fs/quota/quota.c

   1 /*
   2  * Quota code necessary even when VFS quota support is not compiled
   3  * into the kernel.  The interesting stuff is over in dquot.c, here
   4  * we have symbols for initial quotactl(2) handling, the sysctl(2)
   5  * variables, etc - things needed even when quota support disabled.
   6  */
   7
   8 #include <linux/fs.h>
   9 #include <linux/namei.h>
  10 #include <linux/slab.h>
  11 #include <asm/current.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/kernel.h>
  14 #include <linux/security.h>
  15 #include <linux/syscalls.h>
  16 #include <linux/capability.h>
  17 #include <linux/quotaops.h>
  18 #include <linux/types.h>
  19 #include <linux/writeback.h>
  20 #include <linux/nospec.h>
  21
  22 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  23                                      qid_t id)
  24 {
  25         switch (cmd) {
  26         /* these commands do not require any special privilegues */
  27         case Q_GETFMT:
  28         case Q_SYNC:
  29         case Q_GETINFO:
  30         case Q_XGETQSTAT:
  31         case Q_XGETQSTATV:
  32         case Q_XQUOTASYNC:
  33                 break;
  34         /* allow to query information for dquots we "own" */
  35         case Q_GETQUOTA:
  36         case Q_XGETQUOTA:
  37                 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  38                     (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  39                         break;
  40                 /*FALLTHROUGH*/
  41         default:
  42                 if (!capable(CAP_SYS_ADMIN))
  43                         return -EPERM;
  44         }
  45
  46         return security_quotactl(cmd, type, id, sb);
  47 }
  48
  49 static void quota_sync_one(struct super_block *sb, void *arg)
  50 {
  51         int type = *(int *)arg;
  52
  53         if (sb->s_qcop && sb->s_qcop->quota_sync &&
  54             (sb->s_quota_types & (1 << type)))
  55                 sb->s_qcop->quota_sync(sb, type);
  56 }
  57
  58 static int quota_sync_all(int type)
  59 {
  60         int ret;
  61
  62         if (type >= MAXQUOTAS)
  63                 return -EINVAL;
  64         ret = security_quotactl(Q_SYNC, type, 0, NULL);
  65         if (!ret)
  66                 iterate_supers(quota_sync_one, &type);
  67         return ret;
  68 }
  69
  70 unsigned int qtype_enforce_flag(int type)
  71 {
  72         switch (type) {
  73         case USRQUOTA:
  74                 return FS_QUOTA_UDQ_ENFD;
  75         case GRPQUOTA:
  76                 return FS_QUOTA_GDQ_ENFD;
  77         case PRJQUOTA:
  78                 return FS_QUOTA_PDQ_ENFD;
  79         }
  80         return 0;
  81 }
  82
  83 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  84                          struct path *path)
  85 {
  86         if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  87                 return -ENOSYS;
  88         if (sb->s_qcop->quota_enable)
  89                 return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  90         if (IS_ERR(path))
  91                 return PTR_ERR(path);
  92         return sb->s_qcop->quota_on(sb, type, id, path);
  93 }
  94
  95 static int quota_quotaoff(struct super_block *sb, int type)
  96 {
  97         if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
  98                 return -ENOSYS;
  99         if (sb->s_qcop->quota_disable)
 100                 return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 101         return sb->s_qcop->quota_off(sb, type);
 102 }
 103
 104 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 105 {
 106         __u32 fmt;
 107
 108         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
 109         if (!sb_has_quota_active(sb, type)) {
 110                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 111                 return -ESRCH;
 112         }
 113         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 114         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 115         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 116                 return -EFAULT;
 117         return 0;
 118 }
 119
 120 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 121 {
 122         struct qc_state state;
 123         struct qc_type_state *tstate;
 124         struct if_dqinfo uinfo;
 125         int ret;
 126
 127         /* This checks whether qc_state has enough entries... */
 128         BUILD_BUG_ON(MAXQUOTAS > XQM_MAXQUOTAS);
 129         if (!sb->s_qcop->get_state)
 130                 return -ENOSYS;
 131         ret = sb->s_qcop->get_state(sb, &state);
 132         if (ret)
 133                 return ret;
 134         tstate = state.s_state + type;
 135         if (!(tstate->flags & QCI_ACCT_ENABLED))
 136                 return -ESRCH;
 137         memset(&uinfo, 0, sizeof(uinfo));
 138         uinfo.dqi_bgrace = tstate->spc_timelimit;
 139         uinfo.dqi_igrace = tstate->ino_timelimit;
 140         if (tstate->flags & QCI_SYSFILE)
 141                 uinfo.dqi_flags |= DQF_SYS_FILE;
 142         if (tstate->flags & QCI_ROOT_SQUASH)
 143                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 144         uinfo.dqi_valid = IIF_ALL;
 145         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 146                 return -EFAULT;
 147         return 0;
 148 }
 149
 150 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 151 {
 152         struct if_dqinfo info;
 153         struct qc_info qinfo;
 154
 155         if (copy_from_user(&info, addr, sizeof(info)))
 156                 return -EFAULT;
 157         if (!sb->s_qcop->set_info)
 158                 return -ENOSYS;
 159         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 160                 return -EINVAL;
 161         memset(&qinfo, 0, sizeof(qinfo));
 162         if (info.dqi_valid & IIF_FLAGS) {
 163                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 164                         return -EINVAL;
 165                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 166                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 167                 qinfo.i_fieldmask |= QC_FLAGS;
 168         }
 169         if (info.dqi_valid & IIF_BGRACE) {
 170                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 171                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 172         }
 173         if (info.dqi_valid & IIF_IGRACE) {
 174                 qinfo.i_ino_timelimit = info.dqi_igrace;
 175                 qinfo.i_fieldmask |= QC_INO_TIMER;
 176         }
 177         return sb->s_qcop->set_info(sb, type, &qinfo);
 178 }
 179
 180 static inline qsize_t qbtos(qsize_t blocks)
 181 {
 182         return blocks << QIF_DQBLKSIZE_BITS;
 183 }
 184
 185 static inline qsize_t stoqb(qsize_t space)
 186 {
 187         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 188 }
 189
 190 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 191 {
 192         memset(dst, 0, sizeof(*dst));
 193         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 194         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 195         dst->dqb_curspace = src->d_space;
 196         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 197         dst->dqb_isoftlimit = src->d_ino_softlimit;
 198         dst->dqb_curinodes = src->d_ino_count;
 199         dst->dqb_btime = src->d_spc_timer;
 200         dst->dqb_itime = src->d_ino_timer;
 201         dst->dqb_valid = QIF_ALL;
 202 }
 203
 204 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 205                           void __user *addr)
 206 {
 207         struct kqid qid;
 208         struct qc_dqblk fdq;
 209         struct if_dqblk idq;
 210         int ret;
 211
 212         if (!sb->s_qcop->get_dqblk)
 213                 return -ENOSYS;
 214         qid = make_kqid(current_user_ns(), type, id);
 215         if (!qid_has_mapping(sb->s_user_ns, qid))
 216                 return -EINVAL;
 217         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 218         if (ret)
 219                 return ret;
 220         copy_to_if_dqblk(&idq, &fdq);
 221         if (copy_to_user(addr, &idq, sizeof(idq)))
 222                 return -EFAULT;
 223         return 0;
 224 }
 225
 226 /*
 227  * Return quota for next active quota >= this id, if any exists,
 228  * otherwise return -ENOENT via ->get_nextdqblk
 229  */
 230 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 231                           void __user *addr)
 232 {
 233         struct kqid qid;
 234         struct qc_dqblk fdq;
 235         struct if_nextdqblk idq;
 236         int ret;
 237
 238         if (!sb->s_qcop->get_nextdqblk)
 239                 return -ENOSYS;
 240         qid = make_kqid(current_user_ns(), type, id);
 241         if (!qid_has_mapping(sb->s_user_ns, qid))
 242                 return -EINVAL;
 243         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 244         if (ret)
 245                 return ret;
 246         /* struct if_nextdqblk is a superset of struct if_dqblk */
 247         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 248         idq.dqb_id = from_kqid(current_user_ns(), qid);
 249         if (copy_to_user(addr, &idq, sizeof(idq)))
 250                 return -EFAULT;
 251         return 0;
 252 }
 253
 254 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 255 {
 256         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 257         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 258         dst->d_space = src->dqb_curspace;
 259         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 260         dst->d_ino_softlimit = src->dqb_isoftlimit;
 261         dst->d_ino_count = src->dqb_curinodes;
 262         dst->d_spc_timer = src->dqb_btime;
 263         dst->d_ino_timer = src->dqb_itime;
 264
 265         dst->d_fieldmask = 0;
 266         if (src->dqb_valid & QIF_BLIMITS)
 267                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 268         if (src->dqb_valid & QIF_SPACE)
 269                 dst->d_fieldmask |= QC_SPACE;
 270         if (src->dqb_valid & QIF_ILIMITS)
 271                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 272         if (src->dqb_valid & QIF_INODES)
 273                 dst->d_fieldmask |= QC_INO_COUNT;
 274         if (src->dqb_valid & QIF_BTIME)
 275                 dst->d_fieldmask |= QC_SPC_TIMER;
 276         if (src->dqb_valid & QIF_ITIME)
 277                 dst->d_fieldmask |= QC_INO_TIMER;
 278 }
 279
 280 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 281                           void __user *addr)
 282 {
 283         struct qc_dqblk fdq;
 284         struct if_dqblk idq;
 285         struct kqid qid;
 286
 287         if (copy_from_user(&idq, addr, sizeof(idq)))
 288                 return -EFAULT;
 289         if (!sb->s_qcop->set_dqblk)
 290                 return -ENOSYS;
 291         qid = make_kqid(current_user_ns(), type, id);
 292         if (!qid_has_mapping(sb->s_user_ns, qid))
 293                 return -EINVAL;
 294         copy_from_if_dqblk(&fdq, &idq);
 295         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 296 }
 297
 298 static int quota_enable(struct super_block *sb, void __user *addr)
 299 {
 300         __u32 flags;
 301
 302         if (copy_from_user(&flags, addr, sizeof(flags)))
 303                 return -EFAULT;
 304         if (!sb->s_qcop->quota_enable)
 305                 return -ENOSYS;
 306         return sb->s_qcop->quota_enable(sb, flags);
 307 }
 308
 309 static int quota_disable(struct super_block *sb, void __user *addr)
 310 {
 311         __u32 flags;
 312
 313         if (copy_from_user(&flags, addr, sizeof(flags)))
 314                 return -EFAULT;
 315         if (!sb->s_qcop->quota_disable)
 316                 return -ENOSYS;
 317         return sb->s_qcop->quota_disable(sb, flags);
 318 }
 319
 320 static int quota_state_to_flags(struct qc_state *state)
 321 {
 322         int flags = 0;
 323
 324         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 325                 flags |= FS_QUOTA_UDQ_ACCT;
 326         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 327                 flags |= FS_QUOTA_UDQ_ENFD;
 328         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 329                 flags |= FS_QUOTA_GDQ_ACCT;
 330         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 331                 flags |= FS_QUOTA_GDQ_ENFD;
 332         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 333                 flags |= FS_QUOTA_PDQ_ACCT;
 334         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 335                 flags |= FS_QUOTA_PDQ_ENFD;
 336         return flags;
 337 }
 338
 339 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
 340 {
 341         int type;
 342         struct qc_state state;
 343         int ret;
 344
 345         memset(&state, 0, sizeof (struct qc_state));
 346         ret = sb->s_qcop->get_state(sb, &state);
 347         if (ret < 0)
 348                 return ret;
 349
 350         memset(fqs, 0, sizeof(*fqs));
 351         fqs->qs_version = FS_QSTAT_VERSION;
 352         fqs->qs_flags = quota_state_to_flags(&state);
 353         /* No quota enabled? */
 354         if (!fqs->qs_flags)
 355                 return -ENOSYS;
 356         fqs->qs_incoredqs = state.s_incoredqs;
 357         /*
 358          * GETXSTATE quotactl has space for just one set of time limits so
 359          * report them for the first enabled quota type
 360          */
 361         for (type = 0; type < XQM_MAXQUOTAS; type++)
 362                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 363                         break;
 364         BUG_ON(type == XQM_MAXQUOTAS);
 365         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 366         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 367         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 368         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 369         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 370
 371         /* Inodes may be allocated even if inactive; copy out if present */
 372         if (state.s_state[USRQUOTA].ino) {
 373                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 374                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 375                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 376         }
 377         if (state.s_state[GRPQUOTA].ino) {
 378                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 379                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 380                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 381         }
 382         if (state.s_state[PRJQUOTA].ino) {
 383                 /*
 384                  * Q_XGETQSTAT doesn't have room for both group and project
 385                  * quotas.  So, allow the project quota values to be copied out
 386                  * only if there is no group quota information available.
 387                  */
 388                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 389                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 390                         fqs->qs_gquota.qfs_nblks =
 391                                         state.s_state[PRJQUOTA].blocks;
 392                         fqs->qs_gquota.qfs_nextents =
 393                                         state.s_state[PRJQUOTA].nextents;
 394                 }
 395         }
 396         return 0;
 397 }
 398
 399 static int quota_getxstate(struct super_block *sb, void __user *addr)
 400 {
 401         struct fs_quota_stat fqs;
 402         int ret;
 403
 404         if (!sb->s_qcop->get_state)
 405                 return -ENOSYS;
 406         ret = quota_getstate(sb, &fqs);
 407         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 408                 return -EFAULT;
 409         return ret;
 410 }
 411
 412 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
 413 {
 414         int type;
 415         struct qc_state state;
 416         int ret;
 417
 418         memset(&state, 0, sizeof (struct qc_state));
 419         ret = sb->s_qcop->get_state(sb, &state);
 420         if (ret < 0)
 421                 return ret;
 422
 423         memset(fqs, 0, sizeof(*fqs));
 424         fqs->qs_version = FS_QSTAT_VERSION;
 425         fqs->qs_flags = quota_state_to_flags(&state);
 426         /* No quota enabled? */
 427         if (!fqs->qs_flags)
 428                 return -ENOSYS;
 429         fqs->qs_incoredqs = state.s_incoredqs;
 430         /*
 431          * GETXSTATV quotactl has space for just one set of time limits so
 432          * report them for the first enabled quota type
 433          */
 434         for (type = 0; type < XQM_MAXQUOTAS; type++)
 435                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 436                         break;
 437         BUG_ON(type == XQM_MAXQUOTAS);
 438         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 439         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 440         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 441         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 442         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 443
 444         /* Inodes may be allocated even if inactive; copy out if present */
 445         if (state.s_state[USRQUOTA].ino) {
 446                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 447                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 448                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 449         }
 450         if (state.s_state[GRPQUOTA].ino) {
 451                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 452                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 453                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 454         }
 455         if (state.s_state[PRJQUOTA].ino) {
 456                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 457                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 458                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 459         }
 460         return 0;
 461 }
 462
 463 static int quota_getxstatev(struct super_block *sb, void __user *addr)
 464 {
 465         struct fs_quota_statv fqs;
 466         int ret;
 467
 468         if (!sb->s_qcop->get_state)
 469                 return -ENOSYS;
 470
 471         memset(&fqs, 0, sizeof(fqs));
 472         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 473                 return -EFAULT;
 474
 475         /* If this kernel doesn't support user specified version, fail */
 476         switch (fqs.qs_version) {
 477         case FS_QSTATV_VERSION1:
 478                 break;
 479         default:
 480                 return -EINVAL;
 481         }
 482         ret = quota_getstatev(sb, &fqs);
 483         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 484                 return -EFAULT;
 485         return ret;
 486 }
 487
 488 /*
 489  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 490  * out of there as xfsprogs rely on definitions being in that header file. So
 491  * just define same functions here for quota purposes.
 492  */
 493 #define XFS_BB_SHIFT 9
 494
 495 static inline u64 quota_bbtob(u64 blocks)
 496 {
 497         return blocks << XFS_BB_SHIFT;
 498 }
 499
 500 static inline u64 quota_btobb(u64 bytes)
 501 {
 502         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 503 }
 504
 505 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 506 {
 507         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 508         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 509         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 510         dst->d_ino_softlimit = src->d_ino_softlimit;
 511         dst->d_space = quota_bbtob(src->d_bcount);
 512         dst->d_ino_count = src->d_icount;
 513         dst->d_ino_timer = src->d_itimer;
 514         dst->d_spc_timer = src->d_btimer;
 515         dst->d_ino_warns = src->d_iwarns;
 516         dst->d_spc_warns = src->d_bwarns;
 517         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 518         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 519         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 520         dst->d_rt_spc_timer = src->d_rtbtimer;
 521         dst->d_rt_spc_warns = src->d_rtbwarns;
 522         dst->d_fieldmask = 0;
 523         if (src->d_fieldmask & FS_DQ_ISOFT)
 524                 dst->d_fieldmask |= QC_INO_SOFT;
 525         if (src->d_fieldmask & FS_DQ_IHARD)
 526                 dst->d_fieldmask |= QC_INO_HARD;
 527         if (src->d_fieldmask & FS_DQ_BSOFT)
 528                 dst->d_fieldmask |= QC_SPC_SOFT;
 529         if (src->d_fieldmask & FS_DQ_BHARD)
 530                 dst->d_fieldmask |= QC_SPC_HARD;
 531         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 532                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 533         if (src->d_fieldmask & FS_DQ_RTBHARD)
 534                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 535         if (src->d_fieldmask & FS_DQ_BTIMER)
 536                 dst->d_fieldmask |= QC_SPC_TIMER;
 537         if (src->d_fieldmask & FS_DQ_ITIMER)
 538                 dst->d_fieldmask |= QC_INO_TIMER;
 539         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 540                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 541         if (src->d_fieldmask & FS_DQ_BWARNS)
 542                 dst->d_fieldmask |= QC_SPC_WARNS;
 543         if (src->d_fieldmask & FS_DQ_IWARNS)
 544                 dst->d_fieldmask |= QC_INO_WARNS;
 545         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 546                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 547         if (src->d_fieldmask & FS_DQ_BCOUNT)
 548                 dst->d_fieldmask |= QC_SPACE;
 549         if (src->d_fieldmask & FS_DQ_ICOUNT)
 550                 dst->d_fieldmask |= QC_INO_COUNT;
 551         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 552                 dst->d_fieldmask |= QC_RT_SPACE;
 553 }
 554
 555 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 556                                        struct fs_disk_quota *src)
 557 {
 558         memset(dst, 0, sizeof(*dst));
 559         dst->i_spc_timelimit = src->d_btimer;
 560         dst->i_ino_timelimit = src->d_itimer;
 561         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 562         dst->i_ino_warnlimit = src->d_iwarns;
 563         dst->i_spc_warnlimit = src->d_bwarns;
 564         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 565         if (src->d_fieldmask & FS_DQ_BWARNS)
 566                 dst->i_fieldmask |= QC_SPC_WARNS;
 567         if (src->d_fieldmask & FS_DQ_IWARNS)
 568                 dst->i_fieldmask |= QC_INO_WARNS;
 569         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 570                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 571         if (src->d_fieldmask & FS_DQ_BTIMER)
 572                 dst->i_fieldmask |= QC_SPC_TIMER;
 573         if (src->d_fieldmask & FS_DQ_ITIMER)
 574                 dst->i_fieldmask |= QC_INO_TIMER;
 575         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 576                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 577 }
 578
 579 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 580                            void __user *addr)
 581 {
 582         struct fs_disk_quota fdq;
 583         struct qc_dqblk qdq;
 584         struct kqid qid;
 585
 586         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 587                 return -EFAULT;
 588         if (!sb->s_qcop->set_dqblk)
 589                 return -ENOSYS;
 590         qid = make_kqid(current_user_ns(), type, id);
 591         if (!qid_has_mapping(sb->s_user_ns, qid))
 592                 return -EINVAL;
 593         /* Are we actually setting timer / warning limits for all users? */
 594         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 595             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 596                 struct qc_info qinfo;
 597                 int ret;
 598
 599                 if (!sb->s_qcop->set_info)
 600                         return -EINVAL;
 601                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 602                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 603                 if (ret)
 604                         return ret;
 605                 /* These are already done */
 606                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 607         }
 608         copy_from_xfs_dqblk(&qdq, &fdq);
 609         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 610 }
 611
 612 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 613                               int type, qid_t id)
 614 {
 615         memset(dst, 0, sizeof(*dst));
 616         dst->d_version = FS_DQUOT_VERSION;
 617         dst->d_id = id;
 618         if (type == USRQUOTA)
 619                 dst->d_flags = FS_USER_QUOTA;
 620         else if (type == PRJQUOTA)
 621                 dst->d_flags = FS_PROJ_QUOTA;
 622         else
 623                 dst->d_flags = FS_GROUP_QUOTA;
 624         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 625         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 626         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 627         dst->d_ino_softlimit = src->d_ino_softlimit;
 628         dst->d_bcount = quota_btobb(src->d_space);
 629         dst->d_icount = src->d_ino_count;
 630         dst->d_itimer = src->d_ino_timer;
 631         dst->d_btimer = src->d_spc_timer;
 632         dst->d_iwarns = src->d_ino_warns;
 633         dst->d_bwarns = src->d_spc_warns;
 634         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 635         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 636         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 637         dst->d_rtbtimer = src->d_rt_spc_timer;
 638         dst->d_rtbwarns = src->d_rt_spc_warns;
 639 }
 640
 641 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 642                            void __user *addr)
 643 {
 644         struct fs_disk_quota fdq;
 645         struct qc_dqblk qdq;
 646         struct kqid qid;
 647         int ret;
 648
 649         if (!sb->s_qcop->get_dqblk)
 650                 return -ENOSYS;
 651         qid = make_kqid(current_user_ns(), type, id);
 652         if (!qid_has_mapping(sb->s_user_ns, qid))
 653                 return -EINVAL;
 654         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 655         if (ret)
 656                 return ret;
 657         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 658         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 659                 return -EFAULT;
 660         return ret;
 661 }
 662
 663 /*
 664  * Return quota for next active quota >= this id, if any exists,
 665  * otherwise return -ENOENT via ->get_nextdqblk.
 666  */
 667 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 668                             void __user *addr)
 669 {
 670         struct fs_disk_quota fdq;
 671         struct qc_dqblk qdq;
 672         struct kqid qid;
 673         qid_t id_out;
 674         int ret;
 675
 676         if (!sb->s_qcop->get_nextdqblk)
 677                 return -ENOSYS;
 678         qid = make_kqid(current_user_ns(), type, id);
 679         if (!qid_has_mapping(sb->s_user_ns, qid))
 680                 return -EINVAL;
 681         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 682         if (ret)
 683                 return ret;
 684         id_out = from_kqid(current_user_ns(), qid);
 685         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 686         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 687                 return -EFAULT;
 688         return ret;
 689 }
 690
 691 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 692 {
 693         __u32 flags;
 694
 695         if (copy_from_user(&flags, addr, sizeof(flags)))
 696                 return -EFAULT;
 697         if (!sb->s_qcop->rm_xquota)
 698                 return -ENOSYS;
 699         return sb->s_qcop->rm_xquota(sb, flags);
 700 }
 701
 702 /* Copy parameters and call proper function */
 703 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 704                        void __user *addr, struct path *path)
 705 {
 706         int ret;
 707
 708         if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
 709                 return -EINVAL;
 710         type = array_index_nospec(type, MAXQUOTAS);
 711         /*
 712          * Quota not supported on this fs? Check this before s_quota_types
 713          * since they needn't be set if quota is not supported at all.
 714          */
 715         if (!sb->s_qcop)
 716                 return -ENOSYS;
 717         if (!(sb->s_quota_types & (1 << type)))
 718                 return -EINVAL;
 719
 720         ret = check_quotactl_permission(sb, type, cmd, id);
 721         if (ret < 0)
 722                 return ret;
 723
 724         switch (cmd) {
 725         case Q_QUOTAON:
 726                 return quota_quotaon(sb, type, id, path);
 727         case Q_QUOTAOFF:
 728                 return quota_quotaoff(sb, type);
 729         case Q_GETFMT:
 730                 return quota_getfmt(sb, type, addr);
 731         case Q_GETINFO:
 732                 return quota_getinfo(sb, type, addr);
 733         case Q_SETINFO:
 734                 return quota_setinfo(sb, type, addr);
 735         case Q_GETQUOTA:
 736                 return quota_getquota(sb, type, id, addr);
 737         case Q_GETNEXTQUOTA:
 738                 return quota_getnextquota(sb, type, id, addr);
 739         case Q_SETQUOTA:
 740                 return quota_setquota(sb, type, id, addr);
 741         case Q_SYNC:
 742                 if (!sb->s_qcop->quota_sync)
 743                         return -ENOSYS;
 744                 return sb->s_qcop->quota_sync(sb, type);
 745         case Q_XQUOTAON:
 746                 return quota_enable(sb, addr);
 747         case Q_XQUOTAOFF:
 748                 return quota_disable(sb, addr);
 749         case Q_XQUOTARM:
 750                 return quota_rmxquota(sb, addr);
 751         case Q_XGETQSTAT:
 752                 return quota_getxstate(sb, addr);
 753         case Q_XGETQSTATV:
 754                 return quota_getxstatev(sb, addr);
 755         case Q_XSETQLIM:
 756                 return quota_setxquota(sb, type, id, addr);
 757         case Q_XGETQUOTA:
 758                 return quota_getxquota(sb, type, id, addr);
 759         case Q_XGETNEXTQUOTA:
 760                 return quota_getnextxquota(sb, type, id, addr);
 761         case Q_XQUOTASYNC:
 762                 if (sb->s_flags & MS_RDONLY)
 763                         return -EROFS;
 764                 /* XFS quotas are fully coherent now, making this call a noop */
 765                 return 0;
 766         default:
 767                 return -EINVAL;
 768         }
 769 }
 770
 771 #ifdef CONFIG_BLOCK
 772
 773 /* Return 1 if 'cmd' will block on frozen filesystem */
 774 static int quotactl_cmd_write(int cmd)
 775 {
 776         /*
 777          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 778          * as dquot_acquire() may allocate space for new structure and OCFS2
 779          * needs to increment on-disk use count.
 780          */
 781         switch (cmd) {
 782         case Q_GETFMT:
 783         case Q_GETINFO:
 784         case Q_SYNC:
 785         case Q_XGETQSTAT:
 786         case Q_XGETQSTATV:
 787         case Q_XGETQUOTA:
 788         case Q_XGETNEXTQUOTA:
 789         case Q_XQUOTASYNC:
 790                 return 0;
 791         }
 792         return 1;
 793 }
 794
 795 #endif /* CONFIG_BLOCK */
 796
 797 /*
 798  * look up a superblock on which quota ops will be performed
 799  * - use the name of a block device to find the superblock thereon
 800  */
 801 static struct super_block *quotactl_block(const char __user *special, int cmd)
 802 {
 803 #ifdef CONFIG_BLOCK
 804         struct block_device *bdev;
 805         struct super_block *sb;
 806         struct filename *tmp = getname(special);
 807
 808         if (IS_ERR(tmp))
 809                 return ERR_CAST(tmp);
 810         bdev = lookup_bdev(tmp->name);
 811         putname(tmp);
 812         if (IS_ERR(bdev))
 813                 return ERR_CAST(bdev);
 814         if (quotactl_cmd_write(cmd))
 815                 sb = get_super_thawed(bdev);
 816         else
 817                 sb = get_super(bdev);
 818         bdput(bdev);
 819         if (!sb)
 820                 return ERR_PTR(-ENODEV);
 821
 822         return sb;
 823 #else
 824         return ERR_PTR(-ENODEV);
 825 #endif
 826 }
 827
 828 /*
 829  * This is the system call interface. This communicates with
 830  * the user-level programs. Currently this only supports diskquota
 831  * calls. Maybe we need to add the process quotas etc. in the future,
 832  * but we probably should use rlimits for that.
 833  */
 834 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 835                 qid_t, id, void __user *, addr)
 836 {
 837         uint cmds, type;
 838         struct super_block *sb = NULL;
 839         struct path path, *pathp = NULL;
 840         int ret;
 841
 842         cmds = cmd >> SUBCMDSHIFT;
 843         type = cmd & SUBCMDMASK;
 844
 845         /*
 846          * As a special case Q_SYNC can be called without a specific device.
 847          * It will iterate all superblocks that have quota enabled and call
 848          * the sync action on each of them.
 849          */
 850         if (!special) {
 851                 if (cmds == Q_SYNC)
 852                         return quota_sync_all(type);
 853                 return -ENODEV;
 854         }
 855
 856         /*
 857          * Path for quotaon has to be resolved before grabbing superblock
 858          * because that gets s_umount sem which is also possibly needed by path
 859          * resolution (think about autofs) and thus deadlocks could arise.
 860          */
 861         if (cmds == Q_QUOTAON) {
 862                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 863                 if (ret)
 864                         pathp = ERR_PTR(ret);
 865                 else
 866                         pathp = &path;
 867         }
 868
 869         sb = quotactl_block(special, cmds);
 870         if (IS_ERR(sb)) {
 871                 ret = PTR_ERR(sb);
 872                 goto out;
 873         }
 874
 875         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 876
 877         drop_super(sb);
 878 out:
 879         if (pathp && !IS_ERR(pathp))
 880                 path_put(pathp);
 881         return ret;
 882 }