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         if (!sb->s_qcop->get_state)
 125                 return -ENOSYS;
 126         ret = sb->s_qcop->get_state(sb, &state);
 127         if (ret)
 128                 return ret;
 129         tstate = state.s_state + type;
 130         if (!(tstate->flags & QCI_ACCT_ENABLED))
 131                 return -ESRCH;
 132         memset(&uinfo, 0, sizeof(uinfo));
 133         uinfo.dqi_bgrace = tstate->spc_timelimit;
 134         uinfo.dqi_igrace = tstate->ino_timelimit;
 135         if (tstate->flags & QCI_SYSFILE)
 136                 uinfo.dqi_flags |= DQF_SYS_FILE;
 137         if (tstate->flags & QCI_ROOT_SQUASH)
 138                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 139         uinfo.dqi_valid = IIF_ALL;
 140         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 141                 return -EFAULT;
 142         return 0;
 143 }
 144
 145 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 146 {
 147         struct if_dqinfo info;
 148         struct qc_info qinfo;
 149
 150         if (copy_from_user(&info, addr, sizeof(info)))
 151                 return -EFAULT;
 152         if (!sb->s_qcop->set_info)
 153                 return -ENOSYS;
 154         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 155                 return -EINVAL;
 156         memset(&qinfo, 0, sizeof(qinfo));
 157         if (info.dqi_valid & IIF_FLAGS) {
 158                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 159                         return -EINVAL;
 160                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 161                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 162                 qinfo.i_fieldmask |= QC_FLAGS;
 163         }
 164         if (info.dqi_valid & IIF_BGRACE) {
 165                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 166                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 167         }
 168         if (info.dqi_valid & IIF_IGRACE) {
 169                 qinfo.i_ino_timelimit = info.dqi_igrace;
 170                 qinfo.i_fieldmask |= QC_INO_TIMER;
 171         }
 172         return sb->s_qcop->set_info(sb, type, &qinfo);
 173 }
 174
 175 static inline qsize_t qbtos(qsize_t blocks)
 176 {
 177         return blocks << QIF_DQBLKSIZE_BITS;
 178 }
 179
 180 static inline qsize_t stoqb(qsize_t space)
 181 {
 182         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 183 }
 184
 185 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 186 {
 187         memset(dst, 0, sizeof(*dst));
 188         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 189         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 190         dst->dqb_curspace = src->d_space;
 191         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 192         dst->dqb_isoftlimit = src->d_ino_softlimit;
 193         dst->dqb_curinodes = src->d_ino_count;
 194         dst->dqb_btime = src->d_spc_timer;
 195         dst->dqb_itime = src->d_ino_timer;
 196         dst->dqb_valid = QIF_ALL;
 197 }
 198
 199 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 200                           void __user *addr)
 201 {
 202         struct kqid qid;
 203         struct qc_dqblk fdq;
 204         struct if_dqblk idq;
 205         int ret;
 206
 207         if (!sb->s_qcop->get_dqblk)
 208                 return -ENOSYS;
 209         qid = make_kqid(current_user_ns(), type, id);
 210         if (!qid_has_mapping(sb->s_user_ns, qid))
 211                 return -EINVAL;
 212         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 213         if (ret)
 214                 return ret;
 215         copy_to_if_dqblk(&idq, &fdq);
 216         if (copy_to_user(addr, &idq, sizeof(idq)))
 217                 return -EFAULT;
 218         return 0;
 219 }
 220
 221 /*
 222  * Return quota for next active quota >= this id, if any exists,
 223  * otherwise return -ENOENT via ->get_nextdqblk
 224  */
 225 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 226                           void __user *addr)
 227 {
 228         struct kqid qid;
 229         struct qc_dqblk fdq;
 230         struct if_nextdqblk idq;
 231         int ret;
 232
 233         if (!sb->s_qcop->get_nextdqblk)
 234                 return -ENOSYS;
 235         qid = make_kqid(current_user_ns(), type, id);
 236         if (!qid_has_mapping(sb->s_user_ns, qid))
 237                 return -EINVAL;
 238         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 239         if (ret)
 240                 return ret;
 241         /* struct if_nextdqblk is a superset of struct if_dqblk */
 242         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 243         idq.dqb_id = from_kqid(current_user_ns(), qid);
 244         if (copy_to_user(addr, &idq, sizeof(idq)))
 245                 return -EFAULT;
 246         return 0;
 247 }
 248
 249 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 250 {
 251         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 252         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 253         dst->d_space = src->dqb_curspace;
 254         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 255         dst->d_ino_softlimit = src->dqb_isoftlimit;
 256         dst->d_ino_count = src->dqb_curinodes;
 257         dst->d_spc_timer = src->dqb_btime;
 258         dst->d_ino_timer = src->dqb_itime;
 259
 260         dst->d_fieldmask = 0;
 261         if (src->dqb_valid & QIF_BLIMITS)
 262                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 263         if (src->dqb_valid & QIF_SPACE)
 264                 dst->d_fieldmask |= QC_SPACE;
 265         if (src->dqb_valid & QIF_ILIMITS)
 266                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 267         if (src->dqb_valid & QIF_INODES)
 268                 dst->d_fieldmask |= QC_INO_COUNT;
 269         if (src->dqb_valid & QIF_BTIME)
 270                 dst->d_fieldmask |= QC_SPC_TIMER;
 271         if (src->dqb_valid & QIF_ITIME)
 272                 dst->d_fieldmask |= QC_INO_TIMER;
 273 }
 274
 275 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 276                           void __user *addr)
 277 {
 278         struct qc_dqblk fdq;
 279         struct if_dqblk idq;
 280         struct kqid qid;
 281
 282         if (copy_from_user(&idq, addr, sizeof(idq)))
 283                 return -EFAULT;
 284         if (!sb->s_qcop->set_dqblk)
 285                 return -ENOSYS;
 286         qid = make_kqid(current_user_ns(), type, id);
 287         if (!qid_has_mapping(sb->s_user_ns, qid))
 288                 return -EINVAL;
 289         copy_from_if_dqblk(&fdq, &idq);
 290         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 291 }
 292
 293 static int quota_enable(struct super_block *sb, void __user *addr)
 294 {
 295         __u32 flags;
 296
 297         if (copy_from_user(&flags, addr, sizeof(flags)))
 298                 return -EFAULT;
 299         if (!sb->s_qcop->quota_enable)
 300                 return -ENOSYS;
 301         return sb->s_qcop->quota_enable(sb, flags);
 302 }
 303
 304 static int quota_disable(struct super_block *sb, void __user *addr)
 305 {
 306         __u32 flags;
 307
 308         if (copy_from_user(&flags, addr, sizeof(flags)))
 309                 return -EFAULT;
 310         if (!sb->s_qcop->quota_disable)
 311                 return -ENOSYS;
 312         return sb->s_qcop->quota_disable(sb, flags);
 313 }
 314
 315 static int quota_state_to_flags(struct qc_state *state)
 316 {
 317         int flags = 0;
 318
 319         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 320                 flags |= FS_QUOTA_UDQ_ACCT;
 321         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 322                 flags |= FS_QUOTA_UDQ_ENFD;
 323         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 324                 flags |= FS_QUOTA_GDQ_ACCT;
 325         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 326                 flags |= FS_QUOTA_GDQ_ENFD;
 327         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 328                 flags |= FS_QUOTA_PDQ_ACCT;
 329         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 330                 flags |= FS_QUOTA_PDQ_ENFD;
 331         return flags;
 332 }
 333
 334 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
 335 {
 336         int type;
 337         struct qc_state state;
 338         int ret;
 339
 340         memset(&state, 0, sizeof (struct qc_state));
 341         ret = sb->s_qcop->get_state(sb, &state);
 342         if (ret < 0)
 343                 return ret;
 344
 345         memset(fqs, 0, sizeof(*fqs));
 346         fqs->qs_version = FS_QSTAT_VERSION;
 347         fqs->qs_flags = quota_state_to_flags(&state);
 348         /* No quota enabled? */
 349         if (!fqs->qs_flags)
 350                 return -ENOSYS;
 351         fqs->qs_incoredqs = state.s_incoredqs;
 352         /*
 353          * GETXSTATE quotactl has space for just one set of time limits so
 354          * report them for the first enabled quota type
 355          */
 356         for (type = 0; type < MAXQUOTAS; type++)
 357                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 358                         break;
 359         BUG_ON(type == MAXQUOTAS);
 360         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 361         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 362         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 363         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 364         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 365
 366         /* Inodes may be allocated even if inactive; copy out if present */
 367         if (state.s_state[USRQUOTA].ino) {
 368                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 369                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 370                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 371         }
 372         if (state.s_state[GRPQUOTA].ino) {
 373                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 374                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 375                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 376         }
 377         if (state.s_state[PRJQUOTA].ino) {
 378                 /*
 379                  * Q_XGETQSTAT doesn't have room for both group and project
 380                  * quotas.  So, allow the project quota values to be copied out
 381                  * only if there is no group quota information available.
 382                  */
 383                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 384                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 385                         fqs->qs_gquota.qfs_nblks =
 386                                         state.s_state[PRJQUOTA].blocks;
 387                         fqs->qs_gquota.qfs_nextents =
 388                                         state.s_state[PRJQUOTA].nextents;
 389                 }
 390         }
 391         return 0;
 392 }
 393
 394 static int quota_getxstate(struct super_block *sb, void __user *addr)
 395 {
 396         struct fs_quota_stat fqs;
 397         int ret;
 398
 399         if (!sb->s_qcop->get_state)
 400                 return -ENOSYS;
 401         ret = quota_getstate(sb, &fqs);
 402         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 403                 return -EFAULT;
 404         return ret;
 405 }
 406
 407 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
 408 {
 409         int type;
 410         struct qc_state state;
 411         int ret;
 412
 413         memset(&state, 0, sizeof (struct qc_state));
 414         ret = sb->s_qcop->get_state(sb, &state);
 415         if (ret < 0)
 416                 return ret;
 417
 418         memset(fqs, 0, sizeof(*fqs));
 419         fqs->qs_version = FS_QSTAT_VERSION;
 420         fqs->qs_flags = quota_state_to_flags(&state);
 421         /* No quota enabled? */
 422         if (!fqs->qs_flags)
 423                 return -ENOSYS;
 424         fqs->qs_incoredqs = state.s_incoredqs;
 425         /*
 426          * GETXSTATV quotactl has space for just one set of time limits so
 427          * report them for the first enabled quota type
 428          */
 429         for (type = 0; type < MAXQUOTAS; type++)
 430                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 431                         break;
 432         BUG_ON(type == MAXQUOTAS);
 433         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 434         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 435         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 436         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 437         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 438
 439         /* Inodes may be allocated even if inactive; copy out if present */
 440         if (state.s_state[USRQUOTA].ino) {
 441                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 442                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 443                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 444         }
 445         if (state.s_state[GRPQUOTA].ino) {
 446                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 447                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 448                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 449         }
 450         if (state.s_state[PRJQUOTA].ino) {
 451                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 452                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 453                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 454         }
 455         return 0;
 456 }
 457
 458 static int quota_getxstatev(struct super_block *sb, void __user *addr)
 459 {
 460         struct fs_quota_statv fqs;
 461         int ret;
 462
 463         if (!sb->s_qcop->get_state)
 464                 return -ENOSYS;
 465
 466         memset(&fqs, 0, sizeof(fqs));
 467         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 468                 return -EFAULT;
 469
 470         /* If this kernel doesn't support user specified version, fail */
 471         switch (fqs.qs_version) {
 472         case FS_QSTATV_VERSION1:
 473                 break;
 474         default:
 475                 return -EINVAL;
 476         }
 477         ret = quota_getstatev(sb, &fqs);
 478         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 479                 return -EFAULT;
 480         return ret;
 481 }
 482
 483 /*
 484  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 485  * out of there as xfsprogs rely on definitions being in that header file. So
 486  * just define same functions here for quota purposes.
 487  */
 488 #define XFS_BB_SHIFT 9
 489
 490 static inline u64 quota_bbtob(u64 blocks)
 491 {
 492         return blocks << XFS_BB_SHIFT;
 493 }
 494
 495 static inline u64 quota_btobb(u64 bytes)
 496 {
 497         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 498 }
 499
 500 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 501 {
 502         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 503         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 504         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 505         dst->d_ino_softlimit = src->d_ino_softlimit;
 506         dst->d_space = quota_bbtob(src->d_bcount);
 507         dst->d_ino_count = src->d_icount;
 508         dst->d_ino_timer = src->d_itimer;
 509         dst->d_spc_timer = src->d_btimer;
 510         dst->d_ino_warns = src->d_iwarns;
 511         dst->d_spc_warns = src->d_bwarns;
 512         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 513         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 514         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 515         dst->d_rt_spc_timer = src->d_rtbtimer;
 516         dst->d_rt_spc_warns = src->d_rtbwarns;
 517         dst->d_fieldmask = 0;
 518         if (src->d_fieldmask & FS_DQ_ISOFT)
 519                 dst->d_fieldmask |= QC_INO_SOFT;
 520         if (src->d_fieldmask & FS_DQ_IHARD)
 521                 dst->d_fieldmask |= QC_INO_HARD;
 522         if (src->d_fieldmask & FS_DQ_BSOFT)
 523                 dst->d_fieldmask |= QC_SPC_SOFT;
 524         if (src->d_fieldmask & FS_DQ_BHARD)
 525                 dst->d_fieldmask |= QC_SPC_HARD;
 526         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 527                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 528         if (src->d_fieldmask & FS_DQ_RTBHARD)
 529                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 530         if (src->d_fieldmask & FS_DQ_BTIMER)
 531                 dst->d_fieldmask |= QC_SPC_TIMER;
 532         if (src->d_fieldmask & FS_DQ_ITIMER)
 533                 dst->d_fieldmask |= QC_INO_TIMER;
 534         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 535                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 536         if (src->d_fieldmask & FS_DQ_BWARNS)
 537                 dst->d_fieldmask |= QC_SPC_WARNS;
 538         if (src->d_fieldmask & FS_DQ_IWARNS)
 539                 dst->d_fieldmask |= QC_INO_WARNS;
 540         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 541                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 542         if (src->d_fieldmask & FS_DQ_BCOUNT)
 543                 dst->d_fieldmask |= QC_SPACE;
 544         if (src->d_fieldmask & FS_DQ_ICOUNT)
 545                 dst->d_fieldmask |= QC_INO_COUNT;
 546         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 547                 dst->d_fieldmask |= QC_RT_SPACE;
 548 }
 549
 550 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 551                                        struct fs_disk_quota *src)
 552 {
 553         memset(dst, 0, sizeof(*dst));
 554         dst->i_spc_timelimit = src->d_btimer;
 555         dst->i_ino_timelimit = src->d_itimer;
 556         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 557         dst->i_ino_warnlimit = src->d_iwarns;
 558         dst->i_spc_warnlimit = src->d_bwarns;
 559         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 560         if (src->d_fieldmask & FS_DQ_BWARNS)
 561                 dst->i_fieldmask |= QC_SPC_WARNS;
 562         if (src->d_fieldmask & FS_DQ_IWARNS)
 563                 dst->i_fieldmask |= QC_INO_WARNS;
 564         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 565                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 566         if (src->d_fieldmask & FS_DQ_BTIMER)
 567                 dst->i_fieldmask |= QC_SPC_TIMER;
 568         if (src->d_fieldmask & FS_DQ_ITIMER)
 569                 dst->i_fieldmask |= QC_INO_TIMER;
 570         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 571                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 572 }
 573
 574 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 575                            void __user *addr)
 576 {
 577         struct fs_disk_quota fdq;
 578         struct qc_dqblk qdq;
 579         struct kqid qid;
 580
 581         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 582                 return -EFAULT;
 583         if (!sb->s_qcop->set_dqblk)
 584                 return -ENOSYS;
 585         qid = make_kqid(current_user_ns(), type, id);
 586         if (!qid_has_mapping(sb->s_user_ns, qid))
 587                 return -EINVAL;
 588         /* Are we actually setting timer / warning limits for all users? */
 589         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 590             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 591                 struct qc_info qinfo;
 592                 int ret;
 593
 594                 if (!sb->s_qcop->set_info)
 595                         return -EINVAL;
 596                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 597                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 598                 if (ret)
 599                         return ret;
 600                 /* These are already done */
 601                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 602         }
 603         copy_from_xfs_dqblk(&qdq, &fdq);
 604         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 605 }
 606
 607 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 608                               int type, qid_t id)
 609 {
 610         memset(dst, 0, sizeof(*dst));
 611         dst->d_version = FS_DQUOT_VERSION;
 612         dst->d_id = id;
 613         if (type == USRQUOTA)
 614                 dst->d_flags = FS_USER_QUOTA;
 615         else if (type == PRJQUOTA)
 616                 dst->d_flags = FS_PROJ_QUOTA;
 617         else
 618                 dst->d_flags = FS_GROUP_QUOTA;
 619         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 620         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 621         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 622         dst->d_ino_softlimit = src->d_ino_softlimit;
 623         dst->d_bcount = quota_btobb(src->d_space);
 624         dst->d_icount = src->d_ino_count;
 625         dst->d_itimer = src->d_ino_timer;
 626         dst->d_btimer = src->d_spc_timer;
 627         dst->d_iwarns = src->d_ino_warns;
 628         dst->d_bwarns = src->d_spc_warns;
 629         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 630         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 631         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 632         dst->d_rtbtimer = src->d_rt_spc_timer;
 633         dst->d_rtbwarns = src->d_rt_spc_warns;
 634 }
 635
 636 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 637                            void __user *addr)
 638 {
 639         struct fs_disk_quota fdq;
 640         struct qc_dqblk qdq;
 641         struct kqid qid;
 642         int ret;
 643
 644         if (!sb->s_qcop->get_dqblk)
 645                 return -ENOSYS;
 646         qid = make_kqid(current_user_ns(), type, id);
 647         if (!qid_has_mapping(sb->s_user_ns, qid))
 648                 return -EINVAL;
 649         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 650         if (ret)
 651                 return ret;
 652         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 653         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 654                 return -EFAULT;
 655         return ret;
 656 }
 657
 658 /*
 659  * Return quota for next active quota >= this id, if any exists,
 660  * otherwise return -ENOENT via ->get_nextdqblk.
 661  */
 662 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 663                             void __user *addr)
 664 {
 665         struct fs_disk_quota fdq;
 666         struct qc_dqblk qdq;
 667         struct kqid qid;
 668         qid_t id_out;
 669         int ret;
 670
 671         if (!sb->s_qcop->get_nextdqblk)
 672                 return -ENOSYS;
 673         qid = make_kqid(current_user_ns(), type, id);
 674         if (!qid_has_mapping(sb->s_user_ns, qid))
 675                 return -EINVAL;
 676         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 677         if (ret)
 678                 return ret;
 679         id_out = from_kqid(current_user_ns(), qid);
 680         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 681         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 682                 return -EFAULT;
 683         return ret;
 684 }
 685
 686 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 687 {
 688         __u32 flags;
 689
 690         if (copy_from_user(&flags, addr, sizeof(flags)))
 691                 return -EFAULT;
 692         if (!sb->s_qcop->rm_xquota)
 693                 return -ENOSYS;
 694         return sb->s_qcop->rm_xquota(sb, flags);
 695 }
 696
 697 /* Copy parameters and call proper function */
 698 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 699                        void __user *addr, const struct path *path)
 700 {
 701         int ret;
 702
 703         if (type >= MAXQUOTAS)
 704                 return -EINVAL;
 705         type = array_index_nospec(type, MAXQUOTAS);
 706         /*
 707          * Quota not supported on this fs? Check this before s_quota_types
 708          * since they needn't be set if quota is not supported at all.
 709          */
 710         if (!sb->s_qcop)
 711                 return -ENOSYS;
 712         if (!(sb->s_quota_types & (1 << type)))
 713                 return -EINVAL;
 714
 715         ret = check_quotactl_permission(sb, type, cmd, id);
 716         if (ret < 0)
 717                 return ret;
 718
 719         switch (cmd) {
 720         case Q_QUOTAON:
 721                 return quota_quotaon(sb, type, id, path);
 722         case Q_QUOTAOFF:
 723                 return quota_quotaoff(sb, type);
 724         case Q_GETFMT:
 725                 return quota_getfmt(sb, type, addr);
 726         case Q_GETINFO:
 727                 return quota_getinfo(sb, type, addr);
 728         case Q_SETINFO:
 729                 return quota_setinfo(sb, type, addr);
 730         case Q_GETQUOTA:
 731                 return quota_getquota(sb, type, id, addr);
 732         case Q_GETNEXTQUOTA:
 733                 return quota_getnextquota(sb, type, id, addr);
 734         case Q_SETQUOTA:
 735                 return quota_setquota(sb, type, id, addr);
 736         case Q_SYNC:
 737                 if (!sb->s_qcop->quota_sync)
 738                         return -ENOSYS;
 739                 return sb->s_qcop->quota_sync(sb, type);
 740         case Q_XQUOTAON:
 741                 return quota_enable(sb, addr);
 742         case Q_XQUOTAOFF:
 743                 return quota_disable(sb, addr);
 744         case Q_XQUOTARM:
 745                 return quota_rmxquota(sb, addr);
 746         case Q_XGETQSTAT:
 747                 return quota_getxstate(sb, addr);
 748         case Q_XGETQSTATV:
 749                 return quota_getxstatev(sb, addr);
 750         case Q_XSETQLIM:
 751                 return quota_setxquota(sb, type, id, addr);
 752         case Q_XGETQUOTA:
 753                 return quota_getxquota(sb, type, id, addr);
 754         case Q_XGETNEXTQUOTA:
 755                 return quota_getnextxquota(sb, type, id, addr);
 756         case Q_XQUOTASYNC:
 757                 if (sb_rdonly(sb))
 758                         return -EROFS;
 759                 /* XFS quotas are fully coherent now, making this call a noop */
 760                 return 0;
 761         default:
 762                 return -EINVAL;
 763         }
 764 }
 765
 766 #ifdef CONFIG_BLOCK
 767
 768 /* Return 1 if 'cmd' will block on frozen filesystem */
 769 static int quotactl_cmd_write(int cmd)
 770 {
 771         /*
 772          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 773          * as dquot_acquire() may allocate space for new structure and OCFS2
 774          * needs to increment on-disk use count.
 775          */
 776         switch (cmd) {
 777         case Q_GETFMT:
 778         case Q_GETINFO:
 779         case Q_SYNC:
 780         case Q_XGETQSTAT:
 781         case Q_XGETQSTATV:
 782         case Q_XGETQUOTA:
 783         case Q_XGETNEXTQUOTA:
 784         case Q_XQUOTASYNC:
 785                 return 0;
 786         }
 787         return 1;
 788 }
 789 #endif /* CONFIG_BLOCK */
 790
 791 /* Return true if quotactl command is manipulating quota on/off state */
 792 static bool quotactl_cmd_onoff(int cmd)
 793 {
 794         return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 795                  (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 796 }
 797
 798 /*
 799  * look up a superblock on which quota ops will be performed
 800  * - use the name of a block device to find the superblock thereon
 801  */
 802 static struct super_block *quotactl_block(const char __user *special, int cmd)
 803 {
 804 #ifdef CONFIG_BLOCK
 805         struct block_device *bdev;
 806         struct super_block *sb;
 807         struct filename *tmp = getname(special);
 808
 809         if (IS_ERR(tmp))
 810                 return ERR_CAST(tmp);
 811         bdev = lookup_bdev(tmp->name);
 812         putname(tmp);
 813         if (IS_ERR(bdev))
 814                 return ERR_CAST(bdev);
 815         if (quotactl_cmd_onoff(cmd))
 816                 sb = get_super_exclusive_thawed(bdev);
 817         else if (quotactl_cmd_write(cmd))
 818                 sb = get_super_thawed(bdev);
 819         else
 820                 sb = get_super(bdev);
 821         bdput(bdev);
 822         if (!sb)
 823                 return ERR_PTR(-ENODEV);
 824
 825         return sb;
 826 #else
 827         return ERR_PTR(-ENODEV);
 828 #endif
 829 }
 830
 831 /*
 832  * This is the system call interface. This communicates with
 833  * the user-level programs. Currently this only supports diskquota
 834  * calls. Maybe we need to add the process quotas etc. in the future,
 835  * but we probably should use rlimits for that.
 836  */
 837 int kernel_quotactl(unsigned int cmd, const char __user *special,
 838                     qid_t id, void __user *addr)
 839 {
 840         uint cmds, type;
 841         struct super_block *sb = NULL;
 842         struct path path, *pathp = NULL;
 843         int ret;
 844
 845         cmds = cmd >> SUBCMDSHIFT;
 846         type = cmd & SUBCMDMASK;
 847
 848         /*
 849          * As a special case Q_SYNC can be called without a specific device.
 850          * It will iterate all superblocks that have quota enabled and call
 851          * the sync action on each of them.
 852          */
 853         if (!special) {
 854                 if (cmds == Q_SYNC)
 855                         return quota_sync_all(type);
 856                 return -ENODEV;
 857         }
 858
 859         /*
 860          * Path for quotaon has to be resolved before grabbing superblock
 861          * because that gets s_umount sem which is also possibly needed by path
 862          * resolution (think about autofs) and thus deadlocks could arise.
 863          */
 864         if (cmds == Q_QUOTAON) {
 865                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 866                 if (ret)
 867                         pathp = ERR_PTR(ret);
 868                 else
 869                         pathp = &path;
 870         }
 871
 872         sb = quotactl_block(special, cmds);
 873         if (IS_ERR(sb)) {
 874                 ret = PTR_ERR(sb);
 875                 goto out;
 876         }
 877
 878         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 879
 880         if (!quotactl_cmd_onoff(cmds))
 881                 drop_super(sb);
 882         else
 883                 drop_super_exclusive(sb);
 884 out:
 885         if (pathp && !IS_ERR(pathp))
 886                 path_put(pathp);
 887         return ret;
 888 }
 889
 890 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 891                 qid_t, id, void __user *, addr)
 892 {
 893         return kernel_quotactl(cmd, special, id, addr);
 894 }