fs/quota/quota.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Quota code necessary even when VFS quota support is not compiled
   4  * into the kernel.  The interesting stuff is over in dquot.c, here
   5  * we have symbols for initial quotactl(2) handling, the sysctl(2)
   6  * variables, etc - things needed even when quota support disabled.
   7  */
   8
   9 #include <linux/fs.h>
  10 #include <linux/namei.h>
  11 #include <linux/slab.h>
  12 #include <asm/current.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/kernel.h>
  15 #include <linux/security.h>
  16 #include <linux/syscalls.h>
  17 #include <linux/capability.h>
  18 #include <linux/quotaops.h>
  19 #include <linux/types.h>
  20 #include <linux/writeback.h>
  21 #include <linux/nospec.h>
  22 #include "compat.h"
  23 #include "../internal.h"
  24
  25 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  26                                      qid_t id)
  27 {
  28         switch (cmd) {
  29         /* these commands do not require any special privilegues */
  30         case Q_GETFMT:
  31         case Q_SYNC:
  32         case Q_GETINFO:
  33         case Q_XGETQSTAT:
  34         case Q_XGETQSTATV:
  35         case Q_XQUOTASYNC:
  36                 break;
  37         /* allow to query information for dquots we "own" */
  38         case Q_GETQUOTA:
  39         case Q_XGETQUOTA:
  40                 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  41                     (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  42                         break;
  43                 fallthrough;
  44         default:
  45                 if (!capable(CAP_SYS_ADMIN))
  46                         return -EPERM;
  47         }
  48
  49         return security_quotactl(cmd, type, id, sb);
  50 }
  51
  52 static void quota_sync_one(struct super_block *sb, void *arg)
  53 {
  54         int type = *(int *)arg;
  55
  56         if (sb->s_qcop && sb->s_qcop->quota_sync &&
  57             (sb->s_quota_types & (1 << type)))
  58                 sb->s_qcop->quota_sync(sb, type);
  59 }
  60
  61 static int quota_sync_all(int type)
  62 {
  63         int ret;
  64
  65         ret = security_quotactl(Q_SYNC, type, 0, NULL);
  66         if (!ret)
  67                 iterate_supers(quota_sync_one, &type);
  68         return ret;
  69 }
  70
  71 unsigned int qtype_enforce_flag(int type)
  72 {
  73         switch (type) {
  74         case USRQUOTA:
  75                 return FS_QUOTA_UDQ_ENFD;
  76         case GRPQUOTA:
  77                 return FS_QUOTA_GDQ_ENFD;
  78         case PRJQUOTA:
  79                 return FS_QUOTA_PDQ_ENFD;
  80         }
  81         return 0;
  82 }
  83
  84 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  85                          const struct path *path)
  86 {
  87         if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  88                 return -ENOSYS;
  89         if (sb->s_qcop->quota_enable)
  90                 return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  91         if (IS_ERR(path))
  92                 return PTR_ERR(path);
  93         return sb->s_qcop->quota_on(sb, type, id, path);
  94 }
  95
  96 static int quota_quotaoff(struct super_block *sb, int type)
  97 {
  98         if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
  99                 return -ENOSYS;
 100         if (sb->s_qcop->quota_disable)
 101                 return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 102         return sb->s_qcop->quota_off(sb, type);
 103 }
 104
 105 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 106 {
 107         __u32 fmt;
 108
 109         if (!sb_has_quota_active(sb, type))
 110                 return -ESRCH;
 111         fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 112         if (copy_to_user(addr, &fmt, sizeof(fmt)))
 113                 return -EFAULT;
 114         return 0;
 115 }
 116
 117 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 118 {
 119         struct qc_state state;
 120         struct qc_type_state *tstate;
 121         struct if_dqinfo uinfo;
 122         int ret;
 123
 124         if (!sb->s_qcop->get_state)
 125                 return -ENOSYS;
 126         ret = sb->s_qcop->get_state(sb, &state);
 127         if (ret)
 128                 return ret;
 129         tstate = state.s_state + type;
 130         if (!(tstate->flags & QCI_ACCT_ENABLED))
 131                 return -ESRCH;
 132         memset(&uinfo, 0, sizeof(uinfo));
 133         uinfo.dqi_bgrace = tstate->spc_timelimit;
 134         uinfo.dqi_igrace = tstate->ino_timelimit;
 135         if (tstate->flags & QCI_SYSFILE)
 136                 uinfo.dqi_flags |= DQF_SYS_FILE;
 137         if (tstate->flags & QCI_ROOT_SQUASH)
 138                 uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 139         uinfo.dqi_valid = IIF_ALL;
 140         if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 141                 return -EFAULT;
 142         return 0;
 143 }
 144
 145 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 146 {
 147         struct if_dqinfo info;
 148         struct qc_info qinfo;
 149
 150         if (copy_from_user(&info, addr, sizeof(info)))
 151                 return -EFAULT;
 152         if (!sb->s_qcop->set_info)
 153                 return -ENOSYS;
 154         if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 155                 return -EINVAL;
 156         memset(&qinfo, 0, sizeof(qinfo));
 157         if (info.dqi_valid & IIF_FLAGS) {
 158                 if (info.dqi_flags & ~DQF_SETINFO_MASK)
 159                         return -EINVAL;
 160                 if (info.dqi_flags & DQF_ROOT_SQUASH)
 161                         qinfo.i_flags |= QCI_ROOT_SQUASH;
 162                 qinfo.i_fieldmask |= QC_FLAGS;
 163         }
 164         if (info.dqi_valid & IIF_BGRACE) {
 165                 qinfo.i_spc_timelimit = info.dqi_bgrace;
 166                 qinfo.i_fieldmask |= QC_SPC_TIMER;
 167         }
 168         if (info.dqi_valid & IIF_IGRACE) {
 169                 qinfo.i_ino_timelimit = info.dqi_igrace;
 170                 qinfo.i_fieldmask |= QC_INO_TIMER;
 171         }
 172         return sb->s_qcop->set_info(sb, type, &qinfo);
 173 }
 174
 175 static inline qsize_t qbtos(qsize_t blocks)
 176 {
 177         return blocks << QIF_DQBLKSIZE_BITS;
 178 }
 179
 180 static inline qsize_t stoqb(qsize_t space)
 181 {
 182         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 183 }
 184
 185 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 186 {
 187         memset(dst, 0, sizeof(*dst));
 188         dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 189         dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 190         dst->dqb_curspace = src->d_space;
 191         dst->dqb_ihardlimit = src->d_ino_hardlimit;
 192         dst->dqb_isoftlimit = src->d_ino_softlimit;
 193         dst->dqb_curinodes = src->d_ino_count;
 194         dst->dqb_btime = src->d_spc_timer;
 195         dst->dqb_itime = src->d_ino_timer;
 196         dst->dqb_valid = QIF_ALL;
 197 }
 198
 199 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 200                           void __user *addr)
 201 {
 202         struct kqid qid;
 203         struct qc_dqblk fdq;
 204         struct if_dqblk idq;
 205         int ret;
 206
 207         if (!sb->s_qcop->get_dqblk)
 208                 return -ENOSYS;
 209         qid = make_kqid(current_user_ns(), type, id);
 210         if (!qid_has_mapping(sb->s_user_ns, qid))
 211                 return -EINVAL;
 212         ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 213         if (ret)
 214                 return ret;
 215         copy_to_if_dqblk(&idq, &fdq);
 216
 217         if (compat_need_64bit_alignment_fixup()) {
 218                 struct compat_if_dqblk __user *compat_dqblk = addr;
 219
 220                 if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
 221                         return -EFAULT;
 222                 if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 223                         return -EFAULT;
 224         } else {
 225                 if (copy_to_user(addr, &idq, sizeof(idq)))
 226                         return -EFAULT;
 227         }
 228         return 0;
 229 }
 230
 231 /*
 232  * Return quota for next active quota >= this id, if any exists,
 233  * otherwise return -ENOENT via ->get_nextdqblk
 234  */
 235 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 236                           void __user *addr)
 237 {
 238         struct kqid qid;
 239         struct qc_dqblk fdq;
 240         struct if_nextdqblk idq;
 241         int ret;
 242
 243         if (!sb->s_qcop->get_nextdqblk)
 244                 return -ENOSYS;
 245         qid = make_kqid(current_user_ns(), type, id);
 246         if (!qid_has_mapping(sb->s_user_ns, qid))
 247                 return -EINVAL;
 248         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 249         if (ret)
 250                 return ret;
 251         /* struct if_nextdqblk is a superset of struct if_dqblk */
 252         copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 253         idq.dqb_id = from_kqid(current_user_ns(), qid);
 254         if (copy_to_user(addr, &idq, sizeof(idq)))
 255                 return -EFAULT;
 256         return 0;
 257 }
 258
 259 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 260 {
 261         dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 262         dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 263         dst->d_space = src->dqb_curspace;
 264         dst->d_ino_hardlimit = src->dqb_ihardlimit;
 265         dst->d_ino_softlimit = src->dqb_isoftlimit;
 266         dst->d_ino_count = src->dqb_curinodes;
 267         dst->d_spc_timer = src->dqb_btime;
 268         dst->d_ino_timer = src->dqb_itime;
 269
 270         dst->d_fieldmask = 0;
 271         if (src->dqb_valid & QIF_BLIMITS)
 272                 dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 273         if (src->dqb_valid & QIF_SPACE)
 274                 dst->d_fieldmask |= QC_SPACE;
 275         if (src->dqb_valid & QIF_ILIMITS)
 276                 dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 277         if (src->dqb_valid & QIF_INODES)
 278                 dst->d_fieldmask |= QC_INO_COUNT;
 279         if (src->dqb_valid & QIF_BTIME)
 280                 dst->d_fieldmask |= QC_SPC_TIMER;
 281         if (src->dqb_valid & QIF_ITIME)
 282                 dst->d_fieldmask |= QC_INO_TIMER;
 283 }
 284
 285 static int quota_setquota(struct super_block *sb, int type, qid_t id,
 286                           void __user *addr)
 287 {
 288         struct qc_dqblk fdq;
 289         struct if_dqblk idq;
 290         struct kqid qid;
 291
 292         if (compat_need_64bit_alignment_fixup()) {
 293                 struct compat_if_dqblk __user *compat_dqblk = addr;
 294
 295                 if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
 296                     get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 297                         return -EFAULT;
 298         } else {
 299                 if (copy_from_user(&idq, addr, sizeof(idq)))
 300                         return -EFAULT;
 301         }
 302         if (!sb->s_qcop->set_dqblk)
 303                 return -ENOSYS;
 304         qid = make_kqid(current_user_ns(), type, id);
 305         if (!qid_has_mapping(sb->s_user_ns, qid))
 306                 return -EINVAL;
 307         copy_from_if_dqblk(&fdq, &idq);
 308         return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 309 }
 310
 311 static int quota_enable(struct super_block *sb, void __user *addr)
 312 {
 313         __u32 flags;
 314
 315         if (copy_from_user(&flags, addr, sizeof(flags)))
 316                 return -EFAULT;
 317         if (!sb->s_qcop->quota_enable)
 318                 return -ENOSYS;
 319         return sb->s_qcop->quota_enable(sb, flags);
 320 }
 321
 322 static int quota_disable(struct super_block *sb, void __user *addr)
 323 {
 324         __u32 flags;
 325
 326         if (copy_from_user(&flags, addr, sizeof(flags)))
 327                 return -EFAULT;
 328         if (!sb->s_qcop->quota_disable)
 329                 return -ENOSYS;
 330         return sb->s_qcop->quota_disable(sb, flags);
 331 }
 332
 333 static int quota_state_to_flags(struct qc_state *state)
 334 {
 335         int flags = 0;
 336
 337         if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 338                 flags |= FS_QUOTA_UDQ_ACCT;
 339         if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 340                 flags |= FS_QUOTA_UDQ_ENFD;
 341         if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 342                 flags |= FS_QUOTA_GDQ_ACCT;
 343         if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 344                 flags |= FS_QUOTA_GDQ_ENFD;
 345         if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 346                 flags |= FS_QUOTA_PDQ_ACCT;
 347         if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 348                 flags |= FS_QUOTA_PDQ_ENFD;
 349         return flags;
 350 }
 351
 352 static int quota_getstate(struct super_block *sb, int type,
 353                           struct fs_quota_stat *fqs)
 354 {
 355         struct qc_state state;
 356         int ret;
 357
 358         memset(&state, 0, sizeof (struct qc_state));
 359         ret = sb->s_qcop->get_state(sb, &state);
 360         if (ret < 0)
 361                 return ret;
 362
 363         memset(fqs, 0, sizeof(*fqs));
 364         fqs->qs_version = FS_QSTAT_VERSION;
 365         fqs->qs_flags = quota_state_to_flags(&state);
 366         /* No quota enabled? */
 367         if (!fqs->qs_flags)
 368                 return -ENOSYS;
 369         fqs->qs_incoredqs = state.s_incoredqs;
 370
 371         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 372         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 373         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 374         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 375         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 376
 377         /* Inodes may be allocated even if inactive; copy out if present */
 378         if (state.s_state[USRQUOTA].ino) {
 379                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 380                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 381                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 382         }
 383         if (state.s_state[GRPQUOTA].ino) {
 384                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 385                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 386                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 387         }
 388         if (state.s_state[PRJQUOTA].ino) {
 389                 /*
 390                  * Q_XGETQSTAT doesn't have room for both group and project
 391                  * quotas.  So, allow the project quota values to be copied out
 392                  * only if there is no group quota information available.
 393                  */
 394                 if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 395                         fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 396                         fqs->qs_gquota.qfs_nblks =
 397                                         state.s_state[PRJQUOTA].blocks;
 398                         fqs->qs_gquota.qfs_nextents =
 399                                         state.s_state[PRJQUOTA].nextents;
 400                 }
 401         }
 402         return 0;
 403 }
 404
 405 static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
 406                 struct fs_qfilestat *from)
 407 {
 408         if (copy_to_user(to, from, sizeof(*to)) ||
 409             put_user(from->qfs_nextents, &to->qfs_nextents))
 410                 return -EFAULT;
 411         return 0;
 412 }
 413
 414 static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
 415                 struct fs_quota_stat *from)
 416 {
 417         if (put_user(from->qs_version, &to->qs_version) ||
 418             put_user(from->qs_flags, &to->qs_flags) ||
 419             put_user(from->qs_pad, &to->qs_pad) ||
 420             compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
 421             compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
 422             put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
 423             put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
 424             put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
 425             put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
 426             put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
 427             put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
 428                 return -EFAULT;
 429         return 0;
 430 }
 431
 432 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
 433 {
 434         struct fs_quota_stat fqs;
 435         int ret;
 436
 437         if (!sb->s_qcop->get_state)
 438                 return -ENOSYS;
 439         ret = quota_getstate(sb, type, &fqs);
 440         if (ret)
 441                 return ret;
 442
 443         if (compat_need_64bit_alignment_fixup())
 444                 return compat_copy_fs_quota_stat(addr, &fqs);
 445         if (copy_to_user(addr, &fqs, sizeof(fqs)))
 446                 return -EFAULT;
 447         return 0;
 448 }
 449
 450 static int quota_getstatev(struct super_block *sb, int type,
 451                            struct fs_quota_statv *fqs)
 452 {
 453         struct qc_state state;
 454         int ret;
 455
 456         memset(&state, 0, sizeof (struct qc_state));
 457         ret = sb->s_qcop->get_state(sb, &state);
 458         if (ret < 0)
 459                 return ret;
 460
 461         memset(fqs, 0, sizeof(*fqs));
 462         fqs->qs_version = FS_QSTAT_VERSION;
 463         fqs->qs_flags = quota_state_to_flags(&state);
 464         /* No quota enabled? */
 465         if (!fqs->qs_flags)
 466                 return -ENOSYS;
 467         fqs->qs_incoredqs = state.s_incoredqs;
 468
 469         fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 470         fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 471         fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 472         fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 473         fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 474
 475         /* Inodes may be allocated even if inactive; copy out if present */
 476         if (state.s_state[USRQUOTA].ino) {
 477                 fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 478                 fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 479                 fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 480         }
 481         if (state.s_state[GRPQUOTA].ino) {
 482                 fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 483                 fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 484                 fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 485         }
 486         if (state.s_state[PRJQUOTA].ino) {
 487                 fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 488                 fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 489                 fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 490         }
 491         return 0;
 492 }
 493
 494 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
 495 {
 496         struct fs_quota_statv fqs;
 497         int ret;
 498
 499         if (!sb->s_qcop->get_state)
 500                 return -ENOSYS;
 501
 502         memset(&fqs, 0, sizeof(fqs));
 503         if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 504                 return -EFAULT;
 505
 506         /* If this kernel doesn't support user specified version, fail */
 507         switch (fqs.qs_version) {
 508         case FS_QSTATV_VERSION1:
 509                 break;
 510         default:
 511                 return -EINVAL;
 512         }
 513         ret = quota_getstatev(sb, type, &fqs);
 514         if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 515                 return -EFAULT;
 516         return ret;
 517 }
 518
 519 /*
 520  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 521  * out of there as xfsprogs rely on definitions being in that header file. So
 522  * just define same functions here for quota purposes.
 523  */
 524 #define XFS_BB_SHIFT 9
 525
 526 static inline u64 quota_bbtob(u64 blocks)
 527 {
 528         return blocks << XFS_BB_SHIFT;
 529 }
 530
 531 static inline u64 quota_btobb(u64 bytes)
 532 {
 533         return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 534 }
 535
 536 static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
 537                 __s32 timer, __s8 timer_hi)
 538 {
 539         if (d->d_fieldmask & FS_DQ_BIGTIME)
 540                 return (u32)timer | (s64)timer_hi << 32;
 541         return timer;
 542 }
 543
 544 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 545 {
 546         dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 547         dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 548         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 549         dst->d_ino_softlimit = src->d_ino_softlimit;
 550         dst->d_space = quota_bbtob(src->d_bcount);
 551         dst->d_ino_count = src->d_icount;
 552         dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
 553                                                   src->d_itimer_hi);
 554         dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
 555                                                   src->d_btimer_hi);
 556         dst->d_ino_warns = src->d_iwarns;
 557         dst->d_spc_warns = src->d_bwarns;
 558         dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 559         dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 560         dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 561         dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
 562                                                      src->d_rtbtimer_hi);
 563         dst->d_rt_spc_warns = src->d_rtbwarns;
 564         dst->d_fieldmask = 0;
 565         if (src->d_fieldmask & FS_DQ_ISOFT)
 566                 dst->d_fieldmask |= QC_INO_SOFT;
 567         if (src->d_fieldmask & FS_DQ_IHARD)
 568                 dst->d_fieldmask |= QC_INO_HARD;
 569         if (src->d_fieldmask & FS_DQ_BSOFT)
 570                 dst->d_fieldmask |= QC_SPC_SOFT;
 571         if (src->d_fieldmask & FS_DQ_BHARD)
 572                 dst->d_fieldmask |= QC_SPC_HARD;
 573         if (src->d_fieldmask & FS_DQ_RTBSOFT)
 574                 dst->d_fieldmask |= QC_RT_SPC_SOFT;
 575         if (src->d_fieldmask & FS_DQ_RTBHARD)
 576                 dst->d_fieldmask |= QC_RT_SPC_HARD;
 577         if (src->d_fieldmask & FS_DQ_BTIMER)
 578                 dst->d_fieldmask |= QC_SPC_TIMER;
 579         if (src->d_fieldmask & FS_DQ_ITIMER)
 580                 dst->d_fieldmask |= QC_INO_TIMER;
 581         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 582                 dst->d_fieldmask |= QC_RT_SPC_TIMER;
 583         if (src->d_fieldmask & FS_DQ_BWARNS)
 584                 dst->d_fieldmask |= QC_SPC_WARNS;
 585         if (src->d_fieldmask & FS_DQ_IWARNS)
 586                 dst->d_fieldmask |= QC_INO_WARNS;
 587         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 588                 dst->d_fieldmask |= QC_RT_SPC_WARNS;
 589         if (src->d_fieldmask & FS_DQ_BCOUNT)
 590                 dst->d_fieldmask |= QC_SPACE;
 591         if (src->d_fieldmask & FS_DQ_ICOUNT)
 592                 dst->d_fieldmask |= QC_INO_COUNT;
 593         if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 594                 dst->d_fieldmask |= QC_RT_SPACE;
 595 }
 596
 597 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 598                                        struct fs_disk_quota *src)
 599 {
 600         memset(dst, 0, sizeof(*dst));
 601         dst->i_spc_timelimit = src->d_btimer;
 602         dst->i_ino_timelimit = src->d_itimer;
 603         dst->i_rt_spc_timelimit = src->d_rtbtimer;
 604         dst->i_ino_warnlimit = src->d_iwarns;
 605         dst->i_spc_warnlimit = src->d_bwarns;
 606         dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 607         if (src->d_fieldmask & FS_DQ_BWARNS)
 608                 dst->i_fieldmask |= QC_SPC_WARNS;
 609         if (src->d_fieldmask & FS_DQ_IWARNS)
 610                 dst->i_fieldmask |= QC_INO_WARNS;
 611         if (src->d_fieldmask & FS_DQ_RTBWARNS)
 612                 dst->i_fieldmask |= QC_RT_SPC_WARNS;
 613         if (src->d_fieldmask & FS_DQ_BTIMER)
 614                 dst->i_fieldmask |= QC_SPC_TIMER;
 615         if (src->d_fieldmask & FS_DQ_ITIMER)
 616                 dst->i_fieldmask |= QC_INO_TIMER;
 617         if (src->d_fieldmask & FS_DQ_RTBTIMER)
 618                 dst->i_fieldmask |= QC_RT_SPC_TIMER;
 619 }
 620
 621 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 622                            void __user *addr)
 623 {
 624         struct fs_disk_quota fdq;
 625         struct qc_dqblk qdq;
 626         struct kqid qid;
 627
 628         if (copy_from_user(&fdq, addr, sizeof(fdq)))
 629                 return -EFAULT;
 630         if (!sb->s_qcop->set_dqblk)
 631                 return -ENOSYS;
 632         qid = make_kqid(current_user_ns(), type, id);
 633         if (!qid_has_mapping(sb->s_user_ns, qid))
 634                 return -EINVAL;
 635         /* Are we actually setting timer / warning limits for all users? */
 636         if (from_kqid(sb->s_user_ns, qid) == 0 &&
 637             fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 638                 struct qc_info qinfo;
 639                 int ret;
 640
 641                 if (!sb->s_qcop->set_info)
 642                         return -EINVAL;
 643                 copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 644                 ret = sb->s_qcop->set_info(sb, type, &qinfo);
 645                 if (ret)
 646                         return ret;
 647                 /* These are already done */
 648                 fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 649         }
 650         copy_from_xfs_dqblk(&qdq, &fdq);
 651         return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 652 }
 653
 654 static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
 655                 __s32 *timer_lo, __s8 *timer_hi, s64 timer)
 656 {
 657         *timer_lo = timer;
 658         if (d->d_fieldmask & FS_DQ_BIGTIME)
 659                 *timer_hi = timer >> 32;
 660 }
 661
 662 static inline bool want_bigtime(s64 timer)
 663 {
 664         return timer > S32_MAX || timer < S32_MIN;
 665 }
 666
 667 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 668                               int type, qid_t id)
 669 {
 670         memset(dst, 0, sizeof(*dst));
 671         if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
 672             want_bigtime(src->d_rt_spc_timer))
 673                 dst->d_fieldmask |= FS_DQ_BIGTIME;
 674         dst->d_version = FS_DQUOT_VERSION;
 675         dst->d_id = id;
 676         if (type == USRQUOTA)
 677                 dst->d_flags = FS_USER_QUOTA;
 678         else if (type == PRJQUOTA)
 679                 dst->d_flags = FS_PROJ_QUOTA;
 680         else
 681                 dst->d_flags = FS_GROUP_QUOTA;
 682         dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 683         dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 684         dst->d_ino_hardlimit = src->d_ino_hardlimit;
 685         dst->d_ino_softlimit = src->d_ino_softlimit;
 686         dst->d_bcount = quota_btobb(src->d_space);
 687         dst->d_icount = src->d_ino_count;
 688         copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
 689                              src->d_ino_timer);
 690         copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
 691                              src->d_spc_timer);
 692         dst->d_iwarns = src->d_ino_warns;
 693         dst->d_bwarns = src->d_spc_warns;
 694         dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 695         dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 696         dst->d_rtbcount = quota_btobb(src->d_rt_space);
 697         copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
 698                              src->d_rt_spc_timer);
 699         dst->d_rtbwarns = src->d_rt_spc_warns;
 700 }
 701
 702 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 703                            void __user *addr)
 704 {
 705         struct fs_disk_quota fdq;
 706         struct qc_dqblk qdq;
 707         struct kqid qid;
 708         int ret;
 709
 710         if (!sb->s_qcop->get_dqblk)
 711                 return -ENOSYS;
 712         qid = make_kqid(current_user_ns(), type, id);
 713         if (!qid_has_mapping(sb->s_user_ns, qid))
 714                 return -EINVAL;
 715         ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 716         if (ret)
 717                 return ret;
 718         copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 719         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 720                 return -EFAULT;
 721         return ret;
 722 }
 723
 724 /*
 725  * Return quota for next active quota >= this id, if any exists,
 726  * otherwise return -ENOENT via ->get_nextdqblk.
 727  */
 728 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 729                             void __user *addr)
 730 {
 731         struct fs_disk_quota fdq;
 732         struct qc_dqblk qdq;
 733         struct kqid qid;
 734         qid_t id_out;
 735         int ret;
 736
 737         if (!sb->s_qcop->get_nextdqblk)
 738                 return -ENOSYS;
 739         qid = make_kqid(current_user_ns(), type, id);
 740         if (!qid_has_mapping(sb->s_user_ns, qid))
 741                 return -EINVAL;
 742         ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 743         if (ret)
 744                 return ret;
 745         id_out = from_kqid(current_user_ns(), qid);
 746         copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 747         if (copy_to_user(addr, &fdq, sizeof(fdq)))
 748                 return -EFAULT;
 749         return ret;
 750 }
 751
 752 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 753 {
 754         __u32 flags;
 755
 756         if (copy_from_user(&flags, addr, sizeof(flags)))
 757                 return -EFAULT;
 758         if (!sb->s_qcop->rm_xquota)
 759                 return -ENOSYS;
 760         return sb->s_qcop->rm_xquota(sb, flags);
 761 }
 762
 763 /* Copy parameters and call proper function */
 764 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 765                        void __user *addr, const struct path *path)
 766 {
 767         int ret;
 768
 769         type = array_index_nospec(type, MAXQUOTAS);
 770         /*
 771          * Quota not supported on this fs? Check this before s_quota_types
 772          * since they needn't be set if quota is not supported at all.
 773          */
 774         if (!sb->s_qcop)
 775                 return -ENOSYS;
 776         if (!(sb->s_quota_types & (1 << type)))
 777                 return -EINVAL;
 778
 779         ret = check_quotactl_permission(sb, type, cmd, id);
 780         if (ret < 0)
 781                 return ret;
 782
 783         switch (cmd) {
 784         case Q_QUOTAON:
 785                 return quota_quotaon(sb, type, id, path);
 786         case Q_QUOTAOFF:
 787                 return quota_quotaoff(sb, type);
 788         case Q_GETFMT:
 789                 return quota_getfmt(sb, type, addr);
 790         case Q_GETINFO:
 791                 return quota_getinfo(sb, type, addr);
 792         case Q_SETINFO:
 793                 return quota_setinfo(sb, type, addr);
 794         case Q_GETQUOTA:
 795                 return quota_getquota(sb, type, id, addr);
 796         case Q_GETNEXTQUOTA:
 797                 return quota_getnextquota(sb, type, id, addr);
 798         case Q_SETQUOTA:
 799                 return quota_setquota(sb, type, id, addr);
 800         case Q_SYNC:
 801                 if (!sb->s_qcop->quota_sync)
 802                         return -ENOSYS;
 803                 return sb->s_qcop->quota_sync(sb, type);
 804         case Q_XQUOTAON:
 805                 return quota_enable(sb, addr);
 806         case Q_XQUOTAOFF:
 807                 return quota_disable(sb, addr);
 808         case Q_XQUOTARM:
 809                 return quota_rmxquota(sb, addr);
 810         case Q_XGETQSTAT:
 811                 return quota_getxstate(sb, type, addr);
 812         case Q_XGETQSTATV:
 813                 return quota_getxstatev(sb, type, addr);
 814         case Q_XSETQLIM:
 815                 return quota_setxquota(sb, type, id, addr);
 816         case Q_XGETQUOTA:
 817                 return quota_getxquota(sb, type, id, addr);
 818         case Q_XGETNEXTQUOTA:
 819                 return quota_getnextxquota(sb, type, id, addr);
 820         case Q_XQUOTASYNC:
 821                 if (sb_rdonly(sb))
 822                         return -EROFS;
 823                 /* XFS quotas are fully coherent now, making this call a noop */
 824                 return 0;
 825         default:
 826                 return -EINVAL;
 827         }
 828 }
 829
 830 #ifdef CONFIG_BLOCK
 831
 832 /* Return 1 if 'cmd' will block on frozen filesystem */
 833 static int quotactl_cmd_write(int cmd)
 834 {
 835         /*
 836          * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 837          * as dquot_acquire() may allocate space for new structure and OCFS2
 838          * needs to increment on-disk use count.
 839          */
 840         switch (cmd) {
 841         case Q_GETFMT:
 842         case Q_GETINFO:
 843         case Q_SYNC:
 844         case Q_XGETQSTAT:
 845         case Q_XGETQSTATV:
 846         case Q_XGETQUOTA:
 847         case Q_XGETNEXTQUOTA:
 848         case Q_XQUOTASYNC:
 849                 return 0;
 850         }
 851         return 1;
 852 }
 853 #endif /* CONFIG_BLOCK */
 854
 855 /* Return true if quotactl command is manipulating quota on/off state */
 856 static bool quotactl_cmd_onoff(int cmd)
 857 {
 858         return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 859                  (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 860 }
 861
 862 /*
 863  * look up a superblock on which quota ops will be performed
 864  * - use the name of a block device to find the superblock thereon
 865  */
 866 static struct super_block *quotactl_block(const char __user *special, int cmd)
 867 {
 868 #ifdef CONFIG_BLOCK
 869         struct block_device *bdev;
 870         struct super_block *sb;
 871         struct filename *tmp = getname(special);
 872         bool excl = false, thawed = false;
 873
 874         if (IS_ERR(tmp))
 875                 return ERR_CAST(tmp);
 876         bdev = lookup_bdev(tmp->name);
 877         putname(tmp);
 878         if (IS_ERR(bdev))
 879                 return ERR_CAST(bdev);
 880
 881         if (quotactl_cmd_onoff(cmd)) {
 882                 excl = true;
 883                 thawed = true;
 884         } else if (quotactl_cmd_write(cmd)) {
 885                 thawed = true;
 886         }
 887
 888 retry:
 889         sb = __get_super(bdev, excl);
 890         if (thawed && sb && sb->s_writers.frozen != SB_UNFROZEN) {
 891                 if (excl)
 892                         up_write(&sb->s_umount);
 893                 else
 894                         up_read(&sb->s_umount);
 895                 wait_event(sb->s_writers.wait_unfrozen,
 896                            sb->s_writers.frozen == SB_UNFROZEN);
 897                 put_super(sb);
 898                 goto retry;
 899         }
 900
 901         bdput(bdev);
 902         if (!sb)
 903                 return ERR_PTR(-ENODEV);
 904         return sb;
 905
 906 #else
 907         return ERR_PTR(-ENODEV);
 908 #endif
 909 }
 910
 911 /*
 912  * This is the system call interface. This communicates with
 913  * the user-level programs. Currently this only supports diskquota
 914  * calls. Maybe we need to add the process quotas etc. in the future,
 915  * but we probably should use rlimits for that.
 916  */
 917 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 918                 qid_t, id, void __user *, addr)
 919 {
 920         uint cmds, type;
 921         struct super_block *sb = NULL;
 922         struct path path, *pathp = NULL;
 923         int ret;
 924
 925         cmds = cmd >> SUBCMDSHIFT;
 926         type = cmd & SUBCMDMASK;
 927
 928         if (type >= MAXQUOTAS)
 929                 return -EINVAL;
 930
 931         /*
 932          * As a special case Q_SYNC can be called without a specific device.
 933          * It will iterate all superblocks that have quota enabled and call
 934          * the sync action on each of them.
 935          */
 936         if (!special) {
 937                 if (cmds == Q_SYNC)
 938                         return quota_sync_all(type);
 939                 return -ENODEV;
 940         }
 941
 942         /*
 943          * Path for quotaon has to be resolved before grabbing superblock
 944          * because that gets s_umount sem which is also possibly needed by path
 945          * resolution (think about autofs) and thus deadlocks could arise.
 946          */
 947         if (cmds == Q_QUOTAON) {
 948                 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 949                 if (ret)
 950                         pathp = ERR_PTR(ret);
 951                 else
 952                         pathp = &path;
 953         }
 954
 955         sb = quotactl_block(special, cmds);
 956         if (IS_ERR(sb)) {
 957                 ret = PTR_ERR(sb);
 958                 goto out;
 959         }
 960
 961         ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 962
 963         if (!quotactl_cmd_onoff(cmds))
 964                 drop_super(sb);
 965         else
 966                 drop_super_exclusive(sb);
 967 out:
 968         if (pathp && !IS_ERR(pathp))
 969                 path_put(pathp);
 970         return ret;
 971 }