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, int cmd, 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 (!ret && copy_to_user(addr, &uinfo, sizeof(uinfo)))
 145                 return -EFAULT;
 146         return ret;
 147 }
 148
 149 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 150 {
 151         struct if_dqinfo info;
 152
 153         if (copy_from_user(&info, addr, sizeof(info)))
 154                 return -EFAULT;
 155         if (!sb->s_qcop->set_info)
 156                 return -ENOSYS;
 157         return sb->s_qcop->set_info(sb, type, &info);
 158 }
 159
 160 static inline qsize_t qbtos(qsize_t blocks)
 161 {
 162         return blocks << QIF_DQBLKSIZE_BITS;
 163 }
 164
 165 static inline qsize_t stoqb(qsize_t space)
 166 {
 167         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 168 }
 169
 170 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 171 {
 172         memset(dst, 0, sizeof(*dst));
 173         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 174         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 175         dst->dqb_curspace = src->d_space;
 176         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 177         dst->dqb_isoftlimit = src->d_ino_softlimit;
 178         dst->dqb_curinodes = src->d_ino_count;
 179         dst->dqb_btime = src->d_spc_timer;
 180         dst->dqb_itime = src->d_ino_timer;
 181         dst->dqb_valid = QIF_ALL;
 182 }
 183
 184 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 185                           void __user *addr)
 186 {
 187         struct kqid qid;
 188         struct qc_dqblk fdq;
 189         struct if_dqblk idq;
 190         int ret;
 191
 192         if (!sb->s_qcop->get_dqblk)
 193                 return -ENOSYS;
 194         qid = make_kqid(current_user_ns(), type, id);
 195         if (!qid_valid(qid))
 196                 return -EINVAL;
 197         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 198         if (ret)
 199                 return ret;
 200         copy_to_if_dqblk(&idq, &fdq);
 201         if (copy_to_user(addr, &idq, sizeof(idq)))
 202                 return -EFAULT;
 203         return 0;
 204 }
 205
 206 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 207 {
 208         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 209         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 210         dst->d_space = src->dqb_curspace;
 211         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 212         dst->d_ino_softlimit = src->dqb_isoftlimit;
 213         dst->d_ino_count = src->dqb_curinodes;
 214         dst->d_spc_timer = src->dqb_btime;
 215         dst->d_ino_timer = src->dqb_itime;
 216
 217         dst->d_fieldmask = 0;
 218         if (src->dqb_valid & QIF_BLIMITS)
 219                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 220         if (src->dqb_valid & QIF_SPACE)
 221                 dst->d_fieldmask |= QC_SPACE;
 222         if (src->dqb_valid & QIF_ILIMITS)
 223                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 224         if (src->dqb_valid & QIF_INODES)
 225                 dst->d_fieldmask |= QC_INO_COUNT;
 226         if (src->dqb_valid & QIF_BTIME)
 227                 dst->d_fieldmask |= QC_SPC_TIMER;
 228         if (src->dqb_valid & QIF_ITIME)
 229                 dst->d_fieldmask |= QC_INO_TIMER;
 230 }
 231
 232 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 233                           void __user *addr)
 234 {
 235         struct qc_dqblk fdq;
 236         struct if_dqblk idq;
 237         struct kqid qid;
 238
 239         if (copy_from_user(&idq, addr, sizeof(idq)))
 240                 return -EFAULT;
 241         if (!sb->s_qcop->set_dqblk)
 242                 return -ENOSYS;
 243         qid = make_kqid(current_user_ns(), type, id);
 244         if (!qid_valid(qid))
 245                 return -EINVAL;
 246         copy_from_if_dqblk(&fdq, &idq);
 247         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 248 }
 249
 250 static int quota_enable(struct super_block *sb, void __user *addr)
 251 {
 252         __u32 flags;
 253
 254         if (copy_from_user(&flags, addr, sizeof(flags)))
 255                 return -EFAULT;
 256         if (!sb->s_qcop->quota_enable)
 257                 return -ENOSYS;
 258         return sb->s_qcop->quota_enable(sb, flags);
 259 }
 260
 261 static int quota_disable(struct super_block *sb, void __user *addr)
 262 {
 263         __u32 flags;
 264
 265         if (copy_from_user(&flags, addr, sizeof(flags)))
 266                 return -EFAULT;
 267         if (!sb->s_qcop->quota_disable)
 268                 return -ENOSYS;
 269         return sb->s_qcop->quota_disable(sb, flags);
 270 }
 271
 272 static int quota_state_to_flags(struct qc_state *state)
 273 {
 274         int flags = 0;
 275
 276         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 277                 flags |= FS_QUOTA_UDQ_ACCT;
 278         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 279                 flags |= FS_QUOTA_UDQ_ENFD;
 280         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 281                 flags |= FS_QUOTA_GDQ_ACCT;
 282         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 283                 flags |= FS_QUOTA_GDQ_ENFD;
 284         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 285                 flags |= FS_QUOTA_PDQ_ACCT;
 286         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 287                 flags |= FS_QUOTA_PDQ_ENFD;
 288         return flags;
 289 }
 290
 291 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
 292 {
 293         int type;
 294         struct qc_state state;
 295         int ret;
 296
 297         ret = sb->s_qcop->get_state(sb, &state);
 298         if (ret < 0)
 299                 return ret;
 300
 301         memset(fqs, 0, sizeof(*fqs));
 302         fqs->qs_version = FS_QSTAT_VERSION;
 303         fqs->qs_flags = quota_state_to_flags(&state);
 304         /* No quota enabled? */
 305         if (!fqs->qs_flags)
 306                 return -ENOSYS;
 307         fqs->qs_incoredqs = state.s_incoredqs;
 308         /*
 309          * GETXSTATE quotactl has space for just one set of time limits so
 310          * report them for the first enabled quota type
 311          */
 312         for (type = 0; type < XQM_MAXQUOTAS; type++)
 313                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 314                         break;
 315         BUG_ON(type == XQM_MAXQUOTAS);
 316         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 317         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 318         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 319         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 320         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 321         if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
 322                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 323                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 324                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 325         }
 326         if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
 327                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 328                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 329                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 330         }
 331         if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
 332                 /*
 333                  * Q_XGETQSTAT doesn't have room for both group and project
 334                  * quotas.  So, allow the project quota values to be copied out
 335                  * only if there is no group quota information available.
 336                  */
 337                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 338                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 339                         fqs->qs_gquota.qfs_nblks =
 340                                         state.s_state[PRJQUOTA].blocks;
 341                         fqs->qs_gquota.qfs_nextents =
 342                                         state.s_state[PRJQUOTA].nextents;
 343                 }
 344         }
 345         return 0;
 346 }
 347
 348 static int quota_getxstate(struct super_block *sb, void __user *addr)
 349 {
 350         struct fs_quota_stat fqs;
 351         int ret;
 352
 353         if (!sb->s_qcop->get_xstate && !sb->s_qcop->get_state)
 354                 return -ENOSYS;
 355         if (sb->s_qcop->get_state)
 356                 ret = quota_getstate(sb, &fqs);
 357         else
 358                 ret = sb->s_qcop->get_xstate(sb, &fqs);
 359         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 360                 return -EFAULT;
 361         return ret;
 362 }
 363
 364 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
 365 {
 366         int type;
 367         struct qc_state state;
 368         int ret;
 369
 370         ret = sb->s_qcop->get_state(sb, &state);
 371         if (ret < 0)
 372                 return ret;
 373
 374         memset(fqs, 0, sizeof(*fqs));
 375         fqs->qs_version = FS_QSTAT_VERSION;
 376         fqs->qs_flags = quota_state_to_flags(&state);
 377         /* No quota enabled? */
 378         if (!fqs->qs_flags)
 379                 return -ENOSYS;
 380         fqs->qs_incoredqs = state.s_incoredqs;
 381         /*
 382          * GETXSTATV quotactl has space for just one set of time limits so
 383          * report them for the first enabled quota type
 384          */
 385         for (type = 0; type < XQM_MAXQUOTAS; type++)
 386                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 387                         break;
 388         BUG_ON(type == XQM_MAXQUOTAS);
 389         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 390         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 391         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 392         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 393         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 394         if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
 395                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 396                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 397                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 398         }
 399         if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
 400                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 401                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 402                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 403         }
 404         if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
 405                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 406                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 407                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 408         }
 409         return 0;
 410 }
 411
 412 static int quota_getxstatev(struct super_block *sb, void __user *addr)
 413 {
 414         struct fs_quota_statv fqs;
 415         int ret;
 416
 417         if (!sb->s_qcop->get_xstatev && !sb->s_qcop->get_state)
 418                 return -ENOSYS;
 419
 420         memset(&fqs, 0, sizeof(fqs));
 421         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 422                 return -EFAULT;
 423
 424         /* If this kernel doesn't support user specified version, fail */
 425         switch (fqs.qs_version) {
 426         case FS_QSTATV_VERSION1:
 427                 break;
 428         default:
 429                 return -EINVAL;
 430         }
 431         if (sb->s_qcop->get_state)
 432                 ret = quota_getstatev(sb, &fqs);
 433         else
 434                 ret = sb->s_qcop->get_xstatev(sb, &fqs);
 435         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 436                 return -EFAULT;
 437         return ret;
 438 }
 439
 440 /*
 441  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 442  * out of there as xfsprogs rely on definitions being in that header file. So
 443  * just define same functions here for quota purposes.
 444  */
 445 #define XFS_BB_SHIFT 9
 446
 447 static inline u64 quota_bbtob(u64 blocks)
 448 {
 449         return blocks << XFS_BB_SHIFT;
 450 }
 451
 452 static inline u64 quota_btobb(u64 bytes)
 453 {
 454         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 455 }
 456
 457 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 458 {
 459         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 460         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 461         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 462         dst->d_ino_softlimit = src->d_ino_softlimit;
 463         dst->d_space = quota_bbtob(src->d_bcount);
 464         dst->d_ino_count = src->d_icount;
 465         dst->d_ino_timer = src->d_itimer;
 466         dst->d_spc_timer = src->d_btimer;
 467         dst->d_ino_warns = src->d_iwarns;
 468         dst->d_spc_warns = src->d_bwarns;
 469         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 470         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 471         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 472         dst->d_rt_spc_timer = src->d_rtbtimer;
 473         dst->d_rt_spc_warns = src->d_rtbwarns;
 474         dst->d_fieldmask = 0;
 475         if (src->d_fieldmask & FS_DQ_ISOFT)
 476                 dst->d_fieldmask |= QC_INO_SOFT;
 477         if (src->d_fieldmask & FS_DQ_IHARD)
 478                 dst->d_fieldmask |= QC_INO_HARD;
 479         if (src->d_fieldmask & FS_DQ_BSOFT)
 480                 dst->d_fieldmask |= QC_SPC_SOFT;
 481         if (src->d_fieldmask & FS_DQ_BHARD)
 482                 dst->d_fieldmask |= QC_SPC_HARD;
 483         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 484                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 485         if (src->d_fieldmask & FS_DQ_RTBHARD)
 486                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 487         if (src->d_fieldmask & FS_DQ_BTIMER)
 488                 dst->d_fieldmask |= QC_SPC_TIMER;
 489         if (src->d_fieldmask & FS_DQ_ITIMER)
 490                 dst->d_fieldmask |= QC_INO_TIMER;
 491         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 492                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 493         if (src->d_fieldmask & FS_DQ_BWARNS)
 494                 dst->d_fieldmask |= QC_SPC_WARNS;
 495         if (src->d_fieldmask & FS_DQ_IWARNS)
 496                 dst->d_fieldmask |= QC_INO_WARNS;
 497         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 498                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 499         if (src->d_fieldmask & FS_DQ_BCOUNT)
 500                 dst->d_fieldmask |= QC_SPACE;
 501         if (src->d_fieldmask & FS_DQ_ICOUNT)
 502                 dst->d_fieldmask |= QC_INO_COUNT;
 503         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 504                 dst->d_fieldmask |= QC_RT_SPACE;
 505 }
 506
 507 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 508                            void __user *addr)
 509 {
 510         struct fs_disk_quota fdq;
 511         struct qc_dqblk qdq;
 512         struct kqid qid;
 513
 514         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 515                 return -EFAULT;
 516         if (!sb->s_qcop->set_dqblk)
 517                 return -ENOSYS;
 518         qid = make_kqid(current_user_ns(), type, id);
 519         if (!qid_valid(qid))
 520                 return -EINVAL;
 521         copy_from_xfs_dqblk(&qdq, &fdq);
 522         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 523 }
 524
 525 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 526                               int type, qid_t id)
 527 {
 528         memset(dst, 0, sizeof(*dst));
 529         dst->d_version = FS_DQUOT_VERSION;
 530         dst->d_id = id;
 531         if (type == USRQUOTA)
 532                 dst->d_flags = FS_USER_QUOTA;
 533         else if (type == PRJQUOTA)
 534                 dst->d_flags = FS_PROJ_QUOTA;
 535         else
 536                 dst->d_flags = FS_GROUP_QUOTA;
 537         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 538         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 539         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 540         dst->d_ino_softlimit = src->d_ino_softlimit;
 541         dst->d_bcount = quota_btobb(src->d_space);
 542         dst->d_icount = src->d_ino_count;
 543         dst->d_itimer = src->d_ino_timer;
 544         dst->d_btimer = src->d_spc_timer;
 545         dst->d_iwarns = src->d_ino_warns;
 546         dst->d_bwarns = src->d_spc_warns;
 547         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 548         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 549         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 550         dst->d_rtbtimer = src->d_rt_spc_timer;
 551         dst->d_rtbwarns = src->d_rt_spc_warns;
 552 }
 553
 554 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 555                            void __user *addr)
 556 {
 557         struct fs_disk_quota fdq;
 558         struct qc_dqblk qdq;
 559         struct kqid qid;
 560         int ret;
 561
 562         if (!sb->s_qcop->get_dqblk)
 563                 return -ENOSYS;
 564         qid = make_kqid(current_user_ns(), type, id);
 565         if (!qid_valid(qid))
 566                 return -EINVAL;
 567         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 568         if (ret)
 569                 return ret;
 570         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 571         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 572                 return -EFAULT;
 573         return ret;
 574 }
 575
 576 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 577 {
 578         __u32 flags;
 579
 580         if (copy_from_user(&flags, addr, sizeof(flags)))
 581                 return -EFAULT;
 582         if (!sb->s_qcop->rm_xquota)
 583                 return -ENOSYS;
 584         return sb->s_qcop->rm_xquota(sb, flags);
 585 }
 586
 587 /* Copy parameters and call proper function */
 588 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 589                        void __user *addr, struct path *path)
 590 {
 591         int ret;
 592
 593         if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
 594                 return -EINVAL;
 595         /*
 596          * Quota not supported on this fs? Check this before s_quota_types
 597          * since they needn't be set if quota is not supported at all.
 598          */
 599         if (!sb->s_qcop)
 600                 return -ENOSYS;
 601         if (!(sb->s_quota_types & (1 << type)))
 602                 return -EINVAL;
 603
 604         ret = check_quotactl_permission(sb, type, cmd, id);
 605         if (ret < 0)
 606                 return ret;
 607
 608         switch (cmd) {
 609         case Q_QUOTAON:
 610                 return quota_quotaon(sb, type, cmd, id, path);
 611         case Q_QUOTAOFF:
 612                 return quota_quotaoff(sb, type);
 613         case Q_GETFMT:
 614                 return quota_getfmt(sb, type, addr);
 615         case Q_GETINFO:
 616                 return quota_getinfo(sb, type, addr);
 617         case Q_SETINFO:
 618                 return quota_setinfo(sb, type, addr);
 619         case Q_GETQUOTA:
 620                 return quota_getquota(sb, type, id, addr);
 621         case Q_SETQUOTA:
 622                 return quota_setquota(sb, type, id, addr);
 623         case Q_SYNC:
 624                 if (!sb->s_qcop->quota_sync)
 625                         return -ENOSYS;
 626                 return sb->s_qcop->quota_sync(sb, type);
 627         case Q_XQUOTAON:
 628                 return quota_enable(sb, addr);
 629         case Q_XQUOTAOFF:
 630                 return quota_disable(sb, addr);
 631         case Q_XQUOTARM:
 632                 return quota_rmxquota(sb, addr);
 633         case Q_XGETQSTAT:
 634                 return quota_getxstate(sb, addr);
 635         case Q_XGETQSTATV:
 636                 return quota_getxstatev(sb, addr);
 637         case Q_XSETQLIM:
 638                 return quota_setxquota(sb, type, id, addr);
 639         case Q_XGETQUOTA:
 640                 return quota_getxquota(sb, type, id, addr);
 641         case Q_XQUOTASYNC:
 642                 if (sb->s_flags & MS_RDONLY)
 643                         return -EROFS;
 644                 /* XFS quotas are fully coherent now, making this call a noop */
 645                 return 0;
 646         default:
 647                 return -EINVAL;
 648         }
 649 }
 650
 651 #ifdef CONFIG_BLOCK
 652
 653 /* Return 1 if 'cmd' will block on frozen filesystem */
 654 static int quotactl_cmd_write(int cmd)
 655 {
 656         switch (cmd) {
 657         case Q_GETFMT:
 658         case Q_GETINFO:
 659         case Q_SYNC:
 660         case Q_XGETQSTAT:
 661         case Q_XGETQSTATV:
 662         case Q_XGETQUOTA:
 663         case Q_XQUOTASYNC:
 664                 return 0;
 665         }
 666         return 1;
 667 }
 668
 669 #endif /* CONFIG_BLOCK */
 670
 671 /*
 672  * look up a superblock on which quota ops will be performed
 673  * - use the name of a block device to find the superblock thereon
 674  */
 675 static struct super_block *quotactl_block(const char __user *special, int cmd)
 676 {
 677 #ifdef CONFIG_BLOCK
 678         struct block_device *bdev;
 679         struct super_block *sb;
 680         struct filename *tmp = getname(special);
 681
 682         if (IS_ERR(tmp))
 683                 return ERR_CAST(tmp);
 684         bdev = lookup_bdev(tmp->name);
 685         putname(tmp);
 686         if (IS_ERR(bdev))
 687                 return ERR_CAST(bdev);
 688         if (quotactl_cmd_write(cmd))
 689                 sb = get_super_thawed(bdev);
 690         else
 691                 sb = get_super(bdev);
 692         bdput(bdev);
 693         if (!sb)
 694                 return ERR_PTR(-ENODEV);
 695
 696         return sb;
 697 #else
 698         return ERR_PTR(-ENODEV);
 699 #endif
 700 }
 701
 702 /*
 703  * This is the system call interface. This communicates with
 704  * the user-level programs. Currently this only supports diskquota
 705  * calls. Maybe we need to add the process quotas etc. in the future,
 706  * but we probably should use rlimits for that.
 707  */
 708 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 709                 qid_t, id, void __user *, addr)
 710 {
 711         uint cmds, type;
 712         struct super_block *sb = NULL;
 713         struct path path, *pathp = NULL;
 714         int ret;
 715
 716         cmds = cmd >> SUBCMDSHIFT;
 717         type = cmd & SUBCMDMASK;
 718
 719         /*
 720          * As a special case Q_SYNC can be called without a specific device.
 721          * It will iterate all superblocks that have quota enabled and call
 722          * the sync action on each of them.
 723          */
 724         if (!special) {
 725                 if (cmds == Q_SYNC)
 726                         return quota_sync_all(type);
 727                 return -ENODEV;
 728         }
 729
 730         /*
 731          * Path for quotaon has to be resolved before grabbing superblock
 732          * because that gets s_umount sem which is also possibly needed by path
 733          * resolution (think about autofs) and thus deadlocks could arise.
 734          */
 735         if (cmds == Q_QUOTAON) {
 736                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 737                 if (ret)
 738                         pathp = ERR_PTR(ret);
 739                 else
 740                         pathp = &path;
 741         }
 742
 743         sb = quotactl_block(special, cmds);
 744         if (IS_ERR(sb)) {
 745                 ret = PTR_ERR(sb);
 746                 goto out;
 747         }
 748
 749         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 750
 751         drop_super(sb);
 752 out:
 753         if (pathp && !IS_ERR(pathp))
 754                 path_put(pathp);
 755         return ret;
 756 }