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, int cmd, 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_valid(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 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 227 {
 228         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 229         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 230         dst->d_space = src->dqb_curspace;
 231         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 232         dst->d_ino_softlimit = src->dqb_isoftlimit;
 233         dst->d_ino_count = src->dqb_curinodes;
 234         dst->d_spc_timer = src->dqb_btime;
 235         dst->d_ino_timer = src->dqb_itime;
 236
 237         dst->d_fieldmask = 0;
 238         if (src->dqb_valid & QIF_BLIMITS)
 239                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 240         if (src->dqb_valid & QIF_SPACE)
 241                 dst->d_fieldmask |= QC_SPACE;
 242         if (src->dqb_valid & QIF_ILIMITS)
 243                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 244         if (src->dqb_valid & QIF_INODES)
 245                 dst->d_fieldmask |= QC_INO_COUNT;
 246         if (src->dqb_valid & QIF_BTIME)
 247                 dst->d_fieldmask |= QC_SPC_TIMER;
 248         if (src->dqb_valid & QIF_ITIME)
 249                 dst->d_fieldmask |= QC_INO_TIMER;
 250 }
 251
 252 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 253                           void __user *addr)
 254 {
 255         struct qc_dqblk fdq;
 256         struct if_dqblk idq;
 257         struct kqid qid;
 258
 259         if (copy_from_user(&idq, addr, sizeof(idq)))
 260                 return -EFAULT;
 261         if (!sb->s_qcop->set_dqblk)
 262                 return -ENOSYS;
 263         qid = make_kqid(current_user_ns(), type, id);
 264         if (!qid_valid(qid))
 265                 return -EINVAL;
 266         copy_from_if_dqblk(&fdq, &idq);
 267         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 268 }
 269
 270 static int quota_enable(struct super_block *sb, void __user *addr)
 271 {
 272         __u32 flags;
 273
 274         if (copy_from_user(&flags, addr, sizeof(flags)))
 275                 return -EFAULT;
 276         if (!sb->s_qcop->quota_enable)
 277                 return -ENOSYS;
 278         return sb->s_qcop->quota_enable(sb, flags);
 279 }
 280
 281 static int quota_disable(struct super_block *sb, void __user *addr)
 282 {
 283         __u32 flags;
 284
 285         if (copy_from_user(&flags, addr, sizeof(flags)))
 286                 return -EFAULT;
 287         if (!sb->s_qcop->quota_disable)
 288                 return -ENOSYS;
 289         return sb->s_qcop->quota_disable(sb, flags);
 290 }
 291
 292 static int quota_state_to_flags(struct qc_state *state)
 293 {
 294         int flags = 0;
 295
 296         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 297                 flags |= FS_QUOTA_UDQ_ACCT;
 298         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 299                 flags |= FS_QUOTA_UDQ_ENFD;
 300         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 301                 flags |= FS_QUOTA_GDQ_ACCT;
 302         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 303                 flags |= FS_QUOTA_GDQ_ENFD;
 304         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 305                 flags |= FS_QUOTA_PDQ_ACCT;
 306         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 307                 flags |= FS_QUOTA_PDQ_ENFD;
 308         return flags;
 309 }
 310
 311 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
 312 {
 313         int type;
 314         struct qc_state state;
 315         int ret;
 316
 317         ret = sb->s_qcop->get_state(sb, &state);
 318         if (ret < 0)
 319                 return ret;
 320
 321         memset(fqs, 0, sizeof(*fqs));
 322         fqs->qs_version = FS_QSTAT_VERSION;
 323         fqs->qs_flags = quota_state_to_flags(&state);
 324         /* No quota enabled? */
 325         if (!fqs->qs_flags)
 326                 return -ENOSYS;
 327         fqs->qs_incoredqs = state.s_incoredqs;
 328         /*
 329          * GETXSTATE quotactl has space for just one set of time limits so
 330          * report them for the first enabled quota type
 331          */
 332         for (type = 0; type < XQM_MAXQUOTAS; type++)
 333                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 334                         break;
 335         BUG_ON(type == XQM_MAXQUOTAS);
 336         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 337         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 338         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 339         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 340         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 341         if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
 342                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 343                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 344                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 345         }
 346         if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
 347                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 348                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 349                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 350         }
 351         if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
 352                 /*
 353                  * Q_XGETQSTAT doesn't have room for both group and project
 354                  * quotas.  So, allow the project quota values to be copied out
 355                  * only if there is no group quota information available.
 356                  */
 357                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 358                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 359                         fqs->qs_gquota.qfs_nblks =
 360                                         state.s_state[PRJQUOTA].blocks;
 361                         fqs->qs_gquota.qfs_nextents =
 362                                         state.s_state[PRJQUOTA].nextents;
 363                 }
 364         }
 365         return 0;
 366 }
 367
 368 static int quota_getxstate(struct super_block *sb, void __user *addr)
 369 {
 370         struct fs_quota_stat fqs;
 371         int ret;
 372
 373         if (!sb->s_qcop->get_state)
 374                 return -ENOSYS;
 375         ret = quota_getstate(sb, &fqs);
 376         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 377                 return -EFAULT;
 378         return ret;
 379 }
 380
 381 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
 382 {
 383         int type;
 384         struct qc_state state;
 385         int ret;
 386
 387         ret = sb->s_qcop->get_state(sb, &state);
 388         if (ret < 0)
 389                 return ret;
 390
 391         memset(fqs, 0, sizeof(*fqs));
 392         fqs->qs_version = FS_QSTAT_VERSION;
 393         fqs->qs_flags = quota_state_to_flags(&state);
 394         /* No quota enabled? */
 395         if (!fqs->qs_flags)
 396                 return -ENOSYS;
 397         fqs->qs_incoredqs = state.s_incoredqs;
 398         /*
 399          * GETXSTATV quotactl has space for just one set of time limits so
 400          * report them for the first enabled quota type
 401          */
 402         for (type = 0; type < XQM_MAXQUOTAS; type++)
 403                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 404                         break;
 405         BUG_ON(type == XQM_MAXQUOTAS);
 406         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 407         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 408         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 409         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 410         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 411         if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
 412                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 413                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 414                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 415         }
 416         if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
 417                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 418                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 419                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 420         }
 421         if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
 422                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 423                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 424                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 425         }
 426         return 0;
 427 }
 428
 429 static int quota_getxstatev(struct super_block *sb, void __user *addr)
 430 {
 431         struct fs_quota_statv fqs;
 432         int ret;
 433
 434         if (!sb->s_qcop->get_state)
 435                 return -ENOSYS;
 436
 437         memset(&fqs, 0, sizeof(fqs));
 438         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 439                 return -EFAULT;
 440
 441         /* If this kernel doesn't support user specified version, fail */
 442         switch (fqs.qs_version) {
 443         case FS_QSTATV_VERSION1:
 444                 break;
 445         default:
 446                 return -EINVAL;
 447         }
 448         ret = quota_getstatev(sb, &fqs);
 449         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 450                 return -EFAULT;
 451         return ret;
 452 }
 453
 454 /*
 455  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 456  * out of there as xfsprogs rely on definitions being in that header file. So
 457  * just define same functions here for quota purposes.
 458  */
 459 #define XFS_BB_SHIFT 9
 460
 461 static inline u64 quota_bbtob(u64 blocks)
 462 {
 463         return blocks << XFS_BB_SHIFT;
 464 }
 465
 466 static inline u64 quota_btobb(u64 bytes)
 467 {
 468         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 469 }
 470
 471 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 472 {
 473         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 474         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 475         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 476         dst->d_ino_softlimit = src->d_ino_softlimit;
 477         dst->d_space = quota_bbtob(src->d_bcount);
 478         dst->d_ino_count = src->d_icount;
 479         dst->d_ino_timer = src->d_itimer;
 480         dst->d_spc_timer = src->d_btimer;
 481         dst->d_ino_warns = src->d_iwarns;
 482         dst->d_spc_warns = src->d_bwarns;
 483         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 484         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 485         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 486         dst->d_rt_spc_timer = src->d_rtbtimer;
 487         dst->d_rt_spc_warns = src->d_rtbwarns;
 488         dst->d_fieldmask = 0;
 489         if (src->d_fieldmask & FS_DQ_ISOFT)
 490                 dst->d_fieldmask |= QC_INO_SOFT;
 491         if (src->d_fieldmask & FS_DQ_IHARD)
 492                 dst->d_fieldmask |= QC_INO_HARD;
 493         if (src->d_fieldmask & FS_DQ_BSOFT)
 494                 dst->d_fieldmask |= QC_SPC_SOFT;
 495         if (src->d_fieldmask & FS_DQ_BHARD)
 496                 dst->d_fieldmask |= QC_SPC_HARD;
 497         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 498                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 499         if (src->d_fieldmask & FS_DQ_RTBHARD)
 500                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 501         if (src->d_fieldmask & FS_DQ_BTIMER)
 502                 dst->d_fieldmask |= QC_SPC_TIMER;
 503         if (src->d_fieldmask & FS_DQ_ITIMER)
 504                 dst->d_fieldmask |= QC_INO_TIMER;
 505         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 506                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 507         if (src->d_fieldmask & FS_DQ_BWARNS)
 508                 dst->d_fieldmask |= QC_SPC_WARNS;
 509         if (src->d_fieldmask & FS_DQ_IWARNS)
 510                 dst->d_fieldmask |= QC_INO_WARNS;
 511         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 512                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 513         if (src->d_fieldmask & FS_DQ_BCOUNT)
 514                 dst->d_fieldmask |= QC_SPACE;
 515         if (src->d_fieldmask & FS_DQ_ICOUNT)
 516                 dst->d_fieldmask |= QC_INO_COUNT;
 517         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 518                 dst->d_fieldmask |= QC_RT_SPACE;
 519 }
 520
 521 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 522                                        struct fs_disk_quota *src)
 523 {
 524         memset(dst, 0, sizeof(*dst));
 525         dst->i_spc_timelimit = src->d_btimer;
 526         dst->i_ino_timelimit = src->d_itimer;
 527         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 528         dst->i_ino_warnlimit = src->d_iwarns;
 529         dst->i_spc_warnlimit = src->d_bwarns;
 530         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 531         if (src->d_fieldmask & FS_DQ_BWARNS)
 532                 dst->i_fieldmask |= QC_SPC_WARNS;
 533         if (src->d_fieldmask & FS_DQ_IWARNS)
 534                 dst->i_fieldmask |= QC_INO_WARNS;
 535         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 536                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 537         if (src->d_fieldmask & FS_DQ_BTIMER)
 538                 dst->i_fieldmask |= QC_SPC_TIMER;
 539         if (src->d_fieldmask & FS_DQ_ITIMER)
 540                 dst->i_fieldmask |= QC_INO_TIMER;
 541         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 542                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 543 }
 544
 545 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 546                            void __user *addr)
 547 {
 548         struct fs_disk_quota fdq;
 549         struct qc_dqblk qdq;
 550         struct kqid qid;
 551
 552         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 553                 return -EFAULT;
 554         if (!sb->s_qcop->set_dqblk)
 555                 return -ENOSYS;
 556         qid = make_kqid(current_user_ns(), type, id);
 557         if (!qid_valid(qid))
 558                 return -EINVAL;
 559         /* Are we actually setting timer / warning limits for all users? */
 560         if (from_kqid(&init_user_ns, qid) == 0 &&
 561             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 562                 struct qc_info qinfo;
 563                 int ret;
 564
 565                 if (!sb->s_qcop->set_info)
 566                         return -EINVAL;
 567                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 568                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 569                 if (ret)
 570                         return ret;
 571                 /* These are already done */
 572                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 573         }
 574         copy_from_xfs_dqblk(&qdq, &fdq);
 575         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 576 }
 577
 578 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 579                               int type, qid_t id)
 580 {
 581         memset(dst, 0, sizeof(*dst));
 582         dst->d_version = FS_DQUOT_VERSION;
 583         dst->d_id = id;
 584         if (type == USRQUOTA)
 585                 dst->d_flags = FS_USER_QUOTA;
 586         else if (type == PRJQUOTA)
 587                 dst->d_flags = FS_PROJ_QUOTA;
 588         else
 589                 dst->d_flags = FS_GROUP_QUOTA;
 590         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 591         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 592         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 593         dst->d_ino_softlimit = src->d_ino_softlimit;
 594         dst->d_bcount = quota_btobb(src->d_space);
 595         dst->d_icount = src->d_ino_count;
 596         dst->d_itimer = src->d_ino_timer;
 597         dst->d_btimer = src->d_spc_timer;
 598         dst->d_iwarns = src->d_ino_warns;
 599         dst->d_bwarns = src->d_spc_warns;
 600         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 601         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 602         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 603         dst->d_rtbtimer = src->d_rt_spc_timer;
 604         dst->d_rtbwarns = src->d_rt_spc_warns;
 605 }
 606
 607 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 608                            void __user *addr)
 609 {
 610         struct fs_disk_quota fdq;
 611         struct qc_dqblk qdq;
 612         struct kqid qid;
 613         int ret;
 614
 615         if (!sb->s_qcop->get_dqblk)
 616                 return -ENOSYS;
 617         qid = make_kqid(current_user_ns(), type, id);
 618         if (!qid_valid(qid))
 619                 return -EINVAL;
 620         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 621         if (ret)
 622                 return ret;
 623         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 624         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 625                 return -EFAULT;
 626         return ret;
 627 }
 628
 629 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 630 {
 631         __u32 flags;
 632
 633         if (copy_from_user(&flags, addr, sizeof(flags)))
 634                 return -EFAULT;
 635         if (!sb->s_qcop->rm_xquota)
 636                 return -ENOSYS;
 637         return sb->s_qcop->rm_xquota(sb, flags);
 638 }
 639
 640 /* Copy parameters and call proper function */
 641 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 642                        void __user *addr, struct path *path)
 643 {
 644         int ret;
 645
 646         if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
 647                 return -EINVAL;
 648         type = array_index_nospec(type, MAXQUOTAS);
 649         /*
 650          * Quota not supported on this fs? Check this before s_quota_types
 651          * since they needn't be set if quota is not supported at all.
 652          */
 653         if (!sb->s_qcop)
 654                 return -ENOSYS;
 655         if (!(sb->s_quota_types & (1 << type)))
 656                 return -EINVAL;
 657
 658         ret = check_quotactl_permission(sb, type, cmd, id);
 659         if (ret < 0)
 660                 return ret;
 661
 662         switch (cmd) {
 663         case Q_QUOTAON:
 664                 return quota_quotaon(sb, type, cmd, id, path);
 665         case Q_QUOTAOFF:
 666                 return quota_quotaoff(sb, type);
 667         case Q_GETFMT:
 668                 return quota_getfmt(sb, type, addr);
 669         case Q_GETINFO:
 670                 return quota_getinfo(sb, type, addr);
 671         case Q_SETINFO:
 672                 return quota_setinfo(sb, type, addr);
 673         case Q_GETQUOTA:
 674                 return quota_getquota(sb, type, id, addr);
 675         case Q_SETQUOTA:
 676                 return quota_setquota(sb, type, id, addr);
 677         case Q_SYNC:
 678                 if (!sb->s_qcop->quota_sync)
 679                         return -ENOSYS;
 680                 return sb->s_qcop->quota_sync(sb, type);
 681         case Q_XQUOTAON:
 682                 return quota_enable(sb, addr);
 683         case Q_XQUOTAOFF:
 684                 return quota_disable(sb, addr);
 685         case Q_XQUOTARM:
 686                 return quota_rmxquota(sb, addr);
 687         case Q_XGETQSTAT:
 688                 return quota_getxstate(sb, addr);
 689         case Q_XGETQSTATV:
 690                 return quota_getxstatev(sb, addr);
 691         case Q_XSETQLIM:
 692                 return quota_setxquota(sb, type, id, addr);
 693         case Q_XGETQUOTA:
 694                 return quota_getxquota(sb, type, id, addr);
 695         case Q_XQUOTASYNC:
 696                 if (sb->s_flags & MS_RDONLY)
 697                         return -EROFS;
 698                 /* XFS quotas are fully coherent now, making this call a noop */
 699                 return 0;
 700         default:
 701                 return -EINVAL;
 702         }
 703 }
 704
 705 #ifdef CONFIG_BLOCK
 706
 707 /* Return 1 if 'cmd' will block on frozen filesystem */
 708 static int quotactl_cmd_write(int cmd)
 709 {
 710         switch (cmd) {
 711         case Q_GETFMT:
 712         case Q_GETINFO:
 713         case Q_SYNC:
 714         case Q_XGETQSTAT:
 715         case Q_XGETQSTATV:
 716         case Q_XGETQUOTA:
 717         case Q_XQUOTASYNC:
 718                 return 0;
 719         }
 720         return 1;
 721 }
 722
 723 #endif /* CONFIG_BLOCK */
 724
 725 /*
 726  * look up a superblock on which quota ops will be performed
 727  * - use the name of a block device to find the superblock thereon
 728  */
 729 static struct super_block *quotactl_block(const char __user *special, int cmd)
 730 {
 731 #ifdef CONFIG_BLOCK
 732         struct block_device *bdev;
 733         struct super_block *sb;
 734         struct filename *tmp = getname(special);
 735
 736         if (IS_ERR(tmp))
 737                 return ERR_CAST(tmp);
 738         bdev = lookup_bdev(tmp->name);
 739         putname(tmp);
 740         if (IS_ERR(bdev))
 741                 return ERR_CAST(bdev);
 742         if (quotactl_cmd_write(cmd))
 743                 sb = get_super_thawed(bdev);
 744         else
 745                 sb = get_super(bdev);
 746         bdput(bdev);
 747         if (!sb)
 748                 return ERR_PTR(-ENODEV);
 749
 750         return sb;
 751 #else
 752         return ERR_PTR(-ENODEV);
 753 #endif
 754 }
 755
 756 /*
 757  * This is the system call interface. This communicates with
 758  * the user-level programs. Currently this only supports diskquota
 759  * calls. Maybe we need to add the process quotas etc. in the future,
 760  * but we probably should use rlimits for that.
 761  */
 762 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 763                 qid_t, id, void __user *, addr)
 764 {
 765         uint cmds, type;
 766         struct super_block *sb = NULL;
 767         struct path path, *pathp = NULL;
 768         int ret;
 769
 770         cmds = cmd >> SUBCMDSHIFT;
 771         type = cmd & SUBCMDMASK;
 772
 773         /*
 774          * As a special case Q_SYNC can be called without a specific device.
 775          * It will iterate all superblocks that have quota enabled and call
 776          * the sync action on each of them.
 777          */
 778         if (!special) {
 779                 if (cmds == Q_SYNC)
 780                         return quota_sync_all(type);
 781                 return -ENODEV;
 782         }
 783
 784         /*
 785          * Path for quotaon has to be resolved before grabbing superblock
 786          * because that gets s_umount sem which is also possibly needed by path
 787          * resolution (think about autofs) and thus deadlocks could arise.
 788          */
 789         if (cmds == Q_QUOTAON) {
 790                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 791                 if (ret)
 792                         pathp = ERR_PTR(ret);
 793                 else
 794                         pathp = &path;
 795         }
 796
 797         sb = quotactl_block(special, cmds);
 798         if (IS_ERR(sb)) {
 799                 ret = PTR_ERR(sb);
 800                 goto out;
 801         }
 802
 803         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 804
 805         drop_super(sb);
 806 out:
 807         if (pathp && !IS_ERR(pathp))
 808                 path_put(pathp);
 809         return ret;
 810 }