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