fs/quota/quota.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Quota code necessary even when VFS quota support is not compiled
   4  * into the kernel.  The interesting stuff is over in dquot.c, here
   5  * we have symbols for initial quotactl(2) handling, the sysctl(2)
   6  * variables, etc - things needed even when quota support disabled.
   7  */
   8
   9 #include <linux/fs.h>
  10 #include <linux/namei.h>
  11 #include <linux/slab.h>
  12 #include <asm/current.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/kernel.h>
  15 #include <linux/security.h>
  16 #include <linux/syscalls.h>
  17 #include <linux/capability.h>
  18 #include <linux/quotaops.h>
  19 #include <linux/types.h>
  20 #include <linux/writeback.h>
  21 #include <linux/nospec.h>
  22
  23 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  24                                      qid_t id)
  25 {
  26         switch (cmd) {
  27         /* these commands do not require any special privilegues */
  28         case Q_GETFMT:
  29         case Q_SYNC:
  30         case Q_GETINFO:
  31         case Q_XGETQSTAT:
  32         case Q_XGETQSTATV:
  33         case Q_XQUOTASYNC:
  34                 break;
  35         /* allow to query information for dquots we "own" */
  36         case Q_GETQUOTA:
  37         case Q_XGETQUOTA:
  38                 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  39                     (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  40                         break;
  41                 /*FALLTHROUGH*/
  42         default:
  43                 if (!capable(CAP_SYS_ADMIN))
  44                         return -EPERM;
  45         }
  46
  47         return security_quotactl(cmd, type, id, sb);
  48 }
  49
  50 static void quota_sync_one(struct super_block *sb, void *arg)
  51 {
  52         int type = *(int *)arg;
  53
  54         if (sb->s_qcop && sb->s_qcop->quota_sync &&
  55             (sb->s_quota_types & (1 << type)))
  56                 sb->s_qcop->quota_sync(sb, type);
  57 }
  58
  59 static int quota_sync_all(int type)
  60 {
  61         int ret;
  62
  63         if (type >= MAXQUOTAS)
  64                 return -EINVAL;
  65         ret = security_quotactl(Q_SYNC, type, 0, NULL);
  66         if (!ret)
  67                 iterate_supers(quota_sync_one, &type);
  68         return ret;
  69 }
  70
  71 unsigned int qtype_enforce_flag(int type)
  72 {
  73         switch (type) {
  74         case USRQUOTA:
  75                 return FS_QUOTA_UDQ_ENFD;
  76         case GRPQUOTA:
  77                 return FS_QUOTA_GDQ_ENFD;
  78         case PRJQUOTA:
  79                 return FS_QUOTA_PDQ_ENFD;
  80         }
  81         return 0;
  82 }
  83
  84 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  85                          const struct path *path)
  86 {
  87         if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  88                 return -ENOSYS;
  89         if (sb->s_qcop->quota_enable)
  90                 return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  91         if (IS_ERR(path))
  92                 return PTR_ERR(path);
  93         return sb->s_qcop->quota_on(sb, type, id, path);
  94 }
  95
  96 static int quota_quotaoff(struct super_block *sb, int type)
  97 {
  98         if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
  99                 return -ENOSYS;
 100         if (sb->s_qcop->quota_disable)
 101                 return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 102         return sb->s_qcop->quota_off(sb, type);
 103 }
 104
 105 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 106 {
 107         __u32 fmt;
 108
 109         if (!sb_has_quota_active(sb, type))
 110                 return -ESRCH;
 111         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 112         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 113                 return -EFAULT;
 114         return 0;
 115 }
 116
 117 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 118 {
 119         struct qc_state state;
 120         struct qc_type_state *tstate;
 121         struct if_dqinfo uinfo;
 122         int ret;
 123
 124         if (!sb->s_qcop->get_state)
 125                 return -ENOSYS;
 126         ret = sb->s_qcop->get_state(sb, &state);
 127         if (ret)
 128                 return ret;
 129         tstate = state.s_state + type;
 130         if (!(tstate->flags & QCI_ACCT_ENABLED))
 131                 return -ESRCH;
 132         memset(&uinfo, 0, sizeof(uinfo));
 133         uinfo.dqi_bgrace = tstate->spc_timelimit;
 134         uinfo.dqi_igrace = tstate->ino_timelimit;
 135         if (tstate->flags & QCI_SYSFILE)
 136                 uinfo.dqi_flags |= DQF_SYS_FILE;
 137         if (tstate->flags & QCI_ROOT_SQUASH)
 138                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 139         uinfo.dqi_valid = IIF_ALL;
 140         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 141                 return -EFAULT;
 142         return 0;
 143 }
 144
 145 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 146 {
 147         struct if_dqinfo info;
 148         struct qc_info qinfo;
 149
 150         if (copy_from_user(&info, addr, sizeof(info)))
 151                 return -EFAULT;
 152         if (!sb->s_qcop->set_info)
 153                 return -ENOSYS;
 154         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 155                 return -EINVAL;
 156         memset(&qinfo, 0, sizeof(qinfo));
 157         if (info.dqi_valid & IIF_FLAGS) {
 158                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 159                         return -EINVAL;
 160                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 161                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 162                 qinfo.i_fieldmask |= QC_FLAGS;
 163         }
 164         if (info.dqi_valid & IIF_BGRACE) {
 165                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 166                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 167         }
 168         if (info.dqi_valid & IIF_IGRACE) {
 169                 qinfo.i_ino_timelimit = info.dqi_igrace;
 170                 qinfo.i_fieldmask |= QC_INO_TIMER;
 171         }
 172         return sb->s_qcop->set_info(sb, type, &qinfo);
 173 }
 174
 175 static inline qsize_t qbtos(qsize_t blocks)
 176 {
 177         return blocks << QIF_DQBLKSIZE_BITS;
 178 }
 179
 180 static inline qsize_t stoqb(qsize_t space)
 181 {
 182         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 183 }
 184
 185 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 186 {
 187         memset(dst, 0, sizeof(*dst));
 188         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 189         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 190         dst->dqb_curspace = src->d_space;
 191         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 192         dst->dqb_isoftlimit = src->d_ino_softlimit;
 193         dst->dqb_curinodes = src->d_ino_count;
 194         dst->dqb_btime = src->d_spc_timer;
 195         dst->dqb_itime = src->d_ino_timer;
 196         dst->dqb_valid = QIF_ALL;
 197 }
 198
 199 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 200                           void __user *addr)
 201 {
 202         struct kqid qid;
 203         struct qc_dqblk fdq;
 204         struct if_dqblk idq;
 205         int ret;
 206
 207         if (!sb->s_qcop->get_dqblk)
 208                 return -ENOSYS;
 209         qid = make_kqid(current_user_ns(), type, id);
 210         if (!qid_has_mapping(sb->s_user_ns, qid))
 211                 return -EINVAL;
 212         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 213         if (ret)
 214                 return ret;
 215         copy_to_if_dqblk(&idq, &fdq);
 216         if (copy_to_user(addr, &idq, sizeof(idq)))
 217                 return -EFAULT;
 218         return 0;
 219 }
 220
 221 /*
 222  * Return quota for next active quota >= this id, if any exists,
 223  * otherwise return -ENOENT via ->get_nextdqblk
 224  */
 225 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 226                           void __user *addr)
 227 {
 228         struct kqid qid;
 229         struct qc_dqblk fdq;
 230         struct if_nextdqblk idq;
 231         int ret;
 232
 233         if (!sb->s_qcop->get_nextdqblk)
 234                 return -ENOSYS;
 235         qid = make_kqid(current_user_ns(), type, id);
 236         if (!qid_has_mapping(sb->s_user_ns, qid))
 237                 return -EINVAL;
 238         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 239         if (ret)
 240                 return ret;
 241         /* struct if_nextdqblk is a superset of struct if_dqblk */
 242         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 243         idq.dqb_id = from_kqid(current_user_ns(), qid);
 244         if (copy_to_user(addr, &idq, sizeof(idq)))
 245                 return -EFAULT;
 246         return 0;
 247 }
 248
 249 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 250 {
 251         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 252         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 253         dst->d_space = src->dqb_curspace;
 254         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 255         dst->d_ino_softlimit = src->dqb_isoftlimit;
 256         dst->d_ino_count = src->dqb_curinodes;
 257         dst->d_spc_timer = src->dqb_btime;
 258         dst->d_ino_timer = src->dqb_itime;
 259
 260         dst->d_fieldmask = 0;
 261         if (src->dqb_valid & QIF_BLIMITS)
 262                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 263         if (src->dqb_valid & QIF_SPACE)
 264                 dst->d_fieldmask |= QC_SPACE;
 265         if (src->dqb_valid & QIF_ILIMITS)
 266                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 267         if (src->dqb_valid & QIF_INODES)
 268                 dst->d_fieldmask |= QC_INO_COUNT;
 269         if (src->dqb_valid & QIF_BTIME)
 270                 dst->d_fieldmask |= QC_SPC_TIMER;
 271         if (src->dqb_valid & QIF_ITIME)
 272                 dst->d_fieldmask |= QC_INO_TIMER;
 273 }
 274
 275 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 276                           void __user *addr)
 277 {
 278         struct qc_dqblk fdq;
 279         struct if_dqblk idq;
 280         struct kqid qid;
 281
 282         if (copy_from_user(&idq, addr, sizeof(idq)))
 283                 return -EFAULT;
 284         if (!sb->s_qcop->set_dqblk)
 285                 return -ENOSYS;
 286         qid = make_kqid(current_user_ns(), type, id);
 287         if (!qid_has_mapping(sb->s_user_ns, qid))
 288                 return -EINVAL;
 289         copy_from_if_dqblk(&fdq, &idq);
 290         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 291 }
 292
 293 static int quota_enable(struct super_block *sb, void __user *addr)
 294 {
 295         __u32 flags;
 296
 297         if (copy_from_user(&flags, addr, sizeof(flags)))
 298                 return -EFAULT;
 299         if (!sb->s_qcop->quota_enable)
 300                 return -ENOSYS;
 301         return sb->s_qcop->quota_enable(sb, flags);
 302 }
 303
 304 static int quota_disable(struct super_block *sb, void __user *addr)
 305 {
 306         __u32 flags;
 307
 308         if (copy_from_user(&flags, addr, sizeof(flags)))
 309                 return -EFAULT;
 310         if (!sb->s_qcop->quota_disable)
 311                 return -ENOSYS;
 312         return sb->s_qcop->quota_disable(sb, flags);
 313 }
 314
 315 static int quota_state_to_flags(struct qc_state *state)
 316 {
 317         int flags = 0;
 318
 319         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 320                 flags |= FS_QUOTA_UDQ_ACCT;
 321         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 322                 flags |= FS_QUOTA_UDQ_ENFD;
 323         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 324                 flags |= FS_QUOTA_GDQ_ACCT;
 325         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 326                 flags |= FS_QUOTA_GDQ_ENFD;
 327         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 328                 flags |= FS_QUOTA_PDQ_ACCT;
 329         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 330                 flags |= FS_QUOTA_PDQ_ENFD;
 331         return flags;
 332 }
 333
 334 static int quota_getstate(struct super_block *sb, int type,
 335                           struct fs_quota_stat *fqs)
 336 {
 337         struct qc_state state;
 338         int ret;
 339
 340         memset(&state, 0, sizeof (struct qc_state));
 341         ret = sb->s_qcop->get_state(sb, &state);
 342         if (ret < 0)
 343                 return ret;
 344
 345         memset(fqs, 0, sizeof(*fqs));
 346         fqs->qs_version = FS_QSTAT_VERSION;
 347         fqs->qs_flags = quota_state_to_flags(&state);
 348         /* No quota enabled? */
 349         if (!fqs->qs_flags)
 350                 return -ENOSYS;
 351         fqs->qs_incoredqs = state.s_incoredqs;
 352
 353         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 354         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 355         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 356         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 357         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 358
 359         /* Inodes may be allocated even if inactive; copy out if present */
 360         if (state.s_state[USRQUOTA].ino) {
 361                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 362                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 363                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 364         }
 365         if (state.s_state[GRPQUOTA].ino) {
 366                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 367                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 368                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 369         }
 370         if (state.s_state[PRJQUOTA].ino) {
 371                 /*
 372                  * Q_XGETQSTAT doesn't have room for both group and project
 373                  * quotas.  So, allow the project quota values to be copied out
 374                  * only if there is no group quota information available.
 375                  */
 376                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 377                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 378                         fqs->qs_gquota.qfs_nblks =
 379                                         state.s_state[PRJQUOTA].blocks;
 380                         fqs->qs_gquota.qfs_nextents =
 381                                         state.s_state[PRJQUOTA].nextents;
 382                 }
 383         }
 384         return 0;
 385 }
 386
 387 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
 388 {
 389         struct fs_quota_stat fqs;
 390         int ret;
 391
 392         if (!sb->s_qcop->get_state)
 393                 return -ENOSYS;
 394         ret = quota_getstate(sb, type, &fqs);
 395         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 396                 return -EFAULT;
 397         return ret;
 398 }
 399
 400 static int quota_getstatev(struct super_block *sb, int type,
 401                            struct fs_quota_statv *fqs)
 402 {
 403         struct qc_state state;
 404         int ret;
 405
 406         memset(&state, 0, sizeof (struct qc_state));
 407         ret = sb->s_qcop->get_state(sb, &state);
 408         if (ret < 0)
 409                 return ret;
 410
 411         memset(fqs, 0, sizeof(*fqs));
 412         fqs->qs_version = FS_QSTAT_VERSION;
 413         fqs->qs_flags = quota_state_to_flags(&state);
 414         /* No quota enabled? */
 415         if (!fqs->qs_flags)
 416                 return -ENOSYS;
 417         fqs->qs_incoredqs = state.s_incoredqs;
 418
 419         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 420         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 421         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 422         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 423         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 424
 425         /* Inodes may be allocated even if inactive; copy out if present */
 426         if (state.s_state[USRQUOTA].ino) {
 427                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 428                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 429                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 430         }
 431         if (state.s_state[GRPQUOTA].ino) {
 432                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 433                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 434                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 435         }
 436         if (state.s_state[PRJQUOTA].ino) {
 437                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 438                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 439                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 440         }
 441         return 0;
 442 }
 443
 444 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
 445 {
 446         struct fs_quota_statv fqs;
 447         int ret;
 448
 449         if (!sb->s_qcop->get_state)
 450                 return -ENOSYS;
 451
 452         memset(&fqs, 0, sizeof(fqs));
 453         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 454                 return -EFAULT;
 455
 456         /* If this kernel doesn't support user specified version, fail */
 457         switch (fqs.qs_version) {
 458         case FS_QSTATV_VERSION1:
 459                 break;
 460         default:
 461                 return -EINVAL;
 462         }
 463         ret = quota_getstatev(sb, type, &fqs);
 464         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 465                 return -EFAULT;
 466         return ret;
 467 }
 468
 469 /*
 470  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 471  * out of there as xfsprogs rely on definitions being in that header file. So
 472  * just define same functions here for quota purposes.
 473  */
 474 #define XFS_BB_SHIFT 9
 475
 476 static inline u64 quota_bbtob(u64 blocks)
 477 {
 478         return blocks << XFS_BB_SHIFT;
 479 }
 480
 481 static inline u64 quota_btobb(u64 bytes)
 482 {
 483         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 484 }
 485
 486 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 487 {
 488         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 489         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 490         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 491         dst->d_ino_softlimit = src->d_ino_softlimit;
 492         dst->d_space = quota_bbtob(src->d_bcount);
 493         dst->d_ino_count = src->d_icount;
 494         dst->d_ino_timer = src->d_itimer;
 495         dst->d_spc_timer = src->d_btimer;
 496         dst->d_ino_warns = src->d_iwarns;
 497         dst->d_spc_warns = src->d_bwarns;
 498         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 499         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 500         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 501         dst->d_rt_spc_timer = src->d_rtbtimer;
 502         dst->d_rt_spc_warns = src->d_rtbwarns;
 503         dst->d_fieldmask = 0;
 504         if (src->d_fieldmask & FS_DQ_ISOFT)
 505                 dst->d_fieldmask |= QC_INO_SOFT;
 506         if (src->d_fieldmask & FS_DQ_IHARD)
 507                 dst->d_fieldmask |= QC_INO_HARD;
 508         if (src->d_fieldmask & FS_DQ_BSOFT)
 509                 dst->d_fieldmask |= QC_SPC_SOFT;
 510         if (src->d_fieldmask & FS_DQ_BHARD)
 511                 dst->d_fieldmask |= QC_SPC_HARD;
 512         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 513                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 514         if (src->d_fieldmask & FS_DQ_RTBHARD)
 515                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 516         if (src->d_fieldmask & FS_DQ_BTIMER)
 517                 dst->d_fieldmask |= QC_SPC_TIMER;
 518         if (src->d_fieldmask & FS_DQ_ITIMER)
 519                 dst->d_fieldmask |= QC_INO_TIMER;
 520         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 521                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 522         if (src->d_fieldmask & FS_DQ_BWARNS)
 523                 dst->d_fieldmask |= QC_SPC_WARNS;
 524         if (src->d_fieldmask & FS_DQ_IWARNS)
 525                 dst->d_fieldmask |= QC_INO_WARNS;
 526         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 527                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 528         if (src->d_fieldmask & FS_DQ_BCOUNT)
 529                 dst->d_fieldmask |= QC_SPACE;
 530         if (src->d_fieldmask & FS_DQ_ICOUNT)
 531                 dst->d_fieldmask |= QC_INO_COUNT;
 532         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 533                 dst->d_fieldmask |= QC_RT_SPACE;
 534 }
 535
 536 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 537                                        struct fs_disk_quota *src)
 538 {
 539         memset(dst, 0, sizeof(*dst));
 540         dst->i_spc_timelimit = src->d_btimer;
 541         dst->i_ino_timelimit = src->d_itimer;
 542         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 543         dst->i_ino_warnlimit = src->d_iwarns;
 544         dst->i_spc_warnlimit = src->d_bwarns;
 545         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 546         if (src->d_fieldmask & FS_DQ_BWARNS)
 547                 dst->i_fieldmask |= QC_SPC_WARNS;
 548         if (src->d_fieldmask & FS_DQ_IWARNS)
 549                 dst->i_fieldmask |= QC_INO_WARNS;
 550         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 551                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 552         if (src->d_fieldmask & FS_DQ_BTIMER)
 553                 dst->i_fieldmask |= QC_SPC_TIMER;
 554         if (src->d_fieldmask & FS_DQ_ITIMER)
 555                 dst->i_fieldmask |= QC_INO_TIMER;
 556         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 557                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 558 }
 559
 560 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 561                            void __user *addr)
 562 {
 563         struct fs_disk_quota fdq;
 564         struct qc_dqblk qdq;
 565         struct kqid qid;
 566
 567         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 568                 return -EFAULT;
 569         if (!sb->s_qcop->set_dqblk)
 570                 return -ENOSYS;
 571         qid = make_kqid(current_user_ns(), type, id);
 572         if (!qid_has_mapping(sb->s_user_ns, qid))
 573                 return -EINVAL;
 574         /* Are we actually setting timer / warning limits for all users? */
 575         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 576             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 577                 struct qc_info qinfo;
 578                 int ret;
 579
 580                 if (!sb->s_qcop->set_info)
 581                         return -EINVAL;
 582                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 583                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 584                 if (ret)
 585                         return ret;
 586                 /* These are already done */
 587                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 588         }
 589         copy_from_xfs_dqblk(&qdq, &fdq);
 590         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 591 }
 592
 593 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 594                               int type, qid_t id)
 595 {
 596         memset(dst, 0, sizeof(*dst));
 597         dst->d_version = FS_DQUOT_VERSION;
 598         dst->d_id = id;
 599         if (type == USRQUOTA)
 600                 dst->d_flags = FS_USER_QUOTA;
 601         else if (type == PRJQUOTA)
 602                 dst->d_flags = FS_PROJ_QUOTA;
 603         else
 604                 dst->d_flags = FS_GROUP_QUOTA;
 605         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 606         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 607         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 608         dst->d_ino_softlimit = src->d_ino_softlimit;
 609         dst->d_bcount = quota_btobb(src->d_space);
 610         dst->d_icount = src->d_ino_count;
 611         dst->d_itimer = src->d_ino_timer;
 612         dst->d_btimer = src->d_spc_timer;
 613         dst->d_iwarns = src->d_ino_warns;
 614         dst->d_bwarns = src->d_spc_warns;
 615         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 616         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 617         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 618         dst->d_rtbtimer = src->d_rt_spc_timer;
 619         dst->d_rtbwarns = src->d_rt_spc_warns;
 620 }
 621
 622 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 623                            void __user *addr)
 624 {
 625         struct fs_disk_quota fdq;
 626         struct qc_dqblk qdq;
 627         struct kqid qid;
 628         int ret;
 629
 630         if (!sb->s_qcop->get_dqblk)
 631                 return -ENOSYS;
 632         qid = make_kqid(current_user_ns(), type, id);
 633         if (!qid_has_mapping(sb->s_user_ns, qid))
 634                 return -EINVAL;
 635         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 636         if (ret)
 637                 return ret;
 638         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 639         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 640                 return -EFAULT;
 641         return ret;
 642 }
 643
 644 /*
 645  * Return quota for next active quota >= this id, if any exists,
 646  * otherwise return -ENOENT via ->get_nextdqblk.
 647  */
 648 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 649                             void __user *addr)
 650 {
 651         struct fs_disk_quota fdq;
 652         struct qc_dqblk qdq;
 653         struct kqid qid;
 654         qid_t id_out;
 655         int ret;
 656
 657         if (!sb->s_qcop->get_nextdqblk)
 658                 return -ENOSYS;
 659         qid = make_kqid(current_user_ns(), type, id);
 660         if (!qid_has_mapping(sb->s_user_ns, qid))
 661                 return -EINVAL;
 662         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 663         if (ret)
 664                 return ret;
 665         id_out = from_kqid(current_user_ns(), qid);
 666         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 667         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 668                 return -EFAULT;
 669         return ret;
 670 }
 671
 672 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 673 {
 674         __u32 flags;
 675
 676         if (copy_from_user(&flags, addr, sizeof(flags)))
 677                 return -EFAULT;
 678         if (!sb->s_qcop->rm_xquota)
 679                 return -ENOSYS;
 680         return sb->s_qcop->rm_xquota(sb, flags);
 681 }
 682
 683 /* Copy parameters and call proper function */
 684 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 685                        void __user *addr, const struct path *path)
 686 {
 687         int ret;
 688
 689         if (type >= MAXQUOTAS)
 690                 return -EINVAL;
 691         type = array_index_nospec(type, MAXQUOTAS);
 692         /*
 693          * Quota not supported on this fs? Check this before s_quota_types
 694          * since they needn't be set if quota is not supported at all.
 695          */
 696         if (!sb->s_qcop)
 697                 return -ENOSYS;
 698         if (!(sb->s_quota_types & (1 << type)))
 699                 return -EINVAL;
 700
 701         ret = check_quotactl_permission(sb, type, cmd, id);
 702         if (ret < 0)
 703                 return ret;
 704
 705         switch (cmd) {
 706         case Q_QUOTAON:
 707                 return quota_quotaon(sb, type, id, path);
 708         case Q_QUOTAOFF:
 709                 return quota_quotaoff(sb, type);
 710         case Q_GETFMT:
 711                 return quota_getfmt(sb, type, addr);
 712         case Q_GETINFO:
 713                 return quota_getinfo(sb, type, addr);
 714         case Q_SETINFO:
 715                 return quota_setinfo(sb, type, addr);
 716         case Q_GETQUOTA:
 717                 return quota_getquota(sb, type, id, addr);
 718         case Q_GETNEXTQUOTA:
 719                 return quota_getnextquota(sb, type, id, addr);
 720         case Q_SETQUOTA:
 721                 return quota_setquota(sb, type, id, addr);
 722         case Q_SYNC:
 723                 if (!sb->s_qcop->quota_sync)
 724                         return -ENOSYS;
 725                 return sb->s_qcop->quota_sync(sb, type);
 726         case Q_XQUOTAON:
 727                 return quota_enable(sb, addr);
 728         case Q_XQUOTAOFF:
 729                 return quota_disable(sb, addr);
 730         case Q_XQUOTARM:
 731                 return quota_rmxquota(sb, addr);
 732         case Q_XGETQSTAT:
 733                 return quota_getxstate(sb, type, addr);
 734         case Q_XGETQSTATV:
 735                 return quota_getxstatev(sb, type, addr);
 736         case Q_XSETQLIM:
 737                 return quota_setxquota(sb, type, id, addr);
 738         case Q_XGETQUOTA:
 739                 return quota_getxquota(sb, type, id, addr);
 740         case Q_XGETNEXTQUOTA:
 741                 return quota_getnextxquota(sb, type, id, addr);
 742         case Q_XQUOTASYNC:
 743                 if (sb_rdonly(sb))
 744                         return -EROFS;
 745                 /* XFS quotas are fully coherent now, making this call a noop */
 746                 return 0;
 747         default:
 748                 return -EINVAL;
 749         }
 750 }
 751
 752 #ifdef CONFIG_BLOCK
 753
 754 /* Return 1 if 'cmd' will block on frozen filesystem */
 755 static int quotactl_cmd_write(int cmd)
 756 {
 757         /*
 758          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 759          * as dquot_acquire() may allocate space for new structure and OCFS2
 760          * needs to increment on-disk use count.
 761          */
 762         switch (cmd) {
 763         case Q_GETFMT:
 764         case Q_GETINFO:
 765         case Q_SYNC:
 766         case Q_XGETQSTAT:
 767         case Q_XGETQSTATV:
 768         case Q_XGETQUOTA:
 769         case Q_XGETNEXTQUOTA:
 770         case Q_XQUOTASYNC:
 771                 return 0;
 772         }
 773         return 1;
 774 }
 775 #endif /* CONFIG_BLOCK */
 776
 777 /* Return true if quotactl command is manipulating quota on/off state */
 778 static bool quotactl_cmd_onoff(int cmd)
 779 {
 780         return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 781                  (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 782 }
 783
 784 /*
 785  * look up a superblock on which quota ops will be performed
 786  * - use the name of a block device to find the superblock thereon
 787  */
 788 static struct super_block *quotactl_block(const char __user *special, int cmd)
 789 {
 790 #ifdef CONFIG_BLOCK
 791         struct block_device *bdev;
 792         struct super_block *sb;
 793         struct filename *tmp = getname(special);
 794
 795         if (IS_ERR(tmp))
 796                 return ERR_CAST(tmp);
 797         bdev = lookup_bdev(tmp->name);
 798         putname(tmp);
 799         if (IS_ERR(bdev))
 800                 return ERR_CAST(bdev);
 801         if (quotactl_cmd_onoff(cmd))
 802                 sb = get_super_exclusive_thawed(bdev);
 803         else if (quotactl_cmd_write(cmd))
 804                 sb = get_super_thawed(bdev);
 805         else
 806                 sb = get_super(bdev);
 807         bdput(bdev);
 808         if (!sb)
 809                 return ERR_PTR(-ENODEV);
 810
 811         return sb;
 812 #else
 813         return ERR_PTR(-ENODEV);
 814 #endif
 815 }
 816
 817 /*
 818  * This is the system call interface. This communicates with
 819  * the user-level programs. Currently this only supports diskquota
 820  * calls. Maybe we need to add the process quotas etc. in the future,
 821  * but we probably should use rlimits for that.
 822  */
 823 int kernel_quotactl(unsigned int cmd, const char __user *special,
 824                     qid_t id, void __user *addr)
 825 {
 826         uint cmds, type;
 827         struct super_block *sb = NULL;
 828         struct path path, *pathp = NULL;
 829         int ret;
 830
 831         cmds = cmd >> SUBCMDSHIFT;
 832         type = cmd & SUBCMDMASK;
 833
 834         /*
 835          * As a special case Q_SYNC can be called without a specific device.
 836          * It will iterate all superblocks that have quota enabled and call
 837          * the sync action on each of them.
 838          */
 839         if (!special) {
 840                 if (cmds == Q_SYNC)
 841                         return quota_sync_all(type);
 842                 return -ENODEV;
 843         }
 844
 845         /*
 846          * Path for quotaon has to be resolved before grabbing superblock
 847          * because that gets s_umount sem which is also possibly needed by path
 848          * resolution (think about autofs) and thus deadlocks could arise.
 849          */
 850         if (cmds == Q_QUOTAON) {
 851                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 852                 if (ret)
 853                         pathp = ERR_PTR(ret);
 854                 else
 855                         pathp = &path;
 856         }
 857
 858         sb = quotactl_block(special, cmds);
 859         if (IS_ERR(sb)) {
 860                 ret = PTR_ERR(sb);
 861                 goto out;
 862         }
 863
 864         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 865
 866         if (!quotactl_cmd_onoff(cmds))
 867                 drop_super(sb);
 868         else
 869                 drop_super_exclusive(sb);
 870 out:
 871         if (pathp && !IS_ERR(pathp))
 872                 path_put(pathp);
 873         return ret;
 874 }
 875
 876 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 877                 qid_t, id, void __user *, addr)
 878 {
 879         return kernel_quotactl(cmd, special, id, addr);
 880 }