fs/xfs/xfs_dquot.c

   1 /*
   2  * Copyright (c) 2000-2003 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_bit.h"
  21 #include "xfs_log.h"
  22 #include "xfs_trans.h"
  23 #include "xfs_sb.h"
  24 #include "xfs_ag.h"
  25 #include "xfs_alloc.h"
  26 #include "xfs_quota.h"
  27 #include "xfs_mount.h"
  28 #include "xfs_bmap_btree.h"
  29 #include "xfs_inode.h"
  30 #include "xfs_bmap.h"
  31 #include "xfs_rtalloc.h"
  32 #include "xfs_error.h"
  33 #include "xfs_itable.h"
  34 #include "xfs_attr.h"
  35 #include "xfs_buf_item.h"
  36 #include "xfs_trans_space.h"
  37 #include "xfs_trans_priv.h"
  38 #include "xfs_qm.h"
  39 #include "xfs_trace.h"
  40
  41 /*
  42  * Lock order:
  43  *
  44  * ip->i_lock
  45  *   qi->qi_tree_lock
  46  *     dquot->q_qlock (xfs_dqlock() and friends)
  47  *       dquot->q_flush (xfs_dqflock() and friends)
  48  *       qi->qi_lru_lock
  49  *
  50  * If two dquots need to be locked the order is user before group/project,
  51  * otherwise by the lowest id first, see xfs_dqlock2.
  52  */
  53
  54 #ifdef DEBUG
  55 xfs_buftarg_t *xfs_dqerror_target;
  56 int xfs_do_dqerror;
  57 int xfs_dqreq_num;
  58 int xfs_dqerror_mod = 33;
  59 #endif
  60
  61 struct kmem_zone                *xfs_qm_dqtrxzone;
  62 static struct kmem_zone         *xfs_qm_dqzone;
  63
  64 static struct lock_class_key xfs_dquot_other_class;
  65
  66 /*
  67  * This is called to free all the memory associated with a dquot
  68  */
  69 void
  70 xfs_qm_dqdestroy(
  71         xfs_dquot_t     *dqp)
  72 {
  73         ASSERT(list_empty(&dqp->q_lru));
  74
  75         mutex_destroy(&dqp->q_qlock);
  76         kmem_zone_free(xfs_qm_dqzone, dqp);
  77
  78         XFS_STATS_DEC(xs_qm_dquot);
  79 }
  80
  81 /*
  82  * If default limits are in force, push them into the dquot now.
  83  * We overwrite the dquot limits only if they are zero and this
  84  * is not the root dquot.
  85  */
  86 void
  87 xfs_qm_adjust_dqlimits(
  88         xfs_mount_t             *mp,
  89         xfs_disk_dquot_t        *d)
  90 {
  91         xfs_quotainfo_t         *q = mp->m_quotainfo;
  92
  93         ASSERT(d->d_id);
  94
  95         if (q->qi_bsoftlimit && !d->d_blk_softlimit)
  96                 d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
  97         if (q->qi_bhardlimit && !d->d_blk_hardlimit)
  98                 d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
  99         if (q->qi_isoftlimit && !d->d_ino_softlimit)
 100                 d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
 101         if (q->qi_ihardlimit && !d->d_ino_hardlimit)
 102                 d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
 103         if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
 104                 d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
 105         if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
 106                 d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
 107 }
 108
 109 /*
 110  * Check the limits and timers of a dquot and start or reset timers
 111  * if necessary.
 112  * This gets called even when quota enforcement is OFF, which makes our
 113  * life a little less complicated. (We just don't reject any quota
 114  * reservations in that case, when enforcement is off).
 115  * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 116  * enforcement's off.
 117  * In contrast, warnings are a little different in that they don't
 118  * 'automatically' get started when limits get exceeded.  They do
 119  * get reset to zero, however, when we find the count to be under
 120  * the soft limit (they are only ever set non-zero via userspace).
 121  */
 122 void
 123 xfs_qm_adjust_dqtimers(
 124         xfs_mount_t             *mp,
 125         xfs_disk_dquot_t        *d)
 126 {
 127         ASSERT(d->d_id);
 128
 129 #ifdef DEBUG
 130         if (d->d_blk_hardlimit)
 131                 ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
 132                        be64_to_cpu(d->d_blk_hardlimit));
 133         if (d->d_ino_hardlimit)
 134                 ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
 135                        be64_to_cpu(d->d_ino_hardlimit));
 136         if (d->d_rtb_hardlimit)
 137                 ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
 138                        be64_to_cpu(d->d_rtb_hardlimit));
 139 #endif
 140
 141         if (!d->d_btimer) {
 142                 if ((d->d_blk_softlimit &&
 143                      (be64_to_cpu(d->d_bcount) >
 144                       be64_to_cpu(d->d_blk_softlimit))) ||
 145                     (d->d_blk_hardlimit &&
 146                      (be64_to_cpu(d->d_bcount) >
 147                       be64_to_cpu(d->d_blk_hardlimit)))) {
 148                         d->d_btimer = cpu_to_be32(get_seconds() +
 149                                         mp->m_quotainfo->qi_btimelimit);
 150                 } else {
 151                         d->d_bwarns = 0;
 152                 }
 153         } else {
 154                 if ((!d->d_blk_softlimit ||
 155                      (be64_to_cpu(d->d_bcount) <=
 156                       be64_to_cpu(d->d_blk_softlimit))) &&
 157                     (!d->d_blk_hardlimit ||
 158                     (be64_to_cpu(d->d_bcount) <=
 159                      be64_to_cpu(d->d_blk_hardlimit)))) {
 160                         d->d_btimer = 0;
 161                 }
 162         }
 163
 164         if (!d->d_itimer) {
 165                 if ((d->d_ino_softlimit &&
 166                      (be64_to_cpu(d->d_icount) >
 167                       be64_to_cpu(d->d_ino_softlimit))) ||
 168                     (d->d_ino_hardlimit &&
 169                      (be64_to_cpu(d->d_icount) >
 170                       be64_to_cpu(d->d_ino_hardlimit)))) {
 171                         d->d_itimer = cpu_to_be32(get_seconds() +
 172                                         mp->m_quotainfo->qi_itimelimit);
 173                 } else {
 174                         d->d_iwarns = 0;
 175                 }
 176         } else {
 177                 if ((!d->d_ino_softlimit ||
 178                      (be64_to_cpu(d->d_icount) <=
 179                       be64_to_cpu(d->d_ino_softlimit)))  &&
 180                     (!d->d_ino_hardlimit ||
 181                      (be64_to_cpu(d->d_icount) <=
 182                       be64_to_cpu(d->d_ino_hardlimit)))) {
 183                         d->d_itimer = 0;
 184                 }
 185         }
 186
 187         if (!d->d_rtbtimer) {
 188                 if ((d->d_rtb_softlimit &&
 189                      (be64_to_cpu(d->d_rtbcount) >
 190                       be64_to_cpu(d->d_rtb_softlimit))) ||
 191                     (d->d_rtb_hardlimit &&
 192                      (be64_to_cpu(d->d_rtbcount) >
 193                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 194                         d->d_rtbtimer = cpu_to_be32(get_seconds() +
 195                                         mp->m_quotainfo->qi_rtbtimelimit);
 196                 } else {
 197                         d->d_rtbwarns = 0;
 198                 }
 199         } else {
 200                 if ((!d->d_rtb_softlimit ||
 201                      (be64_to_cpu(d->d_rtbcount) <=
 202                       be64_to_cpu(d->d_rtb_softlimit))) &&
 203                     (!d->d_rtb_hardlimit ||
 204                      (be64_to_cpu(d->d_rtbcount) <=
 205                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 206                         d->d_rtbtimer = 0;
 207                 }
 208         }
 209 }
 210
 211 /*
 212  * initialize a buffer full of dquots and log the whole thing
 213  */
 214 STATIC void
 215 xfs_qm_init_dquot_blk(
 216         xfs_trans_t     *tp,
 217         xfs_mount_t     *mp,
 218         xfs_dqid_t      id,
 219         uint            type,
 220         xfs_buf_t       *bp)
 221 {
 222         struct xfs_quotainfo    *q = mp->m_quotainfo;
 223         xfs_dqblk_t     *d;
 224         int             curid, i;
 225
 226         ASSERT(tp);
 227         ASSERT(xfs_buf_islocked(bp));
 228
 229         d = bp->b_addr;
 230
 231         /*
 232          * ID of the first dquot in the block - id's are zero based.
 233          */
 234         curid = id - (id % q->qi_dqperchunk);
 235         ASSERT(curid >= 0);
 236         memset(d, 0, BBTOB(q->qi_dqchunklen));
 237         for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) {
 238                 d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 239                 d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 240                 d->dd_diskdq.d_id = cpu_to_be32(curid);
 241                 d->dd_diskdq.d_flags = type;
 242         }
 243
 244         xfs_trans_dquot_buf(tp, bp,
 245                             (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
 246                             ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
 247                              XFS_BLF_GDQUOT_BUF)));
 248         xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
 249 }
 250
 251 static void
 252 xfs_dquot_buf_verify(
 253         struct xfs_buf          *bp)
 254 {
 255         struct xfs_mount        *mp = bp->b_target->bt_mount;
 256         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 257         struct xfs_disk_dquot   *ddq;
 258         xfs_dqid_t              id = 0;
 259         int                     i;
 260
 261         /*
 262          * On the first read of the buffer, verify that each dquot is valid.
 263          * We don't know what the id of the dquot is supposed to be, just that
 264          * they should be increasing monotonically within the buffer. If the
 265          * first id is corrupt, then it will fail on the second dquot in the
 266          * buffer so corruptions could point to the wrong dquot in this case.
 267          */
 268         for (i = 0; i < mp->m_quotainfo->qi_dqperchunk; i++) {
 269                 int     error;
 270
 271                 ddq = &d[i].dd_diskdq;
 272
 273                 if (i == 0)
 274                         id = be32_to_cpu(ddq->d_id);
 275
 276                 error = xfs_qm_dqcheck(mp, ddq, id + i, 0, XFS_QMOPT_DOWARN,
 277                                         "xfs_dquot_read_verify");
 278                 if (error) {
 279                         XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, d);
 280                         xfs_buf_ioerror(bp, EFSCORRUPTED);
 281                         break;
 282                 }
 283         }
 284 }
 285
 286 static void
 287 xfs_dquot_buf_read_verify(
 288         struct xfs_buf  *bp)
 289 {
 290         xfs_dquot_buf_verify(bp);
 291 }
 292
 293 void
 294 xfs_dquot_buf_write_verify(
 295         struct xfs_buf  *bp)
 296 {
 297         xfs_dquot_buf_verify(bp);
 298 }
 299
 300 const struct xfs_buf_ops xfs_dquot_buf_ops = {
 301         .verify_read = xfs_dquot_buf_read_verify,
 302         .verify_write = xfs_dquot_buf_write_verify,
 303 };
 304
 305 /*
 306  * Allocate a block and fill it with dquots.
 307  * This is called when the bmapi finds a hole.
 308  */
 309 STATIC int
 310 xfs_qm_dqalloc(
 311         xfs_trans_t     **tpp,
 312         xfs_mount_t     *mp,
 313         xfs_dquot_t     *dqp,
 314         xfs_inode_t     *quotip,
 315         xfs_fileoff_t   offset_fsb,
 316         xfs_buf_t       **O_bpp)
 317 {
 318         xfs_fsblock_t   firstblock;
 319         xfs_bmap_free_t flist;
 320         xfs_bmbt_irec_t map;
 321         int             nmaps, error, committed;
 322         xfs_buf_t       *bp;
 323         xfs_trans_t     *tp = *tpp;
 324
 325         ASSERT(tp != NULL);
 326
 327         trace_xfs_dqalloc(dqp);
 328
 329         /*
 330          * Initialize the bmap freelist prior to calling bmapi code.
 331          */
 332         xfs_bmap_init(&flist, &firstblock);
 333         xfs_ilock(quotip, XFS_ILOCK_EXCL);
 334         /*
 335          * Return if this type of quotas is turned off while we didn't
 336          * have an inode lock
 337          */
 338         if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
 339                 xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 340                 return (ESRCH);
 341         }
 342
 343         xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
 344         nmaps = 1;
 345         error = xfs_bmapi_write(tp, quotip, offset_fsb,
 346                                 XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
 347                                 &firstblock, XFS_QM_DQALLOC_SPACE_RES(mp),
 348                                 &map, &nmaps, &flist);
 349         if (error)
 350                 goto error0;
 351         ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
 352         ASSERT(nmaps == 1);
 353         ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 354                (map.br_startblock != HOLESTARTBLOCK));
 355
 356         /*
 357          * Keep track of the blkno to save a lookup later
 358          */
 359         dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 360
 361         /* now we can just get the buffer (there's nothing to read yet) */
 362         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 363                                dqp->q_blkno,
 364                                mp->m_quotainfo->qi_dqchunklen,
 365                                0);
 366
 367         error = xfs_buf_geterror(bp);
 368         if (error)
 369                 goto error1;
 370         bp->b_ops = &xfs_dquot_buf_ops;
 371
 372         /*
 373          * Make a chunk of dquots out of this buffer and log
 374          * the entire thing.
 375          */
 376         xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
 377                               dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
 378
 379         /*
 380          * xfs_bmap_finish() may commit the current transaction and
 381          * start a second transaction if the freelist is not empty.
 382          *
 383          * Since we still want to modify this buffer, we need to
 384          * ensure that the buffer is not released on commit of
 385          * the first transaction and ensure the buffer is added to the
 386          * second transaction.
 387          *
 388          * If there is only one transaction then don't stop the buffer
 389          * from being released when it commits later on.
 390          */
 391
 392         xfs_trans_bhold(tp, bp);
 393
 394         if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
 395                 goto error1;
 396         }
 397
 398         if (committed) {
 399                 tp = *tpp;
 400                 xfs_trans_bjoin(tp, bp);
 401         } else {
 402                 xfs_trans_bhold_release(tp, bp);
 403         }
 404
 405         *O_bpp = bp;
 406         return 0;
 407
 408       error1:
 409         xfs_bmap_cancel(&flist);
 410       error0:
 411         xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 412
 413         return (error);
 414 }
 415 STATIC int
 416 xfs_qm_dqrepair(
 417         struct xfs_mount        *mp,
 418         struct xfs_trans        *tp,
 419         struct xfs_dquot        *dqp,
 420         xfs_dqid_t              firstid,
 421         struct xfs_buf          **bpp)
 422 {
 423         int                     error;
 424         struct xfs_disk_dquot   *ddq;
 425         struct xfs_dqblk        *d;
 426         int                     i;
 427
 428         /*
 429          * Read the buffer without verification so we get the corrupted
 430          * buffer returned to us. make sure we verify it on write, though.
 431          */
 432         error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, dqp->q_blkno,
 433                                    mp->m_quotainfo->qi_dqchunklen,
 434                                    0, bpp, NULL);
 435
 436         if (error) {
 437                 ASSERT(*bpp == NULL);
 438                 return XFS_ERROR(error);
 439         }
 440         (*bpp)->b_ops = &xfs_dquot_buf_ops;
 441
 442         ASSERT(xfs_buf_islocked(*bpp));
 443         d = (struct xfs_dqblk *)(*bpp)->b_addr;
 444
 445         /* Do the actual repair of dquots in this buffer */
 446         for (i = 0; i < mp->m_quotainfo->qi_dqperchunk; i++) {
 447                 ddq = &d[i].dd_diskdq;
 448                 error = xfs_qm_dqcheck(mp, ddq, firstid + i,
 449                                        dqp->dq_flags & XFS_DQ_ALLTYPES,
 450                                        XFS_QMOPT_DQREPAIR, "xfs_qm_dqrepair");
 451                 if (error) {
 452                         /* repair failed, we're screwed */
 453                         xfs_trans_brelse(tp, *bpp);
 454                         return XFS_ERROR(EIO);
 455                 }
 456         }
 457
 458         return 0;
 459 }
 460
 461 /*
 462  * Maps a dquot to the buffer containing its on-disk version.
 463  * This returns a ptr to the buffer containing the on-disk dquot
 464  * in the bpp param, and a ptr to the on-disk dquot within that buffer
 465  */
 466 STATIC int
 467 xfs_qm_dqtobp(
 468         xfs_trans_t             **tpp,
 469         xfs_dquot_t             *dqp,
 470         xfs_disk_dquot_t        **O_ddpp,
 471         xfs_buf_t               **O_bpp,
 472         uint                    flags)
 473 {
 474         xfs_bmbt_irec_t map;
 475         int             nmaps = 1, error;
 476         xfs_buf_t       *bp;
 477         xfs_inode_t     *quotip = XFS_DQ_TO_QIP(dqp);
 478         xfs_mount_t     *mp = dqp->q_mount;
 479         xfs_dqid_t      id = be32_to_cpu(dqp->q_core.d_id);
 480         xfs_trans_t     *tp = (tpp ? *tpp : NULL);
 481
 482         dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
 483
 484         xfs_ilock(quotip, XFS_ILOCK_SHARED);
 485         if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
 486                 /*
 487                  * Return if this type of quotas is turned off while we
 488                  * didn't have the quota inode lock.
 489                  */
 490                 xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 491                 return ESRCH;
 492         }
 493
 494         /*
 495          * Find the block map; no allocations yet
 496          */
 497         error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
 498                                XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
 499
 500         xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 501         if (error)
 502                 return error;
 503
 504         ASSERT(nmaps == 1);
 505         ASSERT(map.br_blockcount == 1);
 506
 507         /*
 508          * Offset of dquot in the (fixed sized) dquot chunk.
 509          */
 510         dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
 511                 sizeof(xfs_dqblk_t);
 512
 513         ASSERT(map.br_startblock != DELAYSTARTBLOCK);
 514         if (map.br_startblock == HOLESTARTBLOCK) {
 515                 /*
 516                  * We don't allocate unless we're asked to
 517                  */
 518                 if (!(flags & XFS_QMOPT_DQALLOC))
 519                         return ENOENT;
 520
 521                 ASSERT(tp);
 522                 error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
 523                                         dqp->q_fileoffset, &bp);
 524                 if (error)
 525                         return error;
 526                 tp = *tpp;
 527         } else {
 528                 trace_xfs_dqtobp_read(dqp);
 529
 530                 /*
 531                  * store the blkno etc so that we don't have to do the
 532                  * mapping all the time
 533                  */
 534                 dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 535
 536                 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 537                                            dqp->q_blkno,
 538                                            mp->m_quotainfo->qi_dqchunklen,
 539                                            0, &bp, &xfs_dquot_buf_ops);
 540
 541                 if (error == EFSCORRUPTED && (flags & XFS_QMOPT_DQREPAIR)) {
 542                         xfs_dqid_t firstid = (xfs_dqid_t)map.br_startoff *
 543                                                 mp->m_quotainfo->qi_dqperchunk;
 544                         ASSERT(bp == NULL);
 545                         error = xfs_qm_dqrepair(mp, tp, dqp, firstid, &bp);
 546                 }
 547
 548                 if (error) {
 549                         ASSERT(bp == NULL);
 550                         return XFS_ERROR(error);
 551                 }
 552         }
 553
 554         ASSERT(xfs_buf_islocked(bp));
 555         *O_bpp = bp;
 556         *O_ddpp = bp->b_addr + dqp->q_bufoffset;
 557
 558         return (0);
 559 }
 560
 561
 562 /*
 563  * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
 564  * and release the buffer immediately.
 565  *
 566  * If XFS_QMOPT_DQALLOC is set, allocate a dquot on disk if it needed.
 567  */
 568 int
 569 xfs_qm_dqread(
 570         struct xfs_mount        *mp,
 571         xfs_dqid_t              id,
 572         uint                    type,
 573         uint                    flags,
 574         struct xfs_dquot        **O_dqpp)
 575 {
 576         struct xfs_dquot        *dqp;
 577         struct xfs_disk_dquot   *ddqp;
 578         struct xfs_buf          *bp;
 579         struct xfs_trans        *tp = NULL;
 580         int                     error;
 581         int                     cancelflags = 0;
 582
 583
 584         dqp = kmem_zone_zalloc(xfs_qm_dqzone, KM_SLEEP);
 585
 586         dqp->dq_flags = type;
 587         dqp->q_core.d_id = cpu_to_be32(id);
 588         dqp->q_mount = mp;
 589         INIT_LIST_HEAD(&dqp->q_lru);
 590         mutex_init(&dqp->q_qlock);
 591         init_waitqueue_head(&dqp->q_pinwait);
 592
 593         /*
 594          * Because we want to use a counting completion, complete
 595          * the flush completion once to allow a single access to
 596          * the flush completion without blocking.
 597          */
 598         init_completion(&dqp->q_flush);
 599         complete(&dqp->q_flush);
 600
 601         /*
 602          * Make sure group quotas have a different lock class than user
 603          * quotas.
 604          */
 605         if (!(type & XFS_DQ_USER))
 606                 lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
 607
 608         XFS_STATS_INC(xs_qm_dquot);
 609
 610         trace_xfs_dqread(dqp);
 611
 612         if (flags & XFS_QMOPT_DQALLOC) {
 613                 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
 614                 error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp),
 615                                           XFS_QM_DQALLOC_LOG_RES(mp), 0,
 616                                           XFS_TRANS_PERM_LOG_RES,
 617                                           XFS_WRITE_LOG_COUNT);
 618                 if (error)
 619                         goto error1;
 620                 cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 621         }
 622
 623         /*
 624          * get a pointer to the on-disk dquot and the buffer containing it
 625          * dqp already knows its own type (GROUP/USER).
 626          */
 627         error = xfs_qm_dqtobp(&tp, dqp, &ddqp, &bp, flags);
 628         if (error) {
 629                 /*
 630                  * This can happen if quotas got turned off (ESRCH),
 631                  * or if the dquot didn't exist on disk and we ask to
 632                  * allocate (ENOENT).
 633                  */
 634                 trace_xfs_dqread_fail(dqp);
 635                 cancelflags |= XFS_TRANS_ABORT;
 636                 goto error1;
 637         }
 638
 639         /* copy everything from disk dquot to the incore dquot */
 640         memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
 641         xfs_qm_dquot_logitem_init(dqp);
 642
 643         /*
 644          * Reservation counters are defined as reservation plus current usage
 645          * to avoid having to add every time.
 646          */
 647         dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
 648         dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
 649         dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
 650
 651         /* Mark the buf so that this will stay incore a little longer */
 652         xfs_buf_set_ref(bp, XFS_DQUOT_REF);
 653
 654         /*
 655          * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
 656          * So we need to release with xfs_trans_brelse().
 657          * The strategy here is identical to that of inodes; we lock
 658          * the dquot in xfs_qm_dqget() before making it accessible to
 659          * others. This is because dquots, like inodes, need a good level of
 660          * concurrency, and we don't want to take locks on the entire buffers
 661          * for dquot accesses.
 662          * Note also that the dquot buffer may even be dirty at this point, if
 663          * this particular dquot was repaired. We still aren't afraid to
 664          * brelse it because we have the changes incore.
 665          */
 666         ASSERT(xfs_buf_islocked(bp));
 667         xfs_trans_brelse(tp, bp);
 668
 669         if (tp) {
 670                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 671                 if (error)
 672                         goto error0;
 673         }
 674
 675         *O_dqpp = dqp;
 676         return error;
 677
 678 error1:
 679         if (tp)
 680                 xfs_trans_cancel(tp, cancelflags);
 681 error0:
 682         xfs_qm_dqdestroy(dqp);
 683         *O_dqpp = NULL;
 684         return error;
 685 }
 686
 687 /*
 688  * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 689  * a locked dquot, doing an allocation (if requested) as needed.
 690  * When both an inode and an id are given, the inode's id takes precedence.
 691  * That is, if the id changes while we don't hold the ilock inside this
 692  * function, the new dquot is returned, not necessarily the one requested
 693  * in the id argument.
 694  */
 695 int
 696 xfs_qm_dqget(
 697         xfs_mount_t     *mp,
 698         xfs_inode_t     *ip,      /* locked inode (optional) */
 699         xfs_dqid_t      id,       /* uid/projid/gid depending on type */
 700         uint            type,     /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
 701         uint            flags,    /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
 702         xfs_dquot_t     **O_dqpp) /* OUT : locked incore dquot */
 703 {
 704         struct xfs_quotainfo    *qi = mp->m_quotainfo;
 705         struct radix_tree_root *tree = XFS_DQUOT_TREE(qi, type);
 706         struct xfs_dquot        *dqp;
 707         int                     error;
 708
 709         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 710         if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
 711             (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
 712             (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
 713                 return (ESRCH);
 714         }
 715
 716 #ifdef DEBUG
 717         if (xfs_do_dqerror) {
 718                 if ((xfs_dqerror_target == mp->m_ddev_targp) &&
 719                     (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
 720                         xfs_debug(mp, "Returning error in dqget");
 721                         return (EIO);
 722                 }
 723         }
 724
 725         ASSERT(type == XFS_DQ_USER ||
 726                type == XFS_DQ_PROJ ||
 727                type == XFS_DQ_GROUP);
 728         if (ip) {
 729                 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 730                 ASSERT(xfs_inode_dquot(ip, type) == NULL);
 731         }
 732 #endif
 733
 734 restart:
 735         mutex_lock(&qi->qi_tree_lock);
 736         dqp = radix_tree_lookup(tree, id);
 737         if (dqp) {
 738                 xfs_dqlock(dqp);
 739                 if (dqp->dq_flags & XFS_DQ_FREEING) {
 740                         xfs_dqunlock(dqp);
 741                         mutex_unlock(&qi->qi_tree_lock);
 742                         trace_xfs_dqget_freeing(dqp);
 743                         delay(1);
 744                         goto restart;
 745                 }
 746
 747                 dqp->q_nrefs++;
 748                 mutex_unlock(&qi->qi_tree_lock);
 749
 750                 trace_xfs_dqget_hit(dqp);
 751                 XFS_STATS_INC(xs_qm_dqcachehits);
 752                 *O_dqpp = dqp;
 753                 return 0;
 754         }
 755         mutex_unlock(&qi->qi_tree_lock);
 756         XFS_STATS_INC(xs_qm_dqcachemisses);
 757
 758         /*
 759          * Dquot cache miss. We don't want to keep the inode lock across
 760          * a (potential) disk read. Also we don't want to deal with the lock
 761          * ordering between quotainode and this inode. OTOH, dropping the inode
 762          * lock here means dealing with a chown that can happen before
 763          * we re-acquire the lock.
 764          */
 765         if (ip)
 766                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 767
 768         error = xfs_qm_dqread(mp, id, type, flags, &dqp);
 769
 770         if (ip)
 771                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 772
 773         if (error)
 774                 return error;
 775
 776         if (ip) {
 777                 /*
 778                  * A dquot could be attached to this inode by now, since
 779                  * we had dropped the ilock.
 780                  */
 781                 if (xfs_this_quota_on(mp, type)) {
 782                         struct xfs_dquot        *dqp1;
 783
 784                         dqp1 = xfs_inode_dquot(ip, type);
 785                         if (dqp1) {
 786                                 xfs_qm_dqdestroy(dqp);
 787                                 dqp = dqp1;
 788                                 xfs_dqlock(dqp);
 789                                 goto dqret;
 790                         }
 791                 } else {
 792                         /* inode stays locked on return */
 793                         xfs_qm_dqdestroy(dqp);
 794                         return XFS_ERROR(ESRCH);
 795                 }
 796         }
 797
 798         mutex_lock(&qi->qi_tree_lock);
 799         error = -radix_tree_insert(tree, id, dqp);
 800         if (unlikely(error)) {
 801                 WARN_ON(error != EEXIST);
 802
 803                 /*
 804                  * Duplicate found. Just throw away the new dquot and start
 805                  * over.
 806                  */
 807                 mutex_unlock(&qi->qi_tree_lock);
 808                 trace_xfs_dqget_dup(dqp);
 809                 xfs_qm_dqdestroy(dqp);
 810                 XFS_STATS_INC(xs_qm_dquot_dups);
 811                 goto restart;
 812         }
 813
 814         /*
 815          * We return a locked dquot to the caller, with a reference taken
 816          */
 817         xfs_dqlock(dqp);
 818         dqp->q_nrefs = 1;
 819
 820         qi->qi_dquots++;
 821         mutex_unlock(&qi->qi_tree_lock);
 822
 823  dqret:
 824         ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
 825         trace_xfs_dqget_miss(dqp);
 826         *O_dqpp = dqp;
 827         return (0);
 828 }
 829
 830
 831 STATIC void
 832 xfs_qm_dqput_final(
 833         struct xfs_dquot        *dqp)
 834 {
 835         struct xfs_quotainfo    *qi = dqp->q_mount->m_quotainfo;
 836         struct xfs_dquot        *gdqp;
 837
 838         trace_xfs_dqput_free(dqp);
 839
 840         mutex_lock(&qi->qi_lru_lock);
 841         if (list_empty(&dqp->q_lru)) {
 842                 list_add_tail(&dqp->q_lru, &qi->qi_lru_list);
 843                 qi->qi_lru_count++;
 844                 XFS_STATS_INC(xs_qm_dquot_unused);
 845         }
 846         mutex_unlock(&qi->qi_lru_lock);
 847
 848         /*
 849          * If we just added a udquot to the freelist, then we want to release
 850          * the gdquot reference that it (probably) has. Otherwise it'll keep
 851          * the gdquot from getting reclaimed.
 852          */
 853         gdqp = dqp->q_gdquot;
 854         if (gdqp) {
 855                 xfs_dqlock(gdqp);
 856                 dqp->q_gdquot = NULL;
 857         }
 858         xfs_dqunlock(dqp);
 859
 860         /*
 861          * If we had a group quota hint, release it now.
 862          */
 863         if (gdqp)
 864                 xfs_qm_dqput(gdqp);
 865 }
 866
 867 /*
 868  * Release a reference to the dquot (decrement ref-count) and unlock it.
 869  *
 870  * If there is a group quota attached to this dquot, carefully release that
 871  * too without tripping over deadlocks'n'stuff.
 872  */
 873 void
 874 xfs_qm_dqput(
 875         struct xfs_dquot        *dqp)
 876 {
 877         ASSERT(dqp->q_nrefs > 0);
 878         ASSERT(XFS_DQ_IS_LOCKED(dqp));
 879
 880         trace_xfs_dqput(dqp);
 881
 882         if (--dqp->q_nrefs > 0)
 883                 xfs_dqunlock(dqp);
 884         else
 885                 xfs_qm_dqput_final(dqp);
 886 }
 887
 888 /*
 889  * Release a dquot. Flush it if dirty, then dqput() it.
 890  * dquot must not be locked.
 891  */
 892 void
 893 xfs_qm_dqrele(
 894         xfs_dquot_t     *dqp)
 895 {
 896         if (!dqp)
 897                 return;
 898
 899         trace_xfs_dqrele(dqp);
 900
 901         xfs_dqlock(dqp);
 902         /*
 903          * We don't care to flush it if the dquot is dirty here.
 904          * That will create stutters that we want to avoid.
 905          * Instead we do a delayed write when we try to reclaim
 906          * a dirty dquot. Also xfs_sync will take part of the burden...
 907          */
 908         xfs_qm_dqput(dqp);
 909 }
 910
 911 /*
 912  * This is the dquot flushing I/O completion routine.  It is called
 913  * from interrupt level when the buffer containing the dquot is
 914  * flushed to disk.  It is responsible for removing the dquot logitem
 915  * from the AIL if it has not been re-logged, and unlocking the dquot's
 916  * flush lock. This behavior is very similar to that of inodes..
 917  */
 918 STATIC void
 919 xfs_qm_dqflush_done(
 920         struct xfs_buf          *bp,
 921         struct xfs_log_item     *lip)
 922 {
 923         xfs_dq_logitem_t        *qip = (struct xfs_dq_logitem *)lip;
 924         xfs_dquot_t             *dqp = qip->qli_dquot;
 925         struct xfs_ail          *ailp = lip->li_ailp;
 926
 927         /*
 928          * We only want to pull the item from the AIL if its
 929          * location in the log has not changed since we started the flush.
 930          * Thus, we only bother if the dquot's lsn has
 931          * not changed. First we check the lsn outside the lock
 932          * since it's cheaper, and then we recheck while
 933          * holding the lock before removing the dquot from the AIL.
 934          */
 935         if ((lip->li_flags & XFS_LI_IN_AIL) &&
 936             lip->li_lsn == qip->qli_flush_lsn) {
 937
 938                 /* xfs_trans_ail_delete() drops the AIL lock. */
 939                 spin_lock(&ailp->xa_lock);
 940                 if (lip->li_lsn == qip->qli_flush_lsn)
 941                         xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
 942                 else
 943                         spin_unlock(&ailp->xa_lock);
 944         }
 945
 946         /*
 947          * Release the dq's flush lock since we're done with it.
 948          */
 949         xfs_dqfunlock(dqp);
 950 }
 951
 952 /*
 953  * Write a modified dquot to disk.
 954  * The dquot must be locked and the flush lock too taken by caller.
 955  * The flush lock will not be unlocked until the dquot reaches the disk,
 956  * but the dquot is free to be unlocked and modified by the caller
 957  * in the interim. Dquot is still locked on return. This behavior is
 958  * identical to that of inodes.
 959  */
 960 int
 961 xfs_qm_dqflush(
 962         struct xfs_dquot        *dqp,
 963         struct xfs_buf          **bpp)
 964 {
 965         struct xfs_mount        *mp = dqp->q_mount;
 966         struct xfs_buf          *bp;
 967         struct xfs_disk_dquot   *ddqp;
 968         int                     error;
 969
 970         ASSERT(XFS_DQ_IS_LOCKED(dqp));
 971         ASSERT(!completion_done(&dqp->q_flush));
 972
 973         trace_xfs_dqflush(dqp);
 974
 975         *bpp = NULL;
 976
 977         xfs_qm_dqunpin_wait(dqp);
 978
 979         /*
 980          * This may have been unpinned because the filesystem is shutting
 981          * down forcibly. If that's the case we must not write this dquot
 982          * to disk, because the log record didn't make it to disk.
 983          *
 984          * We also have to remove the log item from the AIL in this case,
 985          * as we wait for an emptry AIL as part of the unmount process.
 986          */
 987         if (XFS_FORCED_SHUTDOWN(mp)) {
 988                 struct xfs_log_item     *lip = &dqp->q_logitem.qli_item;
 989                 dqp->dq_flags &= ~XFS_DQ_DIRTY;
 990
 991                 spin_lock(&mp->m_ail->xa_lock);
 992                 if (lip->li_flags & XFS_LI_IN_AIL)
 993                         xfs_trans_ail_delete(mp->m_ail, lip,
 994                                              SHUTDOWN_CORRUPT_INCORE);
 995                 else
 996                         spin_unlock(&mp->m_ail->xa_lock);
 997                 error = XFS_ERROR(EIO);
 998                 goto out_unlock;
 999         }
1000
1001         /*
1002          * Get the buffer containing the on-disk dquot
1003          */
1004         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1005                                    mp->m_quotainfo->qi_dqchunklen, 0, &bp, NULL);
1006         if (error)
1007                 goto out_unlock;
1008
1009         /*
1010          * Calculate the location of the dquot inside the buffer.
1011          */
1012         ddqp = bp->b_addr + dqp->q_bufoffset;
1013
1014         /*
1015          * A simple sanity check in case we got a corrupted dquot..
1016          */
1017         error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1018                            XFS_QMOPT_DOWARN, "dqflush (incore copy)");
1019         if (error) {
1020                 xfs_buf_relse(bp);
1021                 xfs_dqfunlock(dqp);
1022                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1023                 return XFS_ERROR(EIO);
1024         }
1025
1026         /* This is the only portion of data that needs to persist */
1027         memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1028
1029         /*
1030          * Clear the dirty field and remember the flush lsn for later use.
1031          */
1032         dqp->dq_flags &= ~XFS_DQ_DIRTY;
1033
1034         xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1035                                         &dqp->q_logitem.qli_item.li_lsn);
1036
1037         /*
1038          * Attach an iodone routine so that we can remove this dquot from the
1039          * AIL and release the flush lock once the dquot is synced to disk.
1040          */
1041         xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1042                                   &dqp->q_logitem.qli_item);
1043
1044         /*
1045          * If the buffer is pinned then push on the log so we won't
1046          * get stuck waiting in the write for too long.
1047          */
1048         if (xfs_buf_ispinned(bp)) {
1049                 trace_xfs_dqflush_force(dqp);
1050                 xfs_log_force(mp, 0);
1051         }
1052
1053         trace_xfs_dqflush_done(dqp);
1054         *bpp = bp;
1055         return 0;
1056
1057 out_unlock:
1058         xfs_dqfunlock(dqp);
1059         return XFS_ERROR(EIO);
1060 }
1061
1062 /*
1063  * Lock two xfs_dquot structures.
1064  *
1065  * To avoid deadlocks we always lock the quota structure with
1066  * the lowerd id first.
1067  */
1068 void
1069 xfs_dqlock2(
1070         xfs_dquot_t     *d1,
1071         xfs_dquot_t     *d2)
1072 {
1073         if (d1 && d2) {
1074                 ASSERT(d1 != d2);
1075                 if (be32_to_cpu(d1->q_core.d_id) >
1076                     be32_to_cpu(d2->q_core.d_id)) {
1077                         mutex_lock(&d2->q_qlock);
1078                         mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1079                 } else {
1080                         mutex_lock(&d1->q_qlock);
1081                         mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1082                 }
1083         } else if (d1) {
1084                 mutex_lock(&d1->q_qlock);
1085         } else if (d2) {
1086                 mutex_lock(&d2->q_qlock);
1087         }
1088 }
1089
1090 int __init
1091 xfs_qm_init(void)
1092 {
1093         xfs_qm_dqzone =
1094                 kmem_zone_init(sizeof(struct xfs_dquot), "xfs_dquot");
1095         if (!xfs_qm_dqzone)
1096                 goto out;
1097
1098         xfs_qm_dqtrxzone =
1099                 kmem_zone_init(sizeof(struct xfs_dquot_acct), "xfs_dqtrx");
1100         if (!xfs_qm_dqtrxzone)
1101                 goto out_free_dqzone;
1102
1103         return 0;
1104
1105 out_free_dqzone:
1106         kmem_zone_destroy(xfs_qm_dqzone);
1107 out:
1108         return -ENOMEM;
1109 }
1110
1111 void
1112 xfs_qm_exit(void)
1113 {
1114         kmem_zone_destroy(xfs_qm_dqtrxzone);
1115         kmem_zone_destroy(xfs_qm_dqzone);
1116 }