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         if (type >= MAXQUOTAS)
  64                 return -EINVAL;
  65         ret = security_quotactl(Q_SYNC, type, 0, NULL);
  66         if (!ret)
  67                 iterate_supers(quota_sync_one, &type);
  68         return ret;
  69 }
  70
  71 unsigned int qtype_enforce_flag(int type)
  72 {
  73         switch (type) {
  74         case USRQUOTA:
  75                 return FS_QUOTA_UDQ_ENFD;
  76         case GRPQUOTA:
  77                 return FS_QUOTA_GDQ_ENFD;
  78         case PRJQUOTA:
  79                 return FS_QUOTA_PDQ_ENFD;
  80         }
  81         return 0;
  82 }
  83
  84 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  85                          const struct path *path)
  86 {
  87         if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  88                 return -ENOSYS;
  89         if (sb->s_qcop->quota_enable)
  90                 return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  91         if (IS_ERR(path))
  92                 return PTR_ERR(path);
  93         return sb->s_qcop->quota_on(sb, type, id, path);
  94 }
  95
  96 static int quota_quotaoff(struct super_block *sb, int type)
  97 {
  98         if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
  99                 return -ENOSYS;
 100         if (sb->s_qcop->quota_disable)
 101                 return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 102         return sb->s_qcop->quota_off(sb, type);
 103 }
 104
 105 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 106 {
 107         __u32 fmt;
 108
 109         if (!sb_has_quota_active(sb, type))
 110                 return -ESRCH;
 111         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 112         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 113                 return -EFAULT;
 114         return 0;
 115 }
 116
 117 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 118 {
 119         struct qc_state state;
 120         struct qc_type_state *tstate;
 121         struct if_dqinfo uinfo;
 122         int ret;
 123
 124         /* This checks whether qc_state has enough entries... */
 125         BUILD_BUG_ON(MAXQUOTAS > XQM_MAXQUOTAS);
 126         if (!sb->s_qcop->get_state)
 127                 return -ENOSYS;
 128         ret = sb->s_qcop->get_state(sb, &state);
 129         if (ret)
 130                 return ret;
 131         tstate = state.s_state + type;
 132         if (!(tstate->flags & QCI_ACCT_ENABLED))
 133                 return -ESRCH;
 134         memset(&uinfo, 0, sizeof(uinfo));
 135         uinfo.dqi_bgrace = tstate->spc_timelimit;
 136         uinfo.dqi_igrace = tstate->ino_timelimit;
 137         if (tstate->flags & QCI_SYSFILE)
 138                 uinfo.dqi_flags |= DQF_SYS_FILE;
 139         if (tstate->flags & QCI_ROOT_SQUASH)
 140                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 141         uinfo.dqi_valid = IIF_ALL;
 142         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 143                 return -EFAULT;
 144         return 0;
 145 }
 146
 147 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 148 {
 149         struct if_dqinfo info;
 150         struct qc_info qinfo;
 151
 152         if (copy_from_user(&info, addr, sizeof(info)))
 153                 return -EFAULT;
 154         if (!sb->s_qcop->set_info)
 155                 return -ENOSYS;
 156         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 157                 return -EINVAL;
 158         memset(&qinfo, 0, sizeof(qinfo));
 159         if (info.dqi_valid & IIF_FLAGS) {
 160                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 161                         return -EINVAL;
 162                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 163                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 164                 qinfo.i_fieldmask |= QC_FLAGS;
 165         }
 166         if (info.dqi_valid & IIF_BGRACE) {
 167                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 168                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 169         }
 170         if (info.dqi_valid & IIF_IGRACE) {
 171                 qinfo.i_ino_timelimit = info.dqi_igrace;
 172                 qinfo.i_fieldmask |= QC_INO_TIMER;
 173         }
 174         return sb->s_qcop->set_info(sb, type, &qinfo);
 175 }
 176
 177 static inline qsize_t qbtos(qsize_t blocks)
 178 {
 179         return blocks << QIF_DQBLKSIZE_BITS;
 180 }
 181
 182 static inline qsize_t stoqb(qsize_t space)
 183 {
 184         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 185 }
 186
 187 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 188 {
 189         memset(dst, 0, sizeof(*dst));
 190         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 191         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 192         dst->dqb_curspace = src->d_space;
 193         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 194         dst->dqb_isoftlimit = src->d_ino_softlimit;
 195         dst->dqb_curinodes = src->d_ino_count;
 196         dst->dqb_btime = src->d_spc_timer;
 197         dst->dqb_itime = src->d_ino_timer;
 198         dst->dqb_valid = QIF_ALL;
 199 }
 200
 201 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 202                           void __user *addr)
 203 {
 204         struct kqid qid;
 205         struct qc_dqblk fdq;
 206         struct if_dqblk idq;
 207         int ret;
 208
 209         if (!sb->s_qcop->get_dqblk)
 210                 return -ENOSYS;
 211         qid = make_kqid(current_user_ns(), type, id);
 212         if (!qid_has_mapping(sb->s_user_ns, qid))
 213                 return -EINVAL;
 214         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 215         if (ret)
 216                 return ret;
 217         copy_to_if_dqblk(&idq, &fdq);
 218         if (copy_to_user(addr, &idq, sizeof(idq)))
 219                 return -EFAULT;
 220         return 0;
 221 }
 222
 223 /*
 224  * Return quota for next active quota >= this id, if any exists,
 225  * otherwise return -ENOENT via ->get_nextdqblk
 226  */
 227 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 228                           void __user *addr)
 229 {
 230         struct kqid qid;
 231         struct qc_dqblk fdq;
 232         struct if_nextdqblk idq;
 233         int ret;
 234
 235         if (!sb->s_qcop->get_nextdqblk)
 236                 return -ENOSYS;
 237         qid = make_kqid(current_user_ns(), type, id);
 238         if (!qid_has_mapping(sb->s_user_ns, qid))
 239                 return -EINVAL;
 240         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 241         if (ret)
 242                 return ret;
 243         /* struct if_nextdqblk is a superset of struct if_dqblk */
 244         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 245         idq.dqb_id = from_kqid(current_user_ns(), qid);
 246         if (copy_to_user(addr, &idq, sizeof(idq)))
 247                 return -EFAULT;
 248         return 0;
 249 }
 250
 251 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 252 {
 253         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 254         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 255         dst->d_space = src->dqb_curspace;
 256         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 257         dst->d_ino_softlimit = src->dqb_isoftlimit;
 258         dst->d_ino_count = src->dqb_curinodes;
 259         dst->d_spc_timer = src->dqb_btime;
 260         dst->d_ino_timer = src->dqb_itime;
 261
 262         dst->d_fieldmask = 0;
 263         if (src->dqb_valid & QIF_BLIMITS)
 264                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 265         if (src->dqb_valid & QIF_SPACE)
 266                 dst->d_fieldmask |= QC_SPACE;
 267         if (src->dqb_valid & QIF_ILIMITS)
 268                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 269         if (src->dqb_valid & QIF_INODES)
 270                 dst->d_fieldmask |= QC_INO_COUNT;
 271         if (src->dqb_valid & QIF_BTIME)
 272                 dst->d_fieldmask |= QC_SPC_TIMER;
 273         if (src->dqb_valid & QIF_ITIME)
 274                 dst->d_fieldmask |= QC_INO_TIMER;
 275 }
 276
 277 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 278                           void __user *addr)
 279 {
 280         struct qc_dqblk fdq;
 281         struct if_dqblk idq;
 282         struct kqid qid;
 283
 284         if (copy_from_user(&idq, addr, sizeof(idq)))
 285                 return -EFAULT;
 286         if (!sb->s_qcop->set_dqblk)
 287                 return -ENOSYS;
 288         qid = make_kqid(current_user_ns(), type, id);
 289         if (!qid_has_mapping(sb->s_user_ns, qid))
 290                 return -EINVAL;
 291         copy_from_if_dqblk(&fdq, &idq);
 292         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 293 }
 294
 295 static int quota_enable(struct super_block *sb, void __user *addr)
 296 {
 297         __u32 flags;
 298
 299         if (copy_from_user(&flags, addr, sizeof(flags)))
 300                 return -EFAULT;
 301         if (!sb->s_qcop->quota_enable)
 302                 return -ENOSYS;
 303         return sb->s_qcop->quota_enable(sb, flags);
 304 }
 305
 306 static int quota_disable(struct super_block *sb, void __user *addr)
 307 {
 308         __u32 flags;
 309
 310         if (copy_from_user(&flags, addr, sizeof(flags)))
 311                 return -EFAULT;
 312         if (!sb->s_qcop->quota_disable)
 313                 return -ENOSYS;
 314         return sb->s_qcop->quota_disable(sb, flags);
 315 }
 316
 317 static int quota_state_to_flags(struct qc_state *state)
 318 {
 319         int flags = 0;
 320
 321         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 322                 flags |= FS_QUOTA_UDQ_ACCT;
 323         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 324                 flags |= FS_QUOTA_UDQ_ENFD;
 325         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 326                 flags |= FS_QUOTA_GDQ_ACCT;
 327         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 328                 flags |= FS_QUOTA_GDQ_ENFD;
 329         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 330                 flags |= FS_QUOTA_PDQ_ACCT;
 331         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 332                 flags |= FS_QUOTA_PDQ_ENFD;
 333         return flags;
 334 }
 335
 336 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
 337 {
 338         int type;
 339         struct qc_state state;
 340         int ret;
 341
 342         memset(&state, 0, sizeof (struct qc_state));
 343         ret = sb->s_qcop->get_state(sb, &state);
 344         if (ret < 0)
 345                 return ret;
 346
 347         memset(fqs, 0, sizeof(*fqs));
 348         fqs->qs_version = FS_QSTAT_VERSION;
 349         fqs->qs_flags = quota_state_to_flags(&state);
 350         /* No quota enabled? */
 351         if (!fqs->qs_flags)
 352                 return -ENOSYS;
 353         fqs->qs_incoredqs = state.s_incoredqs;
 354         /*
 355          * GETXSTATE quotactl has space for just one set of time limits so
 356          * report them for the first enabled quota type
 357          */
 358         for (type = 0; type < XQM_MAXQUOTAS; type++)
 359                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 360                         break;
 361         BUG_ON(type == XQM_MAXQUOTAS);
 362         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 363         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 364         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 365         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 366         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 367
 368         /* Inodes may be allocated even if inactive; copy out if present */
 369         if (state.s_state[USRQUOTA].ino) {
 370                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 371                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 372                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 373         }
 374         if (state.s_state[GRPQUOTA].ino) {
 375                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 376                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 377                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 378         }
 379         if (state.s_state[PRJQUOTA].ino) {
 380                 /*
 381                  * Q_XGETQSTAT doesn't have room for both group and project
 382                  * quotas.  So, allow the project quota values to be copied out
 383                  * only if there is no group quota information available.
 384                  */
 385                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 386                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 387                         fqs->qs_gquota.qfs_nblks =
 388                                         state.s_state[PRJQUOTA].blocks;
 389                         fqs->qs_gquota.qfs_nextents =
 390                                         state.s_state[PRJQUOTA].nextents;
 391                 }
 392         }
 393         return 0;
 394 }
 395
 396 static int quota_getxstate(struct super_block *sb, void __user *addr)
 397 {
 398         struct fs_quota_stat fqs;
 399         int ret;
 400
 401         if (!sb->s_qcop->get_state)
 402                 return -ENOSYS;
 403         ret = quota_getstate(sb, &fqs);
 404         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 405                 return -EFAULT;
 406         return ret;
 407 }
 408
 409 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
 410 {
 411         int type;
 412         struct qc_state state;
 413         int ret;
 414
 415         memset(&state, 0, sizeof (struct qc_state));
 416         ret = sb->s_qcop->get_state(sb, &state);
 417         if (ret < 0)
 418                 return ret;
 419
 420         memset(fqs, 0, sizeof(*fqs));
 421         fqs->qs_version = FS_QSTAT_VERSION;
 422         fqs->qs_flags = quota_state_to_flags(&state);
 423         /* No quota enabled? */
 424         if (!fqs->qs_flags)
 425                 return -ENOSYS;
 426         fqs->qs_incoredqs = state.s_incoredqs;
 427         /*
 428          * GETXSTATV quotactl has space for just one set of time limits so
 429          * report them for the first enabled quota type
 430          */
 431         for (type = 0; type < XQM_MAXQUOTAS; type++)
 432                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 433                         break;
 434         BUG_ON(type == XQM_MAXQUOTAS);
 435         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 436         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 437         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 438         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 439         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 440
 441         /* Inodes may be allocated even if inactive; copy out if present */
 442         if (state.s_state[USRQUOTA].ino) {
 443                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 444                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 445                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 446         }
 447         if (state.s_state[GRPQUOTA].ino) {
 448                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 449                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 450                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 451         }
 452         if (state.s_state[PRJQUOTA].ino) {
 453                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 454                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 455                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 456         }
 457         return 0;
 458 }
 459
 460 static int quota_getxstatev(struct super_block *sb, void __user *addr)
 461 {
 462         struct fs_quota_statv fqs;
 463         int ret;
 464
 465         if (!sb->s_qcop->get_state)
 466                 return -ENOSYS;
 467
 468         memset(&fqs, 0, sizeof(fqs));
 469         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 470                 return -EFAULT;
 471
 472         /* If this kernel doesn't support user specified version, fail */
 473         switch (fqs.qs_version) {
 474         case FS_QSTATV_VERSION1:
 475                 break;
 476         default:
 477                 return -EINVAL;
 478         }
 479         ret = quota_getstatev(sb, &fqs);
 480         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 481                 return -EFAULT;
 482         return ret;
 483 }
 484
 485 /*
 486  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 487  * out of there as xfsprogs rely on definitions being in that header file. So
 488  * just define same functions here for quota purposes.
 489  */
 490 #define XFS_BB_SHIFT 9
 491
 492 static inline u64 quota_bbtob(u64 blocks)
 493 {
 494         return blocks << XFS_BB_SHIFT;
 495 }
 496
 497 static inline u64 quota_btobb(u64 bytes)
 498 {
 499         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 500 }
 501
 502 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 503 {
 504         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 505         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 506         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 507         dst->d_ino_softlimit = src->d_ino_softlimit;
 508         dst->d_space = quota_bbtob(src->d_bcount);
 509         dst->d_ino_count = src->d_icount;
 510         dst->d_ino_timer = src->d_itimer;
 511         dst->d_spc_timer = src->d_btimer;
 512         dst->d_ino_warns = src->d_iwarns;
 513         dst->d_spc_warns = src->d_bwarns;
 514         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 515         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 516         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 517         dst->d_rt_spc_timer = src->d_rtbtimer;
 518         dst->d_rt_spc_warns = src->d_rtbwarns;
 519         dst->d_fieldmask = 0;
 520         if (src->d_fieldmask & FS_DQ_ISOFT)
 521                 dst->d_fieldmask |= QC_INO_SOFT;
 522         if (src->d_fieldmask & FS_DQ_IHARD)
 523                 dst->d_fieldmask |= QC_INO_HARD;
 524         if (src->d_fieldmask & FS_DQ_BSOFT)
 525                 dst->d_fieldmask |= QC_SPC_SOFT;
 526         if (src->d_fieldmask & FS_DQ_BHARD)
 527                 dst->d_fieldmask |= QC_SPC_HARD;
 528         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 529                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 530         if (src->d_fieldmask & FS_DQ_RTBHARD)
 531                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 532         if (src->d_fieldmask & FS_DQ_BTIMER)
 533                 dst->d_fieldmask |= QC_SPC_TIMER;
 534         if (src->d_fieldmask & FS_DQ_ITIMER)
 535                 dst->d_fieldmask |= QC_INO_TIMER;
 536         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 537                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 538         if (src->d_fieldmask & FS_DQ_BWARNS)
 539                 dst->d_fieldmask |= QC_SPC_WARNS;
 540         if (src->d_fieldmask & FS_DQ_IWARNS)
 541                 dst->d_fieldmask |= QC_INO_WARNS;
 542         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 543                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 544         if (src->d_fieldmask & FS_DQ_BCOUNT)
 545                 dst->d_fieldmask |= QC_SPACE;
 546         if (src->d_fieldmask & FS_DQ_ICOUNT)
 547                 dst->d_fieldmask |= QC_INO_COUNT;
 548         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 549                 dst->d_fieldmask |= QC_RT_SPACE;
 550 }
 551
 552 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 553                                        struct fs_disk_quota *src)
 554 {
 555         memset(dst, 0, sizeof(*dst));
 556         dst->i_spc_timelimit = src->d_btimer;
 557         dst->i_ino_timelimit = src->d_itimer;
 558         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 559         dst->i_ino_warnlimit = src->d_iwarns;
 560         dst->i_spc_warnlimit = src->d_bwarns;
 561         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 562         if (src->d_fieldmask & FS_DQ_BWARNS)
 563                 dst->i_fieldmask |= QC_SPC_WARNS;
 564         if (src->d_fieldmask & FS_DQ_IWARNS)
 565                 dst->i_fieldmask |= QC_INO_WARNS;
 566         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 567                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 568         if (src->d_fieldmask & FS_DQ_BTIMER)
 569                 dst->i_fieldmask |= QC_SPC_TIMER;
 570         if (src->d_fieldmask & FS_DQ_ITIMER)
 571                 dst->i_fieldmask |= QC_INO_TIMER;
 572         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 573                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 574 }
 575
 576 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 577                            void __user *addr)
 578 {
 579         struct fs_disk_quota fdq;
 580         struct qc_dqblk qdq;
 581         struct kqid qid;
 582
 583         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 584                 return -EFAULT;
 585         if (!sb->s_qcop->set_dqblk)
 586                 return -ENOSYS;
 587         qid = make_kqid(current_user_ns(), type, id);
 588         if (!qid_has_mapping(sb->s_user_ns, qid))
 589                 return -EINVAL;
 590         /* Are we actually setting timer / warning limits for all users? */
 591         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 592             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 593                 struct qc_info qinfo;
 594                 int ret;
 595
 596                 if (!sb->s_qcop->set_info)
 597                         return -EINVAL;
 598                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 599                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 600                 if (ret)
 601                         return ret;
 602                 /* These are already done */
 603                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 604         }
 605         copy_from_xfs_dqblk(&qdq, &fdq);
 606         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 607 }
 608
 609 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 610                               int type, qid_t id)
 611 {
 612         memset(dst, 0, sizeof(*dst));
 613         dst->d_version = FS_DQUOT_VERSION;
 614         dst->d_id = id;
 615         if (type == USRQUOTA)
 616                 dst->d_flags = FS_USER_QUOTA;
 617         else if (type == PRJQUOTA)
 618                 dst->d_flags = FS_PROJ_QUOTA;
 619         else
 620                 dst->d_flags = FS_GROUP_QUOTA;
 621         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 622         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 623         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 624         dst->d_ino_softlimit = src->d_ino_softlimit;
 625         dst->d_bcount = quota_btobb(src->d_space);
 626         dst->d_icount = src->d_ino_count;
 627         dst->d_itimer = src->d_ino_timer;
 628         dst->d_btimer = src->d_spc_timer;
 629         dst->d_iwarns = src->d_ino_warns;
 630         dst->d_bwarns = src->d_spc_warns;
 631         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 632         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 633         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 634         dst->d_rtbtimer = src->d_rt_spc_timer;
 635         dst->d_rtbwarns = src->d_rt_spc_warns;
 636 }
 637
 638 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 639                            void __user *addr)
 640 {
 641         struct fs_disk_quota fdq;
 642         struct qc_dqblk qdq;
 643         struct kqid qid;
 644         int ret;
 645
 646         if (!sb->s_qcop->get_dqblk)
 647                 return -ENOSYS;
 648         qid = make_kqid(current_user_ns(), type, id);
 649         if (!qid_has_mapping(sb->s_user_ns, qid))
 650                 return -EINVAL;
 651         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 652         if (ret)
 653                 return ret;
 654         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 655         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 656                 return -EFAULT;
 657         return ret;
 658 }
 659
 660 /*
 661  * Return quota for next active quota >= this id, if any exists,
 662  * otherwise return -ENOENT via ->get_nextdqblk.
 663  */
 664 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 665                             void __user *addr)
 666 {
 667         struct fs_disk_quota fdq;
 668         struct qc_dqblk qdq;
 669         struct kqid qid;
 670         qid_t id_out;
 671         int ret;
 672
 673         if (!sb->s_qcop->get_nextdqblk)
 674                 return -ENOSYS;
 675         qid = make_kqid(current_user_ns(), type, id);
 676         if (!qid_has_mapping(sb->s_user_ns, qid))
 677                 return -EINVAL;
 678         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 679         if (ret)
 680                 return ret;
 681         id_out = from_kqid(current_user_ns(), qid);
 682         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 683         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 684                 return -EFAULT;
 685         return ret;
 686 }
 687
 688 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 689 {
 690         __u32 flags;
 691
 692         if (copy_from_user(&flags, addr, sizeof(flags)))
 693                 return -EFAULT;
 694         if (!sb->s_qcop->rm_xquota)
 695                 return -ENOSYS;
 696         return sb->s_qcop->rm_xquota(sb, flags);
 697 }
 698
 699 /* Copy parameters and call proper function */
 700 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 701                        void __user *addr, const struct path *path)
 702 {
 703         int ret;
 704
 705         if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
 706                 return -EINVAL;
 707         type = array_index_nospec(type, MAXQUOTAS);
 708         /*
 709          * Quota not supported on this fs? Check this before s_quota_types
 710          * since they needn't be set if quota is not supported at all.
 711          */
 712         if (!sb->s_qcop)
 713                 return -ENOSYS;
 714         if (!(sb->s_quota_types & (1 << type)))
 715                 return -EINVAL;
 716
 717         ret = check_quotactl_permission(sb, type, cmd, id);
 718         if (ret < 0)
 719                 return ret;
 720
 721         switch (cmd) {
 722         case Q_QUOTAON:
 723                 return quota_quotaon(sb, type, id, path);
 724         case Q_QUOTAOFF:
 725                 return quota_quotaoff(sb, type);
 726         case Q_GETFMT:
 727                 return quota_getfmt(sb, type, addr);
 728         case Q_GETINFO:
 729                 return quota_getinfo(sb, type, addr);
 730         case Q_SETINFO:
 731                 return quota_setinfo(sb, type, addr);
 732         case Q_GETQUOTA:
 733                 return quota_getquota(sb, type, id, addr);
 734         case Q_GETNEXTQUOTA:
 735                 return quota_getnextquota(sb, type, id, addr);
 736         case Q_SETQUOTA:
 737                 return quota_setquota(sb, type, id, addr);
 738         case Q_SYNC:
 739                 if (!sb->s_qcop->quota_sync)
 740                         return -ENOSYS;
 741                 return sb->s_qcop->quota_sync(sb, type);
 742         case Q_XQUOTAON:
 743                 return quota_enable(sb, addr);
 744         case Q_XQUOTAOFF:
 745                 return quota_disable(sb, addr);
 746         case Q_XQUOTARM:
 747                 return quota_rmxquota(sb, addr);
 748         case Q_XGETQSTAT:
 749                 return quota_getxstate(sb, addr);
 750         case Q_XGETQSTATV:
 751                 return quota_getxstatev(sb, addr);
 752         case Q_XSETQLIM:
 753                 return quota_setxquota(sb, type, id, addr);
 754         case Q_XGETQUOTA:
 755                 return quota_getxquota(sb, type, id, addr);
 756         case Q_XGETNEXTQUOTA:
 757                 return quota_getnextxquota(sb, type, id, addr);
 758         case Q_XQUOTASYNC:
 759                 if (sb_rdonly(sb))
 760                         return -EROFS;
 761                 /* XFS quotas are fully coherent now, making this call a noop */
 762                 return 0;
 763         default:
 764                 return -EINVAL;
 765         }
 766 }
 767
 768 #ifdef CONFIG_BLOCK
 769
 770 /* Return 1 if 'cmd' will block on frozen filesystem */
 771 static int quotactl_cmd_write(int cmd)
 772 {
 773         /*
 774          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 775          * as dquot_acquire() may allocate space for new structure and OCFS2
 776          * needs to increment on-disk use count.
 777          */
 778         switch (cmd) {
 779         case Q_GETFMT:
 780         case Q_GETINFO:
 781         case Q_SYNC:
 782         case Q_XGETQSTAT:
 783         case Q_XGETQSTATV:
 784         case Q_XGETQUOTA:
 785         case Q_XGETNEXTQUOTA:
 786         case Q_XQUOTASYNC:
 787                 return 0;
 788         }
 789         return 1;
 790 }
 791 #endif /* CONFIG_BLOCK */
 792
 793 /* Return true if quotactl command is manipulating quota on/off state */
 794 static bool quotactl_cmd_onoff(int cmd)
 795 {
 796         return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 797                  (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 798 }
 799
 800 /*
 801  * look up a superblock on which quota ops will be performed
 802  * - use the name of a block device to find the superblock thereon
 803  */
 804 static struct super_block *quotactl_block(const char __user *special, int cmd)
 805 {
 806 #ifdef CONFIG_BLOCK
 807         struct block_device *bdev;
 808         struct super_block *sb;
 809         struct filename *tmp = getname(special);
 810
 811         if (IS_ERR(tmp))
 812                 return ERR_CAST(tmp);
 813         bdev = lookup_bdev(tmp->name);
 814         putname(tmp);
 815         if (IS_ERR(bdev))
 816                 return ERR_CAST(bdev);
 817         if (quotactl_cmd_onoff(cmd))
 818                 sb = get_super_exclusive_thawed(bdev);
 819         else if (quotactl_cmd_write(cmd))
 820                 sb = get_super_thawed(bdev);
 821         else
 822                 sb = get_super(bdev);
 823         bdput(bdev);
 824         if (!sb)
 825                 return ERR_PTR(-ENODEV);
 826
 827         return sb;
 828 #else
 829         return ERR_PTR(-ENODEV);
 830 #endif
 831 }
 832
 833 /*
 834  * This is the system call interface. This communicates with
 835  * the user-level programs. Currently this only supports diskquota
 836  * calls. Maybe we need to add the process quotas etc. in the future,
 837  * but we probably should use rlimits for that.
 838  */
 839 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 840                 qid_t, id, void __user *, addr)
 841 {
 842         uint cmds, type;
 843         struct super_block *sb = NULL;
 844         struct path path, *pathp = NULL;
 845         int ret;
 846
 847         cmds = cmd >> SUBCMDSHIFT;
 848         type = cmd & SUBCMDMASK;
 849
 850         /*
 851          * As a special case Q_SYNC can be called without a specific device.
 852          * It will iterate all superblocks that have quota enabled and call
 853          * the sync action on each of them.
 854          */
 855         if (!special) {
 856                 if (cmds == Q_SYNC)
 857                         return quota_sync_all(type);
 858                 return -ENODEV;
 859         }
 860
 861         /*
 862          * Path for quotaon has to be resolved before grabbing superblock
 863          * because that gets s_umount sem which is also possibly needed by path
 864          * resolution (think about autofs) and thus deadlocks could arise.
 865          */
 866         if (cmds == Q_QUOTAON) {
 867                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 868                 if (ret)
 869                         pathp = ERR_PTR(ret);
 870                 else
 871                         pathp = &path;
 872         }
 873
 874         sb = quotactl_block(special, cmds);
 875         if (IS_ERR(sb)) {
 876                 ret = PTR_ERR(sb);
 877                 goto out;
 878         }
 879
 880         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 881
 882         if (!quotactl_cmd_onoff(cmds))
 883                 drop_super(sb);
 884         else
 885                 drop_super_exclusive(sb);
 886 out:
 887         if (pathp && !IS_ERR(pathp))
 888                 path_put(pathp);
 889         return ret;
 890 }