fs/quota/quota.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Quota code necessary even when VFS quota support is not compiled
   4  * into the kernel.  The interesting stuff is over in dquot.c, here
   5  * we have symbols for initial quotactl(2) handling, the sysctl(2)
   6  * variables, etc - things needed even when quota support disabled.
   7  */
   8
   9 #include <linux/fs.h>
  10 #include <linux/namei.h>
  11 #include <linux/slab.h>
  12 #include <asm/current.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/kernel.h>
  15 #include <linux/security.h>
  16 #include <linux/syscalls.h>
  17 #include <linux/capability.h>
  18 #include <linux/quotaops.h>
  19 #include <linux/types.h>
  20 #include <linux/writeback.h>
  21 #include <linux/nospec.h>
  22
  23 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  24                                      qid_t id)
  25 {
  26         switch (cmd) {
  27         /* these commands do not require any special privilegues */
  28         case Q_GETFMT:
  29         case Q_SYNC:
  30         case Q_GETINFO:
  31         case Q_XGETQSTAT:
  32         case Q_XGETQSTATV:
  33         case Q_XQUOTASYNC:
  34                 break;
  35         /* allow to query information for dquots we "own" */
  36         case Q_GETQUOTA:
  37         case Q_XGETQUOTA:
  38                 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  39                     (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  40                         break;
  41                 fallthrough;
  42         default:
  43                 if (!capable(CAP_SYS_ADMIN))
  44                         return -EPERM;
  45         }
  46
  47         return security_quotactl(cmd, type, id, sb);
  48 }
  49
  50 static void quota_sync_one(struct super_block *sb, void *arg)
  51 {
  52         int type = *(int *)arg;
  53
  54         if (sb->s_qcop && sb->s_qcop->quota_sync &&
  55             (sb->s_quota_types & (1 << type)))
  56                 sb->s_qcop->quota_sync(sb, type);
  57 }
  58
  59 static int quota_sync_all(int type)
  60 {
  61         int ret;
  62
  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                          const 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         if (!sb_has_quota_active(sb, type))
 108                 return -ESRCH;
 109         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 110         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 111                 return -EFAULT;
 112         return 0;
 113 }
 114
 115 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 116 {
 117         struct qc_state state;
 118         struct qc_type_state *tstate;
 119         struct if_dqinfo uinfo;
 120         int ret;
 121
 122         if (!sb->s_qcop->get_state)
 123                 return -ENOSYS;
 124         ret = sb->s_qcop->get_state(sb, &state);
 125         if (ret)
 126                 return ret;
 127         tstate = state.s_state + type;
 128         if (!(tstate->flags & QCI_ACCT_ENABLED))
 129                 return -ESRCH;
 130         memset(&uinfo, 0, sizeof(uinfo));
 131         uinfo.dqi_bgrace = tstate->spc_timelimit;
 132         uinfo.dqi_igrace = tstate->ino_timelimit;
 133         if (tstate->flags & QCI_SYSFILE)
 134                 uinfo.dqi_flags |= DQF_SYS_FILE;
 135         if (tstate->flags & QCI_ROOT_SQUASH)
 136                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 137         uinfo.dqi_valid = IIF_ALL;
 138         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 139                 return -EFAULT;
 140         return 0;
 141 }
 142
 143 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 144 {
 145         struct if_dqinfo info;
 146         struct qc_info qinfo;
 147
 148         if (copy_from_user(&info, addr, sizeof(info)))
 149                 return -EFAULT;
 150         if (!sb->s_qcop->set_info)
 151                 return -ENOSYS;
 152         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 153                 return -EINVAL;
 154         memset(&qinfo, 0, sizeof(qinfo));
 155         if (info.dqi_valid & IIF_FLAGS) {
 156                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 157                         return -EINVAL;
 158                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 159                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 160                 qinfo.i_fieldmask |= QC_FLAGS;
 161         }
 162         if (info.dqi_valid & IIF_BGRACE) {
 163                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 164                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 165         }
 166         if (info.dqi_valid & IIF_IGRACE) {
 167                 qinfo.i_ino_timelimit = info.dqi_igrace;
 168                 qinfo.i_fieldmask |= QC_INO_TIMER;
 169         }
 170         return sb->s_qcop->set_info(sb, type, &qinfo);
 171 }
 172
 173 static inline qsize_t qbtos(qsize_t blocks)
 174 {
 175         return blocks << QIF_DQBLKSIZE_BITS;
 176 }
 177
 178 static inline qsize_t stoqb(qsize_t space)
 179 {
 180         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 181 }
 182
 183 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 184 {
 185         memset(dst, 0, sizeof(*dst));
 186         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 187         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 188         dst->dqb_curspace = src->d_space;
 189         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 190         dst->dqb_isoftlimit = src->d_ino_softlimit;
 191         dst->dqb_curinodes = src->d_ino_count;
 192         dst->dqb_btime = src->d_spc_timer;
 193         dst->dqb_itime = src->d_ino_timer;
 194         dst->dqb_valid = QIF_ALL;
 195 }
 196
 197 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 198                           void __user *addr)
 199 {
 200         struct kqid qid;
 201         struct qc_dqblk fdq;
 202         struct if_dqblk idq;
 203         int ret;
 204
 205         if (!sb->s_qcop->get_dqblk)
 206                 return -ENOSYS;
 207         qid = make_kqid(current_user_ns(), type, id);
 208         if (!qid_has_mapping(sb->s_user_ns, qid))
 209                 return -EINVAL;
 210         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 211         if (ret)
 212                 return ret;
 213         copy_to_if_dqblk(&idq, &fdq);
 214         if (copy_to_user(addr, &idq, sizeof(idq)))
 215                 return -EFAULT;
 216         return 0;
 217 }
 218
 219 /*
 220  * Return quota for next active quota >= this id, if any exists,
 221  * otherwise return -ENOENT via ->get_nextdqblk
 222  */
 223 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 224                           void __user *addr)
 225 {
 226         struct kqid qid;
 227         struct qc_dqblk fdq;
 228         struct if_nextdqblk idq;
 229         int ret;
 230
 231         if (!sb->s_qcop->get_nextdqblk)
 232                 return -ENOSYS;
 233         qid = make_kqid(current_user_ns(), type, id);
 234         if (!qid_has_mapping(sb->s_user_ns, qid))
 235                 return -EINVAL;
 236         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 237         if (ret)
 238                 return ret;
 239         /* struct if_nextdqblk is a superset of struct if_dqblk */
 240         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 241         idq.dqb_id = from_kqid(current_user_ns(), qid);
 242         if (copy_to_user(addr, &idq, sizeof(idq)))
 243                 return -EFAULT;
 244         return 0;
 245 }
 246
 247 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 248 {
 249         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 250         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 251         dst->d_space = src->dqb_curspace;
 252         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 253         dst->d_ino_softlimit = src->dqb_isoftlimit;
 254         dst->d_ino_count = src->dqb_curinodes;
 255         dst->d_spc_timer = src->dqb_btime;
 256         dst->d_ino_timer = src->dqb_itime;
 257
 258         dst->d_fieldmask = 0;
 259         if (src->dqb_valid & QIF_BLIMITS)
 260                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 261         if (src->dqb_valid & QIF_SPACE)
 262                 dst->d_fieldmask |= QC_SPACE;
 263         if (src->dqb_valid & QIF_ILIMITS)
 264                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 265         if (src->dqb_valid & QIF_INODES)
 266                 dst->d_fieldmask |= QC_INO_COUNT;
 267         if (src->dqb_valid & QIF_BTIME)
 268                 dst->d_fieldmask |= QC_SPC_TIMER;
 269         if (src->dqb_valid & QIF_ITIME)
 270                 dst->d_fieldmask |= QC_INO_TIMER;
 271 }
 272
 273 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 274                           void __user *addr)
 275 {
 276         struct qc_dqblk fdq;
 277         struct if_dqblk idq;
 278         struct kqid qid;
 279
 280         if (copy_from_user(&idq, addr, sizeof(idq)))
 281                 return -EFAULT;
 282         if (!sb->s_qcop->set_dqblk)
 283                 return -ENOSYS;
 284         qid = make_kqid(current_user_ns(), type, id);
 285         if (!qid_has_mapping(sb->s_user_ns, qid))
 286                 return -EINVAL;
 287         copy_from_if_dqblk(&fdq, &idq);
 288         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 289 }
 290
 291 static int quota_enable(struct super_block *sb, void __user *addr)
 292 {
 293         __u32 flags;
 294
 295         if (copy_from_user(&flags, addr, sizeof(flags)))
 296                 return -EFAULT;
 297         if (!sb->s_qcop->quota_enable)
 298                 return -ENOSYS;
 299         return sb->s_qcop->quota_enable(sb, flags);
 300 }
 301
 302 static int quota_disable(struct super_block *sb, void __user *addr)
 303 {
 304         __u32 flags;
 305
 306         if (copy_from_user(&flags, addr, sizeof(flags)))
 307                 return -EFAULT;
 308         if (!sb->s_qcop->quota_disable)
 309                 return -ENOSYS;
 310         return sb->s_qcop->quota_disable(sb, flags);
 311 }
 312
 313 static int quota_state_to_flags(struct qc_state *state)
 314 {
 315         int flags = 0;
 316
 317         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 318                 flags |= FS_QUOTA_UDQ_ACCT;
 319         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 320                 flags |= FS_QUOTA_UDQ_ENFD;
 321         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 322                 flags |= FS_QUOTA_GDQ_ACCT;
 323         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 324                 flags |= FS_QUOTA_GDQ_ENFD;
 325         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 326                 flags |= FS_QUOTA_PDQ_ACCT;
 327         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 328                 flags |= FS_QUOTA_PDQ_ENFD;
 329         return flags;
 330 }
 331
 332 static int quota_getstate(struct super_block *sb, int type,
 333                           struct fs_quota_stat *fqs)
 334 {
 335         struct qc_state state;
 336         int ret;
 337
 338         memset(&state, 0, sizeof (struct qc_state));
 339         ret = sb->s_qcop->get_state(sb, &state);
 340         if (ret < 0)
 341                 return ret;
 342
 343         memset(fqs, 0, sizeof(*fqs));
 344         fqs->qs_version = FS_QSTAT_VERSION;
 345         fqs->qs_flags = quota_state_to_flags(&state);
 346         /* No quota enabled? */
 347         if (!fqs->qs_flags)
 348                 return -ENOSYS;
 349         fqs->qs_incoredqs = state.s_incoredqs;
 350
 351         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 352         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 353         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 354         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 355         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 356
 357         /* Inodes may be allocated even if inactive; copy out if present */
 358         if (state.s_state[USRQUOTA].ino) {
 359                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 360                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 361                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 362         }
 363         if (state.s_state[GRPQUOTA].ino) {
 364                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 365                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 366                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 367         }
 368         if (state.s_state[PRJQUOTA].ino) {
 369                 /*
 370                  * Q_XGETQSTAT doesn't have room for both group and project
 371                  * quotas.  So, allow the project quota values to be copied out
 372                  * only if there is no group quota information available.
 373                  */
 374                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 375                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 376                         fqs->qs_gquota.qfs_nblks =
 377                                         state.s_state[PRJQUOTA].blocks;
 378                         fqs->qs_gquota.qfs_nextents =
 379                                         state.s_state[PRJQUOTA].nextents;
 380                 }
 381         }
 382         return 0;
 383 }
 384
 385 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
 386 {
 387         struct fs_quota_stat fqs;
 388         int ret;
 389
 390         if (!sb->s_qcop->get_state)
 391                 return -ENOSYS;
 392         ret = quota_getstate(sb, type, &fqs);
 393         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 394                 return -EFAULT;
 395         return ret;
 396 }
 397
 398 static int quota_getstatev(struct super_block *sb, int type,
 399                            struct fs_quota_statv *fqs)
 400 {
 401         struct qc_state state;
 402         int ret;
 403
 404         memset(&state, 0, sizeof (struct qc_state));
 405         ret = sb->s_qcop->get_state(sb, &state);
 406         if (ret < 0)
 407                 return ret;
 408
 409         memset(fqs, 0, sizeof(*fqs));
 410         fqs->qs_version = FS_QSTAT_VERSION;
 411         fqs->qs_flags = quota_state_to_flags(&state);
 412         /* No quota enabled? */
 413         if (!fqs->qs_flags)
 414                 return -ENOSYS;
 415         fqs->qs_incoredqs = state.s_incoredqs;
 416
 417         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 418         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 419         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 420         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 421         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 422
 423         /* Inodes may be allocated even if inactive; copy out if present */
 424         if (state.s_state[USRQUOTA].ino) {
 425                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 426                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 427                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 428         }
 429         if (state.s_state[GRPQUOTA].ino) {
 430                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 431                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 432                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 433         }
 434         if (state.s_state[PRJQUOTA].ino) {
 435                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 436                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 437                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 438         }
 439         return 0;
 440 }
 441
 442 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
 443 {
 444         struct fs_quota_statv fqs;
 445         int ret;
 446
 447         if (!sb->s_qcop->get_state)
 448                 return -ENOSYS;
 449
 450         memset(&fqs, 0, sizeof(fqs));
 451         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 452                 return -EFAULT;
 453
 454         /* If this kernel doesn't support user specified version, fail */
 455         switch (fqs.qs_version) {
 456         case FS_QSTATV_VERSION1:
 457                 break;
 458         default:
 459                 return -EINVAL;
 460         }
 461         ret = quota_getstatev(sb, type, &fqs);
 462         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 463                 return -EFAULT;
 464         return ret;
 465 }
 466
 467 /*
 468  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 469  * out of there as xfsprogs rely on definitions being in that header file. So
 470  * just define same functions here for quota purposes.
 471  */
 472 #define XFS_BB_SHIFT 9
 473
 474 static inline u64 quota_bbtob(u64 blocks)
 475 {
 476         return blocks << XFS_BB_SHIFT;
 477 }
 478
 479 static inline u64 quota_btobb(u64 bytes)
 480 {
 481         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 482 }
 483
 484 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 485 {
 486         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 487         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 488         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 489         dst->d_ino_softlimit = src->d_ino_softlimit;
 490         dst->d_space = quota_bbtob(src->d_bcount);
 491         dst->d_ino_count = src->d_icount;
 492         dst->d_ino_timer = src->d_itimer;
 493         dst->d_spc_timer = src->d_btimer;
 494         dst->d_ino_warns = src->d_iwarns;
 495         dst->d_spc_warns = src->d_bwarns;
 496         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 497         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 498         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 499         dst->d_rt_spc_timer = src->d_rtbtimer;
 500         dst->d_rt_spc_warns = src->d_rtbwarns;
 501         dst->d_fieldmask = 0;
 502         if (src->d_fieldmask & FS_DQ_ISOFT)
 503                 dst->d_fieldmask |= QC_INO_SOFT;
 504         if (src->d_fieldmask & FS_DQ_IHARD)
 505                 dst->d_fieldmask |= QC_INO_HARD;
 506         if (src->d_fieldmask & FS_DQ_BSOFT)
 507                 dst->d_fieldmask |= QC_SPC_SOFT;
 508         if (src->d_fieldmask & FS_DQ_BHARD)
 509                 dst->d_fieldmask |= QC_SPC_HARD;
 510         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 511                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 512         if (src->d_fieldmask & FS_DQ_RTBHARD)
 513                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 514         if (src->d_fieldmask & FS_DQ_BTIMER)
 515                 dst->d_fieldmask |= QC_SPC_TIMER;
 516         if (src->d_fieldmask & FS_DQ_ITIMER)
 517                 dst->d_fieldmask |= QC_INO_TIMER;
 518         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 519                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 520         if (src->d_fieldmask & FS_DQ_BWARNS)
 521                 dst->d_fieldmask |= QC_SPC_WARNS;
 522         if (src->d_fieldmask & FS_DQ_IWARNS)
 523                 dst->d_fieldmask |= QC_INO_WARNS;
 524         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 525                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 526         if (src->d_fieldmask & FS_DQ_BCOUNT)
 527                 dst->d_fieldmask |= QC_SPACE;
 528         if (src->d_fieldmask & FS_DQ_ICOUNT)
 529                 dst->d_fieldmask |= QC_INO_COUNT;
 530         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 531                 dst->d_fieldmask |= QC_RT_SPACE;
 532 }
 533
 534 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 535                                        struct fs_disk_quota *src)
 536 {
 537         memset(dst, 0, sizeof(*dst));
 538         dst->i_spc_timelimit = src->d_btimer;
 539         dst->i_ino_timelimit = src->d_itimer;
 540         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 541         dst->i_ino_warnlimit = src->d_iwarns;
 542         dst->i_spc_warnlimit = src->d_bwarns;
 543         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 544         if (src->d_fieldmask & FS_DQ_BWARNS)
 545                 dst->i_fieldmask |= QC_SPC_WARNS;
 546         if (src->d_fieldmask & FS_DQ_IWARNS)
 547                 dst->i_fieldmask |= QC_INO_WARNS;
 548         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 549                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 550         if (src->d_fieldmask & FS_DQ_BTIMER)
 551                 dst->i_fieldmask |= QC_SPC_TIMER;
 552         if (src->d_fieldmask & FS_DQ_ITIMER)
 553                 dst->i_fieldmask |= QC_INO_TIMER;
 554         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 555                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 556 }
 557
 558 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 559                            void __user *addr)
 560 {
 561         struct fs_disk_quota fdq;
 562         struct qc_dqblk qdq;
 563         struct kqid qid;
 564
 565         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 566                 return -EFAULT;
 567         if (!sb->s_qcop->set_dqblk)
 568                 return -ENOSYS;
 569         qid = make_kqid(current_user_ns(), type, id);
 570         if (!qid_has_mapping(sb->s_user_ns, qid))
 571                 return -EINVAL;
 572         /* Are we actually setting timer / warning limits for all users? */
 573         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 574             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 575                 struct qc_info qinfo;
 576                 int ret;
 577
 578                 if (!sb->s_qcop->set_info)
 579                         return -EINVAL;
 580                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 581                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 582                 if (ret)
 583                         return ret;
 584                 /* These are already done */
 585                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 586         }
 587         copy_from_xfs_dqblk(&qdq, &fdq);
 588         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 589 }
 590
 591 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 592                               int type, qid_t id)
 593 {
 594         memset(dst, 0, sizeof(*dst));
 595         dst->d_version = FS_DQUOT_VERSION;
 596         dst->d_id = id;
 597         if (type == USRQUOTA)
 598                 dst->d_flags = FS_USER_QUOTA;
 599         else if (type == PRJQUOTA)
 600                 dst->d_flags = FS_PROJ_QUOTA;
 601         else
 602                 dst->d_flags = FS_GROUP_QUOTA;
 603         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 604         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 605         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 606         dst->d_ino_softlimit = src->d_ino_softlimit;
 607         dst->d_bcount = quota_btobb(src->d_space);
 608         dst->d_icount = src->d_ino_count;
 609         dst->d_itimer = src->d_ino_timer;
 610         dst->d_btimer = src->d_spc_timer;
 611         dst->d_iwarns = src->d_ino_warns;
 612         dst->d_bwarns = src->d_spc_warns;
 613         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 614         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 615         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 616         dst->d_rtbtimer = src->d_rt_spc_timer;
 617         dst->d_rtbwarns = src->d_rt_spc_warns;
 618 }
 619
 620 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 621                            void __user *addr)
 622 {
 623         struct fs_disk_quota fdq;
 624         struct qc_dqblk qdq;
 625         struct kqid qid;
 626         int ret;
 627
 628         if (!sb->s_qcop->get_dqblk)
 629                 return -ENOSYS;
 630         qid = make_kqid(current_user_ns(), type, id);
 631         if (!qid_has_mapping(sb->s_user_ns, qid))
 632                 return -EINVAL;
 633         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 634         if (ret)
 635                 return ret;
 636         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 637         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 638                 return -EFAULT;
 639         return ret;
 640 }
 641
 642 /*
 643  * Return quota for next active quota >= this id, if any exists,
 644  * otherwise return -ENOENT via ->get_nextdqblk.
 645  */
 646 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 647                             void __user *addr)
 648 {
 649         struct fs_disk_quota fdq;
 650         struct qc_dqblk qdq;
 651         struct kqid qid;
 652         qid_t id_out;
 653         int ret;
 654
 655         if (!sb->s_qcop->get_nextdqblk)
 656                 return -ENOSYS;
 657         qid = make_kqid(current_user_ns(), type, id);
 658         if (!qid_has_mapping(sb->s_user_ns, qid))
 659                 return -EINVAL;
 660         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 661         if (ret)
 662                 return ret;
 663         id_out = from_kqid(current_user_ns(), qid);
 664         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 665         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 666                 return -EFAULT;
 667         return ret;
 668 }
 669
 670 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 671 {
 672         __u32 flags;
 673
 674         if (copy_from_user(&flags, addr, sizeof(flags)))
 675                 return -EFAULT;
 676         if (!sb->s_qcop->rm_xquota)
 677                 return -ENOSYS;
 678         return sb->s_qcop->rm_xquota(sb, flags);
 679 }
 680
 681 /* Copy parameters and call proper function */
 682 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 683                        void __user *addr, const struct path *path)
 684 {
 685         int ret;
 686
 687         type = array_index_nospec(type, MAXQUOTAS);
 688         /*
 689          * Quota not supported on this fs? Check this before s_quota_types
 690          * since they needn't be set if quota is not supported at all.
 691          */
 692         if (!sb->s_qcop)
 693                 return -ENOSYS;
 694         if (!(sb->s_quota_types & (1 << type)))
 695                 return -EINVAL;
 696
 697         ret = check_quotactl_permission(sb, type, cmd, id);
 698         if (ret < 0)
 699                 return ret;
 700
 701         switch (cmd) {
 702         case Q_QUOTAON:
 703                 return quota_quotaon(sb, type, id, path);
 704         case Q_QUOTAOFF:
 705                 return quota_quotaoff(sb, type);
 706         case Q_GETFMT:
 707                 return quota_getfmt(sb, type, addr);
 708         case Q_GETINFO:
 709                 return quota_getinfo(sb, type, addr);
 710         case Q_SETINFO:
 711                 return quota_setinfo(sb, type, addr);
 712         case Q_GETQUOTA:
 713                 return quota_getquota(sb, type, id, addr);
 714         case Q_GETNEXTQUOTA:
 715                 return quota_getnextquota(sb, type, id, addr);
 716         case Q_SETQUOTA:
 717                 return quota_setquota(sb, type, id, addr);
 718         case Q_SYNC:
 719                 if (!sb->s_qcop->quota_sync)
 720                         return -ENOSYS;
 721                 return sb->s_qcop->quota_sync(sb, type);
 722         case Q_XQUOTAON:
 723                 return quota_enable(sb, addr);
 724         case Q_XQUOTAOFF:
 725                 return quota_disable(sb, addr);
 726         case Q_XQUOTARM:
 727                 return quota_rmxquota(sb, addr);
 728         case Q_XGETQSTAT:
 729                 return quota_getxstate(sb, type, addr);
 730         case Q_XGETQSTATV:
 731                 return quota_getxstatev(sb, type, addr);
 732         case Q_XSETQLIM:
 733                 return quota_setxquota(sb, type, id, addr);
 734         case Q_XGETQUOTA:
 735                 return quota_getxquota(sb, type, id, addr);
 736         case Q_XGETNEXTQUOTA:
 737                 return quota_getnextxquota(sb, type, id, addr);
 738         case Q_XQUOTASYNC:
 739                 if (sb_rdonly(sb))
 740                         return -EROFS;
 741                 /* XFS quotas are fully coherent now, making this call a noop */
 742                 return 0;
 743         default:
 744                 return -EINVAL;
 745         }
 746 }
 747
 748 #ifdef CONFIG_BLOCK
 749
 750 /* Return 1 if 'cmd' will block on frozen filesystem */
 751 static int quotactl_cmd_write(int cmd)
 752 {
 753         /*
 754          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 755          * as dquot_acquire() may allocate space for new structure and OCFS2
 756          * needs to increment on-disk use count.
 757          */
 758         switch (cmd) {
 759         case Q_GETFMT:
 760         case Q_GETINFO:
 761         case Q_SYNC:
 762         case Q_XGETQSTAT:
 763         case Q_XGETQSTATV:
 764         case Q_XGETQUOTA:
 765         case Q_XGETNEXTQUOTA:
 766         case Q_XQUOTASYNC:
 767                 return 0;
 768         }
 769         return 1;
 770 }
 771 #endif /* CONFIG_BLOCK */
 772
 773 /* Return true if quotactl command is manipulating quota on/off state */
 774 static bool quotactl_cmd_onoff(int cmd)
 775 {
 776         return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 777                  (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 778 }
 779
 780 /*
 781  * look up a superblock on which quota ops will be performed
 782  * - use the name of a block device to find the superblock thereon
 783  */
 784 static struct super_block *quotactl_block(const char __user *special, int cmd)
 785 {
 786 #ifdef CONFIG_BLOCK
 787         struct block_device *bdev;
 788         struct super_block *sb;
 789         struct filename *tmp = getname(special);
 790
 791         if (IS_ERR(tmp))
 792                 return ERR_CAST(tmp);
 793         bdev = lookup_bdev(tmp->name);
 794         putname(tmp);
 795         if (IS_ERR(bdev))
 796                 return ERR_CAST(bdev);
 797         if (quotactl_cmd_onoff(cmd))
 798                 sb = get_super_exclusive_thawed(bdev);
 799         else if (quotactl_cmd_write(cmd))
 800                 sb = get_super_thawed(bdev);
 801         else
 802                 sb = get_super(bdev);
 803         bdput(bdev);
 804         if (!sb)
 805                 return ERR_PTR(-ENODEV);
 806
 807         return sb;
 808 #else
 809         return ERR_PTR(-ENODEV);
 810 #endif
 811 }
 812
 813 /*
 814  * This is the system call interface. This communicates with
 815  * the user-level programs. Currently this only supports diskquota
 816  * calls. Maybe we need to add the process quotas etc. in the future,
 817  * but we probably should use rlimits for that.
 818  */
 819 int kernel_quotactl(unsigned int cmd, const char __user *special,
 820                     qid_t id, void __user *addr)
 821 {
 822         uint cmds, type;
 823         struct super_block *sb = NULL;
 824         struct path path, *pathp = NULL;
 825         int ret;
 826
 827         cmds = cmd >> SUBCMDSHIFT;
 828         type = cmd & SUBCMDMASK;
 829
 830         if (type >= MAXQUOTAS)
 831                 return -EINVAL;
 832
 833         /*
 834          * As a special case Q_SYNC can be called without a specific device.
 835          * It will iterate all superblocks that have quota enabled and call
 836          * the sync action on each of them.
 837          */
 838         if (!special) {
 839                 if (cmds == Q_SYNC)
 840                         return quota_sync_all(type);
 841                 return -ENODEV;
 842         }
 843
 844         /*
 845          * Path for quotaon has to be resolved before grabbing superblock
 846          * because that gets s_umount sem which is also possibly needed by path
 847          * resolution (think about autofs) and thus deadlocks could arise.
 848          */
 849         if (cmds == Q_QUOTAON) {
 850                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 851                 if (ret)
 852                         pathp = ERR_PTR(ret);
 853                 else
 854                         pathp = &path;
 855         }
 856
 857         sb = quotactl_block(special, cmds);
 858         if (IS_ERR(sb)) {
 859                 ret = PTR_ERR(sb);
 860                 goto out;
 861         }
 862
 863         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 864
 865         if (!quotactl_cmd_onoff(cmds))
 866                 drop_super(sb);
 867         else
 868                 drop_super_exclusive(sb);
 869 out:
 870         if (pathp && !IS_ERR(pathp))
 871                 path_put(pathp);
 872         return ret;
 873 }
 874
 875 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 876                 qid_t, id, void __user *, addr)
 877 {
 878         return kernel_quotactl(cmd, special, id, addr);
 879 }