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         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 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 226 {
 227         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 228         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 229         dst->d_space = src->dqb_curspace;
 230         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 231         dst->d_ino_softlimit = src->dqb_isoftlimit;
 232         dst->d_ino_count = src->dqb_curinodes;
 233         dst->d_spc_timer = src->dqb_btime;
 234         dst->d_ino_timer = src->dqb_itime;
 235
 236         dst->d_fieldmask = 0;
 237         if (src->dqb_valid & QIF_BLIMITS)
 238                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 239         if (src->dqb_valid & QIF_SPACE)
 240                 dst->d_fieldmask |= QC_SPACE;
 241         if (src->dqb_valid & QIF_ILIMITS)
 242                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 243         if (src->dqb_valid & QIF_INODES)
 244                 dst->d_fieldmask |= QC_INO_COUNT;
 245         if (src->dqb_valid & QIF_BTIME)
 246                 dst->d_fieldmask |= QC_SPC_TIMER;
 247         if (src->dqb_valid & QIF_ITIME)
 248                 dst->d_fieldmask |= QC_INO_TIMER;
 249 }
 250
 251 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 252                           void __user *addr)
 253 {
 254         struct qc_dqblk fdq;
 255         struct if_dqblk idq;
 256         struct kqid qid;
 257
 258         if (copy_from_user(&idq, addr, sizeof(idq)))
 259                 return -EFAULT;
 260         if (!sb->s_qcop->set_dqblk)
 261                 return -ENOSYS;
 262         qid = make_kqid(current_user_ns(), type, id);
 263         if (!qid_valid(qid))
 264                 return -EINVAL;
 265         copy_from_if_dqblk(&fdq, &idq);
 266         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 267 }
 268
 269 static int quota_enable(struct super_block *sb, void __user *addr)
 270 {
 271         __u32 flags;
 272
 273         if (copy_from_user(&flags, addr, sizeof(flags)))
 274                 return -EFAULT;
 275         if (!sb->s_qcop->quota_enable)
 276                 return -ENOSYS;
 277         return sb->s_qcop->quota_enable(sb, flags);
 278 }
 279
 280 static int quota_disable(struct super_block *sb, void __user *addr)
 281 {
 282         __u32 flags;
 283
 284         if (copy_from_user(&flags, addr, sizeof(flags)))
 285                 return -EFAULT;
 286         if (!sb->s_qcop->quota_disable)
 287                 return -ENOSYS;
 288         return sb->s_qcop->quota_disable(sb, flags);
 289 }
 290
 291 static int quota_state_to_flags(struct qc_state *state)
 292 {
 293         int flags = 0;
 294
 295         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 296                 flags |= FS_QUOTA_UDQ_ACCT;
 297         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 298                 flags |= FS_QUOTA_UDQ_ENFD;
 299         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 300                 flags |= FS_QUOTA_GDQ_ACCT;
 301         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 302                 flags |= FS_QUOTA_GDQ_ENFD;
 303         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 304                 flags |= FS_QUOTA_PDQ_ACCT;
 305         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 306                 flags |= FS_QUOTA_PDQ_ENFD;
 307         return flags;
 308 }
 309
 310 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
 311 {
 312         int type;
 313         struct qc_state state;
 314         int ret;
 315
 316         ret = sb->s_qcop->get_state(sb, &state);
 317         if (ret < 0)
 318                 return ret;
 319
 320         memset(fqs, 0, sizeof(*fqs));
 321         fqs->qs_version = FS_QSTAT_VERSION;
 322         fqs->qs_flags = quota_state_to_flags(&state);
 323         /* No quota enabled? */
 324         if (!fqs->qs_flags)
 325                 return -ENOSYS;
 326         fqs->qs_incoredqs = state.s_incoredqs;
 327         /*
 328          * GETXSTATE quotactl has space for just one set of time limits so
 329          * report them for the first enabled quota type
 330          */
 331         for (type = 0; type < XQM_MAXQUOTAS; type++)
 332                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 333                         break;
 334         BUG_ON(type == XQM_MAXQUOTAS);
 335         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 336         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 337         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 338         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 339         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 340         if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
 341                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 342                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 343                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 344         }
 345         if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
 346                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 347                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 348                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 349         }
 350         if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
 351                 /*
 352                  * Q_XGETQSTAT doesn't have room for both group and project
 353                  * quotas.  So, allow the project quota values to be copied out
 354                  * only if there is no group quota information available.
 355                  */
 356                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 357                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 358                         fqs->qs_gquota.qfs_nblks =
 359                                         state.s_state[PRJQUOTA].blocks;
 360                         fqs->qs_gquota.qfs_nextents =
 361                                         state.s_state[PRJQUOTA].nextents;
 362                 }
 363         }
 364         return 0;
 365 }
 366
 367 static int quota_getxstate(struct super_block *sb, void __user *addr)
 368 {
 369         struct fs_quota_stat fqs;
 370         int ret;
 371
 372         if (!sb->s_qcop->get_state)
 373                 return -ENOSYS;
 374         ret = quota_getstate(sb, &fqs);
 375         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 376                 return -EFAULT;
 377         return ret;
 378 }
 379
 380 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
 381 {
 382         int type;
 383         struct qc_state state;
 384         int ret;
 385
 386         ret = sb->s_qcop->get_state(sb, &state);
 387         if (ret < 0)
 388                 return ret;
 389
 390         memset(fqs, 0, sizeof(*fqs));
 391         fqs->qs_version = FS_QSTAT_VERSION;
 392         fqs->qs_flags = quota_state_to_flags(&state);
 393         /* No quota enabled? */
 394         if (!fqs->qs_flags)
 395                 return -ENOSYS;
 396         fqs->qs_incoredqs = state.s_incoredqs;
 397         /*
 398          * GETXSTATV quotactl has space for just one set of time limits so
 399          * report them for the first enabled quota type
 400          */
 401         for (type = 0; type < XQM_MAXQUOTAS; type++)
 402                 if (state.s_state[type].flags & QCI_ACCT_ENABLED)
 403                         break;
 404         BUG_ON(type == XQM_MAXQUOTAS);
 405         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 406         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 407         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 408         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 409         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 410         if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
 411                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 412                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 413                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 414         }
 415         if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
 416                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 417                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 418                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 419         }
 420         if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
 421                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 422                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 423                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 424         }
 425         return 0;
 426 }
 427
 428 static int quota_getxstatev(struct super_block *sb, void __user *addr)
 429 {
 430         struct fs_quota_statv fqs;
 431         int ret;
 432
 433         if (!sb->s_qcop->get_state)
 434                 return -ENOSYS;
 435
 436         memset(&fqs, 0, sizeof(fqs));
 437         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 438                 return -EFAULT;
 439
 440         /* If this kernel doesn't support user specified version, fail */
 441         switch (fqs.qs_version) {
 442         case FS_QSTATV_VERSION1:
 443                 break;
 444         default:
 445                 return -EINVAL;
 446         }
 447         ret = quota_getstatev(sb, &fqs);
 448         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 449                 return -EFAULT;
 450         return ret;
 451 }
 452
 453 /*
 454  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 455  * out of there as xfsprogs rely on definitions being in that header file. So
 456  * just define same functions here for quota purposes.
 457  */
 458 #define XFS_BB_SHIFT 9
 459
 460 static inline u64 quota_bbtob(u64 blocks)
 461 {
 462         return blocks << XFS_BB_SHIFT;
 463 }
 464
 465 static inline u64 quota_btobb(u64 bytes)
 466 {
 467         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 468 }
 469
 470 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 471 {
 472         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 473         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 474         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 475         dst->d_ino_softlimit = src->d_ino_softlimit;
 476         dst->d_space = quota_bbtob(src->d_bcount);
 477         dst->d_ino_count = src->d_icount;
 478         dst->d_ino_timer = src->d_itimer;
 479         dst->d_spc_timer = src->d_btimer;
 480         dst->d_ino_warns = src->d_iwarns;
 481         dst->d_spc_warns = src->d_bwarns;
 482         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 483         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 484         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 485         dst->d_rt_spc_timer = src->d_rtbtimer;
 486         dst->d_rt_spc_warns = src->d_rtbwarns;
 487         dst->d_fieldmask = 0;
 488         if (src->d_fieldmask & FS_DQ_ISOFT)
 489                 dst->d_fieldmask |= QC_INO_SOFT;
 490         if (src->d_fieldmask & FS_DQ_IHARD)
 491                 dst->d_fieldmask |= QC_INO_HARD;
 492         if (src->d_fieldmask & FS_DQ_BSOFT)
 493                 dst->d_fieldmask |= QC_SPC_SOFT;
 494         if (src->d_fieldmask & FS_DQ_BHARD)
 495                 dst->d_fieldmask |= QC_SPC_HARD;
 496         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 497                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 498         if (src->d_fieldmask & FS_DQ_RTBHARD)
 499                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 500         if (src->d_fieldmask & FS_DQ_BTIMER)
 501                 dst->d_fieldmask |= QC_SPC_TIMER;
 502         if (src->d_fieldmask & FS_DQ_ITIMER)
 503                 dst->d_fieldmask |= QC_INO_TIMER;
 504         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 505                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 506         if (src->d_fieldmask & FS_DQ_BWARNS)
 507                 dst->d_fieldmask |= QC_SPC_WARNS;
 508         if (src->d_fieldmask & FS_DQ_IWARNS)
 509                 dst->d_fieldmask |= QC_INO_WARNS;
 510         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 511                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 512         if (src->d_fieldmask & FS_DQ_BCOUNT)
 513                 dst->d_fieldmask |= QC_SPACE;
 514         if (src->d_fieldmask & FS_DQ_ICOUNT)
 515                 dst->d_fieldmask |= QC_INO_COUNT;
 516         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 517                 dst->d_fieldmask |= QC_RT_SPACE;
 518 }
 519
 520 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 521                                        struct fs_disk_quota *src)
 522 {
 523         memset(dst, 0, sizeof(*dst));
 524         dst->i_spc_timelimit = src->d_btimer;
 525         dst->i_ino_timelimit = src->d_itimer;
 526         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 527         dst->i_ino_warnlimit = src->d_iwarns;
 528         dst->i_spc_warnlimit = src->d_bwarns;
 529         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 530         if (src->d_fieldmask & FS_DQ_BWARNS)
 531                 dst->i_fieldmask |= QC_SPC_WARNS;
 532         if (src->d_fieldmask & FS_DQ_IWARNS)
 533                 dst->i_fieldmask |= QC_INO_WARNS;
 534         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 535                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 536         if (src->d_fieldmask & FS_DQ_BTIMER)
 537                 dst->i_fieldmask |= QC_SPC_TIMER;
 538         if (src->d_fieldmask & FS_DQ_ITIMER)
 539                 dst->i_fieldmask |= QC_INO_TIMER;
 540         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 541                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 542 }
 543
 544 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 545                            void __user *addr)
 546 {
 547         struct fs_disk_quota fdq;
 548         struct qc_dqblk qdq;
 549         struct kqid qid;
 550
 551         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 552                 return -EFAULT;
 553         if (!sb->s_qcop->set_dqblk)
 554                 return -ENOSYS;
 555         qid = make_kqid(current_user_ns(), type, id);
 556         if (!qid_valid(qid))
 557                 return -EINVAL;
 558         /* Are we actually setting timer / warning limits for all users? */
 559         if (from_kqid(&init_user_ns, qid) == 0 &&
 560             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 561                 struct qc_info qinfo;
 562                 int ret;
 563
 564                 if (!sb->s_qcop->set_info)
 565                         return -EINVAL;
 566                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 567                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 568                 if (ret)
 569                         return ret;
 570                 /* These are already done */
 571                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 572         }
 573         copy_from_xfs_dqblk(&qdq, &fdq);
 574         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 575 }
 576
 577 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 578                               int type, qid_t id)
 579 {
 580         memset(dst, 0, sizeof(*dst));
 581         dst->d_version = FS_DQUOT_VERSION;
 582         dst->d_id = id;
 583         if (type == USRQUOTA)
 584                 dst->d_flags = FS_USER_QUOTA;
 585         else if (type == PRJQUOTA)
 586                 dst->d_flags = FS_PROJ_QUOTA;
 587         else
 588                 dst->d_flags = FS_GROUP_QUOTA;
 589         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 590         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 591         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 592         dst->d_ino_softlimit = src->d_ino_softlimit;
 593         dst->d_bcount = quota_btobb(src->d_space);
 594         dst->d_icount = src->d_ino_count;
 595         dst->d_itimer = src->d_ino_timer;
 596         dst->d_btimer = src->d_spc_timer;
 597         dst->d_iwarns = src->d_ino_warns;
 598         dst->d_bwarns = src->d_spc_warns;
 599         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 600         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 601         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 602         dst->d_rtbtimer = src->d_rt_spc_timer;
 603         dst->d_rtbwarns = src->d_rt_spc_warns;
 604 }
 605
 606 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 607                            void __user *addr)
 608 {
 609         struct fs_disk_quota fdq;
 610         struct qc_dqblk qdq;
 611         struct kqid qid;
 612         int ret;
 613
 614         if (!sb->s_qcop->get_dqblk)
 615                 return -ENOSYS;
 616         qid = make_kqid(current_user_ns(), type, id);
 617         if (!qid_valid(qid))
 618                 return -EINVAL;
 619         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 620         if (ret)
 621                 return ret;
 622         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 623         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 624                 return -EFAULT;
 625         return ret;
 626 }
 627
 628 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 629 {
 630         __u32 flags;
 631
 632         if (copy_from_user(&flags, addr, sizeof(flags)))
 633                 return -EFAULT;
 634         if (!sb->s_qcop->rm_xquota)
 635                 return -ENOSYS;
 636         return sb->s_qcop->rm_xquota(sb, flags);
 637 }
 638
 639 /* Copy parameters and call proper function */
 640 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 641                        void __user *addr, struct path *path)
 642 {
 643         int ret;
 644
 645         if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
 646                 return -EINVAL;
 647         /*
 648          * Quota not supported on this fs? Check this before s_quota_types
 649          * since they needn't be set if quota is not supported at all.
 650          */
 651         if (!sb->s_qcop)
 652                 return -ENOSYS;
 653         if (!(sb->s_quota_types & (1 << type)))
 654                 return -EINVAL;
 655
 656         ret = check_quotactl_permission(sb, type, cmd, id);
 657         if (ret < 0)
 658                 return ret;
 659
 660         switch (cmd) {
 661         case Q_QUOTAON:
 662                 return quota_quotaon(sb, type, cmd, id, path);
 663         case Q_QUOTAOFF:
 664                 return quota_quotaoff(sb, type);
 665         case Q_GETFMT:
 666                 return quota_getfmt(sb, type, addr);
 667         case Q_GETINFO:
 668                 return quota_getinfo(sb, type, addr);
 669         case Q_SETINFO:
 670                 return quota_setinfo(sb, type, addr);
 671         case Q_GETQUOTA:
 672                 return quota_getquota(sb, type, id, addr);
 673         case Q_SETQUOTA:
 674                 return quota_setquota(sb, type, id, addr);
 675         case Q_SYNC:
 676                 if (!sb->s_qcop->quota_sync)
 677                         return -ENOSYS;
 678                 return sb->s_qcop->quota_sync(sb, type);
 679         case Q_XQUOTAON:
 680                 return quota_enable(sb, addr);
 681         case Q_XQUOTAOFF:
 682                 return quota_disable(sb, addr);
 683         case Q_XQUOTARM:
 684                 return quota_rmxquota(sb, addr);
 685         case Q_XGETQSTAT:
 686                 return quota_getxstate(sb, addr);
 687         case Q_XGETQSTATV:
 688                 return quota_getxstatev(sb, addr);
 689         case Q_XSETQLIM:
 690                 return quota_setxquota(sb, type, id, addr);
 691         case Q_XGETQUOTA:
 692                 return quota_getxquota(sb, type, id, addr);
 693         case Q_XQUOTASYNC:
 694                 if (sb->s_flags & MS_RDONLY)
 695                         return -EROFS;
 696                 /* XFS quotas are fully coherent now, making this call a noop */
 697                 return 0;
 698         default:
 699                 return -EINVAL;
 700         }
 701 }
 702
 703 #ifdef CONFIG_BLOCK
 704
 705 /* Return 1 if 'cmd' will block on frozen filesystem */
 706 static int quotactl_cmd_write(int cmd)
 707 {
 708         switch (cmd) {
 709         case Q_GETFMT:
 710         case Q_GETINFO:
 711         case Q_SYNC:
 712         case Q_XGETQSTAT:
 713         case Q_XGETQSTATV:
 714         case Q_XGETQUOTA:
 715         case Q_XQUOTASYNC:
 716                 return 0;
 717         }
 718         return 1;
 719 }
 720
 721 #endif /* CONFIG_BLOCK */
 722
 723 /*
 724  * look up a superblock on which quota ops will be performed
 725  * - use the name of a block device to find the superblock thereon
 726  */
 727 static struct super_block *quotactl_block(const char __user *special, int cmd)
 728 {
 729 #ifdef CONFIG_BLOCK
 730         struct block_device *bdev;
 731         struct super_block *sb;
 732         struct filename *tmp = getname(special);
 733
 734         if (IS_ERR(tmp))
 735                 return ERR_CAST(tmp);
 736         bdev = lookup_bdev(tmp->name);
 737         putname(tmp);
 738         if (IS_ERR(bdev))
 739                 return ERR_CAST(bdev);
 740         if (quotactl_cmd_write(cmd))
 741                 sb = get_super_thawed(bdev);
 742         else
 743                 sb = get_super(bdev);
 744         bdput(bdev);
 745         if (!sb)
 746                 return ERR_PTR(-ENODEV);
 747
 748         return sb;
 749 #else
 750         return ERR_PTR(-ENODEV);
 751 #endif
 752 }
 753
 754 /*
 755  * This is the system call interface. This communicates with
 756  * the user-level programs. Currently this only supports diskquota
 757  * calls. Maybe we need to add the process quotas etc. in the future,
 758  * but we probably should use rlimits for that.
 759  */
 760 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 761                 qid_t, id, void __user *, addr)
 762 {
 763         uint cmds, type;
 764         struct super_block *sb = NULL;
 765         struct path path, *pathp = NULL;
 766         int ret;
 767
 768         cmds = cmd >> SUBCMDSHIFT;
 769         type = cmd & SUBCMDMASK;
 770
 771         /*
 772          * As a special case Q_SYNC can be called without a specific device.
 773          * It will iterate all superblocks that have quota enabled and call
 774          * the sync action on each of them.
 775          */
 776         if (!special) {
 777                 if (cmds == Q_SYNC)
 778                         return quota_sync_all(type);
 779                 return -ENODEV;
 780         }
 781
 782         /*
 783          * Path for quotaon has to be resolved before grabbing superblock
 784          * because that gets s_umount sem which is also possibly needed by path
 785          * resolution (think about autofs) and thus deadlocks could arise.
 786          */
 787         if (cmds == Q_QUOTAON) {
 788                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 789                 if (ret)
 790                         pathp = ERR_PTR(ret);
 791                 else
 792                         pathp = &path;
 793         }
 794
 795         sb = quotactl_block(special, cmds);
 796         if (IS_ERR(sb)) {
 797                 ret = PTR_ERR(sb);
 798                 goto out;
 799         }
 800
 801         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 802
 803         drop_super(sb);
 804 out:
 805         if (pathp && !IS_ERR(pathp))
 806                 path_put(pathp);
 807         return ret;
 808 }