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/mount.h>
  21 #include <linux/writeback.h>
  22 #include <linux/nospec.h>
  23 #include "compat.h"
  24 #include "../internal.h"
  25
  26 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  27                                      qid_t id)
  28 {
  29         switch (cmd) {
  30         /* these commands do not require any special privilegues */
  31         case Q_GETFMT:
  32         case Q_SYNC:
  33         case Q_GETINFO:
  34         case Q_XGETQSTAT:
  35         case Q_XGETQSTATV:
  36         case Q_XQUOTASYNC:
  37                 break;
  38         /* allow to query information for dquots we "own" */
  39         case Q_GETQUOTA:
  40         case Q_XGETQUOTA:
  41                 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  42                     (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  43                         break;
  44                 fallthrough;
  45         default:
  46                 if (!capable(CAP_SYS_ADMIN))
  47                         return -EPERM;
  48         }
  49
  50         return security_quotactl(cmd, type, id, sb);
  51 }
  52
  53 static void quota_sync_one(struct super_block *sb, void *arg)
  54 {
  55         int type = *(int *)arg;
  56
  57         if (sb->s_qcop && sb->s_qcop->quota_sync &&
  58             (sb->s_quota_types & (1 << type)))
  59                 sb->s_qcop->quota_sync(sb, type);
  60 }
  61
  62 static int quota_sync_all(int type)
  63 {
  64         int ret;
  65
  66         ret = security_quotactl(Q_SYNC, type, 0, NULL);
  67         if (!ret)
  68                 iterate_supers(quota_sync_one, &type);
  69         return ret;
  70 }
  71
  72 unsigned int qtype_enforce_flag(int type)
  73 {
  74         switch (type) {
  75         case USRQUOTA:
  76                 return FS_QUOTA_UDQ_ENFD;
  77         case GRPQUOTA:
  78                 return FS_QUOTA_GDQ_ENFD;
  79         case PRJQUOTA:
  80                 return FS_QUOTA_PDQ_ENFD;
  81         }
  82         return 0;
  83 }
  84
  85 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  86                          const struct path *path)
  87 {
  88         if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  89                 return -ENOSYS;
  90         if (sb->s_qcop->quota_enable)
  91                 return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  92         if (IS_ERR(path))
  93                 return PTR_ERR(path);
  94         return sb->s_qcop->quota_on(sb, type, id, path);
  95 }
  96
  97 static int quota_quotaoff(struct super_block *sb, int type)
  98 {
  99         if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
 100                 return -ENOSYS;
 101         if (sb->s_qcop->quota_disable)
 102                 return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 103         return sb->s_qcop->quota_off(sb, type);
 104 }
 105
 106 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 107 {
 108         __u32 fmt;
 109
 110         if (!sb_has_quota_active(sb, type))
 111                 return -ESRCH;
 112         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 113         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 114                 return -EFAULT;
 115         return 0;
 116 }
 117
 118 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 119 {
 120         struct qc_state state;
 121         struct qc_type_state *tstate;
 122         struct if_dqinfo uinfo;
 123         int ret;
 124
 125         if (!sb->s_qcop->get_state)
 126                 return -ENOSYS;
 127         ret = sb->s_qcop->get_state(sb, &state);
 128         if (ret)
 129                 return ret;
 130         tstate = state.s_state + type;
 131         if (!(tstate->flags & QCI_ACCT_ENABLED))
 132                 return -ESRCH;
 133         memset(&uinfo, 0, sizeof(uinfo));
 134         uinfo.dqi_bgrace = tstate->spc_timelimit;
 135         uinfo.dqi_igrace = tstate->ino_timelimit;
 136         if (tstate->flags & QCI_SYSFILE)
 137                 uinfo.dqi_flags |= DQF_SYS_FILE;
 138         if (tstate->flags & QCI_ROOT_SQUASH)
 139                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 140         uinfo.dqi_valid = IIF_ALL;
 141         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 142                 return -EFAULT;
 143         return 0;
 144 }
 145
 146 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 147 {
 148         struct if_dqinfo info;
 149         struct qc_info qinfo;
 150
 151         if (copy_from_user(&info, addr, sizeof(info)))
 152                 return -EFAULT;
 153         if (!sb->s_qcop->set_info)
 154                 return -ENOSYS;
 155         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 156                 return -EINVAL;
 157         memset(&qinfo, 0, sizeof(qinfo));
 158         if (info.dqi_valid & IIF_FLAGS) {
 159                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 160                         return -EINVAL;
 161                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 162                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 163                 qinfo.i_fieldmask |= QC_FLAGS;
 164         }
 165         if (info.dqi_valid & IIF_BGRACE) {
 166                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 167                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 168         }
 169         if (info.dqi_valid & IIF_IGRACE) {
 170                 qinfo.i_ino_timelimit = info.dqi_igrace;
 171                 qinfo.i_fieldmask |= QC_INO_TIMER;
 172         }
 173         return sb->s_qcop->set_info(sb, type, &qinfo);
 174 }
 175
 176 static inline qsize_t qbtos(qsize_t blocks)
 177 {
 178         return blocks << QIF_DQBLKSIZE_BITS;
 179 }
 180
 181 static inline qsize_t stoqb(qsize_t space)
 182 {
 183         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 184 }
 185
 186 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 187 {
 188         memset(dst, 0, sizeof(*dst));
 189         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 190         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 191         dst->dqb_curspace = src->d_space;
 192         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 193         dst->dqb_isoftlimit = src->d_ino_softlimit;
 194         dst->dqb_curinodes = src->d_ino_count;
 195         dst->dqb_btime = src->d_spc_timer;
 196         dst->dqb_itime = src->d_ino_timer;
 197         dst->dqb_valid = QIF_ALL;
 198 }
 199
 200 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 201                           void __user *addr)
 202 {
 203         struct kqid qid;
 204         struct qc_dqblk fdq;
 205         struct if_dqblk idq;
 206         int ret;
 207
 208         if (!sb->s_qcop->get_dqblk)
 209                 return -ENOSYS;
 210         qid = make_kqid(current_user_ns(), type, id);
 211         if (!qid_has_mapping(sb->s_user_ns, qid))
 212                 return -EINVAL;
 213         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 214         if (ret)
 215                 return ret;
 216         copy_to_if_dqblk(&idq, &fdq);
 217
 218         if (compat_need_64bit_alignment_fixup()) {
 219                 struct compat_if_dqblk __user *compat_dqblk = addr;
 220
 221                 if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
 222                         return -EFAULT;
 223                 if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 224                         return -EFAULT;
 225         } else {
 226                 if (copy_to_user(addr, &idq, sizeof(idq)))
 227                         return -EFAULT;
 228         }
 229         return 0;
 230 }
 231
 232 /*
 233  * Return quota for next active quota >= this id, if any exists,
 234  * otherwise return -ENOENT via ->get_nextdqblk
 235  */
 236 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 237                           void __user *addr)
 238 {
 239         struct kqid qid;
 240         struct qc_dqblk fdq;
 241         struct if_nextdqblk idq;
 242         int ret;
 243
 244         if (!sb->s_qcop->get_nextdqblk)
 245                 return -ENOSYS;
 246         qid = make_kqid(current_user_ns(), type, id);
 247         if (!qid_has_mapping(sb->s_user_ns, qid))
 248                 return -EINVAL;
 249         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 250         if (ret)
 251                 return ret;
 252         /* struct if_nextdqblk is a superset of struct if_dqblk */
 253         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 254         idq.dqb_id = from_kqid(current_user_ns(), qid);
 255         if (copy_to_user(addr, &idq, sizeof(idq)))
 256                 return -EFAULT;
 257         return 0;
 258 }
 259
 260 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 261 {
 262         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 263         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 264         dst->d_space = src->dqb_curspace;
 265         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 266         dst->d_ino_softlimit = src->dqb_isoftlimit;
 267         dst->d_ino_count = src->dqb_curinodes;
 268         dst->d_spc_timer = src->dqb_btime;
 269         dst->d_ino_timer = src->dqb_itime;
 270
 271         dst->d_fieldmask = 0;
 272         if (src->dqb_valid & QIF_BLIMITS)
 273                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 274         if (src->dqb_valid & QIF_SPACE)
 275                 dst->d_fieldmask |= QC_SPACE;
 276         if (src->dqb_valid & QIF_ILIMITS)
 277                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 278         if (src->dqb_valid & QIF_INODES)
 279                 dst->d_fieldmask |= QC_INO_COUNT;
 280         if (src->dqb_valid & QIF_BTIME)
 281                 dst->d_fieldmask |= QC_SPC_TIMER;
 282         if (src->dqb_valid & QIF_ITIME)
 283                 dst->d_fieldmask |= QC_INO_TIMER;
 284 }
 285
 286 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 287                           void __user *addr)
 288 {
 289         struct qc_dqblk fdq;
 290         struct if_dqblk idq;
 291         struct kqid qid;
 292
 293         if (compat_need_64bit_alignment_fixup()) {
 294                 struct compat_if_dqblk __user *compat_dqblk = addr;
 295
 296                 if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
 297                     get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 298                         return -EFAULT;
 299         } else {
 300                 if (copy_from_user(&idq, addr, sizeof(idq)))
 301                         return -EFAULT;
 302         }
 303         if (!sb->s_qcop->set_dqblk)
 304                 return -ENOSYS;
 305         qid = make_kqid(current_user_ns(), type, id);
 306         if (!qid_has_mapping(sb->s_user_ns, qid))
 307                 return -EINVAL;
 308         copy_from_if_dqblk(&fdq, &idq);
 309         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 310 }
 311
 312 static int quota_enable(struct super_block *sb, void __user *addr)
 313 {
 314         __u32 flags;
 315
 316         if (copy_from_user(&flags, addr, sizeof(flags)))
 317                 return -EFAULT;
 318         if (!sb->s_qcop->quota_enable)
 319                 return -ENOSYS;
 320         return sb->s_qcop->quota_enable(sb, flags);
 321 }
 322
 323 static int quota_disable(struct super_block *sb, void __user *addr)
 324 {
 325         __u32 flags;
 326
 327         if (copy_from_user(&flags, addr, sizeof(flags)))
 328                 return -EFAULT;
 329         if (!sb->s_qcop->quota_disable)
 330                 return -ENOSYS;
 331         return sb->s_qcop->quota_disable(sb, flags);
 332 }
 333
 334 static int quota_state_to_flags(struct qc_state *state)
 335 {
 336         int flags = 0;
 337
 338         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 339                 flags |= FS_QUOTA_UDQ_ACCT;
 340         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 341                 flags |= FS_QUOTA_UDQ_ENFD;
 342         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 343                 flags |= FS_QUOTA_GDQ_ACCT;
 344         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 345                 flags |= FS_QUOTA_GDQ_ENFD;
 346         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 347                 flags |= FS_QUOTA_PDQ_ACCT;
 348         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 349                 flags |= FS_QUOTA_PDQ_ENFD;
 350         return flags;
 351 }
 352
 353 static int quota_getstate(struct super_block *sb, int type,
 354                           struct fs_quota_stat *fqs)
 355 {
 356         struct qc_state state;
 357         int ret;
 358
 359         memset(&state, 0, sizeof (struct qc_state));
 360         ret = sb->s_qcop->get_state(sb, &state);
 361         if (ret < 0)
 362                 return ret;
 363
 364         memset(fqs, 0, sizeof(*fqs));
 365         fqs->qs_version = FS_QSTAT_VERSION;
 366         fqs->qs_flags = quota_state_to_flags(&state);
 367         /* No quota enabled? */
 368         if (!fqs->qs_flags)
 369                 return -ENOSYS;
 370         fqs->qs_incoredqs = state.s_incoredqs;
 371
 372         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 373         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 374         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 375         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 376         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 377
 378         /* Inodes may be allocated even if inactive; copy out if present */
 379         if (state.s_state[USRQUOTA].ino) {
 380                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 381                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 382                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 383         }
 384         if (state.s_state[GRPQUOTA].ino) {
 385                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 386                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 387                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 388         }
 389         if (state.s_state[PRJQUOTA].ino) {
 390                 /*
 391                  * Q_XGETQSTAT doesn't have room for both group and project
 392                  * quotas.  So, allow the project quota values to be copied out
 393                  * only if there is no group quota information available.
 394                  */
 395                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 396                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 397                         fqs->qs_gquota.qfs_nblks =
 398                                         state.s_state[PRJQUOTA].blocks;
 399                         fqs->qs_gquota.qfs_nextents =
 400                                         state.s_state[PRJQUOTA].nextents;
 401                 }
 402         }
 403         return 0;
 404 }
 405
 406 static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
 407                 struct fs_qfilestat *from)
 408 {
 409         if (copy_to_user(to, from, sizeof(*to)) ||
 410             put_user(from->qfs_nextents, &to->qfs_nextents))
 411                 return -EFAULT;
 412         return 0;
 413 }
 414
 415 static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
 416                 struct fs_quota_stat *from)
 417 {
 418         if (put_user(from->qs_version, &to->qs_version) ||
 419             put_user(from->qs_flags, &to->qs_flags) ||
 420             put_user(from->qs_pad, &to->qs_pad) ||
 421             compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
 422             compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
 423             put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
 424             put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
 425             put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
 426             put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
 427             put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
 428             put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
 429                 return -EFAULT;
 430         return 0;
 431 }
 432
 433 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
 434 {
 435         struct fs_quota_stat fqs;
 436         int ret;
 437
 438         if (!sb->s_qcop->get_state)
 439                 return -ENOSYS;
 440         ret = quota_getstate(sb, type, &fqs);
 441         if (ret)
 442                 return ret;
 443
 444         if (compat_need_64bit_alignment_fixup())
 445                 return compat_copy_fs_quota_stat(addr, &fqs);
 446         if (copy_to_user(addr, &fqs, sizeof(fqs)))
 447                 return -EFAULT;
 448         return 0;
 449 }
 450
 451 static int quota_getstatev(struct super_block *sb, int type,
 452                            struct fs_quota_statv *fqs)
 453 {
 454         struct qc_state state;
 455         int ret;
 456
 457         memset(&state, 0, sizeof (struct qc_state));
 458         ret = sb->s_qcop->get_state(sb, &state);
 459         if (ret < 0)
 460                 return ret;
 461
 462         memset(fqs, 0, sizeof(*fqs));
 463         fqs->qs_version = FS_QSTAT_VERSION;
 464         fqs->qs_flags = quota_state_to_flags(&state);
 465         /* No quota enabled? */
 466         if (!fqs->qs_flags)
 467                 return -ENOSYS;
 468         fqs->qs_incoredqs = state.s_incoredqs;
 469
 470         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 471         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 472         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 473         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 474         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 475         fqs->qs_rtbwarnlimit = state.s_state[type].rt_spc_warnlimit;
 476
 477         /* Inodes may be allocated even if inactive; copy out if present */
 478         if (state.s_state[USRQUOTA].ino) {
 479                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 480                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 481                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 482         }
 483         if (state.s_state[GRPQUOTA].ino) {
 484                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 485                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 486                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 487         }
 488         if (state.s_state[PRJQUOTA].ino) {
 489                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 490                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 491                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 492         }
 493         return 0;
 494 }
 495
 496 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
 497 {
 498         struct fs_quota_statv fqs;
 499         int ret;
 500
 501         if (!sb->s_qcop->get_state)
 502                 return -ENOSYS;
 503
 504         memset(&fqs, 0, sizeof(fqs));
 505         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 506                 return -EFAULT;
 507
 508         /* If this kernel doesn't support user specified version, fail */
 509         switch (fqs.qs_version) {
 510         case FS_QSTATV_VERSION1:
 511                 break;
 512         default:
 513                 return -EINVAL;
 514         }
 515         ret = quota_getstatev(sb, type, &fqs);
 516         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 517                 return -EFAULT;
 518         return ret;
 519 }
 520
 521 /*
 522  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 523  * out of there as xfsprogs rely on definitions being in that header file. So
 524  * just define same functions here for quota purposes.
 525  */
 526 #define XFS_BB_SHIFT 9
 527
 528 static inline u64 quota_bbtob(u64 blocks)
 529 {
 530         return blocks << XFS_BB_SHIFT;
 531 }
 532
 533 static inline u64 quota_btobb(u64 bytes)
 534 {
 535         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 536 }
 537
 538 static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
 539                 __s32 timer, __s8 timer_hi)
 540 {
 541         if (d->d_fieldmask & FS_DQ_BIGTIME)
 542                 return (u32)timer | (s64)timer_hi << 32;
 543         return timer;
 544 }
 545
 546 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 547 {
 548         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 549         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 550         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 551         dst->d_ino_softlimit = src->d_ino_softlimit;
 552         dst->d_space = quota_bbtob(src->d_bcount);
 553         dst->d_ino_count = src->d_icount;
 554         dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
 555                                                   src->d_itimer_hi);
 556         dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
 557                                                   src->d_btimer_hi);
 558         dst->d_ino_warns = src->d_iwarns;
 559         dst->d_spc_warns = src->d_bwarns;
 560         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 561         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 562         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 563         dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
 564                                                      src->d_rtbtimer_hi);
 565         dst->d_rt_spc_warns = src->d_rtbwarns;
 566         dst->d_fieldmask = 0;
 567         if (src->d_fieldmask & FS_DQ_ISOFT)
 568                 dst->d_fieldmask |= QC_INO_SOFT;
 569         if (src->d_fieldmask & FS_DQ_IHARD)
 570                 dst->d_fieldmask |= QC_INO_HARD;
 571         if (src->d_fieldmask & FS_DQ_BSOFT)
 572                 dst->d_fieldmask |= QC_SPC_SOFT;
 573         if (src->d_fieldmask & FS_DQ_BHARD)
 574                 dst->d_fieldmask |= QC_SPC_HARD;
 575         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 576                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 577         if (src->d_fieldmask & FS_DQ_RTBHARD)
 578                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 579         if (src->d_fieldmask & FS_DQ_BTIMER)
 580                 dst->d_fieldmask |= QC_SPC_TIMER;
 581         if (src->d_fieldmask & FS_DQ_ITIMER)
 582                 dst->d_fieldmask |= QC_INO_TIMER;
 583         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 584                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 585         if (src->d_fieldmask & FS_DQ_BWARNS)
 586                 dst->d_fieldmask |= QC_SPC_WARNS;
 587         if (src->d_fieldmask & FS_DQ_IWARNS)
 588                 dst->d_fieldmask |= QC_INO_WARNS;
 589         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 590                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 591         if (src->d_fieldmask & FS_DQ_BCOUNT)
 592                 dst->d_fieldmask |= QC_SPACE;
 593         if (src->d_fieldmask & FS_DQ_ICOUNT)
 594                 dst->d_fieldmask |= QC_INO_COUNT;
 595         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 596                 dst->d_fieldmask |= QC_RT_SPACE;
 597 }
 598
 599 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 600                                        struct fs_disk_quota *src)
 601 {
 602         memset(dst, 0, sizeof(*dst));
 603         dst->i_spc_timelimit = src->d_btimer;
 604         dst->i_ino_timelimit = src->d_itimer;
 605         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 606         dst->i_ino_warnlimit = src->d_iwarns;
 607         dst->i_spc_warnlimit = src->d_bwarns;
 608         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 609         if (src->d_fieldmask & FS_DQ_BWARNS)
 610                 dst->i_fieldmask |= QC_SPC_WARNS;
 611         if (src->d_fieldmask & FS_DQ_IWARNS)
 612                 dst->i_fieldmask |= QC_INO_WARNS;
 613         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 614                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 615         if (src->d_fieldmask & FS_DQ_BTIMER)
 616                 dst->i_fieldmask |= QC_SPC_TIMER;
 617         if (src->d_fieldmask & FS_DQ_ITIMER)
 618                 dst->i_fieldmask |= QC_INO_TIMER;
 619         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 620                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 621 }
 622
 623 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 624                            void __user *addr)
 625 {
 626         struct fs_disk_quota fdq;
 627         struct qc_dqblk qdq;
 628         struct kqid qid;
 629
 630         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 631                 return -EFAULT;
 632         if (!sb->s_qcop->set_dqblk)
 633                 return -ENOSYS;
 634         qid = make_kqid(current_user_ns(), type, id);
 635         if (!qid_has_mapping(sb->s_user_ns, qid))
 636                 return -EINVAL;
 637         /* Are we actually setting timer / warning limits for all users? */
 638         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 639             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 640                 struct qc_info qinfo;
 641                 int ret;
 642
 643                 if (!sb->s_qcop->set_info)
 644                         return -EINVAL;
 645                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 646                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 647                 if (ret)
 648                         return ret;
 649                 /* These are already done */
 650                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 651         }
 652         copy_from_xfs_dqblk(&qdq, &fdq);
 653         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 654 }
 655
 656 static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
 657                 __s32 *timer_lo, __s8 *timer_hi, s64 timer)
 658 {
 659         *timer_lo = timer;
 660         if (d->d_fieldmask & FS_DQ_BIGTIME)
 661                 *timer_hi = timer >> 32;
 662 }
 663
 664 static inline bool want_bigtime(s64 timer)
 665 {
 666         return timer > S32_MAX || timer < S32_MIN;
 667 }
 668
 669 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 670                               int type, qid_t id)
 671 {
 672         memset(dst, 0, sizeof(*dst));
 673         if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
 674             want_bigtime(src->d_rt_spc_timer))
 675                 dst->d_fieldmask |= FS_DQ_BIGTIME;
 676         dst->d_version = FS_DQUOT_VERSION;
 677         dst->d_id = id;
 678         if (type == USRQUOTA)
 679                 dst->d_flags = FS_USER_QUOTA;
 680         else if (type == PRJQUOTA)
 681                 dst->d_flags = FS_PROJ_QUOTA;
 682         else
 683                 dst->d_flags = FS_GROUP_QUOTA;
 684         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 685         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 686         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 687         dst->d_ino_softlimit = src->d_ino_softlimit;
 688         dst->d_bcount = quota_btobb(src->d_space);
 689         dst->d_icount = src->d_ino_count;
 690         copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
 691                              src->d_ino_timer);
 692         copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
 693                              src->d_spc_timer);
 694         dst->d_iwarns = src->d_ino_warns;
 695         dst->d_bwarns = src->d_spc_warns;
 696         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 697         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 698         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 699         copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
 700                              src->d_rt_spc_timer);
 701         dst->d_rtbwarns = src->d_rt_spc_warns;
 702 }
 703
 704 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 705                            void __user *addr)
 706 {
 707         struct fs_disk_quota fdq;
 708         struct qc_dqblk qdq;
 709         struct kqid qid;
 710         int ret;
 711
 712         if (!sb->s_qcop->get_dqblk)
 713                 return -ENOSYS;
 714         qid = make_kqid(current_user_ns(), type, id);
 715         if (!qid_has_mapping(sb->s_user_ns, qid))
 716                 return -EINVAL;
 717         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 718         if (ret)
 719                 return ret;
 720         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 721         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 722                 return -EFAULT;
 723         return ret;
 724 }
 725
 726 /*
 727  * Return quota for next active quota >= this id, if any exists,
 728  * otherwise return -ENOENT via ->get_nextdqblk.
 729  */
 730 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 731                             void __user *addr)
 732 {
 733         struct fs_disk_quota fdq;
 734         struct qc_dqblk qdq;
 735         struct kqid qid;
 736         qid_t id_out;
 737         int ret;
 738
 739         if (!sb->s_qcop->get_nextdqblk)
 740                 return -ENOSYS;
 741         qid = make_kqid(current_user_ns(), type, id);
 742         if (!qid_has_mapping(sb->s_user_ns, qid))
 743                 return -EINVAL;
 744         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 745         if (ret)
 746                 return ret;
 747         id_out = from_kqid(current_user_ns(), qid);
 748         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 749         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 750                 return -EFAULT;
 751         return ret;
 752 }
 753
 754 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 755 {
 756         __u32 flags;
 757
 758         if (copy_from_user(&flags, addr, sizeof(flags)))
 759                 return -EFAULT;
 760         if (!sb->s_qcop->rm_xquota)
 761                 return -ENOSYS;
 762         return sb->s_qcop->rm_xquota(sb, flags);
 763 }
 764
 765 /* Copy parameters and call proper function */
 766 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 767                        void __user *addr, const struct path *path)
 768 {
 769         int ret;
 770
 771         type = array_index_nospec(type, MAXQUOTAS);
 772         /*
 773          * Quota not supported on this fs? Check this before s_quota_types
 774          * since they needn't be set if quota is not supported at all.
 775          */
 776         if (!sb->s_qcop)
 777                 return -ENOSYS;
 778         if (!(sb->s_quota_types & (1 << type)))
 779                 return -EINVAL;
 780
 781         ret = check_quotactl_permission(sb, type, cmd, id);
 782         if (ret < 0)
 783                 return ret;
 784
 785         switch (cmd) {
 786         case Q_QUOTAON:
 787                 return quota_quotaon(sb, type, id, path);
 788         case Q_QUOTAOFF:
 789                 return quota_quotaoff(sb, type);
 790         case Q_GETFMT:
 791                 return quota_getfmt(sb, type, addr);
 792         case Q_GETINFO:
 793                 return quota_getinfo(sb, type, addr);
 794         case Q_SETINFO:
 795                 return quota_setinfo(sb, type, addr);
 796         case Q_GETQUOTA:
 797                 return quota_getquota(sb, type, id, addr);
 798         case Q_GETNEXTQUOTA:
 799                 return quota_getnextquota(sb, type, id, addr);
 800         case Q_SETQUOTA:
 801                 return quota_setquota(sb, type, id, addr);
 802         case Q_SYNC:
 803                 if (!sb->s_qcop->quota_sync)
 804                         return -ENOSYS;
 805                 return sb->s_qcop->quota_sync(sb, type);
 806         case Q_XQUOTAON:
 807                 return quota_enable(sb, addr);
 808         case Q_XQUOTAOFF:
 809                 return quota_disable(sb, addr);
 810         case Q_XQUOTARM:
 811                 return quota_rmxquota(sb, addr);
 812         case Q_XGETQSTAT:
 813                 return quota_getxstate(sb, type, addr);
 814         case Q_XGETQSTATV:
 815                 return quota_getxstatev(sb, type, addr);
 816         case Q_XSETQLIM:
 817                 return quota_setxquota(sb, type, id, addr);
 818         case Q_XGETQUOTA:
 819                 return quota_getxquota(sb, type, id, addr);
 820         case Q_XGETNEXTQUOTA:
 821                 return quota_getnextxquota(sb, type, id, addr);
 822         case Q_XQUOTASYNC:
 823                 if (sb_rdonly(sb))
 824                         return -EROFS;
 825                 /* XFS quotas are fully coherent now, making this call a noop */
 826                 return 0;
 827         default:
 828                 return -EINVAL;
 829         }
 830 }
 831
 832 /* Return 1 if 'cmd' will block on frozen filesystem */
 833 static int quotactl_cmd_write(int cmd)
 834 {
 835         /*
 836          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 837          * as dquot_acquire() may allocate space for new structure and OCFS2
 838          * needs to increment on-disk use count.
 839          */
 840         switch (cmd) {
 841         case Q_GETFMT:
 842         case Q_GETINFO:
 843         case Q_SYNC:
 844         case Q_XGETQSTAT:
 845         case Q_XGETQSTATV:
 846         case Q_XGETQUOTA:
 847         case Q_XGETNEXTQUOTA:
 848         case Q_XQUOTASYNC:
 849                 return 0;
 850         }
 851         return 1;
 852 }
 853
 854 /* Return true if quotactl command is manipulating quota on/off state */
 855 static bool quotactl_cmd_onoff(int cmd)
 856 {
 857         return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 858                  (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 859 }
 860
 861 /*
 862  * look up a superblock on which quota ops will be performed
 863  * - use the name of a block device to find the superblock thereon
 864  */
 865 static struct super_block *quotactl_block(const char __user *special, int cmd)
 866 {
 867 #ifdef CONFIG_BLOCK
 868         struct super_block *sb;
 869         struct filename *tmp = getname(special);
 870         bool excl = false, thawed = false;
 871         int error;
 872         dev_t dev;
 873
 874         if (IS_ERR(tmp))
 875                 return ERR_CAST(tmp);
 876         error = lookup_bdev(tmp->name, &dev);
 877         putname(tmp);
 878         if (error)
 879                 return ERR_PTR(error);
 880
 881         if (quotactl_cmd_onoff(cmd)) {
 882                 excl = true;
 883                 thawed = true;
 884         } else if (quotactl_cmd_write(cmd)) {
 885                 thawed = true;
 886         }
 887
 888 retry:
 889         sb = user_get_super(dev, excl);
 890         if (!sb)
 891                 return ERR_PTR(-ENODEV);
 892         if (thawed && sb->s_writers.frozen != SB_UNFROZEN) {
 893                 if (excl)
 894                         up_write(&sb->s_umount);
 895                 else
 896                         up_read(&sb->s_umount);
 897                 wait_event(sb->s_writers.wait_unfrozen,
 898                            sb->s_writers.frozen == SB_UNFROZEN);
 899                 put_super(sb);
 900                 goto retry;
 901         }
 902         return sb;
 903
 904 #else
 905         return ERR_PTR(-ENODEV);
 906 #endif
 907 }
 908
 909 /*
 910  * This is the system call interface. This communicates with
 911  * the user-level programs. Currently this only supports diskquota
 912  * calls. Maybe we need to add the process quotas etc. in the future,
 913  * but we probably should use rlimits for that.
 914  */
 915 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 916                 qid_t, id, void __user *, addr)
 917 {
 918         uint cmds, type;
 919         struct super_block *sb = NULL;
 920         struct path path, *pathp = NULL;
 921         int ret;
 922
 923         cmds = cmd >> SUBCMDSHIFT;
 924         type = cmd & SUBCMDMASK;
 925
 926         if (type >= MAXQUOTAS)
 927                 return -EINVAL;
 928
 929         /*
 930          * As a special case Q_SYNC can be called without a specific device.
 931          * It will iterate all superblocks that have quota enabled and call
 932          * the sync action on each of them.
 933          */
 934         if (!special) {
 935                 if (cmds == Q_SYNC)
 936                         return quota_sync_all(type);
 937                 return -ENODEV;
 938         }
 939
 940         /*
 941          * Path for quotaon has to be resolved before grabbing superblock
 942          * because that gets s_umount sem which is also possibly needed by path
 943          * resolution (think about autofs) and thus deadlocks could arise.
 944          */
 945         if (cmds == Q_QUOTAON) {
 946                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 947                 if (ret)
 948                         pathp = ERR_PTR(ret);
 949                 else
 950                         pathp = &path;
 951         }
 952
 953         sb = quotactl_block(special, cmds);
 954         if (IS_ERR(sb)) {
 955                 ret = PTR_ERR(sb);
 956                 goto out;
 957         }
 958
 959         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 960
 961         if (!quotactl_cmd_onoff(cmds))
 962                 drop_super(sb);
 963         else
 964                 drop_super_exclusive(sb);
 965 out:
 966         if (pathp && !IS_ERR(pathp))
 967                 path_put(pathp);
 968         return ret;
 969 }
 970
 971 SYSCALL_DEFINE4(quotactl_fd, unsigned int, fd, unsigned int, cmd,
 972                 qid_t, id, void __user *, addr)
 973 {
 974         struct super_block *sb;
 975         unsigned int cmds = cmd >> SUBCMDSHIFT;
 976         unsigned int type = cmd & SUBCMDMASK;
 977         struct fd f;
 978         int ret;
 979
 980         f = fdget_raw(fd);
 981         if (!f.file)
 982                 return -EBADF;
 983
 984         ret = -EINVAL;
 985         if (type >= MAXQUOTAS)
 986                 goto out;
 987
 988         if (quotactl_cmd_write(cmds)) {
 989                 ret = mnt_want_write(f.file->f_path.mnt);
 990                 if (ret)
 991                         goto out;
 992         }
 993
 994         sb = f.file->f_path.mnt->mnt_sb;
 995         if (quotactl_cmd_onoff(cmds))
 996                 down_write(&sb->s_umount);
 997         else
 998                 down_read(&sb->s_umount);
 999
1000         ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
1001
1002         if (quotactl_cmd_onoff(cmds))
1003                 up_write(&sb->s_umount);
1004         else
1005                 up_read(&sb->s_umount);
1006
1007         if (quotactl_cmd_write(cmds))
1008                 mnt_drop_write(f.file->f_path.mnt);
1009 out:
1010         fdput(f);
1011         return ret;
1012 }