fs/quota/quota.c

   1 /*
   2  * Quota code necessary even when VFS quota support is not compiled
   3  * into the kernel.  The interesting stuff is over in dquot.c, here
   4  * we have symbols for initial quotactl(2) handling, the sysctl(2)
   5  * variables, etc - things needed even when quota support disabled.
   6  */
   7
   8 #include <linux/fs.h>
   9 #include <linux/namei.h>
  10 #include <linux/slab.h>
  11 #include <asm/current.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/kernel.h>
  14 #include <linux/security.h>
  15 #include <linux/syscalls.h>
  16 #include <linux/capability.h>
  17 #include <linux/quotaops.h>
  18 #include <linux/types.h>
  19 #include <linux/writeback.h>
  20
  21 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  22                                      qid_t id)
  23 {
  24         switch (cmd) {
  25         /* these commands do not require any special privilegues */
  26         case Q_GETFMT:
  27         case Q_SYNC:
  28         case Q_GETINFO:
  29         case Q_XGETQSTAT:
  30         case Q_XGETQSTATV:
  31         case Q_XQUOTASYNC:
  32                 break;
  33         /* allow to query information for dquots we "own" */
  34         case Q_GETQUOTA:
  35         case Q_XGETQUOTA:
  36                 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  37                     (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  38                         break;
  39                 /*FALLTHROUGH*/
  40         default:
  41                 if (!capable(CAP_SYS_ADMIN))
  42                         return -EPERM;
  43         }
  44
  45         return security_quotactl(cmd, type, id, sb);
  46 }
  47
  48 static void quota_sync_one(struct super_block *sb, void *arg)
  49 {
  50         int type = *(int *)arg;
  51
  52         if (sb->s_qcop && sb->s_qcop->quota_sync &&
  53             (sb->s_quota_types & (1 << type)))
  54                 sb->s_qcop->quota_sync(sb, type);
  55 }
  56
  57 static int quota_sync_all(int type)
  58 {
  59         int ret;
  60
  61         if (type >= MAXQUOTAS)
  62                 return -EINVAL;
  63         ret = security_quotactl(Q_SYNC, type, 0, NULL);
  64         if (!ret)
  65                 iterate_supers(quota_sync_one, &type);
  66         return ret;
  67 }
  68
  69 unsigned int qtype_enforce_flag(int type)
  70 {
  71         switch (type) {
  72         case USRQUOTA:
  73                 return FS_QUOTA_UDQ_ENFD;
  74         case GRPQUOTA:
  75                 return FS_QUOTA_GDQ_ENFD;
  76         case PRJQUOTA:
  77                 return FS_QUOTA_PDQ_ENFD;
  78         }
  79         return 0;
  80 }
  81
  82 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  83                          struct path *path)
  84 {
  85         if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  86                 return -ENOSYS;
  87         if (sb->s_qcop->quota_enable)
  88                 return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  89         if (IS_ERR(path))
  90                 return PTR_ERR(path);
  91         return sb->s_qcop->quota_on(sb, type, id, path);
  92 }
  93
  94 static int quota_quotaoff(struct super_block *sb, int type)
  95 {
  96         if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
  97                 return -ENOSYS;
  98         if (sb->s_qcop->quota_disable)
  99                 return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 100         return sb->s_qcop->quota_off(sb, type);
 101 }
 102
 103 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 104 {
 105         __u32 fmt;
 106
 107         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
 108         if (!sb_has_quota_active(sb, type)) {
 109                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 110                 return -ESRCH;
 111         }
 112         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 113         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 114         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 115                 return -EFAULT;
 116         return 0;
 117 }
 118
 119 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 120 {
 121         struct qc_state state;
 122         struct qc_type_state *tstate;
 123         struct if_dqinfo uinfo;
 124         int ret;
 125
 126         /* This checks whether qc_state has enough entries... */
 127         BUILD_BUG_ON(MAXQUOTAS > XQM_MAXQUOTAS);
 128         if (!sb->s_qcop->get_state)
 129                 return -ENOSYS;
 130         ret = sb->s_qcop->get_state(sb, &state);
 131         if (ret)
 132                 return ret;
 133         tstate = state.s_state + type;
 134         if (!(tstate->flags & QCI_ACCT_ENABLED))
 135                 return -ESRCH;
 136         memset(&uinfo, 0, sizeof(uinfo));
 137         uinfo.dqi_bgrace = tstate->spc_timelimit;
 138         uinfo.dqi_igrace = tstate->ino_timelimit;
 139         if (tstate->flags & QCI_SYSFILE)
 140                 uinfo.dqi_flags |= DQF_SYS_FILE;
 141         if (tstate->flags & QCI_ROOT_SQUASH)
 142                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 143         uinfo.dqi_valid = IIF_ALL;
 144         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 145                 return -EFAULT;
 146         return 0;
 147 }
 148
 149 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 150 {
 151         struct if_dqinfo info;
 152         struct qc_info qinfo;
 153
 154         if (copy_from_user(&info, addr, sizeof(info)))
 155                 return -EFAULT;
 156         if (!sb->s_qcop->set_info)
 157                 return -ENOSYS;
 158         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 159                 return -EINVAL;
 160         memset(&qinfo, 0, sizeof(qinfo));
 161         if (info.dqi_valid & IIF_FLAGS) {
 162                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 163                         return -EINVAL;
 164                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 165                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 166                 qinfo.i_fieldmask |= QC_FLAGS;
 167         }
 168         if (info.dqi_valid & IIF_BGRACE) {
 169                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 170                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 171         }
 172         if (info.dqi_valid & IIF_IGRACE) {
 173                 qinfo.i_ino_timelimit = info.dqi_igrace;
 174                 qinfo.i_fieldmask |= QC_INO_TIMER;
 175         }
 176         return sb->s_qcop->set_info(sb, type, &qinfo);
 177 }
 178
 179 static inline qsize_t qbtos(qsize_t blocks)
 180 {
 181         return blocks << QIF_DQBLKSIZE_BITS;
 182 }
 183
 184 static inline qsize_t stoqb(qsize_t space)
 185 {
 186         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 187 }
 188
 189 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 190 {
 191         memset(dst, 0, sizeof(*dst));
 192         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 193         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 194         dst->dqb_curspace = src->d_space;
 195         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 196         dst->dqb_isoftlimit = src->d_ino_softlimit;
 197         dst->dqb_curinodes = src->d_ino_count;
 198         dst->dqb_btime = src->d_spc_timer;
 199         dst->dqb_itime = src->d_ino_timer;
 200         dst->dqb_valid = QIF_ALL;
 201 }
 202
 203 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 204                           void __user *addr)
 205 {
 206         struct kqid qid;
 207         struct qc_dqblk fdq;
 208         struct if_dqblk idq;
 209         int ret;
 210
 211         if (!sb->s_qcop->get_dqblk)
 212                 return -ENOSYS;
 213         qid = make_kqid(current_user_ns(), type, id);
 214         if (!qid_has_mapping(sb->s_user_ns, qid))
 215                 return -EINVAL;
 216         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 217         if (ret)
 218                 return ret;
 219         copy_to_if_dqblk(&idq, &fdq);
 220         if (copy_to_user(addr, &idq, sizeof(idq)))
 221                 return -EFAULT;
 222         return 0;
 223 }
 224
 225 /*
 226  * Return quota for next active quota >= this id, if any exists,
 227  * otherwise return -ENOENT via ->get_nextdqblk
 228  */
 229 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 230                           void __user *addr)
 231 {
 232         struct kqid qid;
 233         struct qc_dqblk fdq;
 234         struct if_nextdqblk idq;
 235         int ret;
 236
 237         if (!sb->s_qcop->get_nextdqblk)
 238                 return -ENOSYS;
 239         qid = make_kqid(current_user_ns(), type, id);
 240         if (!qid_has_mapping(sb->s_user_ns, qid))
 241                 return -EINVAL;
 242         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 243         if (ret)
 244                 return ret;
 245         /* struct if_nextdqblk is a superset of struct if_dqblk */
 246         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 247         idq.dqb_id = from_kqid(current_user_ns(), qid);
 248         if (copy_to_user(addr, &idq, sizeof(idq)))
 249                 return -EFAULT;
 250         return 0;
 251 }
 252
 253 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 254 {
 255         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 256         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 257         dst->d_space = src->dqb_curspace;
 258         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 259         dst->d_ino_softlimit = src->dqb_isoftlimit;
 260         dst->d_ino_count = src->dqb_curinodes;
 261         dst->d_spc_timer = src->dqb_btime;
 262         dst->d_ino_timer = src->dqb_itime;
 263
 264         dst->d_fieldmask = 0;
 265         if (src->dqb_valid & QIF_BLIMITS)
 266                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 267         if (src->dqb_valid & QIF_SPACE)
 268                 dst->d_fieldmask |= QC_SPACE;
 269         if (src->dqb_valid & QIF_ILIMITS)
 270                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 271         if (src->dqb_valid & QIF_INODES)
 272                 dst->d_fieldmask |= QC_INO_COUNT;
 273         if (src->dqb_valid & QIF_BTIME)
 274                 dst->d_fieldmask |= QC_SPC_TIMER;
 275         if (src->dqb_valid & QIF_ITIME)
 276                 dst->d_fieldmask |= QC_INO_TIMER;
 277 }
 278
 279 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 280                           void __user *addr)
 281 {
 282         struct qc_dqblk fdq;
 283         struct if_dqblk idq;
 284         struct kqid qid;
 285
 286         if (copy_from_user(&idq, addr, sizeof(idq)))
 287                 return -EFAULT;
 288         if (!sb->s_qcop->set_dqblk)
 289                 return -ENOSYS;
 290         qid = make_kqid(current_user_ns(), type, id);
 291         if (!qid_has_mapping(sb->s_user_ns, qid))
 292                 return -EINVAL;
 293         copy_from_if_dqblk(&fdq, &idq);
 294         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 295 }
 296
 297 static int quota_enable(struct super_block *sb, void __user *addr)
 298 {
 299         __u32 flags;
 300
 301         if (copy_from_user(&flags, addr, sizeof(flags)))
 302                 return -EFAULT;
 303         if (!sb->s_qcop->quota_enable)
 304                 return -ENOSYS;
 305         return sb->s_qcop->quota_enable(sb, flags);
 306 }
 307
 308 static int quota_disable(struct super_block *sb, void __user *addr)
 309 {
 310         __u32 flags;
 311
 312         if (copy_from_user(&flags, addr, sizeof(flags)))
 313                 return -EFAULT;
 314         if (!sb->s_qcop->quota_disable)
 315                 return -ENOSYS;
 316         return sb->s_qcop->quota_disable(sb, flags);
 317 }
 318
 319 static int quota_state_to_flags(struct qc_state *state)
 320 {
 321         int flags = 0;
 322
 323         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 324                 flags |= FS_QUOTA_UDQ_ACCT;
 325         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 326                 flags |= FS_QUOTA_UDQ_ENFD;
 327         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 328                 flags |= FS_QUOTA_GDQ_ACCT;
 329         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 330                 flags |= FS_QUOTA_GDQ_ENFD;
 331         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 332                 flags |= FS_QUOTA_PDQ_ACCT;
 333         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 334                 flags |= FS_QUOTA_PDQ_ENFD;
 335         return flags;
 336 }
 337
 338 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
 339 {
 340         int type;
 341         struct qc_state state;
 342         int ret;
 343
 344         memset(&state, 0, sizeof (struct qc_state));
 345         ret = sb->s_qcop->get_state(sb, &state);
 346         if (ret < 0)
 347                 return ret;
 348
 349         memset(fqs, 0, sizeof(*fqs));
 350         fqs->qs_version = FS_QSTAT_VERSION;
 351         fqs->qs_flags = quota_state_to_flags(&state);
 352         /* No quota enabled? */
 353         if (!fqs->qs_flags)
 354                 return -ENOSYS;
 355         fqs->qs_incoredqs = state.s_incoredqs;
 356         /*
 357          * GETXSTATE quotactl has space for just one set of time limits so
 358          * report them for the first enabled quota type
 359          */
 360         for (type = 0; type < XQM_MAXQUOTAS; type++)
 361                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 362                         break;
 363         BUG_ON(type == XQM_MAXQUOTAS);
 364         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 365         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 366         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 367         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 368         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 369
 370         /* Inodes may be allocated even if inactive; copy out if present */
 371         if (state.s_state[USRQUOTA].ino) {
 372                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 373                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 374                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 375         }
 376         if (state.s_state[GRPQUOTA].ino) {
 377                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 378                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 379                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 380         }
 381         if (state.s_state[PRJQUOTA].ino) {
 382                 /*
 383                  * Q_XGETQSTAT doesn't have room for both group and project
 384                  * quotas.  So, allow the project quota values to be copied out
 385                  * only if there is no group quota information available.
 386                  */
 387                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 388                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 389                         fqs->qs_gquota.qfs_nblks =
 390                                         state.s_state[PRJQUOTA].blocks;
 391                         fqs->qs_gquota.qfs_nextents =
 392                                         state.s_state[PRJQUOTA].nextents;
 393                 }
 394         }
 395         return 0;
 396 }
 397
 398 static int quota_getxstate(struct super_block *sb, void __user *addr)
 399 {
 400         struct fs_quota_stat fqs;
 401         int ret;
 402
 403         if (!sb->s_qcop->get_state)
 404                 return -ENOSYS;
 405         ret = quota_getstate(sb, &fqs);
 406         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 407                 return -EFAULT;
 408         return ret;
 409 }
 410
 411 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
 412 {
 413         int type;
 414         struct qc_state state;
 415         int ret;
 416
 417         memset(&state, 0, sizeof (struct qc_state));
 418         ret = sb->s_qcop->get_state(sb, &state);
 419         if (ret < 0)
 420                 return ret;
 421
 422         memset(fqs, 0, sizeof(*fqs));
 423         fqs->qs_version = FS_QSTAT_VERSION;
 424         fqs->qs_flags = quota_state_to_flags(&state);
 425         /* No quota enabled? */
 426         if (!fqs->qs_flags)
 427                 return -ENOSYS;
 428         fqs->qs_incoredqs = state.s_incoredqs;
 429         /*
 430          * GETXSTATV quotactl has space for just one set of time limits so
 431          * report them for the first enabled quota type
 432          */
 433         for (type = 0; type < XQM_MAXQUOTAS; type++)
 434                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 435                         break;
 436         BUG_ON(type == XQM_MAXQUOTAS);
 437         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 438         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 439         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 440         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 441         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 442
 443         /* Inodes may be allocated even if inactive; copy out if present */
 444         if (state.s_state[USRQUOTA].ino) {
 445                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 446                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 447                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 448         }
 449         if (state.s_state[GRPQUOTA].ino) {
 450                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 451                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 452                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 453         }
 454         if (state.s_state[PRJQUOTA].ino) {
 455                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 456                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 457                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 458         }
 459         return 0;
 460 }
 461
 462 static int quota_getxstatev(struct super_block *sb, void __user *addr)
 463 {
 464         struct fs_quota_statv fqs;
 465         int ret;
 466
 467         if (!sb->s_qcop->get_state)
 468                 return -ENOSYS;
 469
 470         memset(&fqs, 0, sizeof(fqs));
 471         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 472                 return -EFAULT;
 473
 474         /* If this kernel doesn't support user specified version, fail */
 475         switch (fqs.qs_version) {
 476         case FS_QSTATV_VERSION1:
 477                 break;
 478         default:
 479                 return -EINVAL;
 480         }
 481         ret = quota_getstatev(sb, &fqs);
 482         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 483                 return -EFAULT;
 484         return ret;
 485 }
 486
 487 /*
 488  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 489  * out of there as xfsprogs rely on definitions being in that header file. So
 490  * just define same functions here for quota purposes.
 491  */
 492 #define XFS_BB_SHIFT 9
 493
 494 static inline u64 quota_bbtob(u64 blocks)
 495 {
 496         return blocks << XFS_BB_SHIFT;
 497 }
 498
 499 static inline u64 quota_btobb(u64 bytes)
 500 {
 501         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 502 }
 503
 504 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 505 {
 506         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 507         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 508         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 509         dst->d_ino_softlimit = src->d_ino_softlimit;
 510         dst->d_space = quota_bbtob(src->d_bcount);
 511         dst->d_ino_count = src->d_icount;
 512         dst->d_ino_timer = src->d_itimer;
 513         dst->d_spc_timer = src->d_btimer;
 514         dst->d_ino_warns = src->d_iwarns;
 515         dst->d_spc_warns = src->d_bwarns;
 516         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 517         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 518         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 519         dst->d_rt_spc_timer = src->d_rtbtimer;
 520         dst->d_rt_spc_warns = src->d_rtbwarns;
 521         dst->d_fieldmask = 0;
 522         if (src->d_fieldmask & FS_DQ_ISOFT)
 523                 dst->d_fieldmask |= QC_INO_SOFT;
 524         if (src->d_fieldmask & FS_DQ_IHARD)
 525                 dst->d_fieldmask |= QC_INO_HARD;
 526         if (src->d_fieldmask & FS_DQ_BSOFT)
 527                 dst->d_fieldmask |= QC_SPC_SOFT;
 528         if (src->d_fieldmask & FS_DQ_BHARD)
 529                 dst->d_fieldmask |= QC_SPC_HARD;
 530         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 531                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 532         if (src->d_fieldmask & FS_DQ_RTBHARD)
 533                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 534         if (src->d_fieldmask & FS_DQ_BTIMER)
 535                 dst->d_fieldmask |= QC_SPC_TIMER;
 536         if (src->d_fieldmask & FS_DQ_ITIMER)
 537                 dst->d_fieldmask |= QC_INO_TIMER;
 538         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 539                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 540         if (src->d_fieldmask & FS_DQ_BWARNS)
 541                 dst->d_fieldmask |= QC_SPC_WARNS;
 542         if (src->d_fieldmask & FS_DQ_IWARNS)
 543                 dst->d_fieldmask |= QC_INO_WARNS;
 544         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 545                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 546         if (src->d_fieldmask & FS_DQ_BCOUNT)
 547                 dst->d_fieldmask |= QC_SPACE;
 548         if (src->d_fieldmask & FS_DQ_ICOUNT)
 549                 dst->d_fieldmask |= QC_INO_COUNT;
 550         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 551                 dst->d_fieldmask |= QC_RT_SPACE;
 552 }
 553
 554 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 555                                        struct fs_disk_quota *src)
 556 {
 557         memset(dst, 0, sizeof(*dst));
 558         dst->i_spc_timelimit = src->d_btimer;
 559         dst->i_ino_timelimit = src->d_itimer;
 560         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 561         dst->i_ino_warnlimit = src->d_iwarns;
 562         dst->i_spc_warnlimit = src->d_bwarns;
 563         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 564         if (src->d_fieldmask & FS_DQ_BWARNS)
 565                 dst->i_fieldmask |= QC_SPC_WARNS;
 566         if (src->d_fieldmask & FS_DQ_IWARNS)
 567                 dst->i_fieldmask |= QC_INO_WARNS;
 568         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 569                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 570         if (src->d_fieldmask & FS_DQ_BTIMER)
 571                 dst->i_fieldmask |= QC_SPC_TIMER;
 572         if (src->d_fieldmask & FS_DQ_ITIMER)
 573                 dst->i_fieldmask |= QC_INO_TIMER;
 574         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 575                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 576 }
 577
 578 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 579                            void __user *addr)
 580 {
 581         struct fs_disk_quota fdq;
 582         struct qc_dqblk qdq;
 583         struct kqid qid;
 584
 585         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 586                 return -EFAULT;
 587         if (!sb->s_qcop->set_dqblk)
 588                 return -ENOSYS;
 589         qid = make_kqid(current_user_ns(), type, id);
 590         if (!qid_has_mapping(sb->s_user_ns, qid))
 591                 return -EINVAL;
 592         /* Are we actually setting timer / warning limits for all users? */
 593         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 594             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 595                 struct qc_info qinfo;
 596                 int ret;
 597
 598                 if (!sb->s_qcop->set_info)
 599                         return -EINVAL;
 600                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 601                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 602                 if (ret)
 603                         return ret;
 604                 /* These are already done */
 605                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 606         }
 607         copy_from_xfs_dqblk(&qdq, &fdq);
 608         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 609 }
 610
 611 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 612                               int type, qid_t id)
 613 {
 614         memset(dst, 0, sizeof(*dst));
 615         dst->d_version = FS_DQUOT_VERSION;
 616         dst->d_id = id;
 617         if (type == USRQUOTA)
 618                 dst->d_flags = FS_USER_QUOTA;
 619         else if (type == PRJQUOTA)
 620                 dst->d_flags = FS_PROJ_QUOTA;
 621         else
 622                 dst->d_flags = FS_GROUP_QUOTA;
 623         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 624         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 625         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 626         dst->d_ino_softlimit = src->d_ino_softlimit;
 627         dst->d_bcount = quota_btobb(src->d_space);
 628         dst->d_icount = src->d_ino_count;
 629         dst->d_itimer = src->d_ino_timer;
 630         dst->d_btimer = src->d_spc_timer;
 631         dst->d_iwarns = src->d_ino_warns;
 632         dst->d_bwarns = src->d_spc_warns;
 633         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 634         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 635         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 636         dst->d_rtbtimer = src->d_rt_spc_timer;
 637         dst->d_rtbwarns = src->d_rt_spc_warns;
 638 }
 639
 640 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 641                            void __user *addr)
 642 {
 643         struct fs_disk_quota fdq;
 644         struct qc_dqblk qdq;
 645         struct kqid qid;
 646         int ret;
 647
 648         if (!sb->s_qcop->get_dqblk)
 649                 return -ENOSYS;
 650         qid = make_kqid(current_user_ns(), type, id);
 651         if (!qid_has_mapping(sb->s_user_ns, qid))
 652                 return -EINVAL;
 653         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 654         if (ret)
 655                 return ret;
 656         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 657         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 658                 return -EFAULT;
 659         return ret;
 660 }
 661
 662 /*
 663  * Return quota for next active quota >= this id, if any exists,
 664  * otherwise return -ENOENT via ->get_nextdqblk.
 665  */
 666 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 667                             void __user *addr)
 668 {
 669         struct fs_disk_quota fdq;
 670         struct qc_dqblk qdq;
 671         struct kqid qid;
 672         qid_t id_out;
 673         int ret;
 674
 675         if (!sb->s_qcop->get_nextdqblk)
 676                 return -ENOSYS;
 677         qid = make_kqid(current_user_ns(), type, id);
 678         if (!qid_has_mapping(sb->s_user_ns, qid))
 679                 return -EINVAL;
 680         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 681         if (ret)
 682                 return ret;
 683         id_out = from_kqid(current_user_ns(), qid);
 684         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 685         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 686                 return -EFAULT;
 687         return ret;
 688 }
 689
 690 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 691 {
 692         __u32 flags;
 693
 694         if (copy_from_user(&flags, addr, sizeof(flags)))
 695                 return -EFAULT;
 696         if (!sb->s_qcop->rm_xquota)
 697                 return -ENOSYS;
 698         return sb->s_qcop->rm_xquota(sb, flags);
 699 }
 700
 701 /* Copy parameters and call proper function */
 702 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 703                        void __user *addr, struct path *path)
 704 {
 705         int ret;
 706
 707         if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
 708                 return -EINVAL;
 709         /*
 710          * Quota not supported on this fs? Check this before s_quota_types
 711          * since they needn't be set if quota is not supported at all.
 712          */
 713         if (!sb->s_qcop)
 714                 return -ENOSYS;
 715         if (!(sb->s_quota_types & (1 << type)))
 716                 return -EINVAL;
 717
 718         ret = check_quotactl_permission(sb, type, cmd, id);
 719         if (ret < 0)
 720                 return ret;
 721
 722         switch (cmd) {
 723         case Q_QUOTAON:
 724                 return quota_quotaon(sb, type, id, path);
 725         case Q_QUOTAOFF:
 726                 return quota_quotaoff(sb, type);
 727         case Q_GETFMT:
 728                 return quota_getfmt(sb, type, addr);
 729         case Q_GETINFO:
 730                 return quota_getinfo(sb, type, addr);
 731         case Q_SETINFO:
 732                 return quota_setinfo(sb, type, addr);
 733         case Q_GETQUOTA:
 734                 return quota_getquota(sb, type, id, addr);
 735         case Q_GETNEXTQUOTA:
 736                 return quota_getnextquota(sb, type, id, addr);
 737         case Q_SETQUOTA:
 738                 return quota_setquota(sb, type, id, addr);
 739         case Q_SYNC:
 740                 if (!sb->s_qcop->quota_sync)
 741                         return -ENOSYS;
 742                 return sb->s_qcop->quota_sync(sb, type);
 743         case Q_XQUOTAON:
 744                 return quota_enable(sb, addr);
 745         case Q_XQUOTAOFF:
 746                 return quota_disable(sb, addr);
 747         case Q_XQUOTARM:
 748                 return quota_rmxquota(sb, addr);
 749         case Q_XGETQSTAT:
 750                 return quota_getxstate(sb, addr);
 751         case Q_XGETQSTATV:
 752                 return quota_getxstatev(sb, addr);
 753         case Q_XSETQLIM:
 754                 return quota_setxquota(sb, type, id, addr);
 755         case Q_XGETQUOTA:
 756                 return quota_getxquota(sb, type, id, addr);
 757         case Q_XGETNEXTQUOTA:
 758                 return quota_getnextxquota(sb, type, id, addr);
 759         case Q_XQUOTASYNC:
 760                 if (sb->s_flags & MS_RDONLY)
 761                         return -EROFS;
 762                 /* XFS quotas are fully coherent now, making this call a noop */
 763                 return 0;
 764         default:
 765                 return -EINVAL;
 766         }
 767 }
 768
 769 #ifdef CONFIG_BLOCK
 770
 771 /* Return 1 if 'cmd' will block on frozen filesystem */
 772 static int quotactl_cmd_write(int cmd)
 773 {
 774         /*
 775          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 776          * as dquot_acquire() may allocate space for new structure and OCFS2
 777          * needs to increment on-disk use count.
 778          */
 779         switch (cmd) {
 780         case Q_GETFMT:
 781         case Q_GETINFO:
 782         case Q_SYNC:
 783         case Q_XGETQSTAT:
 784         case Q_XGETQSTATV:
 785         case Q_XGETQUOTA:
 786         case Q_XGETNEXTQUOTA:
 787         case Q_XQUOTASYNC:
 788                 return 0;
 789         }
 790         return 1;
 791 }
 792
 793 #endif /* CONFIG_BLOCK */
 794
 795 /*
 796  * look up a superblock on which quota ops will be performed
 797  * - use the name of a block device to find the superblock thereon
 798  */
 799 static struct super_block *quotactl_block(const char __user *special, int cmd)
 800 {
 801 #ifdef CONFIG_BLOCK
 802         struct block_device *bdev;
 803         struct super_block *sb;
 804         struct filename *tmp = getname(special);
 805
 806         if (IS_ERR(tmp))
 807                 return ERR_CAST(tmp);
 808         bdev = lookup_bdev(tmp->name);
 809         putname(tmp);
 810         if (IS_ERR(bdev))
 811                 return ERR_CAST(bdev);
 812         if (quotactl_cmd_write(cmd))
 813                 sb = get_super_thawed(bdev);
 814         else
 815                 sb = get_super(bdev);
 816         bdput(bdev);
 817         if (!sb)
 818                 return ERR_PTR(-ENODEV);
 819
 820         return sb;
 821 #else
 822         return ERR_PTR(-ENODEV);
 823 #endif
 824 }
 825
 826 /*
 827  * This is the system call interface. This communicates with
 828  * the user-level programs. Currently this only supports diskquota
 829  * calls. Maybe we need to add the process quotas etc. in the future,
 830  * but we probably should use rlimits for that.
 831  */
 832 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 833                 qid_t, id, void __user *, addr)
 834 {
 835         uint cmds, type;
 836         struct super_block *sb = NULL;
 837         struct path path, *pathp = NULL;
 838         int ret;
 839
 840         cmds = cmd >> SUBCMDSHIFT;
 841         type = cmd & SUBCMDMASK;
 842
 843         /*
 844          * As a special case Q_SYNC can be called without a specific device.
 845          * It will iterate all superblocks that have quota enabled and call
 846          * the sync action on each of them.
 847          */
 848         if (!special) {
 849                 if (cmds == Q_SYNC)
 850                         return quota_sync_all(type);
 851                 return -ENODEV;
 852         }
 853
 854         /*
 855          * Path for quotaon has to be resolved before grabbing superblock
 856          * because that gets s_umount sem which is also possibly needed by path
 857          * resolution (think about autofs) and thus deadlocks could arise.
 858          */
 859         if (cmds == Q_QUOTAON) {
 860                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 861                 if (ret)
 862                         pathp = ERR_PTR(ret);
 863                 else
 864                         pathp = &path;
 865         }
 866
 867         sb = quotactl_block(special, cmds);
 868         if (IS_ERR(sb)) {
 869                 ret = PTR_ERR(sb);
 870                 goto out;
 871         }
 872
 873         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 874
 875         drop_super(sb);
 876 out:
 877         if (pathp && !IS_ERR(pathp))
 878                 path_put(pathp);
 879         return ret;
 880 }