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 #include "compat.h"
  23
  24 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  25                                      qid_t id)
  26 {
  27         switch (cmd) {
  28         /* these commands do not require any special privilegues */
  29         case Q_GETFMT:
  30         case Q_SYNC:
  31         case Q_GETINFO:
  32         case Q_XGETQSTAT:
  33         case Q_XGETQSTATV:
  34         case Q_XQUOTASYNC:
  35                 break;
  36         /* allow to query information for dquots we "own" */
  37         case Q_GETQUOTA:
  38         case Q_XGETQUOTA:
  39                 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  40                     (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  41                         break;
  42                 fallthrough;
  43         default:
  44                 if (!capable(CAP_SYS_ADMIN))
  45                         return -EPERM;
  46         }
  47
  48         return security_quotactl(cmd, type, id, sb);
  49 }
  50
  51 static void quota_sync_one(struct super_block *sb, void *arg)
  52 {
  53         int type = *(int *)arg;
  54
  55         if (sb->s_qcop && sb->s_qcop->quota_sync &&
  56             (sb->s_quota_types & (1 << type)))
  57                 sb->s_qcop->quota_sync(sb, type);
  58 }
  59
  60 static int quota_sync_all(int type)
  61 {
  62         int ret;
  63
  64         ret = security_quotactl(Q_SYNC, type, 0, NULL);
  65         if (!ret)
  66                 iterate_supers(quota_sync_one, &type);
  67         return ret;
  68 }
  69
  70 unsigned int qtype_enforce_flag(int type)
  71 {
  72         switch (type) {
  73         case USRQUOTA:
  74                 return FS_QUOTA_UDQ_ENFD;
  75         case GRPQUOTA:
  76                 return FS_QUOTA_GDQ_ENFD;
  77         case PRJQUOTA:
  78                 return FS_QUOTA_PDQ_ENFD;
  79         }
  80         return 0;
  81 }
  82
  83 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  84                          const struct path *path)
  85 {
  86         if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  87                 return -ENOSYS;
  88         if (sb->s_qcop->quota_enable)
  89                 return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  90         if (IS_ERR(path))
  91                 return PTR_ERR(path);
  92         return sb->s_qcop->quota_on(sb, type, id, path);
  93 }
  94
  95 static int quota_quotaoff(struct super_block *sb, int type)
  96 {
  97         if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
  98                 return -ENOSYS;
  99         if (sb->s_qcop->quota_disable)
 100                 return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 101         return sb->s_qcop->quota_off(sb, type);
 102 }
 103
 104 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 105 {
 106         __u32 fmt;
 107
 108         if (!sb_has_quota_active(sb, type))
 109                 return -ESRCH;
 110         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 111         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 112                 return -EFAULT;
 113         return 0;
 114 }
 115
 116 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 117 {
 118         struct qc_state state;
 119         struct qc_type_state *tstate;
 120         struct if_dqinfo uinfo;
 121         int ret;
 122
 123         if (!sb->s_qcop->get_state)
 124                 return -ENOSYS;
 125         ret = sb->s_qcop->get_state(sb, &state);
 126         if (ret)
 127                 return ret;
 128         tstate = state.s_state + type;
 129         if (!(tstate->flags & QCI_ACCT_ENABLED))
 130                 return -ESRCH;
 131         memset(&uinfo, 0, sizeof(uinfo));
 132         uinfo.dqi_bgrace = tstate->spc_timelimit;
 133         uinfo.dqi_igrace = tstate->ino_timelimit;
 134         if (tstate->flags & QCI_SYSFILE)
 135                 uinfo.dqi_flags |= DQF_SYS_FILE;
 136         if (tstate->flags & QCI_ROOT_SQUASH)
 137                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 138         uinfo.dqi_valid = IIF_ALL;
 139         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 140                 return -EFAULT;
 141         return 0;
 142 }
 143
 144 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 145 {
 146         struct if_dqinfo info;
 147         struct qc_info qinfo;
 148
 149         if (copy_from_user(&info, addr, sizeof(info)))
 150                 return -EFAULT;
 151         if (!sb->s_qcop->set_info)
 152                 return -ENOSYS;
 153         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 154                 return -EINVAL;
 155         memset(&qinfo, 0, sizeof(qinfo));
 156         if (info.dqi_valid & IIF_FLAGS) {
 157                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 158                         return -EINVAL;
 159                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 160                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 161                 qinfo.i_fieldmask |= QC_FLAGS;
 162         }
 163         if (info.dqi_valid & IIF_BGRACE) {
 164                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 165                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 166         }
 167         if (info.dqi_valid & IIF_IGRACE) {
 168                 qinfo.i_ino_timelimit = info.dqi_igrace;
 169                 qinfo.i_fieldmask |= QC_INO_TIMER;
 170         }
 171         return sb->s_qcop->set_info(sb, type, &qinfo);
 172 }
 173
 174 static inline qsize_t qbtos(qsize_t blocks)
 175 {
 176         return blocks << QIF_DQBLKSIZE_BITS;
 177 }
 178
 179 static inline qsize_t stoqb(qsize_t space)
 180 {
 181         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 182 }
 183
 184 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 185 {
 186         memset(dst, 0, sizeof(*dst));
 187         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 188         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 189         dst->dqb_curspace = src->d_space;
 190         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 191         dst->dqb_isoftlimit = src->d_ino_softlimit;
 192         dst->dqb_curinodes = src->d_ino_count;
 193         dst->dqb_btime = src->d_spc_timer;
 194         dst->dqb_itime = src->d_ino_timer;
 195         dst->dqb_valid = QIF_ALL;
 196 }
 197
 198 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 199                           void __user *addr)
 200 {
 201         struct kqid qid;
 202         struct qc_dqblk fdq;
 203         struct if_dqblk idq;
 204         int ret;
 205
 206         if (!sb->s_qcop->get_dqblk)
 207                 return -ENOSYS;
 208         qid = make_kqid(current_user_ns(), type, id);
 209         if (!qid_has_mapping(sb->s_user_ns, qid))
 210                 return -EINVAL;
 211         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 212         if (ret)
 213                 return ret;
 214         copy_to_if_dqblk(&idq, &fdq);
 215
 216         if (compat_need_64bit_alignment_fixup()) {
 217                 struct compat_if_dqblk __user *compat_dqblk = addr;
 218
 219                 if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
 220                         return -EFAULT;
 221                 if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 222                         return -EFAULT;
 223         } else {
 224                 if (copy_to_user(addr, &idq, sizeof(idq)))
 225                         return -EFAULT;
 226         }
 227         return 0;
 228 }
 229
 230 /*
 231  * Return quota for next active quota >= this id, if any exists,
 232  * otherwise return -ENOENT via ->get_nextdqblk
 233  */
 234 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 235                           void __user *addr)
 236 {
 237         struct kqid qid;
 238         struct qc_dqblk fdq;
 239         struct if_nextdqblk idq;
 240         int ret;
 241
 242         if (!sb->s_qcop->get_nextdqblk)
 243                 return -ENOSYS;
 244         qid = make_kqid(current_user_ns(), type, id);
 245         if (!qid_has_mapping(sb->s_user_ns, qid))
 246                 return -EINVAL;
 247         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 248         if (ret)
 249                 return ret;
 250         /* struct if_nextdqblk is a superset of struct if_dqblk */
 251         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 252         idq.dqb_id = from_kqid(current_user_ns(), qid);
 253         if (copy_to_user(addr, &idq, sizeof(idq)))
 254                 return -EFAULT;
 255         return 0;
 256 }
 257
 258 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 259 {
 260         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 261         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 262         dst->d_space = src->dqb_curspace;
 263         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 264         dst->d_ino_softlimit = src->dqb_isoftlimit;
 265         dst->d_ino_count = src->dqb_curinodes;
 266         dst->d_spc_timer = src->dqb_btime;
 267         dst->d_ino_timer = src->dqb_itime;
 268
 269         dst->d_fieldmask = 0;
 270         if (src->dqb_valid & QIF_BLIMITS)
 271                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 272         if (src->dqb_valid & QIF_SPACE)
 273                 dst->d_fieldmask |= QC_SPACE;
 274         if (src->dqb_valid & QIF_ILIMITS)
 275                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 276         if (src->dqb_valid & QIF_INODES)
 277                 dst->d_fieldmask |= QC_INO_COUNT;
 278         if (src->dqb_valid & QIF_BTIME)
 279                 dst->d_fieldmask |= QC_SPC_TIMER;
 280         if (src->dqb_valid & QIF_ITIME)
 281                 dst->d_fieldmask |= QC_INO_TIMER;
 282 }
 283
 284 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 285                           void __user *addr)
 286 {
 287         struct qc_dqblk fdq;
 288         struct if_dqblk idq;
 289         struct kqid qid;
 290
 291         if (compat_need_64bit_alignment_fixup()) {
 292                 struct compat_if_dqblk __user *compat_dqblk = addr;
 293
 294                 if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
 295                     get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 296                         return -EFAULT;
 297         } else {
 298                 if (copy_from_user(&idq, addr, sizeof(idq)))
 299                         return -EFAULT;
 300         }
 301         if (!sb->s_qcop->set_dqblk)
 302                 return -ENOSYS;
 303         qid = make_kqid(current_user_ns(), type, id);
 304         if (!qid_has_mapping(sb->s_user_ns, qid))
 305                 return -EINVAL;
 306         copy_from_if_dqblk(&fdq, &idq);
 307         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 308 }
 309
 310 static int quota_enable(struct super_block *sb, void __user *addr)
 311 {
 312         __u32 flags;
 313
 314         if (copy_from_user(&flags, addr, sizeof(flags)))
 315                 return -EFAULT;
 316         if (!sb->s_qcop->quota_enable)
 317                 return -ENOSYS;
 318         return sb->s_qcop->quota_enable(sb, flags);
 319 }
 320
 321 static int quota_disable(struct super_block *sb, void __user *addr)
 322 {
 323         __u32 flags;
 324
 325         if (copy_from_user(&flags, addr, sizeof(flags)))
 326                 return -EFAULT;
 327         if (!sb->s_qcop->quota_disable)
 328                 return -ENOSYS;
 329         return sb->s_qcop->quota_disable(sb, flags);
 330 }
 331
 332 static int quota_state_to_flags(struct qc_state *state)
 333 {
 334         int flags = 0;
 335
 336         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 337                 flags |= FS_QUOTA_UDQ_ACCT;
 338         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 339                 flags |= FS_QUOTA_UDQ_ENFD;
 340         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 341                 flags |= FS_QUOTA_GDQ_ACCT;
 342         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 343                 flags |= FS_QUOTA_GDQ_ENFD;
 344         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 345                 flags |= FS_QUOTA_PDQ_ACCT;
 346         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 347                 flags |= FS_QUOTA_PDQ_ENFD;
 348         return flags;
 349 }
 350
 351 static int quota_getstate(struct super_block *sb, int type,
 352                           struct fs_quota_stat *fqs)
 353 {
 354         struct qc_state state;
 355         int ret;
 356
 357         memset(&state, 0, sizeof (struct qc_state));
 358         ret = sb->s_qcop->get_state(sb, &state);
 359         if (ret < 0)
 360                 return ret;
 361
 362         memset(fqs, 0, sizeof(*fqs));
 363         fqs->qs_version = FS_QSTAT_VERSION;
 364         fqs->qs_flags = quota_state_to_flags(&state);
 365         /* No quota enabled? */
 366         if (!fqs->qs_flags)
 367                 return -ENOSYS;
 368         fqs->qs_incoredqs = state.s_incoredqs;
 369
 370         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 371         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 372         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 373         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 374         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 375
 376         /* Inodes may be allocated even if inactive; copy out if present */
 377         if (state.s_state[USRQUOTA].ino) {
 378                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 379                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 380                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 381         }
 382         if (state.s_state[GRPQUOTA].ino) {
 383                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 384                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 385                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 386         }
 387         if (state.s_state[PRJQUOTA].ino) {
 388                 /*
 389                  * Q_XGETQSTAT doesn't have room for both group and project
 390                  * quotas.  So, allow the project quota values to be copied out
 391                  * only if there is no group quota information available.
 392                  */
 393                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 394                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 395                         fqs->qs_gquota.qfs_nblks =
 396                                         state.s_state[PRJQUOTA].blocks;
 397                         fqs->qs_gquota.qfs_nextents =
 398                                         state.s_state[PRJQUOTA].nextents;
 399                 }
 400         }
 401         return 0;
 402 }
 403
 404 static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
 405                 struct fs_qfilestat *from)
 406 {
 407         if (copy_to_user(to, from, sizeof(*to)) ||
 408             put_user(from->qfs_nextents, &to->qfs_nextents))
 409                 return -EFAULT;
 410         return 0;
 411 }
 412
 413 static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
 414                 struct fs_quota_stat *from)
 415 {
 416         if (put_user(from->qs_version, &to->qs_version) ||
 417             put_user(from->qs_flags, &to->qs_flags) ||
 418             put_user(from->qs_pad, &to->qs_pad) ||
 419             compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
 420             compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
 421             put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
 422             put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
 423             put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
 424             put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
 425             put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
 426             put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
 427                 return -EFAULT;
 428         return 0;
 429 }
 430
 431 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
 432 {
 433         struct fs_quota_stat fqs;
 434         int ret;
 435
 436         if (!sb->s_qcop->get_state)
 437                 return -ENOSYS;
 438         ret = quota_getstate(sb, type, &fqs);
 439         if (ret)
 440                 return ret;
 441
 442         if (compat_need_64bit_alignment_fixup())
 443                 return compat_copy_fs_quota_stat(addr, &fqs);
 444         if (copy_to_user(addr, &fqs, sizeof(fqs)))
 445                 return -EFAULT;
 446         return 0;
 447 }
 448
 449 static int quota_getstatev(struct super_block *sb, int type,
 450                            struct fs_quota_statv *fqs)
 451 {
 452         struct qc_state state;
 453         int ret;
 454
 455         memset(&state, 0, sizeof (struct qc_state));
 456         ret = sb->s_qcop->get_state(sb, &state);
 457         if (ret < 0)
 458                 return ret;
 459
 460         memset(fqs, 0, sizeof(*fqs));
 461         fqs->qs_version = FS_QSTAT_VERSION;
 462         fqs->qs_flags = quota_state_to_flags(&state);
 463         /* No quota enabled? */
 464         if (!fqs->qs_flags)
 465                 return -ENOSYS;
 466         fqs->qs_incoredqs = state.s_incoredqs;
 467
 468         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 469         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 470         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 471         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 472         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 473
 474         /* Inodes may be allocated even if inactive; copy out if present */
 475         if (state.s_state[USRQUOTA].ino) {
 476                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 477                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 478                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 479         }
 480         if (state.s_state[GRPQUOTA].ino) {
 481                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 482                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 483                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 484         }
 485         if (state.s_state[PRJQUOTA].ino) {
 486                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 487                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 488                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 489         }
 490         return 0;
 491 }
 492
 493 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
 494 {
 495         struct fs_quota_statv fqs;
 496         int ret;
 497
 498         if (!sb->s_qcop->get_state)
 499                 return -ENOSYS;
 500
 501         memset(&fqs, 0, sizeof(fqs));
 502         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 503                 return -EFAULT;
 504
 505         /* If this kernel doesn't support user specified version, fail */
 506         switch (fqs.qs_version) {
 507         case FS_QSTATV_VERSION1:
 508                 break;
 509         default:
 510                 return -EINVAL;
 511         }
 512         ret = quota_getstatev(sb, type, &fqs);
 513         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 514                 return -EFAULT;
 515         return ret;
 516 }
 517
 518 /*
 519  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 520  * out of there as xfsprogs rely on definitions being in that header file. So
 521  * just define same functions here for quota purposes.
 522  */
 523 #define XFS_BB_SHIFT 9
 524
 525 static inline u64 quota_bbtob(u64 blocks)
 526 {
 527         return blocks << XFS_BB_SHIFT;
 528 }
 529
 530 static inline u64 quota_btobb(u64 bytes)
 531 {
 532         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 533 }
 534
 535 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 536 {
 537         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 538         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 539         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 540         dst->d_ino_softlimit = src->d_ino_softlimit;
 541         dst->d_space = quota_bbtob(src->d_bcount);
 542         dst->d_ino_count = src->d_icount;
 543         dst->d_ino_timer = src->d_itimer;
 544         dst->d_spc_timer = src->d_btimer;
 545         dst->d_ino_warns = src->d_iwarns;
 546         dst->d_spc_warns = src->d_bwarns;
 547         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 548         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 549         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 550         dst->d_rt_spc_timer = src->d_rtbtimer;
 551         dst->d_rt_spc_warns = src->d_rtbwarns;
 552         dst->d_fieldmask = 0;
 553         if (src->d_fieldmask & FS_DQ_ISOFT)
 554                 dst->d_fieldmask |= QC_INO_SOFT;
 555         if (src->d_fieldmask & FS_DQ_IHARD)
 556                 dst->d_fieldmask |= QC_INO_HARD;
 557         if (src->d_fieldmask & FS_DQ_BSOFT)
 558                 dst->d_fieldmask |= QC_SPC_SOFT;
 559         if (src->d_fieldmask & FS_DQ_BHARD)
 560                 dst->d_fieldmask |= QC_SPC_HARD;
 561         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 562                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 563         if (src->d_fieldmask & FS_DQ_RTBHARD)
 564                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 565         if (src->d_fieldmask & FS_DQ_BTIMER)
 566                 dst->d_fieldmask |= QC_SPC_TIMER;
 567         if (src->d_fieldmask & FS_DQ_ITIMER)
 568                 dst->d_fieldmask |= QC_INO_TIMER;
 569         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 570                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 571         if (src->d_fieldmask & FS_DQ_BWARNS)
 572                 dst->d_fieldmask |= QC_SPC_WARNS;
 573         if (src->d_fieldmask & FS_DQ_IWARNS)
 574                 dst->d_fieldmask |= QC_INO_WARNS;
 575         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 576                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 577         if (src->d_fieldmask & FS_DQ_BCOUNT)
 578                 dst->d_fieldmask |= QC_SPACE;
 579         if (src->d_fieldmask & FS_DQ_ICOUNT)
 580                 dst->d_fieldmask |= QC_INO_COUNT;
 581         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 582                 dst->d_fieldmask |= QC_RT_SPACE;
 583 }
 584
 585 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 586                                        struct fs_disk_quota *src)
 587 {
 588         memset(dst, 0, sizeof(*dst));
 589         dst->i_spc_timelimit = src->d_btimer;
 590         dst->i_ino_timelimit = src->d_itimer;
 591         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 592         dst->i_ino_warnlimit = src->d_iwarns;
 593         dst->i_spc_warnlimit = src->d_bwarns;
 594         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 595         if (src->d_fieldmask & FS_DQ_BWARNS)
 596                 dst->i_fieldmask |= QC_SPC_WARNS;
 597         if (src->d_fieldmask & FS_DQ_IWARNS)
 598                 dst->i_fieldmask |= QC_INO_WARNS;
 599         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 600                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 601         if (src->d_fieldmask & FS_DQ_BTIMER)
 602                 dst->i_fieldmask |= QC_SPC_TIMER;
 603         if (src->d_fieldmask & FS_DQ_ITIMER)
 604                 dst->i_fieldmask |= QC_INO_TIMER;
 605         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 606                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 607 }
 608
 609 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 610                            void __user *addr)
 611 {
 612         struct fs_disk_quota fdq;
 613         struct qc_dqblk qdq;
 614         struct kqid qid;
 615
 616         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 617                 return -EFAULT;
 618         if (!sb->s_qcop->set_dqblk)
 619                 return -ENOSYS;
 620         qid = make_kqid(current_user_ns(), type, id);
 621         if (!qid_has_mapping(sb->s_user_ns, qid))
 622                 return -EINVAL;
 623         /* Are we actually setting timer / warning limits for all users? */
 624         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 625             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 626                 struct qc_info qinfo;
 627                 int ret;
 628
 629                 if (!sb->s_qcop->set_info)
 630                         return -EINVAL;
 631                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 632                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 633                 if (ret)
 634                         return ret;
 635                 /* These are already done */
 636                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 637         }
 638         copy_from_xfs_dqblk(&qdq, &fdq);
 639         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 640 }
 641
 642 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 643                               int type, qid_t id)
 644 {
 645         memset(dst, 0, sizeof(*dst));
 646         dst->d_version = FS_DQUOT_VERSION;
 647         dst->d_id = id;
 648         if (type == USRQUOTA)
 649                 dst->d_flags = FS_USER_QUOTA;
 650         else if (type == PRJQUOTA)
 651                 dst->d_flags = FS_PROJ_QUOTA;
 652         else
 653                 dst->d_flags = FS_GROUP_QUOTA;
 654         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 655         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 656         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 657         dst->d_ino_softlimit = src->d_ino_softlimit;
 658         dst->d_bcount = quota_btobb(src->d_space);
 659         dst->d_icount = src->d_ino_count;
 660         dst->d_itimer = src->d_ino_timer;
 661         dst->d_btimer = src->d_spc_timer;
 662         dst->d_iwarns = src->d_ino_warns;
 663         dst->d_bwarns = src->d_spc_warns;
 664         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 665         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 666         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 667         dst->d_rtbtimer = src->d_rt_spc_timer;
 668         dst->d_rtbwarns = src->d_rt_spc_warns;
 669 }
 670
 671 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 672                            void __user *addr)
 673 {
 674         struct fs_disk_quota fdq;
 675         struct qc_dqblk qdq;
 676         struct kqid qid;
 677         int ret;
 678
 679         if (!sb->s_qcop->get_dqblk)
 680                 return -ENOSYS;
 681         qid = make_kqid(current_user_ns(), type, id);
 682         if (!qid_has_mapping(sb->s_user_ns, qid))
 683                 return -EINVAL;
 684         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 685         if (ret)
 686                 return ret;
 687         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 688         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 689                 return -EFAULT;
 690         return ret;
 691 }
 692
 693 /*
 694  * Return quota for next active quota >= this id, if any exists,
 695  * otherwise return -ENOENT via ->get_nextdqblk.
 696  */
 697 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 698                             void __user *addr)
 699 {
 700         struct fs_disk_quota fdq;
 701         struct qc_dqblk qdq;
 702         struct kqid qid;
 703         qid_t id_out;
 704         int ret;
 705
 706         if (!sb->s_qcop->get_nextdqblk)
 707                 return -ENOSYS;
 708         qid = make_kqid(current_user_ns(), type, id);
 709         if (!qid_has_mapping(sb->s_user_ns, qid))
 710                 return -EINVAL;
 711         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 712         if (ret)
 713                 return ret;
 714         id_out = from_kqid(current_user_ns(), qid);
 715         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 716         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 717                 return -EFAULT;
 718         return ret;
 719 }
 720
 721 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 722 {
 723         __u32 flags;
 724
 725         if (copy_from_user(&flags, addr, sizeof(flags)))
 726                 return -EFAULT;
 727         if (!sb->s_qcop->rm_xquota)
 728                 return -ENOSYS;
 729         return sb->s_qcop->rm_xquota(sb, flags);
 730 }
 731
 732 /* Copy parameters and call proper function */
 733 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 734                        void __user *addr, const struct path *path)
 735 {
 736         int ret;
 737
 738         type = array_index_nospec(type, MAXQUOTAS);
 739         /*
 740          * Quota not supported on this fs? Check this before s_quota_types
 741          * since they needn't be set if quota is not supported at all.
 742          */
 743         if (!sb->s_qcop)
 744                 return -ENOSYS;
 745         if (!(sb->s_quota_types & (1 << type)))
 746                 return -EINVAL;
 747
 748         ret = check_quotactl_permission(sb, type, cmd, id);
 749         if (ret < 0)
 750                 return ret;
 751
 752         switch (cmd) {
 753         case Q_QUOTAON:
 754                 return quota_quotaon(sb, type, id, path);
 755         case Q_QUOTAOFF:
 756                 return quota_quotaoff(sb, type);
 757         case Q_GETFMT:
 758                 return quota_getfmt(sb, type, addr);
 759         case Q_GETINFO:
 760                 return quota_getinfo(sb, type, addr);
 761         case Q_SETINFO:
 762                 return quota_setinfo(sb, type, addr);
 763         case Q_GETQUOTA:
 764                 return quota_getquota(sb, type, id, addr);
 765         case Q_GETNEXTQUOTA:
 766                 return quota_getnextquota(sb, type, id, addr);
 767         case Q_SETQUOTA:
 768                 return quota_setquota(sb, type, id, addr);
 769         case Q_SYNC:
 770                 if (!sb->s_qcop->quota_sync)
 771                         return -ENOSYS;
 772                 return sb->s_qcop->quota_sync(sb, type);
 773         case Q_XQUOTAON:
 774                 return quota_enable(sb, addr);
 775         case Q_XQUOTAOFF:
 776                 return quota_disable(sb, addr);
 777         case Q_XQUOTARM:
 778                 return quota_rmxquota(sb, addr);
 779         case Q_XGETQSTAT:
 780                 return quota_getxstate(sb, type, addr);
 781         case Q_XGETQSTATV:
 782                 return quota_getxstatev(sb, type, addr);
 783         case Q_XSETQLIM:
 784                 return quota_setxquota(sb, type, id, addr);
 785         case Q_XGETQUOTA:
 786                 return quota_getxquota(sb, type, id, addr);
 787         case Q_XGETNEXTQUOTA:
 788                 return quota_getnextxquota(sb, type, id, addr);
 789         case Q_XQUOTASYNC:
 790                 if (sb_rdonly(sb))
 791                         return -EROFS;
 792                 /* XFS quotas are fully coherent now, making this call a noop */
 793                 return 0;
 794         default:
 795                 return -EINVAL;
 796         }
 797 }
 798
 799 #ifdef CONFIG_BLOCK
 800
 801 /* Return 1 if 'cmd' will block on frozen filesystem */
 802 static int quotactl_cmd_write(int cmd)
 803 {
 804         /*
 805          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 806          * as dquot_acquire() may allocate space for new structure and OCFS2
 807          * needs to increment on-disk use count.
 808          */
 809         switch (cmd) {
 810         case Q_GETFMT:
 811         case Q_GETINFO:
 812         case Q_SYNC:
 813         case Q_XGETQSTAT:
 814         case Q_XGETQSTATV:
 815         case Q_XGETQUOTA:
 816         case Q_XGETNEXTQUOTA:
 817         case Q_XQUOTASYNC:
 818                 return 0;
 819         }
 820         return 1;
 821 }
 822 #endif /* CONFIG_BLOCK */
 823
 824 /* Return true if quotactl command is manipulating quota on/off state */
 825 static bool quotactl_cmd_onoff(int cmd)
 826 {
 827         return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 828                  (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 829 }
 830
 831 /*
 832  * look up a superblock on which quota ops will be performed
 833  * - use the name of a block device to find the superblock thereon
 834  */
 835 static struct super_block *quotactl_block(const char __user *special, int cmd)
 836 {
 837 #ifdef CONFIG_BLOCK
 838         struct block_device *bdev;
 839         struct super_block *sb;
 840         struct filename *tmp = getname(special);
 841
 842         if (IS_ERR(tmp))
 843                 return ERR_CAST(tmp);
 844         bdev = lookup_bdev(tmp->name);
 845         putname(tmp);
 846         if (IS_ERR(bdev))
 847                 return ERR_CAST(bdev);
 848         if (quotactl_cmd_onoff(cmd))
 849                 sb = get_super_exclusive_thawed(bdev);
 850         else if (quotactl_cmd_write(cmd))
 851                 sb = get_super_thawed(bdev);
 852         else
 853                 sb = get_super(bdev);
 854         bdput(bdev);
 855         if (!sb)
 856                 return ERR_PTR(-ENODEV);
 857
 858         return sb;
 859 #else
 860         return ERR_PTR(-ENODEV);
 861 #endif
 862 }
 863
 864 /*
 865  * This is the system call interface. This communicates with
 866  * the user-level programs. Currently this only supports diskquota
 867  * calls. Maybe we need to add the process quotas etc. in the future,
 868  * but we probably should use rlimits for that.
 869  */
 870 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 871                 qid_t, id, void __user *, addr)
 872 {
 873         uint cmds, type;
 874         struct super_block *sb = NULL;
 875         struct path path, *pathp = NULL;
 876         int ret;
 877
 878         cmds = cmd >> SUBCMDSHIFT;
 879         type = cmd & SUBCMDMASK;
 880
 881         if (type >= MAXQUOTAS)
 882                 return -EINVAL;
 883
 884         /*
 885          * As a special case Q_SYNC can be called without a specific device.
 886          * It will iterate all superblocks that have quota enabled and call
 887          * the sync action on each of them.
 888          */
 889         if (!special) {
 890                 if (cmds == Q_SYNC)
 891                         return quota_sync_all(type);
 892                 return -ENODEV;
 893         }
 894
 895         /*
 896          * Path for quotaon has to be resolved before grabbing superblock
 897          * because that gets s_umount sem which is also possibly needed by path
 898          * resolution (think about autofs) and thus deadlocks could arise.
 899          */
 900         if (cmds == Q_QUOTAON) {
 901                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 902                 if (ret)
 903                         pathp = ERR_PTR(ret);
 904                 else
 905                         pathp = &path;
 906         }
 907
 908         sb = quotactl_block(special, cmds);
 909         if (IS_ERR(sb)) {
 910                 ret = PTR_ERR(sb);
 911                 goto out;
 912         }
 913
 914         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 915
 916         if (!quotactl_cmd_onoff(cmds))
 917                 drop_super(sb);
 918         else
 919                 drop_super_exclusive(sb);
 920 out:
 921         if (pathp && !IS_ERR(pathp))
 922                 path_put(pathp);
 923         return ret;
 924 }