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/lm_interface.h>
  49
  50#include "gfs2.h"
  51#include "incore.h"
  52#include "bmap.h"
  53#include "glock.h"
  54#include "glops.h"
  55#include "log.h"
  56#include "meta_io.h"
  57#include "quota.h"
  58#include "rgrp.h"
  59#include "super.h"
  60#include "trans.h"
  61#include "inode.h"
  62#include "ops_address.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 u64 qd2offset(struct gfs2_quota_data *qd)
  82{
  83        u64 offset;
  84
  85        offset = 2 * (u64)qd->qd_id + !test_bit(QDF_USER, &qd->qd_flags);
  86        offset *= sizeof(struct gfs2_quota);
  87
  88        return offset;
  89}
  90
  91static int qd_alloc(struct gfs2_sbd *sdp, int user, u32 id,
  92                    struct gfs2_quota_data **qdp)
  93{
  94        struct gfs2_quota_data *qd;
  95        int error;
  96
  97        qd = kzalloc(sizeof(struct gfs2_quota_data), GFP_KERNEL);
  98        if (!qd)
  99                return -ENOMEM;
 100
 101        qd->qd_count = 1;
 102        qd->qd_id = id;
 103        if (user)
 104                set_bit(QDF_USER, &qd->qd_flags);
 105        qd->qd_slot = -1;
 106
 107        error = gfs2_glock_get(sdp, 2 * (u64)id + !user,
 108                              &gfs2_quota_glops, CREATE, &qd->qd_gl);
 109        if (error)
 110                goto fail;
 111
 112        error = gfs2_lvb_hold(qd->qd_gl);
 113        gfs2_glock_put(qd->qd_gl);
 114        if (error)
 115                goto fail;
 116
 117        *qdp = qd;
 118
 119        return 0;
 120
 121fail:
 122        kfree(qd);
 123        return error;
 124}
 125
 126static int qd_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
 127                  struct gfs2_quota_data **qdp)
 128{
 129        struct gfs2_quota_data *qd = NULL, *new_qd = NULL;
 130        int error, found;
 131
 132        *qdp = NULL;
 133
 134        for (;;) {
 135                found = 0;
 136                spin_lock(&sdp->sd_quota_spin);
 137                list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
 138                        if (qd->qd_id == id &&
 139                            !test_bit(QDF_USER, &qd->qd_flags) == !user) {
 140                                qd->qd_count++;
 141                                found = 1;
 142                                break;
 143                        }
 144                }
 145
 146                if (!found)
 147                        qd = NULL;
 148
 149                if (!qd && new_qd) {
 150                        qd = new_qd;
 151                        list_add(&qd->qd_list, &sdp->sd_quota_list);
 152                        atomic_inc(&sdp->sd_quota_count);
 153                        new_qd = NULL;
 154                }
 155
 156                spin_unlock(&sdp->sd_quota_spin);
 157
 158                if (qd || !create) {
 159                        if (new_qd) {
 160                                gfs2_lvb_unhold(new_qd->qd_gl);
 161                                kfree(new_qd);
 162                        }
 163                        *qdp = qd;
 164                        return 0;
 165                }
 166
 167                error = qd_alloc(sdp, user, id, &new_qd);
 168                if (error)
 169                        return error;
 170        }
 171}
 172
 173static void qd_hold(struct gfs2_quota_data *qd)
 174{
 175        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 176
 177        spin_lock(&sdp->sd_quota_spin);
 178        gfs2_assert(sdp, qd->qd_count);
 179        qd->qd_count++;
 180        spin_unlock(&sdp->sd_quota_spin);
 181}
 182
 183static void qd_put(struct gfs2_quota_data *qd)
 184{
 185        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 186        spin_lock(&sdp->sd_quota_spin);
 187        gfs2_assert(sdp, qd->qd_count);
 188        if (!--qd->qd_count)
 189                qd->qd_last_touched = jiffies;
 190        spin_unlock(&sdp->sd_quota_spin);
 191}
 192
 193static int slot_get(struct gfs2_quota_data *qd)
 194{
 195        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 196        unsigned int c, o = 0, b;
 197        unsigned char byte = 0;
 198
 199        spin_lock(&sdp->sd_quota_spin);
 200
 201        if (qd->qd_slot_count++) {
 202                spin_unlock(&sdp->sd_quota_spin);
 203                return 0;
 204        }
 205
 206        for (c = 0; c < sdp->sd_quota_chunks; c++)
 207                for (o = 0; o < PAGE_SIZE; o++) {
 208                        byte = sdp->sd_quota_bitmap[c][o];
 209                        if (byte != 0xFF)
 210                                goto found;
 211                }
 212
 213        goto fail;
 214
 215found:
 216        for (b = 0; b < 8; b++)
 217                if (!(byte & (1 << b)))
 218                        break;
 219        qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
 220
 221        if (qd->qd_slot >= sdp->sd_quota_slots)
 222                goto fail;
 223
 224        sdp->sd_quota_bitmap[c][o] |= 1 << b;
 225
 226        spin_unlock(&sdp->sd_quota_spin);
 227
 228        return 0;
 229
 230fail:
 231        qd->qd_slot_count--;
 232        spin_unlock(&sdp->sd_quota_spin);
 233        return -ENOSPC;
 234}
 235
 236static void slot_hold(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        qd->qd_slot_count++;
 243        spin_unlock(&sdp->sd_quota_spin);
 244}
 245
 246static void slot_put(struct gfs2_quota_data *qd)
 247{
 248        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 249
 250        spin_lock(&sdp->sd_quota_spin);
 251        gfs2_assert(sdp, qd->qd_slot_count);
 252        if (!--qd->qd_slot_count) {
 253                gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
 254                qd->qd_slot = -1;
 255        }
 256        spin_unlock(&sdp->sd_quota_spin);
 257}
 258
 259static int bh_get(struct gfs2_quota_data *qd)
 260{
 261        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 262        struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
 263        unsigned int block, offset;
 264        struct buffer_head *bh;
 265        int error;
 266        struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 267
 268        mutex_lock(&sdp->sd_quota_mutex);
 269
 270        if (qd->qd_bh_count++) {
 271                mutex_unlock(&sdp->sd_quota_mutex);
 272                return 0;
 273        }
 274
 275        block = qd->qd_slot / sdp->sd_qc_per_block;
 276        offset = qd->qd_slot % sdp->sd_qc_per_block;
 277
 278        bh_map.b_size = 1 << ip->i_inode.i_blkbits;
 279        error = gfs2_block_map(&ip->i_inode, block, &bh_map, 0);
 280        if (error)
 281                goto fail;
 282        error = gfs2_meta_read(ip->i_gl, bh_map.b_blocknr, DIO_WAIT, &bh);
 283        if (error)
 284                goto fail;
 285        error = -EIO;
 286        if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
 287                goto fail_brelse;
 288
 289        qd->qd_bh = bh;
 290        qd->qd_bh_qc = (struct gfs2_quota_change *)
 291                (bh->b_data + sizeof(struct gfs2_meta_header) +
 292                 offset * sizeof(struct gfs2_quota_change));
 293
 294        mutex_unlock(&sdp->sd_quota_mutex);
 295
 296        return 0;
 297
 298fail_brelse:
 299        brelse(bh);
 300fail:
 301        qd->qd_bh_count--;
 302        mutex_unlock(&sdp->sd_quota_mutex);
 303        return error;
 304}
 305
 306static void bh_put(struct gfs2_quota_data *qd)
 307{
 308        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 309
 310        mutex_lock(&sdp->sd_quota_mutex);
 311        gfs2_assert(sdp, qd->qd_bh_count);
 312        if (!--qd->qd_bh_count) {
 313                brelse(qd->qd_bh);
 314                qd->qd_bh = NULL;
 315                qd->qd_bh_qc = NULL;
 316        }
 317        mutex_unlock(&sdp->sd_quota_mutex);
 318}
 319
 320static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
 321{
 322        struct gfs2_quota_data *qd = NULL;
 323        int error;
 324        int found = 0;
 325
 326        *qdp = NULL;
 327
 328        if (sdp->sd_vfs->s_flags & MS_RDONLY)
 329                return 0;
 330
 331        spin_lock(&sdp->sd_quota_spin);
 332
 333        list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
 334                if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
 335                    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
 336                    qd->qd_sync_gen >= sdp->sd_quota_sync_gen)
 337                        continue;
 338
 339                list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 340
 341                set_bit(QDF_LOCKED, &qd->qd_flags);
 342                gfs2_assert_warn(sdp, qd->qd_count);
 343                qd->qd_count++;
 344                qd->qd_change_sync = qd->qd_change;
 345                gfs2_assert_warn(sdp, qd->qd_slot_count);
 346                qd->qd_slot_count++;
 347                found = 1;
 348
 349                break;
 350        }
 351
 352        if (!found)
 353                qd = NULL;
 354
 355        spin_unlock(&sdp->sd_quota_spin);
 356
 357        if (qd) {
 358                gfs2_assert_warn(sdp, qd->qd_change_sync);
 359                error = bh_get(qd);
 360                if (error) {
 361                        clear_bit(QDF_LOCKED, &qd->qd_flags);
 362                        slot_put(qd);
 363                        qd_put(qd);
 364                        return error;
 365                }
 366        }
 367
 368        *qdp = qd;
 369
 370        return 0;
 371}
 372
 373static int qd_trylock(struct gfs2_quota_data *qd)
 374{
 375        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 376
 377        if (sdp->sd_vfs->s_flags & MS_RDONLY)
 378                return 0;
 379
 380        spin_lock(&sdp->sd_quota_spin);
 381
 382        if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
 383            !test_bit(QDF_CHANGE, &qd->qd_flags)) {
 384                spin_unlock(&sdp->sd_quota_spin);
 385                return 0;
 386        }
 387
 388        list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 389
 390        set_bit(QDF_LOCKED, &qd->qd_flags);
 391        gfs2_assert_warn(sdp, qd->qd_count);
 392        qd->qd_count++;
 393        qd->qd_change_sync = qd->qd_change;
 394        gfs2_assert_warn(sdp, qd->qd_slot_count);
 395        qd->qd_slot_count++;
 396
 397        spin_unlock(&sdp->sd_quota_spin);
 398
 399        gfs2_assert_warn(sdp, qd->qd_change_sync);
 400        if (bh_get(qd)) {
 401                clear_bit(QDF_LOCKED, &qd->qd_flags);
 402                slot_put(qd);
 403                qd_put(qd);
 404                return 0;
 405        }
 406
 407        return 1;
 408}
 409
 410static void qd_unlock(struct gfs2_quota_data *qd)
 411{
 412        gfs2_assert_warn(qd->qd_gl->gl_sbd,
 413                         test_bit(QDF_LOCKED, &qd->qd_flags));
 414        clear_bit(QDF_LOCKED, &qd->qd_flags);
 415        bh_put(qd);
 416        slot_put(qd);
 417        qd_put(qd);
 418}
 419
 420static int qdsb_get(struct gfs2_sbd *sdp, int user, u32 id, int create,
 421                    struct gfs2_quota_data **qdp)
 422{
 423        int error;
 424
 425        error = qd_get(sdp, user, id, create, qdp);
 426        if (error)
 427                return error;
 428
 429        error = slot_get(*qdp);
 430        if (error)
 431                goto fail;
 432
 433        error = bh_get(*qdp);
 434        if (error)
 435                goto fail_slot;
 436
 437        return 0;
 438
 439fail_slot:
 440        slot_put(*qdp);
 441fail:
 442        qd_put(*qdp);
 443        return error;
 444}
 445
 446static void qdsb_put(struct gfs2_quota_data *qd)
 447{
 448        bh_put(qd);
 449        slot_put(qd);
 450        qd_put(qd);
 451}
 452
 453int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
 454{
 455        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 456        struct gfs2_alloc *al = ip->i_alloc;
 457        struct gfs2_quota_data **qd = al->al_qd;
 458        int error;
 459
 460        if (gfs2_assert_warn(sdp, !al->al_qd_num) ||
 461            gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags)))
 462                return -EIO;
 463
 464        if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
 465                return 0;
 466
 467        error = qdsb_get(sdp, QUOTA_USER, ip->i_inode.i_uid, CREATE, qd);
 468        if (error)
 469                goto out;
 470        al->al_qd_num++;
 471        qd++;
 472
 473        error = qdsb_get(sdp, QUOTA_GROUP, ip->i_inode.i_gid, CREATE, qd);
 474        if (error)
 475                goto out;
 476        al->al_qd_num++;
 477        qd++;
 478
 479        if (uid != NO_QUOTA_CHANGE && uid != ip->i_inode.i_uid) {
 480                error = qdsb_get(sdp, QUOTA_USER, uid, CREATE, qd);
 481                if (error)
 482                        goto out;
 483                al->al_qd_num++;
 484                qd++;
 485        }
 486
 487        if (gid != NO_QUOTA_CHANGE && gid != ip->i_inode.i_gid) {
 488                error = qdsb_get(sdp, QUOTA_GROUP, gid, CREATE, qd);
 489                if (error)
 490                        goto out;
 491                al->al_qd_num++;
 492                qd++;
 493        }
 494
 495out:
 496        if (error)
 497                gfs2_quota_unhold(ip);
 498        return error;
 499}
 500
 501void gfs2_quota_unhold(struct gfs2_inode *ip)
 502{
 503        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 504        struct gfs2_alloc *al = ip->i_alloc;
 505        unsigned int x;
 506
 507        gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
 508
 509        for (x = 0; x < al->al_qd_num; x++) {
 510                qdsb_put(al->al_qd[x]);
 511                al->al_qd[x] = NULL;
 512        }
 513        al->al_qd_num = 0;
 514}
 515
 516static int sort_qd(const void *a, const void *b)
 517{
 518        const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
 519        const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
 520
 521        if (!test_bit(QDF_USER, &qd_a->qd_flags) !=
 522            !test_bit(QDF_USER, &qd_b->qd_flags)) {
 523                if (test_bit(QDF_USER, &qd_a->qd_flags))
 524                        return -1;
 525                else
 526                        return 1;
 527        }
 528        if (qd_a->qd_id < qd_b->qd_id)
 529                return -1;
 530        if (qd_a->qd_id > qd_b->qd_id)
 531                return 1;
 532
 533        return 0;
 534}
 535
 536static void do_qc(struct gfs2_quota_data *qd, s64 change)
 537{
 538        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 539        struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
 540        struct gfs2_quota_change *qc = qd->qd_bh_qc;
 541        s64 x;
 542
 543        mutex_lock(&sdp->sd_quota_mutex);
 544        gfs2_trans_add_bh(ip->i_gl, qd->qd_bh, 1);
 545
 546        if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
 547                qc->qc_change = 0;
 548                qc->qc_flags = 0;
 549                if (test_bit(QDF_USER, &qd->qd_flags))
 550                        qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
 551                qc->qc_id = cpu_to_be32(qd->qd_id);
 552        }
 553
 554        x = be64_to_cpu(qc->qc_change) + change;
 555        qc->qc_change = cpu_to_be64(x);
 556
 557        spin_lock(&sdp->sd_quota_spin);
 558        qd->qd_change = x;
 559        spin_unlock(&sdp->sd_quota_spin);
 560
 561        if (!x) {
 562                gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
 563                clear_bit(QDF_CHANGE, &qd->qd_flags);
 564                qc->qc_flags = 0;
 565                qc->qc_id = 0;
 566                slot_put(qd);
 567                qd_put(qd);
 568        } else if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
 569                qd_hold(qd);
 570                slot_hold(qd);
 571        }
 572
 573        mutex_unlock(&sdp->sd_quota_mutex);
 574}
 575
 576static void gfs2_quota_in(struct gfs2_quota_host *qu, const void *buf)
 577{
 578        const struct gfs2_quota *str = buf;
 579
 580        qu->qu_limit = be64_to_cpu(str->qu_limit);
 581        qu->qu_warn = be64_to_cpu(str->qu_warn);
 582        qu->qu_value = be64_to_cpu(str->qu_value);
 583        qu->qu_ll_next = be32_to_cpu(str->qu_ll_next);
 584}
 585
 586static void gfs2_quota_out(const struct gfs2_quota_host *qu, void *buf)
 587{
 588        struct gfs2_quota *str = buf;
 589
 590        str->qu_limit = cpu_to_be64(qu->qu_limit);
 591        str->qu_warn = cpu_to_be64(qu->qu_warn);
 592        str->qu_value = cpu_to_be64(qu->qu_value);
 593        str->qu_ll_next = cpu_to_be32(qu->qu_ll_next);
 594        memset(&str->qu_reserved, 0, sizeof(str->qu_reserved));
 595}
 596
 597/**
 598 * gfs2_adjust_quota
 599 *
 600 * This function was mostly borrowed from gfs2_block_truncate_page which was
 601 * in turn mostly borrowed from ext3
 602 */
 603static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
 604                             s64 change, struct gfs2_quota_data *qd)
 605{
 606        struct inode *inode = &ip->i_inode;
 607        struct address_space *mapping = inode->i_mapping;
 608        unsigned long index = loc >> PAGE_CACHE_SHIFT;
 609        unsigned offset = loc & (PAGE_CACHE_SIZE - 1);
 610        unsigned blocksize, iblock, pos;
 611        struct buffer_head *bh;
 612        struct page *page;
 613        void *kaddr;
 614        char *ptr;
 615        struct gfs2_quota_host qp;
 616        s64 value;
 617        int err = -EIO;
 618
 619        if (gfs2_is_stuffed(ip)) {
 620                struct gfs2_alloc *al = NULL;
 621                al = gfs2_alloc_get(ip);
 622                /* just request 1 blk */
 623                al->al_requested = 1;
 624                gfs2_inplace_reserve(ip);
 625                gfs2_unstuff_dinode(ip, NULL);
 626                gfs2_inplace_release(ip);
 627                gfs2_alloc_put(ip);
 628        }
 629        page = grab_cache_page(mapping, index);
 630        if (!page)
 631                return -ENOMEM;
 632
 633        blocksize = inode->i_sb->s_blocksize;
 634        iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
 635
 636        if (!page_has_buffers(page))
 637                create_empty_buffers(page, blocksize, 0);
 638
 639        bh = page_buffers(page);
 640        pos = blocksize;
 641        while (offset >= pos) {
 642                bh = bh->b_this_page;
 643                iblock++;
 644                pos += blocksize;
 645        }
 646
 647        if (!buffer_mapped(bh)) {
 648                gfs2_block_map(inode, iblock, bh, 1);
 649                if (!buffer_mapped(bh))
 650                        goto unlock;
 651        }
 652
 653        if (PageUptodate(page))
 654                set_buffer_uptodate(bh);
 655
 656        if (!buffer_uptodate(bh)) {
 657                ll_rw_block(READ_META, 1, &bh);
 658                wait_on_buffer(bh);
 659                if (!buffer_uptodate(bh))
 660                        goto unlock;
 661        }
 662
 663        gfs2_trans_add_bh(ip->i_gl, bh, 0);
 664
 665        kaddr = kmap_atomic(page, KM_USER0);
 666        ptr = kaddr + offset;
 667        gfs2_quota_in(&qp, ptr);
 668        qp.qu_value += change;
 669        value = qp.qu_value;
 670        gfs2_quota_out(&qp, ptr);
 671        flush_dcache_page(page);
 672        kunmap_atomic(kaddr, KM_USER0);
 673        err = 0;
 674        qd->qd_qb.qb_magic = cpu_to_be32(GFS2_MAGIC);
 675        qd->qd_qb.qb_value = cpu_to_be64(value);
 676        ((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_magic = cpu_to_be32(GFS2_MAGIC);
 677        ((struct gfs2_quota_lvb*)(qd->qd_gl->gl_lvb))->qb_value = cpu_to_be64(value);
 678unlock:
 679        unlock_page(page);
 680        page_cache_release(page);
 681        return err;
 682}
 683
 684static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 685{
 686        struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_sbd;
 687        struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
 688        unsigned int data_blocks, ind_blocks;
 689        struct gfs2_holder *ghs, i_gh;
 690        unsigned int qx, x;
 691        struct gfs2_quota_data *qd;
 692        loff_t offset;
 693        unsigned int nalloc = 0;
 694        struct gfs2_alloc *al = NULL;
 695        int error;
 696
 697        gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
 698                              &data_blocks, &ind_blocks);
 699
 700        ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_KERNEL);
 701        if (!ghs)
 702                return -ENOMEM;
 703
 704        sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
 705        for (qx = 0; qx < num_qd; qx++) {
 706                error = gfs2_glock_nq_init(qda[qx]->qd_gl,
 707                                           LM_ST_EXCLUSIVE,
 708                                           GL_NOCACHE, &ghs[qx]);
 709                if (error)
 710                        goto out;
 711        }
 712
 713        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 714        if (error)
 715                goto out;
 716
 717        for (x = 0; x < num_qd; x++) {
 718                int alloc_required;
 719
 720                offset = qd2offset(qda[x]);
 721                error = gfs2_write_alloc_required(ip, offset,
 722                                                  sizeof(struct gfs2_quota),
 723                                                  &alloc_required);
 724                if (error)
 725                        goto out_gunlock;
 726                if (alloc_required)
 727                        nalloc++;
 728        }
 729
 730        if (nalloc) {
 731                al = gfs2_alloc_get(ip);
 732
 733                al->al_requested = nalloc * (data_blocks + ind_blocks);
 734
 735                error = gfs2_inplace_reserve(ip);
 736                if (error)
 737                        goto out_alloc;
 738
 739                error = gfs2_trans_begin(sdp,
 740                                         al->al_rgd->rd_length +
 741                                         num_qd * data_blocks +
 742                                         nalloc * ind_blocks +
 743                                         RES_DINODE + num_qd +
 744                                         RES_STATFS, 0);
 745                if (error)
 746                        goto out_ipres;
 747        } else {
 748                error = gfs2_trans_begin(sdp,
 749                                         num_qd * data_blocks +
 750                                         RES_DINODE + num_qd, 0);
 751                if (error)
 752                        goto out_gunlock;
 753        }
 754
 755        for (x = 0; x < num_qd; x++) {
 756                qd = qda[x];
 757                offset = qd2offset(qd);
 758                error = gfs2_adjust_quota(ip, offset, qd->qd_change_sync,
 759                                          (struct gfs2_quota_data *)
 760                                          qd);
 761                if (error)
 762                        goto out_end_trans;
 763
 764                do_qc(qd, -qd->qd_change_sync);
 765        }
 766
 767        error = 0;
 768
 769out_end_trans:
 770        gfs2_trans_end(sdp);
 771out_ipres:
 772        if (nalloc)
 773                gfs2_inplace_release(ip);
 774out_alloc:
 775        if (nalloc)
 776                gfs2_alloc_put(ip);
 777out_gunlock:
 778        gfs2_glock_dq_uninit(&i_gh);
 779out:
 780        while (qx--)
 781                gfs2_glock_dq_uninit(&ghs[qx]);
 782        kfree(ghs);
 783        gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
 784        return error;
 785}
 786
 787static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
 788                    struct gfs2_holder *q_gh)
 789{
 790        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 791        struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
 792        struct gfs2_holder i_gh;
 793        struct gfs2_quota_host q;
 794        char buf[sizeof(struct gfs2_quota)];
 795        int error;
 796        struct gfs2_quota_lvb *qlvb;
 797
 798restart:
 799        error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
 800        if (error)
 801                return error;
 802
 803        qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
 804
 805        if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
 806                loff_t pos;
 807                gfs2_glock_dq_uninit(q_gh);
 808                error = gfs2_glock_nq_init(qd->qd_gl,
 809                                          LM_ST_EXCLUSIVE, GL_NOCACHE,
 810                                          q_gh);
 811                if (error)
 812                        return error;
 813
 814                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
 815                if (error)
 816                        goto fail;
 817
 818                memset(buf, 0, sizeof(struct gfs2_quota));
 819                pos = qd2offset(qd);
 820                error = gfs2_internal_read(ip, NULL, buf, &pos,
 821                                           sizeof(struct gfs2_quota));
 822                if (error < 0)
 823                        goto fail_gunlock;
 824
 825                gfs2_glock_dq_uninit(&i_gh);
 826
 827
 828                gfs2_quota_in(&q, buf);
 829                qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
 830                qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
 831                qlvb->__pad = 0;
 832                qlvb->qb_limit = cpu_to_be64(q.qu_limit);
 833                qlvb->qb_warn = cpu_to_be64(q.qu_warn);
 834                qlvb->qb_value = cpu_to_be64(q.qu_value);
 835                qd->qd_qb = *qlvb;
 836
 837                if (gfs2_glock_is_blocking(qd->qd_gl)) {
 838                        gfs2_glock_dq_uninit(q_gh);
 839                        force_refresh = 0;
 840                        goto restart;
 841                }
 842        }
 843
 844        return 0;
 845
 846fail_gunlock:
 847        gfs2_glock_dq_uninit(&i_gh);
 848fail:
 849        gfs2_glock_dq_uninit(q_gh);
 850        return error;
 851}
 852
 853int gfs2_quota_lock(struct gfs2_inode *ip, u32 uid, u32 gid)
 854{
 855        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 856        struct gfs2_alloc *al = ip->i_alloc;
 857        unsigned int x;
 858        int error = 0;
 859
 860        gfs2_quota_hold(ip, uid, gid);
 861
 862        if (capable(CAP_SYS_RESOURCE) ||
 863            sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
 864                return 0;
 865
 866        sort(al->al_qd, al->al_qd_num, sizeof(struct gfs2_quota_data *),
 867             sort_qd, NULL);
 868
 869        for (x = 0; x < al->al_qd_num; x++) {
 870                error = do_glock(al->al_qd[x], NO_FORCE, &al->al_qd_ghs[x]);
 871                if (error)
 872                        break;
 873        }
 874
 875        if (!error)
 876                set_bit(GIF_QD_LOCKED, &ip->i_flags);
 877        else {
 878                while (x--)
 879                        gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
 880                gfs2_quota_unhold(ip);
 881        }
 882
 883        return error;
 884}
 885
 886static int need_sync(struct gfs2_quota_data *qd)
 887{
 888        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 889        struct gfs2_tune *gt = &sdp->sd_tune;
 890        s64 value;
 891        unsigned int num, den;
 892        int do_sync = 1;
 893
 894        if (!qd->qd_qb.qb_limit)
 895                return 0;
 896
 897        spin_lock(&sdp->sd_quota_spin);
 898        value = qd->qd_change;
 899        spin_unlock(&sdp->sd_quota_spin);
 900
 901        spin_lock(&gt->gt_spin);
 902        num = gt->gt_quota_scale_num;
 903        den = gt->gt_quota_scale_den;
 904        spin_unlock(&gt->gt_spin);
 905
 906        if (value < 0)
 907                do_sync = 0;
 908        else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
 909                 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
 910                do_sync = 0;
 911        else {
 912                value *= gfs2_jindex_size(sdp) * num;
 913                do_div(value, den);
 914                value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
 915                if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
 916                        do_sync = 0;
 917        }
 918
 919        return do_sync;
 920}
 921
 922void gfs2_quota_unlock(struct gfs2_inode *ip)
 923{
 924        struct gfs2_alloc *al = ip->i_alloc;
 925        struct gfs2_quota_data *qda[4];
 926        unsigned int count = 0;
 927        unsigned int x;
 928
 929        if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
 930                goto out;
 931
 932        for (x = 0; x < al->al_qd_num; x++) {
 933                struct gfs2_quota_data *qd;
 934                int sync;
 935
 936                qd = al->al_qd[x];
 937                sync = need_sync(qd);
 938
 939                gfs2_glock_dq_uninit(&al->al_qd_ghs[x]);
 940
 941                if (sync && qd_trylock(qd))
 942                        qda[count++] = qd;
 943        }
 944
 945        if (count) {
 946                do_sync(count, qda);
 947                for (x = 0; x < count; x++)
 948                        qd_unlock(qda[x]);
 949        }
 950
 951out:
 952        gfs2_quota_unhold(ip);
 953}
 954
 955#define MAX_LINE 256
 956
 957static int print_message(struct gfs2_quota_data *qd, char *type)
 958{
 959        struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
 960
 961        printk(KERN_INFO "GFS2: fsid=%s: quota %s for %s %u\r\n",
 962               sdp->sd_fsname, type,
 963               (test_bit(QDF_USER, &qd->qd_flags)) ? "user" : "group",
 964               qd->qd_id);
 965
 966        return 0;
 967}
 968
 969int gfs2_quota_check(struct gfs2_inode *ip, u32 uid, u32 gid)
 970{
 971        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 972        struct gfs2_alloc *al = ip->i_alloc;
 973        struct gfs2_quota_data *qd;
 974        s64 value;
 975        unsigned int x;
 976        int error = 0;
 977
 978        if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
 979                return 0;
 980
 981        if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
 982                return 0;
 983
 984        for (x = 0; x < al->al_qd_num; x++) {
 985                qd = al->al_qd[x];
 986
 987                if (!((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
 988                      (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))))
 989                        continue;
 990
 991                value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
 992                spin_lock(&sdp->sd_quota_spin);
 993                value += qd->qd_change;
 994                spin_unlock(&sdp->sd_quota_spin);
 995
 996                if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
 997                        print_message(qd, "exceeded");
 998                        error = -EDQUOT;
 999                        break;
1000                } else if (be64_to_cpu(qd->qd_qb.qb_warn) &&
1001                           (s64)be64_to_cpu(qd->qd_qb.qb_warn) < value &&
1002                           time_after_eq(jiffies, qd->qd_last_warn +
1003                                         gfs2_tune_get(sdp,
1004                                                gt_quota_warn_period) * HZ)) {
1005                        error = print_message(qd, "warning");
1006                        qd->qd_last_warn = jiffies;
1007                }
1008        }
1009
1010        return error;
1011}
1012
1013void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
1014                       u32 uid, u32 gid)
1015{
1016        struct gfs2_alloc *al = ip->i_alloc;
1017        struct gfs2_quota_data *qd;
1018        unsigned int x;
1019
1020        if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), change))
1021                return;
1022        if (ip->i_di.di_flags & GFS2_DIF_SYSTEM)
1023                return;
1024
1025        for (x = 0; x < al->al_qd_num; x++) {
1026                qd = al->al_qd[x];
1027
1028                if ((qd->qd_id == uid && test_bit(QDF_USER, &qd->qd_flags)) ||
1029                    (qd->qd_id == gid && !test_bit(QDF_USER, &qd->qd_flags))) {
1030                        do_qc(qd, change);
1031                }
1032        }
1033}
1034
1035int gfs2_quota_sync(struct gfs2_sbd *sdp)
1036{
1037        struct gfs2_quota_data **qda;
1038        unsigned int max_qd = gfs2_tune_get(sdp, gt_quota_simul_sync);
1039        unsigned int num_qd;
1040        unsigned int x;
1041        int error = 0;
1042
1043        sdp->sd_quota_sync_gen++;
1044
1045        qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
1046        if (!qda)
1047                return -ENOMEM;
1048
1049        do {
1050                num_qd = 0;
1051
1052                for (;;) {
1053                        error = qd_fish(sdp, qda + num_qd);
1054                        if (error || !qda[num_qd])
1055                                break;
1056                        if (++num_qd == max_qd)
1057                                break;
1058                }
1059
1060                if (num_qd) {
1061                        if (!error)
1062                                error = do_sync(num_qd, qda);
1063                        if (!error)
1064                                for (x = 0; x < num_qd; x++)
1065                                        qda[x]->qd_sync_gen =
1066                                                sdp->sd_quota_sync_gen;
1067
1068                        for (x = 0; x < num_qd; x++)
1069                                qd_unlock(qda[x]);
1070                }
1071        } while (!error && num_qd == max_qd);
1072
1073        kfree(qda);
1074
1075        return error;
1076}
1077
1078int gfs2_quota_refresh(struct gfs2_sbd *sdp, int user, u32 id)
1079{
1080        struct gfs2_quota_data *qd;
1081        struct gfs2_holder q_gh;
1082        int error;
1083
1084        error = qd_get(sdp, user, id, CREATE, &qd);
1085        if (error)
1086                return error;
1087
1088        error = do_glock(qd, FORCE, &q_gh);
1089        if (!error)
1090                gfs2_glock_dq_uninit(&q_gh);
1091
1092        qd_put(qd);
1093
1094        return error;
1095}
1096
1097static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
1098{
1099        const struct gfs2_quota_change *str = buf;
1100
1101        qc->qc_change = be64_to_cpu(str->qc_change);
1102        qc->qc_flags = be32_to_cpu(str->qc_flags);
1103        qc->qc_id = be32_to_cpu(str->qc_id);
1104}
1105
1106int gfs2_quota_init(struct gfs2_sbd *sdp)
1107{
1108        struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
1109        unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
1110        unsigned int x, slot = 0;
1111        unsigned int found = 0;
1112        u64 dblock;
1113        u32 extlen = 0;
1114        int error;
1115
1116        if (!ip->i_di.di_size || ip->i_di.di_size > (64 << 20) ||
1117            ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
1118                gfs2_consist_inode(ip);
1119                return -EIO;
1120        }
1121        sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
1122        sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
1123
1124        error = -ENOMEM;
1125
1126        sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
1127                                       sizeof(unsigned char *), GFP_KERNEL);
1128        if (!sdp->sd_quota_bitmap)
1129                return error;
1130
1131        for (x = 0; x < sdp->sd_quota_chunks; x++) {
1132                sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL);
1133                if (!sdp->sd_quota_bitmap[x])
1134                        goto fail;
1135        }
1136
1137        for (x = 0; x < blocks; x++) {
1138                struct buffer_head *bh;
1139                unsigned int y;
1140
1141                if (!extlen) {
1142                        int new = 0;
1143                        error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
1144                        if (error)
1145                                goto fail;
1146                }
1147                error = -EIO;
1148                bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
1149                if (!bh)
1150                        goto fail;
1151                if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
1152                        brelse(bh);
1153                        goto fail;
1154                }
1155
1156                for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
1157                     y++, slot++) {
1158                        struct gfs2_quota_change_host qc;
1159                        struct gfs2_quota_data *qd;
1160
1161                        gfs2_quota_change_in(&qc, bh->b_data +
1162                                          sizeof(struct gfs2_meta_header) +
1163                                          y * sizeof(struct gfs2_quota_change));
1164                        if (!qc.qc_change)
1165                                continue;
1166
1167                        error = qd_alloc(sdp, (qc.qc_flags & GFS2_QCF_USER),
1168                                         qc.qc_id, &qd);
1169                        if (error) {
1170                                brelse(bh);
1171                                goto fail;
1172                        }
1173
1174                        set_bit(QDF_CHANGE, &qd->qd_flags);
1175                        qd->qd_change = qc.qc_change;
1176                        qd->qd_slot = slot;
1177                        qd->qd_slot_count = 1;
1178                        qd->qd_last_touched = jiffies;
1179
1180                        spin_lock(&sdp->sd_quota_spin);
1181                        gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
1182                        list_add(&qd->qd_list, &sdp->sd_quota_list);
1183                        atomic_inc(&sdp->sd_quota_count);
1184                        spin_unlock(&sdp->sd_quota_spin);
1185
1186                        found++;
1187                }
1188
1189                brelse(bh);
1190                dblock++;
1191                extlen--;
1192        }
1193
1194        if (found)
1195                fs_info(sdp, "found %u quota changes\n", found);
1196
1197        return 0;
1198
1199fail:
1200        gfs2_quota_cleanup(sdp);
1201        return error;
1202}
1203
1204void gfs2_quota_scan(struct gfs2_sbd *sdp)
1205{
1206        struct gfs2_quota_data *qd, *safe;
1207        LIST_HEAD(dead);
1208
1209        spin_lock(&sdp->sd_quota_spin);
1210        list_for_each_entry_safe(qd, safe, &sdp->sd_quota_list, qd_list) {
1211                if (!qd->qd_count &&
1212                    time_after_eq(jiffies, qd->qd_last_touched +
1213                                gfs2_tune_get(sdp, gt_quota_cache_secs) * HZ)) {
1214                        list_move(&qd->qd_list, &dead);
1215                        gfs2_assert_warn(sdp,
1216                                         atomic_read(&sdp->sd_quota_count) > 0);
1217                        atomic_dec(&sdp->sd_quota_count);
1218                }
1219        }
1220        spin_unlock(&sdp->sd_quota_spin);
1221
1222        while (!list_empty(&dead)) {
1223                qd = list_entry(dead.next, struct gfs2_quota_data, qd_list);
1224                list_del(&qd->qd_list);
1225
1226                gfs2_assert_warn(sdp, !qd->qd_change);
1227                gfs2_assert_warn(sdp, !qd->qd_slot_count);
1228                gfs2_assert_warn(sdp, !qd->qd_bh_count);
1229
1230                gfs2_lvb_unhold(qd->qd_gl);
1231                kfree(qd);
1232        }
1233}
1234
1235void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
1236{
1237        struct list_head *head = &sdp->sd_quota_list;
1238        struct gfs2_quota_data *qd;
1239        unsigned int x;
1240
1241        spin_lock(&sdp->sd_quota_spin);
1242        while (!list_empty(head)) {
1243                qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
1244
1245                if (qd->qd_count > 1 ||
1246                    (qd->qd_count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
1247                        list_move(&qd->qd_list, head);
1248                        spin_unlock(&sdp->sd_quota_spin);
1249                        schedule();
1250                        spin_lock(&sdp->sd_quota_spin);
1251                        continue;
1252                }
1253
1254                list_del(&qd->qd_list);
1255                atomic_dec(&sdp->sd_quota_count);
1256                spin_unlock(&sdp->sd_quota_spin);
1257
1258                if (!qd->qd_count) {
1259                        gfs2_assert_warn(sdp, !qd->qd_change);
1260                        gfs2_assert_warn(sdp, !qd->qd_slot_count);
1261                } else
1262                        gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
1263                gfs2_assert_warn(sdp, !qd->qd_bh_count);
1264
1265                gfs2_lvb_unhold(qd->qd_gl);
1266                kfree(qd);
1267
1268                spin_lock(&sdp->sd_quota_spin);
1269        }
1270        spin_unlock(&sdp->sd_quota_spin);
1271
1272        gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
1273
1274        if (sdp->sd_quota_bitmap) {
1275                for (x = 0; x < sdp->sd_quota_chunks; x++)
1276                        kfree(sdp->sd_quota_bitmap[x]);
1277                kfree(sdp->sd_quota_bitmap);
1278        }
1279}
1280
1281
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