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