SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 <linux/fs.h>
  47 #include <linux/gfs2_ondisk.h>
  48 #include <asm/semaphore.h>
  49
  50 #include "gfs2.h"
  51 #include "lm_interface.h"
  52 #include "incore.h"
  53 #include "bmap.h"
  54 #include "glock.h"
  55 #include "glops.h"
  56 #include "log.h"
  57 #include "lvb.h"
  58 #include "meta_io.h"
  59 #include "quota.h"
  60 #include "rgrp.h"
  61 #include "super.h"
  62 #include "trans.h"
  63 #include "inode.h"
  64 #include "ops_file.h"
  65 #include "ops_address.h"
  66 #include "util.h"
  67
  68 #define QUOTA_USER 1
  69 #define QUOTA_GROUP 0
  70
  71 static uint64_t qd2offset(struct gfs2_quota_data *qd)
  72 {
  73         uint64_t offset;
  74
  75         offset = 2 * (uint64_t)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
  76         offset *= sizeof(struct gfs2_quota);
  77
  78         return offset;
  79 }
  80
  81 static int qd_alloc(struct gfs2_sbd *sdp, int user, uint32_t id,
  82                     struct gfs2_quota_data **qdp)
  83 {
  84         struct gfs2_quota_data *qd;
  85         int error;
  86
  87         qd = kzalloc(sizeof(struct gfs2_quota_data), GFP_KERNEL);
  88         if (!qd)
  89                 return -ENOMEM;
  90
  91         qd->qd_count = 1;
  92         qd->qd_id = id;
  93         if (user)
  94                 set_bit(QDF_USER, &qd->qd_flags);
  95         qd->qd_slot = -1;
  96
  97         error = gfs2_glock_get(sdp, 2 * (uint64_t)id + !user,
  98                               &gfs2_quota_glops, CREATE, &qd->qd_gl);
  99         if (error)
 100                 goto fail;
 101
 102         error = gfs2_lvb_hold(qd->qd_gl);
 103         gfs2_glock_put(qd->qd_gl);
 104         if (error)
 105                 goto fail;
 106
 107         *qdp = qd;
 108
 109         return 0;
 110
 111  fail:
 112         kfree(qd);
 113         return error;
 114 }
 115
 116 static int qd_get(struct gfs2_sbd *sdp, int user, uint32_t id, int create,
 117                   struct gfs2_quota_data **qdp)
 118 {
 119         struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
 120         int error, found;
 121
 122         *qdp = NULL;
 123
 124         for (;;) {
 125                 found = 0;
 126                 spin_lock(&sdp->sd_quota_spin);
 127                 list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
 128                         if (qd->qd_id == id &&
 129                             !test_bit(QDF_USER, &qd->qd_flags) == !user) {
 130                                 qd->qd_count++;
 131                                 found = 1;
 132                                 break;
 133                         }
 134                 }
 135
 136                 if (!found)
 137                         qd = NULL;
 138
 139                 if (!qd && new_qd) {
 140                         qd = new_qd;
 141                         list_add(&qd->qd_list, &sdp->sd_quota_list);
 142                         atomic_inc(&sdp->sd_quota_count);
 143                         new_qd = NULL;
 144                 }
 145
 146                 spin_unlock(&sdp->sd_quota_spin);
 147
 148                 if (qd || !create) {
 149                         if (new_qd) {
 150                                 gfs2_lvb_unhold(new_qd->qd_gl);
 151                                 kfree(new_qd);
 152                         }
 153                         *qdp = qd;
 154                         return 0;
 155                 }
 156
 157                 error = qd_alloc(sdp, user, id, &new_qd);
 158                 if (error)
 159                         return error;
 160         }
 161 }
 162
 163 static void qd_hold(struct gfs2_quota_data *qd)
 164 {
 165         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 166
 167         spin_lock(&sdp->sd_quota_spin);
 168         gfs2_assert(sdp, qd->qd_count);
 169         qd->qd_count++;
 170         spin_unlock(&sdp->sd_quota_spin);
 171 }
 172
 173 static void qd_put(struct gfs2_quota_data *qd)
 174 {
 175         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 176         spin_lock(&sdp->sd_quota_spin);
 177         gfs2_assert(sdp, qd->qd_count);
 178         if (!--qd->qd_count)
 179                 qd->qd_last_touched = jiffies;
 180         spin_unlock(&sdp->sd_quota_spin);
 181 }
 182
 183 static int slot_get(struct gfs2_quota_data *qd)
 184 {
 185         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 186         unsigned int c, o = 0, b;
 187         unsigned char byte = 0;
 188
 189         spin_lock(&sdp->sd_quota_spin);
 190
 191         if (qd->qd_slot_count++) {
 192                 spin_unlock(&sdp->sd_quota_spin);
 193                 return 0;
 194         }
 195
 196         for (c = 0; c < sdp->sd_quota_chunks; c++)
 197                 for (o = 0; o < PAGE_SIZE; o++) {
 198                         byte = sdp->sd_quota_bitmap[c][o];
 199                         if (byte != 0xFF)
 200                                 goto found;
 201                 }
 202
 203         goto fail;
 204
 205  found:
 206         for (b = 0; b < 8; b++)
 207                 if (!(byte & (1 << b)))
 208                         break;
 209         qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
 210
 211         if (qd->qd_slot >= sdp->sd_quota_slots)
 212                 goto fail;
 213
 214         sdp->sd_quota_bitmap[c][o] |= 1 << b;
 215
 216         spin_unlock(&sdp->sd_quota_spin);
 217
 218         return 0;
 219
 220  fail:
 221         qd->qd_slot_count--;
 222         spin_unlock(&sdp->sd_quota_spin);
 223         return -ENOSPC;
 224 }
 225
 226 static void slot_hold(struct gfs2_quota_data *qd)
 227 {
 228         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 229
 230         spin_lock(&sdp->sd_quota_spin);
 231         gfs2_assert(sdp, qd->qd_slot_count);
 232         qd->qd_slot_count++;
 233         spin_unlock(&sdp->sd_quota_spin);
 234 }
 235
 236 static void slot_put(struct gfs2_quota_data *qd)
 237 {
 238         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 239
 240         spin_lock(&sdp->sd_quota_spin);
 241         gfs2_assert(sdp, qd->qd_slot_count);
 242         if (!--qd->qd_slot_count) {
 243                 gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
 244                 qd->qd_slot = -1;
 245         }
 246         spin_unlock(&sdp->sd_quota_spin);
 247 }
 248
 249 static int bh_get(struct gfs2_quota_data *qd)
 250 {
 251         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 252         struct gfs2_inode *ip = sdp->sd_qc_inode->u.generic_ip;
 253         unsigned int block, offset;
 254         uint64_t dblock;
 255         int new = 0;
 256         struct buffer_head *bh;
 257         int error;
 258
 259         mutex_lock(&sdp->sd_quota_mutex);
 260
 261         if (qd->qd_bh_count++) {
 262                 mutex_unlock(&sdp->sd_quota_mutex);
 263                 return 0;
 264         }
 265
 266         block = qd->qd_slot / sdp->sd_qc_per_block;
 267         offset = qd->qd_slot % sdp->sd_qc_per_block;;
 268
 269         error = gfs2_block_map(ip, block, &new, &dblock, NULL);
 270         if (error)
 271                 goto fail;
 272         error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT, &bh);
 273         if (error)
 274                 goto fail;
 275         error = -EIO;
 276         if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
 277                 goto fail_brelse;
 278
 279         qd->qd_bh = bh;
 280         qd->qd_bh_qc = (struct gfs2_quota_change *)
 281                 (bh->b_data + sizeof(struct gfs2_meta_header) +
 282                  offset * sizeof(struct gfs2_quota_change));
 283
 284         mutex_lock(&sdp->sd_quota_mutex);
 285
 286         return 0;
 287
 288  fail_brelse:
 289         brelse(bh);
 290
 291  fail:
 292         qd->qd_bh_count--;
 293         mutex_unlock(&sdp->sd_quota_mutex);
 294         return error;
 295 }
 296
 297 static void bh_put(struct gfs2_quota_data *qd)
 298 {
 299         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 300
 301         mutex_lock(&sdp->sd_quota_mutex);
 302         gfs2_assert(sdp, qd->qd_bh_count);
 303         if (!--qd->qd_bh_count) {
 304                 brelse(qd->qd_bh);
 305                 qd->qd_bh = NULL;
 306                 qd->qd_bh_qc = NULL;
 307         }
 308         mutex_unlock(&sdp->sd_quota_mutex);
 309 }
 310
 311 static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
 312 {
 313         struct gfs2_quota_data *qd = NULL;
 314         int error;
 315         int found = 0;
 316
 317         *qdp = NULL;
 318
 319         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 320                 return 0;
 321
 322         spin_lock(&sdp->sd_quota_spin);
 323
 324         list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
 325                 if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
 326                     !test_bit(QDF_CHANGE, &qd->qd_flags) ||
 327                     qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
 328                         continue;
 329
 330                 list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 331
 332                 set_bit(QDF_LOCKED, &qd->qd_flags);
 333                 gfs2_assert_warn(sdp, qd->qd_count);
 334                 qd->qd_count++;
 335                 qd->qd_change_sync = qd->qd_change;
 336                 gfs2_assert_warn(sdp, qd->qd_slot_count);
 337                 qd->qd_slot_count++;
 338                 found = 1;
 339
 340                 break;
 341         }
 342
 343         if (!found)
 344                 qd = NULL;
 345
 346         spin_unlock(&sdp->sd_quota_spin);
 347
 348         if (qd) {
 349                 gfs2_assert_warn(sdp, qd->qd_change_sync);
 350                 error = bh_get(qd);
 351                 if (error) {
 352                         clear_bit(QDF_LOCKED, &qd->qd_flags);
 353                         slot_put(qd);
 354                         qd_put(qd);
 355                         return error;
 356                 }
 357         }
 358
 359         *qdp = qd;
 360
 361         return 0;
 362 }
 363
 364 static int qd_trylock(struct gfs2_quota_data *qd)
 365 {
 366         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 367
 368         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 369                 return 0;
 370
 371         spin_lock(&sdp->sd_quota_spin);
 372
 373         if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
 374             !test_bit(QDF_CHANGE, &qd->qd_flags)) {
 375                 spin_unlock(&sdp->sd_quota_spin);
 376                 return 0;
 377         }
 378
 379         list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 380
 381         set_bit(QDF_LOCKED, &qd->qd_flags);
 382         gfs2_assert_warn(sdp, qd->qd_count);
 383         qd->qd_count++;
 384         qd->qd_change_sync = qd->qd_change;
 385         gfs2_assert_warn(sdp, qd->qd_slot_count);
 386         qd->qd_slot_count++;
 387
 388         spin_unlock(&sdp->sd_quota_spin);
 389
 390         gfs2_assert_warn(sdp, qd->qd_change_sync);
 391         if (bh_get(qd)) {
 392                 clear_bit(QDF_LOCKED, &qd->qd_flags);
 393                 slot_put(qd);
 394                 qd_put(qd);
 395                 return 0;
 396         }
 397
 398         return 1;
 399 }
 400
 401 static void qd_unlock(struct gfs2_quota_data *qd)
 402 {
 403         gfs2_assert_warn(qd->qd_gl->gl_sbd,
 404                          test_bit(QDF_LOCKED, &qd->qd_flags));
 405         clear_bit(QDF_LOCKED, &qd->qd_flags);
 406         bh_put(qd);
 407         slot_put(qd);
 408         qd_put(qd);
 409 }
 410
 411 static int qdsb_get(struct gfs2_sbd *sdp, int user, uint32_t id, int create,
 412                     struct gfs2_quota_data **qdp)
 413 {
 414         int error;
 415
 416         error = qd_get(sdp, user, id, create, qdp);
 417         if (error)
 418                 return error;
 419
 420         error = slot_get(*qdp);
 421         if (error)
 422                 goto fail;
 423
 424         error = bh_get(*qdp);
 425         if (error)
 426                 goto fail_slot;
 427
 428         return 0;
 429
 430  fail_slot:
 431         slot_put(*qdp);
 432
 433  fail:
 434         qd_put(*qdp);
 435         return error;
 436 }
 437
 438 static void qdsb_put(struct gfs2_quota_data *qd)
 439 {
 440         bh_put(qd);
 441         slot_put(qd);
 442         qd_put(qd);
 443 }
 444
 445 int gfs2_quota_hold(struct gfs2_inode *ip, uint32_t uid, uint32_t gid)
 446 {
 447         struct gfs2_sbd *sdp = ip->i_sbd;
 448         struct gfs2_alloc *al = &ip->i_alloc;
 449         struct gfs2_quota_data **qd = al->al_qd;
 450         int error;
 451
 452         if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
 453             gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
 454                 return -EIO;
 455
 456         if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
 457                 return 0;
 458
 459         error = qdsb_get(sdp, QUOTA_USER, ip->i_di.di_uid, CREATE, qd);
 460         if (error)
 461                 goto out;
 462         al->al_qd_num++;
 463         qd++;
 464
 465         error = qdsb_get(sdp, QUOTA_GROUP, ip->i_di.di_gid, CREATE, qd);
 466         if (error)
 467                 goto out;
 468         al->al_qd_num++;
 469         qd++;
 470
 471         if (uid != NO_QUOTA_CHANGE && uid != ip->i_di.di_uid) {
 472                 error = qdsb_get(sdp, QUOTA_USER, uid, CREATE, qd);
 473                 if (error)
 474                         goto out;
 475                 al->al_qd_num++;
 476                 qd++;
 477         }
 478
 479         if (gid != NO_QUOTA_CHANGE && gid != ip->i_di.di_gid) {
 480                 error = qdsb_get(sdp, QUOTA_GROUP, gid, CREATE, qd);
 481                 if (error)
 482                         goto out;
 483                 al->al_qd_num++;
 484                 qd++;
 485         }
 486
 487  out:
 488         if (error)
 489                 gfs2_quota_unhold(ip);
 490
 491         return error;
 492 }
 493
 494 void gfs2_quota_unhold(struct gfs2_inode *ip)
 495 {
 496         struct gfs2_sbd *sdp = ip->i_sbd;
 497         struct gfs2_alloc *al = &ip->i_alloc;
 498         unsigned int x;
 499
 500         gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
 501
 502         for (x = 0; x < al->al_qd_num; x++) {
 503                 qdsb_put(al->al_qd[x]);
 504                 al->al_qd[x] = NULL;
 505         }
 506         al->al_qd_num = 0;
 507 }
 508
 509 static int sort_qd(const void *a, const void *b)
 510 {
 511         struct gfs2_quota_data *qd_a = *(struct gfs2_quota_data **)a;
 512         struct gfs2_quota_data *qd_b = *(struct gfs2_quota_data **)b;
 513         int ret = 0;
 514
 515         if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
 516             !test_bit(QDF_USER, &qd_b->qd_flags)) {
 517                 if (test_bit(QDF_USER, &qd_a->qd_flags))
 518                         ret = -1;
 519                 else
 520                         ret = 1;
 521         } else {
 522                 if (qd_a->qd_id < qd_b->qd_id)
 523                         ret = -1;
 524                 else if (qd_a->qd_id > qd_b->qd_id)
 525                         ret = 1;
 526         }
 527
 528         return ret;
 529 }
 530
 531 static void do_qc(struct gfs2_quota_data *qd, int64_t change)
 532 {
 533         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 534         struct gfs2_inode *ip = sdp->sd_qc_inode->u.generic_ip;
 535         struct gfs2_quota_change *qc = qd->qd_bh_qc;
 536         int64_t x;
 537
 538         mutex_lock(&sdp->sd_quota_mutex);
 539         gfs2_trans_add_bh(ip->i_gl, qd->qd_bh, 1);
 540
 541         if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
 542                 qc->qc_change = 0;
 543                 qc->qc_flags = 0;
 544                 if (test_bit(QDF_USER, &qd->qd_flags))
 545                         qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
 546                 qc->qc_id = cpu_to_be32(qd->qd_id);
 547         }
 548
 549         x = qc->qc_change;
 550         x = be64_to_cpu(x) + change;
 551         qc->qc_change = cpu_to_be64(x);
 552
 553         spin_lock(&sdp->sd_quota_spin);
 554         qd->qd_change = x;
 555         spin_unlock(&sdp->sd_quota_spin);
 556
 557         if (!x) {
 558                 gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
 559                 clear_bit(QDF_CHANGE, &qd->qd_flags);
 560                 qc->qc_flags = 0;
 561                 qc->qc_id = 0;
 562                 slot_put(qd);
 563                 qd_put(qd);
 564         } else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
 565                 qd_hold(qd);
 566                 slot_hold(qd);
 567         }
 568
 569         mutex_unlock(&sdp->sd_quota_mutex);
 570 }
 571
 572 /**
 573  * gfs2_adjust_quota
 574  *
 575  * This function was mostly borrowed from gfs2_block_truncate_page which was
 576  * in turn mostly borrowed from ext3
 577  */
 578 static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
 579                              int64_t change, struct gfs2_quota_data *qd)
 580 {
 581         struct inode *inode = ip->i_vnode;
 582         struct address_space *mapping = inode->i_mapping;
 583         unsigned long index = loc >> PAGE_CACHE_SHIFT;
 584         unsigned offset = loc & (PAGE_CACHE_SHIFT - 1);
 585         unsigned blocksize, iblock, pos;
 586         struct buffer_head *bh;
 587         struct page *page;
 588         void *kaddr;
 589         __be64 *ptr;
 590         u64 value;
 591         int err = -EIO;
 592
 593         page = grab_cache_page(mapping, index);
 594         if (!page)
 595                 return -ENOMEM;
 596
 597         blocksize = inode->i_sb->s_blocksize;
 598         iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
 599
 600         if (!page_has_buffers(page))
 601                 create_empty_buffers(page, blocksize, 0);
 602
 603         bh = page_buffers(page);
 604         pos = blocksize;
 605         while (offset >= pos) {
 606                 bh = bh->b_this_page;
 607                 iblock++;
 608                 pos += blocksize;
 609         }
 610
 611         if (!buffer_mapped(bh)) {
 612                 gfs2_get_block(inode, iblock, bh, 1);
 613                 if (!buffer_mapped(bh))
 614                         goto unlock;
 615         }
 616
 617         if (PageUptodate(page))
 618                 set_buffer_uptodate(bh);
 619
 620         if (!buffer_uptodate(bh)) {
 621                 ll_rw_block(READ, 1, &bh);
 622                 wait_on_buffer(bh);
 623                 if (!buffer_uptodate(bh))
 624                         goto unlock;
 625         }
 626
 627         gfs2_trans_add_bh(ip->i_gl, bh, 0);
 628
 629         kaddr = kmap_atomic(page, KM_USER0);
 630         ptr = (__be64 *)(kaddr + offset);
 631         value = *ptr = cpu_to_be64(be64_to_cpu(*ptr) + change);
 632         flush_dcache_page(page);
 633         kunmap_atomic(kaddr, KM_USER0);
 634         err = 0;
 635         qd->qd_qb.qb_magic = cpu_to_be32(GFS2_MAGIC);
 636 #if 0
 637         qd->qd_qb.qb_limit = cpu_to_be64(q.qu_limit);
 638         qd->qd_qb.qb_warn = cpu_to_be64(q.qu_warn);
 639 #endif
 640         qd->qd_qb.qb_value = cpu_to_be64(value);
 641 unlock:
 642         unlock_page(page);
 643         page_cache_release(page);
 644         return err;
 645 }
 646
 647 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 648 {
 649         struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
 650         struct gfs2_inode *ip = sdp->sd_quota_inode->u.generic_ip;
 651         unsigned int data_blocks, ind_blocks;
 652         struct file_ra_state ra_state;
 653         struct gfs2_holder *ghs, i_gh;
 654         unsigned int qx, x;
 655         struct gfs2_quota_data *qd;
 656         loff_t offset;
 657         unsigned int nalloc = 0;
 658         struct gfs2_alloc *al = NULL;
 659         int error;
 660
 661         gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
 662                               &data_blocks, &ind_blocks);
 663
 664         ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_KERNEL);
 665         if (!ghs)
 666                 return -ENOMEM;
 667
 668         sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
 669         for (qx = 0; qx < num_qd; qx++) {
 670                 error = gfs2_glock_nq_init(qda[qx]->qd_gl,
 671                                            LM_ST_EXCLUSIVE,
 672                                            GL_NOCACHE, &ghs[qx]);
 673                 if (error)
 674                         goto out;
 675         }
 676
 677         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 678         if (error)
 679                 goto out;
 680
 681         for (x = 0; x < num_qd; x++) {
 682                 int alloc_required;
 683
 684                 offset = qd2offset(qda[x]);
 685                 error = gfs2_write_alloc_required(ip, offset,
 686                                                   sizeof(struct gfs2_quota),
 687                                                   &alloc_required);
 688                 if (error)
 689                         goto out_gunlock;
 690                 if (alloc_required)
 691                         nalloc++;
 692         }
 693
 694         if (nalloc) {
 695                 al = gfs2_alloc_get(ip);
 696
 697                 al->al_requested = nalloc * (data_blocks + ind_blocks);
 698
 699                 error = gfs2_inplace_reserve(ip);
 700                 if (error)
 701                         goto out_alloc;
 702
 703                 error = gfs2_trans_begin(sdp,
 704                                          al->al_rgd->rd_ri.ri_length +
 705                                          num_qd * data_blocks +
 706                                          nalloc * ind_blocks +
 707                                          RES_DINODE + num_qd +
 708                                          RES_STATFS, 0);
 709                 if (error)
 710                         goto out_ipres;
 711         } else {
 712                 error = gfs2_trans_begin(sdp,
 713                                          num_qd * data_blocks +
 714                                          RES_DINODE + num_qd, 0);
 715                 if (error)
 716                         goto out_gunlock;
 717         }
 718
 719         file_ra_state_init(&ra_state, ip->i_vnode->i_mapping);
 720         for (x = 0; x < num_qd; x++) {
 721                 qd = qda[x];
 722                 offset = qd2offset(qd);
 723                 error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync,
 724                                           (struct gfs2_quota_data *)
 725                                           qd->qd_gl->gl_lvb);
 726                 if (error)
 727                         goto out_end_trans;
 728
 729                 do_qc(qd, -qd->qd_change_sync);
 730         }
 731
 732         error = 0;
 733
 734  out_end_trans:
 735         gfs2_trans_end(sdp);
 736
 737  out_ipres:
 738         if (nalloc)
 739                 gfs2_inplace_release(ip);
 740
 741  out_alloc:
 742         if (nalloc)
 743                 gfs2_alloc_put(ip);
 744
 745  out_gunlock:
 746         gfs2_glock_dq_uninit(&i_gh);
 747
 748  out:
 749         while (qx--)
 750                 gfs2_glock_dq_uninit(&ghs[qx]);
 751         kfree(ghs);
 752         gfs2_log_flush_glock(ip->i_gl);
 753
 754         return error;
 755 }
 756
 757 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
 758                     struct gfs2_holder *q_gh)
 759 {
 760         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 761         struct gfs2_inode *ip = sdp->sd_quota_inode->u.generic_ip;
 762         struct gfs2_holder i_gh;
 763         struct gfs2_quota q;
 764         char buf[sizeof(struct gfs2_quota)];
 765         struct file_ra_state ra_state;
 766         int error;
 767
 768         file_ra_state_init(&ra_state, sdp->sd_quota_inode->i_mapping);
 769  restart:
 770         error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
 771         if (error)
 772                 return error;
 773
 774         gfs2_quota_lvb_in(&qd->qd_qb, qd->qd_gl->gl_lvb);
 775
 776         if (force_refresh || qd->qd_qb.qb_magic != GFS2_MAGIC) {
 777                 loff_t pos;
 778                 gfs2_glock_dq_uninit(q_gh);
 779                 error = gfs2_glock_nq_init(qd->qd_gl,
 780                                           LM_ST_EXCLUSIVE, GL_NOCACHE,
 781                                           q_gh);
 782                 if (error)
 783                         return error;
 784
 785                 error = gfs2_glock_nq_init(ip->i_gl,
 786                                           LM_ST_SHARED, 0,
 787                                           &i_gh);
 788                 if (error)
 789                         goto fail;
 790
 791                 memset(buf, 0, sizeof(struct gfs2_quota));
 792                 pos = qd2offset(qd);
 793                 error = gfs2_internal_read(ip,
 794                                             &ra_state, buf,
 795                                             &pos,
 796                                             sizeof(struct gfs2_quota));
 797                 if (error < 0)
 798                         goto fail_gunlock;
 799
 800                 gfs2_glock_dq_uninit(&i_gh);
 801
 802                 gfs2_quota_in(&q, buf);
 803
 804                 memset(&qd->qd_qb, 0, sizeof(struct gfs2_quota_lvb));
 805                 qd->qd_qb.qb_magic = GFS2_MAGIC;
 806                 qd->qd_qb.qb_limit = q.qu_limit;
 807                 qd->qd_qb.qb_warn = q.qu_warn;
 808                 qd->qd_qb.qb_value = q.qu_value;
 809
 810                 gfs2_quota_lvb_out(&qd->qd_qb, qd->qd_gl->gl_lvb);
 811
 812                 if (gfs2_glock_is_blocking(qd->qd_gl)) {
 813                         gfs2_glock_dq_uninit(q_gh);
 814                         force_refresh = 0;
 815                         goto restart;
 816                 }
 817         }
 818
 819         return 0;
 820
 821  fail_gunlock:
 822         gfs2_glock_dq_uninit(&i_gh);
 823
 824  fail:
 825         gfs2_glock_dq_uninit(q_gh);
 826
 827         return error;
 828 }
 829
 830 int gfs2_quota_lock(struct gfs2_inode *ip, uint32_t uid, uint32_t gid)
 831 {
 832         struct gfs2_sbd *sdp = ip->i_sbd;
 833         struct gfs2_alloc *al = &ip->i_alloc;
 834         unsigned int x;
 835         int error = 0;
 836
 837         gfs2_quota_hold(ip, uid, gid);
 838
 839         if (capable(CAP_SYS_RESOURCE) ||
 840             sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
 841                 return 0;
 842
 843         sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
 844              sort_qd, NULL);
 845
 846         for (x = 0; x < al->al_qd_num; x++) {
 847                 error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
 848                 if (error)
 849                         break;
 850         }
 851
 852         if (!error)
 853                 set_bit(GIF_QD_LOCKED, &ip->i_flags);
 854         else {
 855                 while (x--)
 856                         gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
 857                 gfs2_quota_unhold(ip);
 858         }
 859
 860         return error;
 861 }
 862
 863 static int need_sync(struct gfs2_quota_data *qd)
 864 {
 865         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 866         struct gfs2_tune *gt = &sdp->sd_tune;
 867         int64_t value;
 868         unsigned int num, den;
 869         int do_sync = 1;
 870
 871         if (!qd->qd_qb.qb_limit)
 872                 return 0;
 873
 874         spin_lock(&sdp->sd_quota_spin);
 875         value = qd->qd_change;
 876         spin_unlock(&sdp->sd_quota_spin);
 877
 878         spin_lock(&gt->gt_spin);
 879         num = gt->gt_quota_scale_num;
 880         den = gt->gt_quota_scale_den;
 881         spin_unlock(&gt->gt_spin);
 882
 883         if (value < 0)
 884                 do_sync = 0;
 885         else if (qd->qd_qb.qb_value >= (int64_t)qd->qd_qb.qb_limit)
 886                 do_sync = 0;
 887         else {
 888                 value *= gfs2_jindex_size(sdp) * num;
 889                 do_div(value, den);
 890                 value += qd->qd_qb.qb_value;
 891                 if (value < (int64_t)qd->qd_qb.qb_limit)
 892                         do_sync = 0;
 893         }
 894
 895         return do_sync;
 896 }
 897
 898 void gfs2_quota_unlock(struct gfs2_inode *ip)
 899 {
 900         struct gfs2_alloc *al = &ip->i_alloc;
 901         struct gfs2_quota_data *qda[4];
 902         unsigned int count = 0;
 903         unsigned int x;
 904
 905         if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
 906                 goto out;
 907
 908         for (x = 0; x < al->al_qd_num; x++) {
 909                 struct gfs2_quota_data *qd;
 910                 int sync;
 911
 912                 qd = al->al_qd[x];
 913                 sync = need_sync(qd);
 914
 915                 gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
 916
 917                 if (sync && qd_trylock(qd))
 918                         qda[count++] = qd;
 919         }
 920
 921         if (count) {
 922                 do_sync(count, qda);
 923                 for (x = 0; x < count; x++)
 924                         qd_unlock(qda[x]);
 925         }
 926
 927  out:
 928         gfs2_quota_unhold(ip);
 929 }
 930
 931 #define MAX_LINE 256
 932
 933 static int print_message(struct gfs2_quota_data *qd, char *type)
 934 {
 935         struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 936         char *line;
 937         int len;
 938
 939         line = kmalloc(MAX_LINE, GFP_KERNEL);
 940         if (!line)
 941                 return -ENOMEM;
 942
 943         len = snprintf(line, MAX_LINE-1,
 944                        "GFS2: fsid=%s: quota %s for %s %u\r\n",
 945                        sdp->sd_fsname, type,
 946                        (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
 947                        qd->qd_id);
 948         line[MAX_LINE-1] = 0;
 949
 950         if (current->signal) { /* Is this test still required? */
 951                 tty_write_message(current->signal->tty, line);
 952         }
 953
 954         kfree(line);
 955
 956         return 0;
 957 }
 958
 959 int gfs2_quota_check(struct gfs2_inode *ip, uint32_t uid, uint32_t gid)
 960 {
 961         struct gfs2_sbd *sdp = ip->i_sbd;
 962         struct gfs2_alloc *al = &ip->i_alloc;
 963         struct gfs2_quota_data *qd;
 964         int64_t value;
 965         unsigned int x;
 966         int error = 0;
 967
 968         if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
 969                 return 0;
 970
 971         if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
 972                 return 0;
 973
 974         for (x = 0; x < al->al_qd_num; x++) {
 975                 qd = al->al_qd[x];
 976
 977                 if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
 978                       (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
 979                         continue;
 980
 981                 value = qd->qd_qb.qb_value;
 982                 spin_lock(&sdp->sd_quota_spin);
 983                 value += qd->qd_change;
 984                 spin_unlock(&sdp->sd_quota_spin);
 985
 986                 if (qd->qd_qb.qb_limit && (int64_t)qd->qd_qb.qb_limit < value) {
 987                         print_message(qd, "exceeded");
 988                         error = -EDQUOT;
 989                         break;
 990                 } else if (qd->qd_qb.qb_warn &&
 991                            (int64_t)qd->qd_qb.qb_warn < value &&
 992                            time_after_eq(jiffies, qd->qd_last_warn +
 993                                          gfs2_tune_get(sdp,
 994                                                 gt_quota_warn_period) * HZ)) {
 995                         error = print_message(qd, "warning");
 996                         qd->qd_last_warn = jiffies;
 997                 }
 998         }
 999
1000         return error;
1001 }
1002
1003 void gfs2_quota_change(struct gfs2_inode *ip, int64_t change,
1004                        uint32_t uid, uint32_t gid)
1005 {
1006         struct gfs2_alloc *al = &ip->i_alloc;
1007         struct gfs2_quota_data *qd;
1008         unsigned int x;
1009         unsigned int found = 0;
1010
1011         if (gfs2_assert_warn(ip->i_sbd, change))
1012                 return;
1013         if (ip->i_di.di_flags & GFS2_DIF_SYSTEM)
1014                 return;
1015
1016         for (x = 0; x < al->al_qd_num; x++) {
1017                 qd = al->al_qd[x];
1018
1019                 if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1020                     (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
1021                         do_qc(qd, change);
1022                         found++;
1023                 }
1024         }
1025 }
1026
1027 int gfs2_quota_sync(struct gfs2_sbd *sdp)
1028 {
1029         struct gfs2_quota_data **qda;
1030         unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
1031         unsigned int num_qd;
1032         unsigned int x;
1033         int error = 0;
1034
1035         sdp->sd_quota_sync_gen++;
1036
1037         qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1038         if (!qda)
1039                 return -ENOMEM;
1040
1041         do {
1042                 num_qd = 0;
1043
1044                 for (;;) {
1045                         error = qd_fish(sdp, qda + num_qd);
1046                         if (error || !qda[num_qd])
1047                                 break;
1048                         if (++num_qd == max_qd)
1049                                 break;
1050                 }
1051
1052                 if (num_qd) {
1053                         if (!error)
1054                                 error = do_sync(num_qd, qda);
1055                         if (!error)
1056                                 for (x = 0; x < num_qd; x++)
1057                                         qda[x]->qd_sync_gen =
1058                                                 sdp->sd_quota_sync_gen;
1059
1060                         for (x = 0; x < num_qd; x++)
1061                                 qd_unlock(qda[x]);
1062                 }
1063         } while (!error && num_qd == max_qd);
1064
1065         kfree(qda);
1066
1067         return error;
1068 }
1069
1070 int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, uint32_t id)
1071 {
1072         struct gfs2_quota_data *qd;
1073         struct gfs2_holder q_gh;
1074         int error;
1075
1076         error = qd_get(sdp, user, id, CREATE, &qd);
1077         if (error)
1078                 return error;
1079
1080         error = do_glock(qd, FORCE, &q_gh);
1081         if (!error)
1082                 gfs2_glock_dq_uninit(&q_gh);
1083
1084         qd_put(qd);
1085
1086         return error;
1087 }
1088
1089 int gfs2_quota_read(struct gfs2_sbd *sdp, int user, uint32_t id,
1090                     struct gfs2_quota *q)
1091 {
1092         struct gfs2_quota_data *qd;
1093         struct gfs2_holder q_gh;
1094         int error;
1095
1096         if (((user) ? (id != current->fsuid) : (!in_group_p(id))) &&
1097             !capable(CAP_SYS_ADMIN))
1098                 return -EACCES;
1099
1100         error = qd_get(sdp, user, id, CREATE, &qd);
1101         if (error)
1102                 return error;
1103
1104         error = do_glock(qd, NO_FORCE, &q_gh);
1105         if (error)
1106                 goto out;
1107
1108         memset(q, 0, sizeof(struct gfs2_quota));
1109         q->qu_limit = qd->qd_qb.qb_limit;
1110         q->qu_warn = qd->qd_qb.qb_warn;
1111         q->qu_value = qd->qd_qb.qb_value;
1112
1113         spin_lock(&sdp->sd_quota_spin);
1114         q->qu_value += qd->qd_change;
1115         spin_unlock(&sdp->sd_quota_spin);
1116
1117         gfs2_glock_dq_uninit(&q_gh);
1118
1119  out:
1120         qd_put(qd);
1121
1122         return error;
1123 }
1124
1125 int gfs2_quota_init(struct gfs2_sbd *sdp)
1126 {
1127         struct gfs2_inode *ip = sdp->sd_qc_inode->u.generic_ip;
1128         unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
1129         unsigned int x, slot = 0;
1130         unsigned int found = 0;
1131         uint64_t dblock;
1132         uint32_t extlen = 0;
1133         int error;
1134
1135         if (!ip->i_di.di_size ||
1136             ip->i_di.di_size > (64 << 20) ||
1137             ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
1138                 gfs2_consist_inode(ip);
1139                 return -EIO;
1140         }
1141         sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1142         sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1143
1144         error = -ENOMEM;
1145
1146         sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1147                                        sizeof(unsigned char *), GFP_KERNEL);
1148         if (!sdp->sd_quota_bitmap)
1149                 return error;
1150
1151         for (x = 0; x < sdp->sd_quota_chunks; x++) {
1152                 sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL);
1153                 if (!sdp->sd_quota_bitmap[x])
1154                         goto fail;
1155         }
1156
1157         for (x = 0; x < blocks; x++) {
1158                 struct buffer_head *bh;
1159                 unsigned int y;
1160
1161                 if (!extlen) {
1162                         int new = 0;
1163                         error = gfs2_block_map(ip, x, &new, &dblock, &extlen);
1164                         if (error)
1165                                 goto fail;
1166                 }
1167                 gfs2_meta_ra(ip->i_gl,  dblock, extlen);
1168                 error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT,
1169                                        &bh);
1170                 if (error)
1171                         goto fail;
1172                 error = -EIO;
1173                 if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1174                         brelse(bh);
1175                         goto fail;
1176                 }
1177
1178                 for (y = 0;
1179                      y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1180                      y++, slot++) {
1181                         struct gfs2_quota_change qc;
1182                         struct gfs2_quota_data *qd;
1183
1184                         gfs2_quota_change_in(&qc, bh->b_data +
1185                                           sizeof(struct gfs2_meta_header) +
1186                                           y * sizeof(struct gfs2_quota_change));
1187                         if (!qc.qc_change)
1188                                 continue;
1189
1190                         error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1191                                          qc.qc_id, &qd);
1192                         if (error) {
1193                                 brelse(bh);
1194                                 goto fail;
1195                         }
1196
1197                         set_bit(QDF_CHANGE, &qd->qd_flags);
1198                         qd->qd_change = qc.qc_change;
1199                         qd->qd_slot = slot;
1200                         qd->qd_slot_count = 1;
1201                         qd->qd_last_touched = jiffies;
1202
1203                         spin_lock(&sdp->sd_quota_spin);
1204                         gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1205                         list_add(&qd->qd_list, &sdp->sd_quota_list);
1206                         atomic_inc(&sdp->sd_quota_count);
1207                         spin_unlock(&sdp->sd_quota_spin);
1208
1209                         found++;
1210                 }
1211
1212                 brelse(bh);
1213                 dblock++;
1214                 extlen--;
1215         }
1216
1217         if (found)
1218                 fs_info(sdp, "found %u quota changes\n", found);
1219
1220         return 0;
1221
1222  fail:
1223         gfs2_quota_cleanup(sdp);
1224         return error;
1225 }
1226
1227 void gfs2_quota_scan(struct gfs2_sbd *sdp)
1228 {
1229         struct gfs2_quota_data *qd, *safe;
1230         LIST_HEAD(dead);
1231
1232         spin_lock(&sdp->sd_quota_spin);
1233         list_for_each_entry_safe(qd, safe, &sdp->sd_quota_list, qd_list) {
1234                 if (!qd->qd_count &&
1235                     time_after_eq(jiffies, qd->qd_last_touched +
1236                                 gfs2_tune_get(sdp, gt_quota_cache_secs) * HZ)) {
1237                         list_move(&qd->qd_list, &dead);
1238                         gfs2_assert_warn(sdp,
1239                                          atomic_read(&sdp->sd_quota_count) > 0);
1240                         atomic_dec(&sdp->sd_quota_count);
1241                 }
1242         }
1243         spin_unlock(&sdp->sd_quota_spin);
1244
1245         while (!list_empty(&dead)) {
1246                 qd = list_entry(dead.next, struct gfs2_quota_data, qd_list);
1247                 list_del(&qd->qd_list);
1248
1249                 gfs2_assert_warn(sdp, !qd->qd_change);
1250                 gfs2_assert_warn(sdp, !qd->qd_slot_count);
1251                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
1252
1253                 gfs2_lvb_unhold(qd->qd_gl);
1254                 kfree(qd);
1255         }
1256 }
1257
1258 void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1259 {
1260         struct list_head *head = &sdp->sd_quota_list;
1261         struct gfs2_quota_data *qd;
1262         unsigned int x;
1263
1264         spin_lock(&sdp->sd_quota_spin);
1265         while (!list_empty(head)) {
1266                 qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1267
1268                 if (qd->qd_count > 1 ||
1269                     (qd->qd_count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1270                         list_move(&qd->qd_list, head);
1271                         spin_unlock(&sdp->sd_quota_spin);
1272                         schedule();
1273                         spin_lock(&sdp->sd_quota_spin);
1274                         continue;
1275                 }
1276
1277                 list_del(&qd->qd_list);
1278                 atomic_dec(&sdp->sd_quota_count);
1279                 spin_unlock(&sdp->sd_quota_spin);
1280
1281                 if (!qd->qd_count) {
1282                         gfs2_assert_warn(sdp, !qd->qd_change);
1283                         gfs2_assert_warn(sdp, !qd->qd_slot_count);
1284                 } else
1285                         gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1286                 gfs2_assert_warn(sdp, !qd->qd_bh_count);
1287
1288                 gfs2_lvb_unhold(qd->qd_gl);
1289                 kfree(qd);
1290
1291                 spin_lock(&sdp->sd_quota_spin);
1292         }
1293         spin_unlock(&sdp->sd_quota_spin);
1294
1295         gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1296
1297         if (sdp->sd_quota_bitmap) {
1298                 for (x = 0; x < sdp->sd_quota_chunks; x++)
1299                         kfree(sdp->sd_quota_bitmap[x]);
1300                 kfree(sdp->sd_quota_bitmap);
1301         }
1302 }
1303