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/blkdev.h>
  14 #include <linux/uaccess.h>
  15 #include <linux/kernel.h>
  16 #include <linux/security.h>
  17 #include <linux/syscalls.h>
  18 #include <linux/capability.h>
  19 #include <linux/quotaops.h>
  20 #include <linux/types.h>
  21 #include <linux/mount.h>
  22 #include <linux/writeback.h>
  23 #include <linux/nospec.h>
  24 #include "compat.h"
  25 #include "../internal.h"
  26
  27 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  28                                      qid_t id)
  29 {
  30         switch (cmd) {
  31         /* these commands do not require any special privilegues */
  32         case Q_GETFMT:
  33         case Q_SYNC:
  34         case Q_GETINFO:
  35         case Q_XGETQSTAT:
  36         case Q_XGETQSTATV:
  37         case Q_XQUOTASYNC:
  38                 break;
  39         /* allow to query information for dquots we "own" */
  40         case Q_GETQUOTA:
  41         case Q_XGETQUOTA:
  42                 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  43                     (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  44                         break;
  45                 fallthrough;
  46         default:
  47                 if (!capable(CAP_SYS_ADMIN))
  48                         return -EPERM;
  49         }
  50
  51         return security_quotactl(cmd, type, id, sb);
  52 }
  53
  54 static void quota_sync_one(struct super_block *sb, void *arg)
  55 {
  56         int type = *(int *)arg;
  57
  58         if (sb->s_qcop && sb->s_qcop->quota_sync &&
  59             (sb->s_quota_types & (1 << type)))
  60                 sb->s_qcop->quota_sync(sb, type);
  61 }
  62
  63 static int quota_sync_all(int type)
  64 {
  65         int ret;
  66
  67         ret = security_quotactl(Q_SYNC, type, 0, NULL);
  68         if (!ret)
  69                 iterate_supers(quota_sync_one, &type);
  70         return ret;
  71 }
  72
  73 unsigned int qtype_enforce_flag(int type)
  74 {
  75         switch (type) {
  76         case USRQUOTA:
  77                 return FS_QUOTA_UDQ_ENFD;
  78         case GRPQUOTA:
  79                 return FS_QUOTA_GDQ_ENFD;
  80         case PRJQUOTA:
  81                 return FS_QUOTA_PDQ_ENFD;
  82         }
  83         return 0;
  84 }
  85
  86 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  87                          const struct path *path)
  88 {
  89         if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  90                 return -ENOSYS;
  91         if (sb->s_qcop->quota_enable)
  92                 return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  93         if (IS_ERR(path))
  94                 return PTR_ERR(path);
  95         return sb->s_qcop->quota_on(sb, type, id, path);
  96 }
  97
  98 static int quota_quotaoff(struct super_block *sb, int type)
  99 {
 100         if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
 101                 return -ENOSYS;
 102         if (sb->s_qcop->quota_disable)
 103                 return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 104         return sb->s_qcop->quota_off(sb, type);
 105 }
 106
 107 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 108 {
 109         __u32 fmt;
 110
 111         if (!sb_has_quota_active(sb, type))
 112                 return -ESRCH;
 113         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 114         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 115                 return -EFAULT;
 116         return 0;
 117 }
 118
 119 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 120 {
 121         struct qc_state state;
 122         struct qc_type_state *tstate;
 123         struct if_dqinfo uinfo;
 124         int ret;
 125
 126         if (!sb->s_qcop->get_state)
 127                 return -ENOSYS;
 128         ret = sb->s_qcop->get_state(sb, &state);
 129         if (ret)
 130                 return ret;
 131         tstate = state.s_state + type;
 132         if (!(tstate->flags & QCI_ACCT_ENABLED))
 133                 return -ESRCH;
 134         memset(&uinfo, 0, sizeof(uinfo));
 135         uinfo.dqi_bgrace = tstate->spc_timelimit;
 136         uinfo.dqi_igrace = tstate->ino_timelimit;
 137         if (tstate->flags & QCI_SYSFILE)
 138                 uinfo.dqi_flags |= DQF_SYS_FILE;
 139         if (tstate->flags & QCI_ROOT_SQUASH)
 140                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 141         uinfo.dqi_valid = IIF_ALL;
 142         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 143                 return -EFAULT;
 144         return 0;
 145 }
 146
 147 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 148 {
 149         struct if_dqinfo info;
 150         struct qc_info qinfo;
 151
 152         if (copy_from_user(&info, addr, sizeof(info)))
 153                 return -EFAULT;
 154         if (!sb->s_qcop->set_info)
 155                 return -ENOSYS;
 156         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 157                 return -EINVAL;
 158         memset(&qinfo, 0, sizeof(qinfo));
 159         if (info.dqi_valid & IIF_FLAGS) {
 160                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 161                         return -EINVAL;
 162                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 163                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 164                 qinfo.i_fieldmask |= QC_FLAGS;
 165         }
 166         if (info.dqi_valid & IIF_BGRACE) {
 167                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 168                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 169         }
 170         if (info.dqi_valid & IIF_IGRACE) {
 171                 qinfo.i_ino_timelimit = info.dqi_igrace;
 172                 qinfo.i_fieldmask |= QC_INO_TIMER;
 173         }
 174         return sb->s_qcop->set_info(sb, type, &qinfo);
 175 }
 176
 177 static inline qsize_t qbtos(qsize_t blocks)
 178 {
 179         return blocks << QIF_DQBLKSIZE_BITS;
 180 }
 181
 182 static inline qsize_t stoqb(qsize_t space)
 183 {
 184         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 185 }
 186
 187 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 188 {
 189         memset(dst, 0, sizeof(*dst));
 190         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 191         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 192         dst->dqb_curspace = src->d_space;
 193         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 194         dst->dqb_isoftlimit = src->d_ino_softlimit;
 195         dst->dqb_curinodes = src->d_ino_count;
 196         dst->dqb_btime = src->d_spc_timer;
 197         dst->dqb_itime = src->d_ino_timer;
 198         dst->dqb_valid = QIF_ALL;
 199 }
 200
 201 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 202                           void __user *addr)
 203 {
 204         struct kqid qid;
 205         struct qc_dqblk fdq;
 206         struct if_dqblk idq;
 207         int ret;
 208
 209         if (!sb->s_qcop->get_dqblk)
 210                 return -ENOSYS;
 211         qid = make_kqid(current_user_ns(), type, id);
 212         if (!qid_has_mapping(sb->s_user_ns, qid))
 213                 return -EINVAL;
 214         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 215         if (ret)
 216                 return ret;
 217         copy_to_if_dqblk(&idq, &fdq);
 218
 219         if (compat_need_64bit_alignment_fixup()) {
 220                 struct compat_if_dqblk __user *compat_dqblk = addr;
 221
 222                 if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
 223                         return -EFAULT;
 224                 if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 225                         return -EFAULT;
 226         } else {
 227                 if (copy_to_user(addr, &idq, sizeof(idq)))
 228                         return -EFAULT;
 229         }
 230         return 0;
 231 }
 232
 233 /*
 234  * Return quota for next active quota >= this id, if any exists,
 235  * otherwise return -ENOENT via ->get_nextdqblk
 236  */
 237 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 238                           void __user *addr)
 239 {
 240         struct kqid qid;
 241         struct qc_dqblk fdq;
 242         struct if_nextdqblk idq;
 243         int ret;
 244
 245         if (!sb->s_qcop->get_nextdqblk)
 246                 return -ENOSYS;
 247         qid = make_kqid(current_user_ns(), type, id);
 248         if (!qid_has_mapping(sb->s_user_ns, qid))
 249                 return -EINVAL;
 250         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 251         if (ret)
 252                 return ret;
 253         /* struct if_nextdqblk is a superset of struct if_dqblk */
 254         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 255         idq.dqb_id = from_kqid(current_user_ns(), qid);
 256         if (copy_to_user(addr, &idq, sizeof(idq)))
 257                 return -EFAULT;
 258         return 0;
 259 }
 260
 261 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 262 {
 263         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 264         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 265         dst->d_space = src->dqb_curspace;
 266         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 267         dst->d_ino_softlimit = src->dqb_isoftlimit;
 268         dst->d_ino_count = src->dqb_curinodes;
 269         dst->d_spc_timer = src->dqb_btime;
 270         dst->d_ino_timer = src->dqb_itime;
 271
 272         dst->d_fieldmask = 0;
 273         if (src->dqb_valid & QIF_BLIMITS)
 274                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 275         if (src->dqb_valid & QIF_SPACE)
 276                 dst->d_fieldmask |= QC_SPACE;
 277         if (src->dqb_valid & QIF_ILIMITS)
 278                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 279         if (src->dqb_valid & QIF_INODES)
 280                 dst->d_fieldmask |= QC_INO_COUNT;
 281         if (src->dqb_valid & QIF_BTIME)
 282                 dst->d_fieldmask |= QC_SPC_TIMER;
 283         if (src->dqb_valid & QIF_ITIME)
 284                 dst->d_fieldmask |= QC_INO_TIMER;
 285 }
 286
 287 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 288                           void __user *addr)
 289 {
 290         struct qc_dqblk fdq;
 291         struct if_dqblk idq;
 292         struct kqid qid;
 293
 294         if (compat_need_64bit_alignment_fixup()) {
 295                 struct compat_if_dqblk __user *compat_dqblk = addr;
 296
 297                 if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
 298                     get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 299                         return -EFAULT;
 300         } else {
 301                 if (copy_from_user(&idq, addr, sizeof(idq)))
 302                         return -EFAULT;
 303         }
 304         if (!sb->s_qcop->set_dqblk)
 305                 return -ENOSYS;
 306         qid = make_kqid(current_user_ns(), type, id);
 307         if (!qid_has_mapping(sb->s_user_ns, qid))
 308                 return -EINVAL;
 309         copy_from_if_dqblk(&fdq, &idq);
 310         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 311 }
 312
 313 static int quota_enable(struct super_block *sb, void __user *addr)
 314 {
 315         __u32 flags;
 316
 317         if (copy_from_user(&flags, addr, sizeof(flags)))
 318                 return -EFAULT;
 319         if (!sb->s_qcop->quota_enable)
 320                 return -ENOSYS;
 321         return sb->s_qcop->quota_enable(sb, flags);
 322 }
 323
 324 static int quota_disable(struct super_block *sb, void __user *addr)
 325 {
 326         __u32 flags;
 327
 328         if (copy_from_user(&flags, addr, sizeof(flags)))
 329                 return -EFAULT;
 330         if (!sb->s_qcop->quota_disable)
 331                 return -ENOSYS;
 332         return sb->s_qcop->quota_disable(sb, flags);
 333 }
 334
 335 static int quota_state_to_flags(struct qc_state *state)
 336 {
 337         int flags = 0;
 338
 339         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 340                 flags |= FS_QUOTA_UDQ_ACCT;
 341         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 342                 flags |= FS_QUOTA_UDQ_ENFD;
 343         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 344                 flags |= FS_QUOTA_GDQ_ACCT;
 345         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 346                 flags |= FS_QUOTA_GDQ_ENFD;
 347         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 348                 flags |= FS_QUOTA_PDQ_ACCT;
 349         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 350                 flags |= FS_QUOTA_PDQ_ENFD;
 351         return flags;
 352 }
 353
 354 static int quota_getstate(struct super_block *sb, int type,
 355                           struct fs_quota_stat *fqs)
 356 {
 357         struct qc_state state;
 358         int ret;
 359
 360         memset(&state, 0, sizeof (struct qc_state));
 361         ret = sb->s_qcop->get_state(sb, &state);
 362         if (ret < 0)
 363                 return ret;
 364
 365         memset(fqs, 0, sizeof(*fqs));
 366         fqs->qs_version = FS_QSTAT_VERSION;
 367         fqs->qs_flags = quota_state_to_flags(&state);
 368         /* No quota enabled? */
 369         if (!fqs->qs_flags)
 370                 return -ENOSYS;
 371         fqs->qs_incoredqs = state.s_incoredqs;
 372
 373         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 374         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 375         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 376         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 377         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 378
 379         /* Inodes may be allocated even if inactive; copy out if present */
 380         if (state.s_state[USRQUOTA].ino) {
 381                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 382                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 383                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 384         }
 385         if (state.s_state[GRPQUOTA].ino) {
 386                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 387                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 388                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 389         }
 390         if (state.s_state[PRJQUOTA].ino) {
 391                 /*
 392                  * Q_XGETQSTAT doesn't have room for both group and project
 393                  * quotas.  So, allow the project quota values to be copied out
 394                  * only if there is no group quota information available.
 395                  */
 396                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 397                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 398                         fqs->qs_gquota.qfs_nblks =
 399                                         state.s_state[PRJQUOTA].blocks;
 400                         fqs->qs_gquota.qfs_nextents =
 401                                         state.s_state[PRJQUOTA].nextents;
 402                 }
 403         }
 404         return 0;
 405 }
 406
 407 static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
 408                 struct fs_qfilestat *from)
 409 {
 410         if (copy_to_user(to, from, sizeof(*to)) ||
 411             put_user(from->qfs_nextents, &to->qfs_nextents))
 412                 return -EFAULT;
 413         return 0;
 414 }
 415
 416 static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
 417                 struct fs_quota_stat *from)
 418 {
 419         if (put_user(from->qs_version, &to->qs_version) ||
 420             put_user(from->qs_flags, &to->qs_flags) ||
 421             put_user(from->qs_pad, &to->qs_pad) ||
 422             compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
 423             compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
 424             put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
 425             put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
 426             put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
 427             put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
 428             put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
 429             put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
 430                 return -EFAULT;
 431         return 0;
 432 }
 433
 434 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
 435 {
 436         struct fs_quota_stat fqs;
 437         int ret;
 438
 439         if (!sb->s_qcop->get_state)
 440                 return -ENOSYS;
 441         ret = quota_getstate(sb, type, &fqs);
 442         if (ret)
 443                 return ret;
 444
 445         if (compat_need_64bit_alignment_fixup())
 446                 return compat_copy_fs_quota_stat(addr, &fqs);
 447         if (copy_to_user(addr, &fqs, sizeof(fqs)))
 448                 return -EFAULT;
 449         return 0;
 450 }
 451
 452 static int quota_getstatev(struct super_block *sb, int type,
 453                            struct fs_quota_statv *fqs)
 454 {
 455         struct qc_state state;
 456         int ret;
 457
 458         memset(&state, 0, sizeof (struct qc_state));
 459         ret = sb->s_qcop->get_state(sb, &state);
 460         if (ret < 0)
 461                 return ret;
 462
 463         memset(fqs, 0, sizeof(*fqs));
 464         fqs->qs_version = FS_QSTAT_VERSION;
 465         fqs->qs_flags = quota_state_to_flags(&state);
 466         /* No quota enabled? */
 467         if (!fqs->qs_flags)
 468                 return -ENOSYS;
 469         fqs->qs_incoredqs = state.s_incoredqs;
 470
 471         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 472         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 473         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 474         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 475         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 476         fqs->qs_rtbwarnlimit = state.s_state[type].rt_spc_warnlimit;
 477
 478         /* Inodes may be allocated even if inactive; copy out if present */
 479         if (state.s_state[USRQUOTA].ino) {
 480                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 481                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 482                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 483         }
 484         if (state.s_state[GRPQUOTA].ino) {
 485                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 486                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 487                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 488         }
 489         if (state.s_state[PRJQUOTA].ino) {
 490                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 491                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 492                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 493         }
 494         return 0;
 495 }
 496
 497 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
 498 {
 499         struct fs_quota_statv fqs;
 500         int ret;
 501
 502         if (!sb->s_qcop->get_state)
 503                 return -ENOSYS;
 504
 505         memset(&fqs, 0, sizeof(fqs));
 506         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 507                 return -EFAULT;
 508
 509         /* If this kernel doesn't support user specified version, fail */
 510         switch (fqs.qs_version) {
 511         case FS_QSTATV_VERSION1:
 512                 break;
 513         default:
 514                 return -EINVAL;
 515         }
 516         ret = quota_getstatev(sb, type, &fqs);
 517         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 518                 return -EFAULT;
 519         return ret;
 520 }
 521
 522 /*
 523  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 524  * out of there as xfsprogs rely on definitions being in that header file. So
 525  * just define same functions here for quota purposes.
 526  */
 527 #define XFS_BB_SHIFT 9
 528
 529 static inline u64 quota_bbtob(u64 blocks)
 530 {
 531         return blocks << XFS_BB_SHIFT;
 532 }
 533
 534 static inline u64 quota_btobb(u64 bytes)
 535 {
 536         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 537 }
 538
 539 static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
 540                 __s32 timer, __s8 timer_hi)
 541 {
 542         if (d->d_fieldmask & FS_DQ_BIGTIME)
 543                 return (u32)timer | (s64)timer_hi << 32;
 544         return timer;
 545 }
 546
 547 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 548 {
 549         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 550         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 551         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 552         dst->d_ino_softlimit = src->d_ino_softlimit;
 553         dst->d_space = quota_bbtob(src->d_bcount);
 554         dst->d_ino_count = src->d_icount;
 555         dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
 556                                                   src->d_itimer_hi);
 557         dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
 558                                                   src->d_btimer_hi);
 559         dst->d_ino_warns = src->d_iwarns;
 560         dst->d_spc_warns = src->d_bwarns;
 561         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 562         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 563         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 564         dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
 565                                                      src->d_rtbtimer_hi);
 566         dst->d_rt_spc_warns = src->d_rtbwarns;
 567         dst->d_fieldmask = 0;
 568         if (src->d_fieldmask & FS_DQ_ISOFT)
 569                 dst->d_fieldmask |= QC_INO_SOFT;
 570         if (src->d_fieldmask & FS_DQ_IHARD)
 571                 dst->d_fieldmask |= QC_INO_HARD;
 572         if (src->d_fieldmask & FS_DQ_BSOFT)
 573                 dst->d_fieldmask |= QC_SPC_SOFT;
 574         if (src->d_fieldmask & FS_DQ_BHARD)
 575                 dst->d_fieldmask |= QC_SPC_HARD;
 576         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 577                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 578         if (src->d_fieldmask & FS_DQ_RTBHARD)
 579                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 580         if (src->d_fieldmask & FS_DQ_BTIMER)
 581                 dst->d_fieldmask |= QC_SPC_TIMER;
 582         if (src->d_fieldmask & FS_DQ_ITIMER)
 583                 dst->d_fieldmask |= QC_INO_TIMER;
 584         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 585                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 586         if (src->d_fieldmask & FS_DQ_BWARNS)
 587                 dst->d_fieldmask |= QC_SPC_WARNS;
 588         if (src->d_fieldmask & FS_DQ_IWARNS)
 589                 dst->d_fieldmask |= QC_INO_WARNS;
 590         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 591                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 592         if (src->d_fieldmask & FS_DQ_BCOUNT)
 593                 dst->d_fieldmask |= QC_SPACE;
 594         if (src->d_fieldmask & FS_DQ_ICOUNT)
 595                 dst->d_fieldmask |= QC_INO_COUNT;
 596         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 597                 dst->d_fieldmask |= QC_RT_SPACE;
 598 }
 599
 600 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 601                                        struct fs_disk_quota *src)
 602 {
 603         memset(dst, 0, sizeof(*dst));
 604         dst->i_spc_timelimit = src->d_btimer;
 605         dst->i_ino_timelimit = src->d_itimer;
 606         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 607         dst->i_ino_warnlimit = src->d_iwarns;
 608         dst->i_spc_warnlimit = src->d_bwarns;
 609         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 610         if (src->d_fieldmask & FS_DQ_BWARNS)
 611                 dst->i_fieldmask |= QC_SPC_WARNS;
 612         if (src->d_fieldmask & FS_DQ_IWARNS)
 613                 dst->i_fieldmask |= QC_INO_WARNS;
 614         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 615                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 616         if (src->d_fieldmask & FS_DQ_BTIMER)
 617                 dst->i_fieldmask |= QC_SPC_TIMER;
 618         if (src->d_fieldmask & FS_DQ_ITIMER)
 619                 dst->i_fieldmask |= QC_INO_TIMER;
 620         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 621                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 622 }
 623
 624 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 625                            void __user *addr)
 626 {
 627         struct fs_disk_quota fdq;
 628         struct qc_dqblk qdq;
 629         struct kqid qid;
 630
 631         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 632                 return -EFAULT;
 633         if (!sb->s_qcop->set_dqblk)
 634                 return -ENOSYS;
 635         qid = make_kqid(current_user_ns(), type, id);
 636         if (!qid_has_mapping(sb->s_user_ns, qid))
 637                 return -EINVAL;
 638         /* Are we actually setting timer / warning limits for all users? */
 639         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 640             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 641                 struct qc_info qinfo;
 642                 int ret;
 643
 644                 if (!sb->s_qcop->set_info)
 645                         return -EINVAL;
 646                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 647                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 648                 if (ret)
 649                         return ret;
 650                 /* These are already done */
 651                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 652         }
 653         copy_from_xfs_dqblk(&qdq, &fdq);
 654         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 655 }
 656
 657 static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
 658                 __s32 *timer_lo, __s8 *timer_hi, s64 timer)
 659 {
 660         *timer_lo = timer;
 661         if (d->d_fieldmask & FS_DQ_BIGTIME)
 662                 *timer_hi = timer >> 32;
 663 }
 664
 665 static inline bool want_bigtime(s64 timer)
 666 {
 667         return timer > S32_MAX || timer < S32_MIN;
 668 }
 669
 670 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 671                               int type, qid_t id)
 672 {
 673         memset(dst, 0, sizeof(*dst));
 674         if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
 675             want_bigtime(src->d_rt_spc_timer))
 676                 dst->d_fieldmask |= FS_DQ_BIGTIME;
 677         dst->d_version = FS_DQUOT_VERSION;
 678         dst->d_id = id;
 679         if (type == USRQUOTA)
 680                 dst->d_flags = FS_USER_QUOTA;
 681         else if (type == PRJQUOTA)
 682                 dst->d_flags = FS_PROJ_QUOTA;
 683         else
 684                 dst->d_flags = FS_GROUP_QUOTA;
 685         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 686         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 687         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 688         dst->d_ino_softlimit = src->d_ino_softlimit;
 689         dst->d_bcount = quota_btobb(src->d_space);
 690         dst->d_icount = src->d_ino_count;
 691         copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
 692                              src->d_ino_timer);
 693         copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
 694                              src->d_spc_timer);
 695         dst->d_iwarns = src->d_ino_warns;
 696         dst->d_bwarns = src->d_spc_warns;
 697         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 698         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 699         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 700         copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
 701                              src->d_rt_spc_timer);
 702         dst->d_rtbwarns = src->d_rt_spc_warns;
 703 }
 704
 705 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 706                            void __user *addr)
 707 {
 708         struct fs_disk_quota fdq;
 709         struct qc_dqblk qdq;
 710         struct kqid qid;
 711         int ret;
 712
 713         if (!sb->s_qcop->get_dqblk)
 714                 return -ENOSYS;
 715         qid = make_kqid(current_user_ns(), type, id);
 716         if (!qid_has_mapping(sb->s_user_ns, qid))
 717                 return -EINVAL;
 718         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 719         if (ret)
 720                 return ret;
 721         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 722         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 723                 return -EFAULT;
 724         return ret;
 725 }
 726
 727 /*
 728  * Return quota for next active quota >= this id, if any exists,
 729  * otherwise return -ENOENT via ->get_nextdqblk.
 730  */
 731 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 732                             void __user *addr)
 733 {
 734         struct fs_disk_quota fdq;
 735         struct qc_dqblk qdq;
 736         struct kqid qid;
 737         qid_t id_out;
 738         int ret;
 739
 740         if (!sb->s_qcop->get_nextdqblk)
 741                 return -ENOSYS;
 742         qid = make_kqid(current_user_ns(), type, id);
 743         if (!qid_has_mapping(sb->s_user_ns, qid))
 744                 return -EINVAL;
 745         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 746         if (ret)
 747                 return ret;
 748         id_out = from_kqid(current_user_ns(), qid);
 749         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 750         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 751                 return -EFAULT;
 752         return ret;
 753 }
 754
 755 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 756 {
 757         __u32 flags;
 758
 759         if (copy_from_user(&flags, addr, sizeof(flags)))
 760                 return -EFAULT;
 761         if (!sb->s_qcop->rm_xquota)
 762                 return -ENOSYS;
 763         return sb->s_qcop->rm_xquota(sb, flags);
 764 }
 765
 766 /* Copy parameters and call proper function */
 767 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 768                        void __user *addr, const struct path *path)
 769 {
 770         int ret;
 771
 772         type = array_index_nospec(type, MAXQUOTAS);
 773         /*
 774          * Quota not supported on this fs? Check this before s_quota_types
 775          * since they needn't be set if quota is not supported at all.
 776          */
 777         if (!sb->s_qcop)
 778                 return -ENOSYS;
 779         if (!(sb->s_quota_types & (1 << type)))
 780                 return -EINVAL;
 781
 782         ret = check_quotactl_permission(sb, type, cmd, id);
 783         if (ret < 0)
 784                 return ret;
 785
 786         switch (cmd) {
 787         case Q_QUOTAON:
 788                 return quota_quotaon(sb, type, id, path);
 789         case Q_QUOTAOFF:
 790                 return quota_quotaoff(sb, type);
 791         case Q_GETFMT:
 792                 return quota_getfmt(sb, type, addr);
 793         case Q_GETINFO:
 794                 return quota_getinfo(sb, type, addr);
 795         case Q_SETINFO:
 796                 return quota_setinfo(sb, type, addr);
 797         case Q_GETQUOTA:
 798                 return quota_getquota(sb, type, id, addr);
 799         case Q_GETNEXTQUOTA:
 800                 return quota_getnextquota(sb, type, id, addr);
 801         case Q_SETQUOTA:
 802                 return quota_setquota(sb, type, id, addr);
 803         case Q_SYNC:
 804                 if (!sb->s_qcop->quota_sync)
 805                         return -ENOSYS;
 806                 return sb->s_qcop->quota_sync(sb, type);
 807         case Q_XQUOTAON:
 808                 return quota_enable(sb, addr);
 809         case Q_XQUOTAOFF:
 810                 return quota_disable(sb, addr);
 811         case Q_XQUOTARM:
 812                 return quota_rmxquota(sb, addr);
 813         case Q_XGETQSTAT:
 814                 return quota_getxstate(sb, type, addr);
 815         case Q_XGETQSTATV:
 816                 return quota_getxstatev(sb, type, addr);
 817         case Q_XSETQLIM:
 818                 return quota_setxquota(sb, type, id, addr);
 819         case Q_XGETQUOTA:
 820                 return quota_getxquota(sb, type, id, addr);
 821         case Q_XGETNEXTQUOTA:
 822                 return quota_getnextxquota(sb, type, id, addr);
 823         case Q_XQUOTASYNC:
 824                 if (sb_rdonly(sb))
 825                         return -EROFS;
 826                 /* XFS quotas are fully coherent now, making this call a noop */
 827                 return 0;
 828         default:
 829                 return -EINVAL;
 830         }
 831 }
 832
 833 /* Return 1 if 'cmd' will block on frozen filesystem */
 834 static int quotactl_cmd_write(int cmd)
 835 {
 836         /*
 837          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 838          * as dquot_acquire() may allocate space for new structure and OCFS2
 839          * needs to increment on-disk use count.
 840          */
 841         switch (cmd) {
 842         case Q_GETFMT:
 843         case Q_GETINFO:
 844         case Q_SYNC:
 845         case Q_XGETQSTAT:
 846         case Q_XGETQSTATV:
 847         case Q_XGETQUOTA:
 848         case Q_XGETNEXTQUOTA:
 849         case Q_XQUOTASYNC:
 850                 return 0;
 851         }
 852         return 1;
 853 }
 854
 855 /* Return true if quotactl command is manipulating quota on/off state */
 856 static bool quotactl_cmd_onoff(int cmd)
 857 {
 858         return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 859                  (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 860 }
 861
 862 /*
 863  * look up a superblock on which quota ops will be performed
 864  * - use the name of a block device to find the superblock thereon
 865  */
 866 static struct super_block *quotactl_block(const char __user *special, int cmd)
 867 {
 868 #ifdef CONFIG_BLOCK
 869         struct super_block *sb;
 870         struct filename *tmp = getname(special);
 871         bool excl = false, thawed = false;
 872         int error;
 873         dev_t dev;
 874
 875         if (IS_ERR(tmp))
 876                 return ERR_CAST(tmp);
 877         error = lookup_bdev(tmp->name, &dev);
 878         putname(tmp);
 879         if (error)
 880                 return ERR_PTR(error);
 881
 882         if (quotactl_cmd_onoff(cmd)) {
 883                 excl = true;
 884                 thawed = true;
 885         } else if (quotactl_cmd_write(cmd)) {
 886                 thawed = true;
 887         }
 888
 889 retry:
 890         sb = user_get_super(dev, excl);
 891         if (!sb)
 892                 return ERR_PTR(-ENODEV);
 893         if (thawed && sb->s_writers.frozen != SB_UNFROZEN) {
 894                 if (excl)
 895                         up_write(&sb->s_umount);
 896                 else
 897                         up_read(&sb->s_umount);
 898                 wait_event(sb->s_writers.wait_unfrozen,
 899                            sb->s_writers.frozen == SB_UNFROZEN);
 900                 put_super(sb);
 901                 goto retry;
 902         }
 903         return sb;
 904
 905 #else
 906         return ERR_PTR(-ENODEV);
 907 #endif
 908 }
 909
 910 /*
 911  * This is the system call interface. This communicates with
 912  * the user-level programs. Currently this only supports diskquota
 913  * calls. Maybe we need to add the process quotas etc. in the future,
 914  * but we probably should use rlimits for that.
 915  */
 916 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 917                 qid_t, id, void __user *, addr)
 918 {
 919         uint cmds, type;
 920         struct super_block *sb = NULL;
 921         struct path path, *pathp = NULL;
 922         int ret;
 923
 924         cmds = cmd >> SUBCMDSHIFT;
 925         type = cmd & SUBCMDMASK;
 926
 927         if (type >= MAXQUOTAS)
 928                 return -EINVAL;
 929
 930         /*
 931          * As a special case Q_SYNC can be called without a specific device.
 932          * It will iterate all superblocks that have quota enabled and call
 933          * the sync action on each of them.
 934          */
 935         if (!special) {
 936                 if (cmds == Q_SYNC)
 937                         return quota_sync_all(type);
 938                 return -ENODEV;
 939         }
 940
 941         /*
 942          * Path for quotaon has to be resolved before grabbing superblock
 943          * because that gets s_umount sem which is also possibly needed by path
 944          * resolution (think about autofs) and thus deadlocks could arise.
 945          */
 946         if (cmds == Q_QUOTAON) {
 947                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 948                 if (ret)
 949                         pathp = ERR_PTR(ret);
 950                 else
 951                         pathp = &path;
 952         }
 953
 954         sb = quotactl_block(special, cmds);
 955         if (IS_ERR(sb)) {
 956                 ret = PTR_ERR(sb);
 957                 goto out;
 958         }
 959
 960         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 961
 962         if (!quotactl_cmd_onoff(cmds))
 963                 drop_super(sb);
 964         else
 965                 drop_super_exclusive(sb);
 966 out:
 967         if (pathp && !IS_ERR(pathp))
 968                 path_put(pathp);
 969         return ret;
 970 }
 971
 972 SYSCALL_DEFINE4(quotactl_fd, unsigned int, fd, unsigned int, cmd,
 973                 qid_t, id, void __user *, addr)
 974 {
 975         struct super_block *sb;
 976         unsigned int cmds = cmd >> SUBCMDSHIFT;
 977         unsigned int type = cmd & SUBCMDMASK;
 978         struct fd f;
 979         int ret;
 980
 981         f = fdget_raw(fd);
 982         if (!f.file)
 983                 return -EBADF;
 984
 985         ret = -EINVAL;
 986         if (type >= MAXQUOTAS)
 987                 goto out;
 988
 989         if (quotactl_cmd_write(cmds)) {
 990                 ret = mnt_want_write(f.file->f_path.mnt);
 991                 if (ret)
 992                         goto out;
 993         }
 994
 995         sb = f.file->f_path.mnt->mnt_sb;
 996         if (quotactl_cmd_onoff(cmds))
 997                 down_write(&sb->s_umount);
 998         else
 999                 down_read(&sb->s_umount);
1000
1001         ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
1002
1003         if (quotactl_cmd_onoff(cmds))
1004                 up_write(&sb->s_umount);
1005         else
1006                 up_read(&sb->s_umount);
1007
1008         if (quotactl_cmd_write(cmds))
1009                 mnt_drop_write(f.file->f_path.mnt);
1010 out:
1011         fdput(f);
1012         return ret;
1013 }