 0;
 885
 886         if (current->signal) { /* Is this test still required? */
 887                 tty_write_message(current->signal->tty, line);
 888         }
 889
 890         kfree(line);
 891
 892         return 0;
 893 }
 894
 895 int gfs2_quota_check(struct gfs2_inode *ip, uint32_t uid, uint32_t gid)
 896 {
 897         struct gfs2_sbd *sdp = ip->i_sbd;
 898         struct gfs2_alloc *al = &ip->i_alloc;
 899         struct gfs2_quota_data *qd;
 900         int64_t value;
 901         unsigned int x;
 902         int error = 0;
 903
 904         if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
 905                 return 0;
 906
 907         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
 908                 return 0;
 909
 910         for (x = 0; x < al->al_qd_num; x++) {
 911                 qd = al->al_qd[x];
 912
 913                 if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
 914                       (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
 915                         continue;
 916
 917                 value = qd->qd_qb.qb_value;
 918                 spin_lock(&sdp->sd_quota_spin);
 919                 value += qd->qd_change;
 920                 spin_unlock(&sdp->sd_quota_spin);
 921
 922                 if (qd->qd_qb.qb_limit && (int64_t)qd->qd_qb.qb_limit < value) {
 923                         print_message(qd, "exceeded");
 924                         error = -EDQUOT;
 925                         break;
 926                 } else if (qd->qd_qb.qb_warn &&
 927                            (int64_t)qd->qd_qb.qb_warn < value &&
 928                            time_after_eq(jiffies, qd->qd_last_warn +
 929                                          gfs2_tune_get(sdp, gt_quota_warn_period) * HZ)) {
 930                         error = print_message(qd, "warning");
 931                         qd->qd_last_warn = jiffies;
 932                 }
 933         }
 934
 935         return error;
 936 }
 937
 938 void gfs2_quota_change(struct gfs2_inode *ip, int64_t change,
 939                        uint32_t uid, uint32_t gid)
 940 {
 941         struct gfs2_alloc *al = &ip->i_alloc;
 942         struct gfs2_quota_data *qd;
 943         unsigned int x;
 944         unsigned int found = 0;
 945
 946         if (gfs2_assert_warn(ip->i_sbd, change))
 947                 return;
 948         if (ip->i_di.di_flags & GFS2_DIF_SYSTEM)
 949                 return;
 950
 951         for (x = 0; x < al->al_qd_num; x++) {
 952                 qd = al->al_qd[x];
 953
 954                 if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
 955                     (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
 956                         do_qc(qd, change);
 957                         found++;
 958                 }
 959         }
 960 }
 961
 962 int gfs2_quota_sync(struct gfs2_sbd *sdp)
 963 {
 964         struct gfs2_quota_data **qda;
 965         unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
 966         unsigned int num_qd;
 967         unsigned int x;
 968         int error = 0;
 969
 970         sdp->sd_quota_sync_gen++;
 971
 972         qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
 973         if (!qda)
 974                 return -ENOMEM;
 975
 976         do {
 977                 num_qd = 0;
 978
 979                 for (;;) {
 980                         error = qd_fish(sdp, qda + num_qd);
 981                         if (error || !qda[num_qd])
 982                                 break;
 983                         if (++num_qd == max_qd)
 984                                 break;
 985                 }
 986
 987                 if (num_qd) {
 988                         if (!error)
 989                                 error = do_sync(num_qd, qda);
 990                         if (!error)
 991                                 for (x = 0; x < num_qd; x++)
 992                                         qda[x]->qd_sync_gen =
 993                                                 sdp->sd_quota_sync_gen;
 994
 995                         for (x = 0; x < num_qd; x++)
 996                                 qd_unlock(qda[x]);
 997                 }
 998         } while (!error && num_qd == max_qd);
 999
1000         kfree(qda);
1001
1002         return error;
1003 }
1004
1005 int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, uint32_t id)
1006 {
1007         struct gfs2_quota_data *qd;
1008         struct gfs2_holder q_gh;
1009         int error;
1010
1011         error = qd_get(sdp, user, id, CREATE, &qd);
1012         if (error)
1013                 return error;
1014
1015         error = do_glock(qd, FORCE, &q_gh);
1016         if (!error)
1017                 gfs2_glock_dq_uninit(&q_gh);
1018
1019         qd_put(qd);
1020
1021         return error;
1022 }
1023
1024 int gfs2_quota_read(struct gfs2_sbd *sdp, int user, uint32_t id,
1025                     struct gfs2_quota *q)
1026 {
1027         struct gfs2_quota_data *qd;
1028         struct gfs2_holder q_gh;
1029         int error;
1030
1031         if (((user) ? (id != current->fsuid) : (!in_group_p(id))) &&
1032             !capable(CAP_SYS_ADMIN))
1033                 return -EACCES;
1034
1035         error = qd_get(sdp, user, id, CREATE, &qd);
1036         if (error)
1037                 return error;
1038
1039         error = do_glock(qd, NO_FORCE, &q_gh);
1040         if (error)
1041                 goto out;
1042
1043         memset(q, 0, sizeof(struct gfs2_quota));
1044         q->qu_limit = qd->qd_qb.qb_limit;
1045         q->qu_warn = qd->qd_qb.qb_warn;
1046         q->qu_value = qd->qd_qb.qb_value;
1047
1048         spin_lock(&sdp->sd_quota_spin);
1049         q->qu_value += qd->qd_change;
1050         spin_unlock(&sdp->sd_quota_spin);
1051
1052         gfs2_glock_dq_uninit(&q_gh);
1053
1054  out:
1055         qd_put(qd);
1056
1057         return error;
1058 }
1059
1060 int gfs2_quota_init(struct gfs2_sbd *sdp)
1061 {
1062         struct gfs2_inode *ip = sdp->sd_qc_inode;
1063         unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
1064         unsigned int x, slot = 0;
1065         unsigned int found = 0;
1066         uint64_t dblock;
1067         uint32_t extlen = 0;
1068         int error;
1069
1070         if (!ip->i_di.di_size ||
1071             ip->i_di.di_size > (64 << 20) ||
1072             ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
1073                 gfs2_consist_inode(ip);
1074                 return -EIO;
1075         }
1076         sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1077         sdp->sd_quota_chunks = DIV_RU(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1078
1079         error = -ENOMEM;
1080
1081         sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1082                                        sizeof(unsigned char *), GFP_KERNEL);
1083         if (!sdp->sd_quota_bitmap)
1084                 return error;
1085
1086         for (x = 0; x < sdp->sd_quota_chunks; x++) {
1087                 sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL);
1088                 if (!sdp->sd_quota_bitmap[x])
1089                         goto fail;
1090         }
1091
1092         for (x = 0; x < blocks; x++) {
1093                 struct buffer_head *bh;
1094                 unsigned int y;
1095
1096                 if (!extlen) {
1097                         int new = 0;
1098                         error = gfs2_block_map(ip, x, &new, &dblock, &extlen);
1099                         if (error)
1100                                 goto fail;
1101                 }
1102                 gfs2_meta_ra(ip->i_gl,  dblock, extlen);
1103                 error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT,
1104                                        &bh);
1105                 if (error)
1106                         goto fail;
1107                 error = -EIO;
1108                 if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1109                         brelse(bh);
1110                         goto fail;
1111                 }
1112
1113                 for (y = 0;
1114                      y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1115                      y++, slot++) {
1116                         struct gfs2_quota_change qc;
1117                         struct gfs2_quota_data *qd;
1118
1119                         gfs2_quota_change_in(&qc, bh->b_data +
1120                                           sizeof(struct gfs2_meta_header) +
1121                                           y * sizeof(struct gfs2_quota_change));
1122                         if (!qc.qc_change)
1123                                 continue;
1124
1125                         error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1126                                          qc.qc_id, &qd);
1127                         if (error) {
1128                                 brelse(bh);
1129                                 goto fail;
1130                         }
1131
1132                         set_bit(QDF_CHANGE, &qd->qd_flags);
1133                         qd->qd_change = qc.qc_change;
1134                         qd->qd_slot = slot;
1135                         qd->qd_slot_count = 1;
1136                         qd->qd_last_touched = jiffies;
1137
1138                         spin_lock(&sdp->sd_quota_spin);
1139                         gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1140                         list_add(&qd->qd_list, &sdp->sd_quota_list);
1141                         atomic_inc(&sdp->sd_quota_count);
1142                         spin_unlock(&sdp->sd_quota_spin);
1143
1144                         found++;
1145                 }
1146
1147                 brelse(bh);
1148                 dblock++;
1149                 extlen--;
1150         }
1151
1152         if (found)
1153                 fs_info(sdp, "found %u quota changes\n", found);
1154
1155         return 0;
1156
1157  fail:
1158         gfs2_quota_cleanup(sdp);
1159         return error;
1160 }
1161
1162 void gfs2_quota_scan(struct gfs2_sbd *sdp)
1163 {
1164         struct gfs2_quota_data *qd, *safe;
1165         LIST_HEAD(dead);
1166
1167         spin_lock(&sdp->sd_quota_spin);
1168         list_for_each_entry_safe(qd, safe, &sdp->sd_quota_list, qd_list) {
1169                 if (!qd->qd_count &&
1170                     time_after_eq(jiffies, qd->qd_last_touched +
1171                                 gfs2_tune_get(sdp, gt_quota_cache_secs) * HZ)) {
1172                         list_move(&qd->qd_list, &dead);
1173                         gfs2_assert_warn(sdp,
1174                                          atomic_read(&sdp->sd_quota_count) > 0);
1175                         atomic_dec(&sdp->sd_quota_count);
1176                 }
1177         }
1178         spin_unlock(&sdp->sd_quota_spin);
1179
1180         while (!list_empty(&dead)) {
1181                 qd = list_entry(dead.next, struct gfs2_quota_data, qd_list);
1182                 list_del(&qd->qd_list);
1183
1184                 gfs2_assert_warn(sdp, !qd->qd_change);
1185                 gfs2_assert_warn(sdp, !qd->qd_slot_count);
1186                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
1187
1188                 gfs2_lvb_unhold(qd->qd_gl);
1189                 kfree(qd);
1190         }
1191 }
1192
1193 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1194 {
1195         struct list_head *head = &sdp->sd_quota_list;
1196         struct gfs2_quota_data *qd;
1197         unsigned int x;
1198
1199         spin_lock(&sdp->sd_quota_spin);
1200         while (!list_empty(head)) {
1201                 qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1202
1203                 if (qd->qd_count > 1 ||
1204                     (qd->qd_count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1205                         list_move(&qd->qd_list, head);
1206                         spin_unlock(&sdp->sd_quota_spin);
1207                         schedule();
1208                         spin_lock(&sdp->sd_quota_spin);
1209                         continue;
1210                 }
1211
1212                 list_del(&qd->qd_list);
1213                 atomic_dec(&sdp->sd_quota_count);
1214                 spin_unlock(&sdp->sd_quota_spin);
1215
1216                 if (!qd->qd_count) {
1217                         gfs2_assert_warn(sdp, !qd->qd_change);
1218                         gfs2_assert_warn(sdp, !qd->qd_slot_count);
1219                 } else
1220                         gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1221                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
1222
1223                 gfs2_lvb_unhold(qd->qd_gl);
1224                 kfree(qd);
1225
1226                 spin_lock(&sdp->sd_quota_spin);
1227         }
1228         spin_unlock(&sdp->sd_quota_spin);
1229
1230         gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1231
1232         if (sdp->sd_quota_bitmap) {
1233                 for (x = 0; x < sdp->sd_quota_chunks; x++)
1234                         kfree(sdp->sd_quota_bitmap[x]);
1235                 kfree(sdp->sd_quota_bitmap);
1236         }
1237 }
1238