linux/fs/quota/quota.c
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   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/mount.h>
  21#include <linux/writeback.h>
  22#include <linux/nospec.h>
  23#include "compat.h"
  24#include "../internal.h"
  25
  26static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  27                                     qid_t id)
  28{
  29        switch (cmd) {
  30        /* these commands do not require any special privilegues */
  31        case Q_GETFMT:
  32        case Q_SYNC:
  33        case Q_GETINFO:
  34        case Q_XGETQSTAT:
  35        case Q_XGETQSTATV:
  36        case Q_XQUOTASYNC:
  37                break;
  38        /* allow to query information for dquots we "own" */
  39        case Q_GETQUOTA:
  40        case Q_XGETQUOTA:
  41                if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  42                    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  43                        break;
  44                fallthrough;
  45        default:
  46                if (!capable(CAP_SYS_ADMIN))
  47                        return -EPERM;
  48        }
  49
  50        return security_quotactl(cmd, type, id, sb);
  51}
  52
  53static void quota_sync_one(struct super_block *sb, void *arg)
  54{
  55        int type = *(int *)arg;
  56
  57        if (sb->s_qcop && sb->s_qcop->quota_sync &&
  58            (sb->s_quota_types & (1 << type)))
  59                sb->s_qcop->quota_sync(sb, type);
  60}
  61
  62static int quota_sync_all(int type)
  63{
  64        int ret;
  65
  66        ret = security_quotactl(Q_SYNC, type, 0, NULL);
  67        if (!ret)
  68                iterate_supers(quota_sync_one, &type);
  69        return ret;
  70}
  71
  72unsigned int qtype_enforce_flag(int type)
  73{
  74        switch (type) {
  75        case USRQUOTA:
  76                return FS_QUOTA_UDQ_ENFD;
  77        case GRPQUOTA:
  78                return FS_QUOTA_GDQ_ENFD;
  79        case PRJQUOTA:
  80                return FS_QUOTA_PDQ_ENFD;
  81        }
  82        return 0;
  83}
  84
  85static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  86                         const struct path *path)
  87{
  88        if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  89                return -ENOSYS;
  90        if (sb->s_qcop->quota_enable)
  91                return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  92        if (IS_ERR(path))
  93                return PTR_ERR(path);
  94        return sb->s_qcop->quota_on(sb, type, id, path);
  95}
  96
  97static int quota_quotaoff(struct super_block *sb, int type)
  98{
  99        if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
 100                return -ENOSYS;
 101        if (sb->s_qcop->quota_disable)
 102                return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 103        return sb->s_qcop->quota_off(sb, type);
 104}
 105
 106static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 107{
 108        __u32 fmt;
 109
 110        if (!sb_has_quota_active(sb, type))
 111                return -ESRCH;
 112        fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 113        if (copy_to_user(addr, &fmt, sizeof(fmt)))
 114                return -EFAULT;
 115        return 0;
 116}
 117
 118static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 119{
 120        struct qc_state state;
 121        struct qc_type_state *tstate;
 122        struct if_dqinfo uinfo;
 123        int ret;
 124
 125        if (!sb->s_qcop->get_state)
 126                return -ENOSYS;
 127        ret = sb->s_qcop->get_state(sb, &state);
 128        if (ret)
 129                return ret;
 130        tstate = state.s_state + type;
 131        if (!(tstate->flags & QCI_ACCT_ENABLED))
 132                return -ESRCH;
 133        memset(&uinfo, 0, sizeof(uinfo));
 134        uinfo.dqi_bgrace = tstate->spc_timelimit;
 135        uinfo.dqi_igrace = tstate->ino_timelimit;
 136        if (tstate->flags & QCI_SYSFILE)
 137                uinfo.dqi_flags |= DQF_SYS_FILE;
 138        if (tstate->flags & QCI_ROOT_SQUASH)
 139                uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 140        uinfo.dqi_valid = IIF_ALL;
 141        if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 142                return -EFAULT;
 143        return 0;
 144}
 145
 146static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 147{
 148        struct if_dqinfo info;
 149        struct qc_info qinfo;
 150
 151        if (copy_from_user(&info, addr, sizeof(info)))
 152                return -EFAULT;
 153        if (!sb->s_qcop->set_info)
 154                return -ENOSYS;
 155        if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 156                return -EINVAL;
 157        memset(&qinfo, 0, sizeof(qinfo));
 158        if (info.dqi_valid & IIF_FLAGS) {
 159                if (info.dqi_flags & ~DQF_SETINFO_MASK)
 160                        return -EINVAL;
 161                if (info.dqi_flags & DQF_ROOT_SQUASH)
 162                        qinfo.i_flags |= QCI_ROOT_SQUASH;
 163                qinfo.i_fieldmask |= QC_FLAGS;
 164        }
 165        if (info.dqi_valid & IIF_BGRACE) {
 166                qinfo.i_spc_timelimit = info.dqi_bgrace;
 167                qinfo.i_fieldmask |= QC_SPC_TIMER;
 168        }
 169        if (info.dqi_valid & IIF_IGRACE) {
 170                qinfo.i_ino_timelimit = info.dqi_igrace;
 171                qinfo.i_fieldmask |= QC_INO_TIMER;
 172        }
 173        return sb->s_qcop->set_info(sb, type, &qinfo);
 174}
 175
 176static inline qsize_t qbtos(qsize_t blocks)
 177{
 178        return blocks << QIF_DQBLKSIZE_BITS;
 179}
 180
 181static inline qsize_t stoqb(qsize_t space)
 182{
 183        return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 184}
 185
 186static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 187{
 188        memset(dst, 0, sizeof(*dst));
 189        dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 190        dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 191        dst->dqb_curspace = src->d_space;
 192        dst->dqb_ihardlimit = src->d_ino_hardlimit;
 193        dst->dqb_isoftlimit = src->d_ino_softlimit;
 194        dst->dqb_curinodes = src->d_ino_count;
 195        dst->dqb_btime = src->d_spc_timer;
 196        dst->dqb_itime = src->d_ino_timer;
 197        dst->dqb_valid = QIF_ALL;
 198}
 199
 200static int quota_getquota(struct super_block *sb, int type, qid_t id,
 201                          void __user *addr)
 202{
 203        struct kqid qid;
 204        struct qc_dqblk fdq;
 205        struct if_dqblk idq;
 206        int ret;
 207
 208        if (!sb->s_qcop->get_dqblk)
 209                return -ENOSYS;
 210        qid = make_kqid(current_user_ns(), type, id);
 211        if (!qid_has_mapping(sb->s_user_ns, qid))
 212                return -EINVAL;
 213        ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 214        if (ret)
 215                return ret;
 216        copy_to_if_dqblk(&idq, &fdq);
 217
 218        if (compat_need_64bit_alignment_fixup()) {
 219                struct compat_if_dqblk __user *compat_dqblk = addr;
 220
 221                if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
 222                        return -EFAULT;
 223                if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 224                        return -EFAULT;
 225        } else {
 226                if (copy_to_user(addr, &idq, sizeof(idq)))
 227                        return -EFAULT;
 228        }
 229        return 0;
 230}
 231
 232/*
 233 * Return quota for next active quota >= this id, if any exists,
 234 * otherwise return -ENOENT via ->get_nextdqblk
 235 */
 236static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 237                          void __user *addr)
 238{
 239        struct kqid qid;
 240        struct qc_dqblk fdq;
 241        struct if_nextdqblk idq;
 242        int ret;
 243
 244        if (!sb->s_qcop->get_nextdqblk)
 245                return -ENOSYS;
 246        qid = make_kqid(current_user_ns(), type, id);
 247        if (!qid_has_mapping(sb->s_user_ns, qid))
 248                return -EINVAL;
 249        ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 250        if (ret)
 251                return ret;
 252        /* struct if_nextdqblk is a superset of struct if_dqblk */
 253        copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 254        idq.dqb_id = from_kqid(current_user_ns(), qid);
 255        if (copy_to_user(addr, &idq, sizeof(idq)))
 256                return -EFAULT;
 257        return 0;
 258}
 259
 260static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 261{
 262        dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 263        dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 264        dst->d_space = src->dqb_curspace;
 265        dst->d_ino_hardlimit = src->dqb_ihardlimit;
 266        dst->d_ino_softlimit = src->dqb_isoftlimit;
 267        dst->d_ino_count = src->dqb_curinodes;
 268        dst->d_spc_timer = src->dqb_btime;
 269        dst->d_ino_timer = src->dqb_itime;
 270
 271        dst->d_fieldmask = 0;
 272        if (src->dqb_valid & QIF_BLIMITS)
 273                dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 274        if (src->dqb_valid & QIF_SPACE)
 275                dst->d_fieldmask |= QC_SPACE;
 276        if (src->dqb_valid & QIF_ILIMITS)
 277                dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 278        if (src->dqb_valid & QIF_INODES)
 279                dst->d_fieldmask |= QC_INO_COUNT;
 280        if (src->dqb_valid & QIF_BTIME)
 281                dst->d_fieldmask |= QC_SPC_TIMER;
 282        if (src->dqb_valid & QIF_ITIME)
 283                dst->d_fieldmask |= QC_INO_TIMER;
 284}
 285
 286static int quota_setquota(struct super_block *sb, int type, qid_t id,
 287                          void __user *addr)
 288{
 289        struct qc_dqblk fdq;
 290        struct if_dqblk idq;
 291        struct kqid qid;
 292
 293        if (compat_need_64bit_alignment_fixup()) {
 294                struct compat_if_dqblk __user *compat_dqblk = addr;
 295
 296                if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
 297                    get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 298                        return -EFAULT;
 299        } else {
 300                if (copy_from_user(&idq, addr, sizeof(idq)))
 301                        return -EFAULT;
 302        }
 303        if (!sb->s_qcop->set_dqblk)
 304                return -ENOSYS;
 305        qid = make_kqid(current_user_ns(), type, id);
 306        if (!qid_has_mapping(sb->s_user_ns, qid))
 307                return -EINVAL;
 308        copy_from_if_dqblk(&fdq, &idq);
 309        return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 310}
 311
 312static int quota_enable(struct super_block *sb, void __user *addr)
 313{
 314        __u32 flags;
 315
 316        if (copy_from_user(&flags, addr, sizeof(flags)))
 317                return -EFAULT;
 318        if (!sb->s_qcop->quota_enable)
 319                return -ENOSYS;
 320        return sb->s_qcop->quota_enable(sb, flags);
 321}
 322
 323static int quota_disable(struct super_block *sb, void __user *addr)
 324{
 325        __u32 flags;
 326
 327        if (copy_from_user(&flags, addr, sizeof(flags)))
 328                return -EFAULT;
 329        if (!sb->s_qcop->quota_disable)
 330                return -ENOSYS;
 331        return sb->s_qcop->quota_disable(sb, flags);
 332}
 333
 334static int quota_state_to_flags(struct qc_state *state)
 335{
 336        int flags = 0;
 337
 338        if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 339                flags |= FS_QUOTA_UDQ_ACCT;
 340        if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 341                flags |= FS_QUOTA_UDQ_ENFD;
 342        if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 343                flags |= FS_QUOTA_GDQ_ACCT;
 344        if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 345                flags |= FS_QUOTA_GDQ_ENFD;
 346        if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 347                flags |= FS_QUOTA_PDQ_ACCT;
 348        if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 349                flags |= FS_QUOTA_PDQ_ENFD;
 350        return flags;
 351}
 352
 353static int quota_getstate(struct super_block *sb, int type,
 354                          struct fs_quota_stat *fqs)
 355{
 356        struct qc_state state;
 357        int ret;
 358
 359        memset(&state, 0, sizeof (struct qc_state));
 360        ret = sb->s_qcop->get_state(sb, &state);
 361        if (ret < 0)
 362                return ret;
 363
 364        memset(fqs, 0, sizeof(*fqs));
 365        fqs->qs_version = FS_QSTAT_VERSION;
 366        fqs->qs_flags = quota_state_to_flags(&state);
 367        /* No quota enabled? */
 368        if (!fqs->qs_flags)
 369                return -ENOSYS;
 370        fqs->qs_incoredqs = state.s_incoredqs;
 371
 372        fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 373        fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 374        fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 375        fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 376        fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 377
 378        /* Inodes may be allocated even if inactive; copy out if present */
 379        if (state.s_state[USRQUOTA].ino) {
 380                fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 381                fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 382                fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 383        }
 384        if (state.s_state[GRPQUOTA].ino) {
 385                fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 386                fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 387                fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 388        }
 389        if (state.s_state[PRJQUOTA].ino) {
 390                /*
 391                 * Q_XGETQSTAT doesn't have room for both group and project
 392                 * quotas.  So, allow the project quota values to be copied out
 393                 * only if there is no group quota information available.
 394                 */
 395                if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 396                        fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 397                        fqs->qs_gquota.qfs_nblks =
 398                                        state.s_state[PRJQUOTA].blocks;
 399                        fqs->qs_gquota.qfs_nextents =
 400                                        state.s_state[PRJQUOTA].nextents;
 401                }
 402        }
 403        return 0;
 404}
 405
 406static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
 407                struct fs_qfilestat *from)
 408{
 409        if (copy_to_user(to, from, sizeof(*to)) ||
 410            put_user(from->qfs_nextents, &to->qfs_nextents))
 411                return -EFAULT;
 412        return 0;
 413}
 414
 415static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
 416                struct fs_quota_stat *from)
 417{
 418        if (put_user(from->qs_version, &to->qs_version) ||
 419            put_user(from->qs_flags, &to->qs_flags) ||
 420            put_user(from->qs_pad, &to->qs_pad) ||
 421            compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
 422            compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
 423            put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
 424            put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
 425            put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
 426            put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
 427            put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
 428            put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
 429                return -EFAULT;
 430        return 0;
 431}
 432
 433static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
 434{
 435        struct fs_quota_stat fqs;
 436        int ret;
 437
 438        if (!sb->s_qcop->get_state)
 439                return -ENOSYS;
 440        ret = quota_getstate(sb, type, &fqs);
 441        if (ret)
 442                return ret;
 443
 444        if (compat_need_64bit_alignment_fixup())
 445                return compat_copy_fs_quota_stat(addr, &fqs);
 446        if (copy_to_user(addr, &fqs, sizeof(fqs)))
 447                return -EFAULT;
 448        return 0;
 449}
 450
 451static int quota_getstatev(struct super_block *sb, int type,
 452                           struct fs_quota_statv *fqs)
 453{
 454        struct qc_state state;
 455        int ret;
 456
 457        memset(&state, 0, sizeof (struct qc_state));
 458        ret = sb->s_qcop->get_state(sb, &state);
 459        if (ret < 0)
 460                return ret;
 461
 462        memset(fqs, 0, sizeof(*fqs));
 463        fqs->qs_version = FS_QSTAT_VERSION;
 464        fqs->qs_flags = quota_state_to_flags(&state);
 465        /* No quota enabled? */
 466        if (!fqs->qs_flags)
 467                return -ENOSYS;
 468        fqs->qs_incoredqs = state.s_incoredqs;
 469
 470        fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 471        fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 472        fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 473        fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 474        fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 475        fqs->qs_rtbwarnlimit = state.s_state[type].rt_spc_warnlimit;
 476
 477        /* Inodes may be allocated even if inactive; copy out if present */
 478        if (state.s_state[USRQUOTA].ino) {
 479                fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 480                fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 481                fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 482        }
 483        if (state.s_state[GRPQUOTA].ino) {
 484                fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 485                fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 486                fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 487        }
 488        if (state.s_state[PRJQUOTA].ino) {
 489                fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 490                fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 491                fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 492        }
 493        return 0;
 494}
 495
 496static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
 497{
 498        struct fs_quota_statv fqs;
 499        int ret;
 500
 501        if (!sb->s_qcop->get_state)
 502                return -ENOSYS;
 503
 504        memset(&fqs, 0, sizeof(fqs));
 505        if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 506                return -EFAULT;
 507
 508        /* If this kernel doesn't support user specified version, fail */
 509        switch (fqs.qs_version) {
 510        case FS_QSTATV_VERSION1:
 511                break;
 512        default:
 513                return -EINVAL;
 514        }
 515        ret = quota_getstatev(sb, type, &fqs);
 516        if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 517                return -EFAULT;
 518        return ret;
 519}
 520
 521/*
 522 * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 523 * out of there as xfsprogs rely on definitions being in that header file. So
 524 * just define same functions here for quota purposes.
 525 */
 526#define XFS_BB_SHIFT 9
 527
 528static inline u64 quota_bbtob(u64 blocks)
 529{
 530        return blocks << XFS_BB_SHIFT;
 531}
 532
 533static inline u64 quota_btobb(u64 bytes)
 534{
 535        return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 536}
 537
 538static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
 539                __s32 timer, __s8 timer_hi)
 540{
 541        if (d->d_fieldmask & FS_DQ_BIGTIME)
 542                return (u32)timer | (s64)timer_hi << 32;
 543        return timer;
 544}
 545
 546static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 547{
 548        dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 549        dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 550        dst->d_ino_hardlimit = src->d_ino_hardlimit;
 551        dst->d_ino_softlimit = src->d_ino_softlimit;
 552        dst->d_space = quota_bbtob(src->d_bcount);
 553        dst->d_ino_count = src->d_icount;
 554        dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
 555                                                  src->d_itimer_hi);
 556        dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
 557                                                  src->d_btimer_hi);
 558        dst->d_ino_warns = src->d_iwarns;
 559        dst->d_spc_warns = src->d_bwarns;
 560        dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 561        dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 562        dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 563        dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
 564                                                     src->d_rtbtimer_hi);
 565        dst->d_rt_spc_warns = src->d_rtbwarns;
 566        dst->d_fieldmask = 0;
 567        if (src->d_fieldmask & FS_DQ_ISOFT)
 568                dst->d_fieldmask |= QC_INO_SOFT;
 569        if (src->d_fieldmask & FS_DQ_IHARD)
 570                dst->d_fieldmask |= QC_INO_HARD;
 571        if (src->d_fieldmask & FS_DQ_BSOFT)
 572                dst->d_fieldmask |= QC_SPC_SOFT;
 573        if (src->d_fieldmask & FS_DQ_BHARD)
 574                dst->d_fieldmask |= QC_SPC_HARD;
 575        if (src->d_fieldmask & FS_DQ_RTBSOFT)
 576                dst->d_fieldmask |= QC_RT_SPC_SOFT;
 577        if (src->d_fieldmask & FS_DQ_RTBHARD)
 578                dst->d_fieldmask |= QC_RT_SPC_HARD;
 579        if (src->d_fieldmask & FS_DQ_BTIMER)
 580                dst->d_fieldmask |= QC_SPC_TIMER;
 581        if (src->d_fieldmask & FS_DQ_ITIMER)
 582                dst->d_fieldmask |= QC_INO_TIMER;
 583        if (src->d_fieldmask & FS_DQ_RTBTIMER)
 584                dst->d_fieldmask |= QC_RT_SPC_TIMER;
 585        if (src->d_fieldmask & FS_DQ_BWARNS)
 586                dst->d_fieldmask |= QC_SPC_WARNS;
 587        if (src->d_fieldmask & FS_DQ_IWARNS)
 588                dst->d_fieldmask |= QC_INO_WARNS;
 589        if (src->d_fieldmask & FS_DQ_RTBWARNS)
 590                dst->d_fieldmask |= QC_RT_SPC_WARNS;
 591        if (src->d_fieldmask & FS_DQ_BCOUNT)
 592                dst->d_fieldmask |= QC_SPACE;
 593        if (src->d_fieldmask & FS_DQ_ICOUNT)
 594                dst->d_fieldmask |= QC_INO_COUNT;
 595        if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 596                dst->d_fieldmask |= QC_RT_SPACE;
 597}
 598
 599static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 600                                       struct fs_disk_quota *src)
 601{
 602        memset(dst, 0, sizeof(*dst));
 603        dst->i_spc_timelimit = src->d_btimer;
 604        dst->i_ino_timelimit = src->d_itimer;
 605        dst->i_rt_spc_timelimit = src->d_rtbtimer;
 606        dst->i_ino_warnlimit = src->d_iwarns;
 607        dst->i_spc_warnlimit = src->d_bwarns;
 608        dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 609        if (src->d_fieldmask & FS_DQ_BWARNS)
 610                dst->i_fieldmask |= QC_SPC_WARNS;
 611        if (src->d_fieldmask & FS_DQ_IWARNS)
 612                dst->i_fieldmask |= QC_INO_WARNS;
 613        if (src->d_fieldmask & FS_DQ_RTBWARNS)
 614                dst->i_fieldmask |= QC_RT_SPC_WARNS;
 615        if (src->d_fieldmask & FS_DQ_BTIMER)
 616                dst->i_fieldmask |= QC_SPC_TIMER;
 617        if (src->d_fieldmask & FS_DQ_ITIMER)
 618                dst->i_fieldmask |= QC_INO_TIMER;
 619        if (src->d_fieldmask & FS_DQ_RTBTIMER)
 620                dst->i_fieldmask |= QC_RT_SPC_TIMER;
 621}
 622
 623static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 624                           void __user *addr)
 625{
 626        struct fs_disk_quota fdq;
 627        struct qc_dqblk qdq;
 628        struct kqid qid;
 629
 630        if (copy_from_user(&fdq, addr, sizeof(fdq)))
 631                return -EFAULT;
 632        if (!sb->s_qcop->set_dqblk)
 633                return -ENOSYS;
 634        qid = make_kqid(current_user_ns(), type, id);
 635        if (!qid_has_mapping(sb->s_user_ns, qid))
 636                return -EINVAL;
 637        /* Are we actually setting timer / warning limits for all users? */
 638        if (from_kqid(sb->s_user_ns, qid) == 0 &&
 639            fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 640                struct qc_info qinfo;
 641                int ret;
 642
 643                if (!sb->s_qcop->set_info)
 644                        return -EINVAL;
 645                copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 646                ret = sb->s_qcop->set_info(sb, type, &qinfo);
 647                if (ret)
 648                        return ret;
 649                /* These are already done */
 650                fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 651        }
 652        copy_from_xfs_dqblk(&qdq, &fdq);
 653        return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 654}
 655
 656static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
 657                __s32 *timer_lo, __s8 *timer_hi, s64 timer)
 658{
 659        *timer_lo = timer;
 660        if (d->d_fieldmask & FS_DQ_BIGTIME)
 661                *timer_hi = timer >> 32;
 662}
 663
 664static inline bool want_bigtime(s64 timer)
 665{
 666        return timer > S32_MAX || timer < S32_MIN;
 667}
 668
 669static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 670                              int type, qid_t id)
 671{
 672        memset(dst, 0, sizeof(*dst));
 673        if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
 674            want_bigtime(src->d_rt_spc_timer))
 675                dst->d_fieldmask |= FS_DQ_BIGTIME;
 676        dst->d_version = FS_DQUOT_VERSION;
 677        dst->d_id = id;
 678        if (type == USRQUOTA)
 679                dst->d_flags = FS_USER_QUOTA;
 680        else if (type == PRJQUOTA)
 681                dst->d_flags = FS_PROJ_QUOTA;
 682        else
 683                dst->d_flags = FS_GROUP_QUOTA;
 684        dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 685        dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 686        dst->d_ino_hardlimit = src->d_ino_hardlimit;
 687        dst->d_ino_softlimit = src->d_ino_softlimit;
 688        dst->d_bcount = quota_btobb(src->d_space);
 689        dst->d_icount = src->d_ino_count;
 690        copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
 691                             src->d_ino_timer);
 692        copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
 693                             src->d_spc_timer);
 694        dst->d_iwarns = src->d_ino_warns;
 695        dst->d_bwarns = src->d_spc_warns;
 696        dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 697        dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 698        dst->d_rtbcount = quota_btobb(src->d_rt_space);
 699        copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
 700                             src->d_rt_spc_timer);
 701        dst->d_rtbwarns = src->d_rt_spc_warns;
 702}
 703
 704static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 705                           void __user *addr)
 706{
 707        struct fs_disk_quota fdq;
 708        struct qc_dqblk qdq;
 709        struct kqid qid;
 710        int ret;
 711
 712        if (!sb->s_qcop->get_dqblk)
 713                return -ENOSYS;
 714        qid = make_kqid(current_user_ns(), type, id);
 715        if (!qid_has_mapping(sb->s_user_ns, qid))
 716                return -EINVAL;
 717        ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 718        if (ret)
 719                return ret;
 720        copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 721        if (copy_to_user(addr, &fdq, sizeof(fdq)))
 722                return -EFAULT;
 723        return ret;
 724}
 725
 726/*
 727 * Return quota for next active quota >= this id, if any exists,
 728 * otherwise return -ENOENT via ->get_nextdqblk.
 729 */
 730static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 731                            void __user *addr)
 732{
 733        struct fs_disk_quota fdq;
 734        struct qc_dqblk qdq;
 735        struct kqid qid;
 736        qid_t id_out;
 737        int ret;
 738
 739        if (!sb->s_qcop->get_nextdqblk)
 740                return -ENOSYS;
 741        qid = make_kqid(current_user_ns(), type, id);
 742        if (!qid_has_mapping(sb->s_user_ns, qid))
 743                return -EINVAL;
 744        ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 745        if (ret)
 746                return ret;
 747        id_out = from_kqid(current_user_ns(), qid);
 748        copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 749        if (copy_to_user(addr, &fdq, sizeof(fdq)))
 750                return -EFAULT;
 751        return ret;
 752}
 753
 754static int quota_rmxquota(struct super_block *sb, void __user *addr)
 755{
 756        __u32 flags;
 757
 758        if (copy_from_user(&flags, addr, sizeof(flags)))
 759                return -EFAULT;
 760        if (!sb->s_qcop->rm_xquota)
 761                return -ENOSYS;
 762        return sb->s_qcop->rm_xquota(sb, flags);
 763}
 764
 765/* Copy parameters and call proper function */
 766static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 767                       void __user *addr, const struct path *path)
 768{
 769        int ret;
 770
 771        type = array_index_nospec(type, MAXQUOTAS);
 772        /*
 773         * Quota not supported on this fs? Check this before s_quota_types
 774         * since they needn't be set if quota is not supported at all.
 775         */
 776        if (!sb->s_qcop)
 777                return -ENOSYS;
 778        if (!(sb->s_quota_types & (1 << type)))
 779                return -EINVAL;
 780
 781        ret = check_quotactl_permission(sb, type, cmd, id);
 782        if (ret < 0)
 783                return ret;
 784
 785        switch (cmd) {
 786        case Q_QUOTAON:
 787                return quota_quotaon(sb, type, id, path);
 788        case Q_QUOTAOFF:
 789                return quota_quotaoff(sb, type);
 790        case Q_GETFMT:
 791                return quota_getfmt(sb, type, addr);
 792        case Q_GETINFO:
 793                return quota_getinfo(sb, type, addr);
 794        case Q_SETINFO:
 795                return quota_setinfo(sb, type, addr);
 796        case Q_GETQUOTA:
 797                return quota_getquota(sb, type, id, addr);
 798        case Q_GETNEXTQUOTA:
 799                return quota_getnextquota(sb, type, id, addr);
 800        case Q_SETQUOTA:
 801                return quota_setquota(sb, type, id, addr);
 802        case Q_SYNC:
 803                if (!sb->s_qcop->quota_sync)
 804                        return -ENOSYS;
 805                return sb->s_qcop->quota_sync(sb, type);
 806        case Q_XQUOTAON:
 807                return quota_enable(sb, addr);
 808        case Q_XQUOTAOFF:
 809                return quota_disable(sb, addr);
 810        case Q_XQUOTARM:
 811                return quota_rmxquota(sb, addr);
 812        case Q_XGETQSTAT:
 813                return quota_getxstate(sb, type, addr);
 814        case Q_XGETQSTATV:
 815                return quota_getxstatev(sb, type, addr);
 816        case Q_XSETQLIM:
 817                return quota_setxquota(sb, type, id, addr);
 818        case Q_XGETQUOTA:
 819                return quota_getxquota(sb, type, id, addr);
 820        case Q_XGETNEXTQUOTA:
 821                return quota_getnextxquota(sb, type, id, addr);
 822        case Q_XQUOTASYNC:
 823                if (sb_rdonly(sb))
 824                        return -EROFS;
 825                /* XFS quotas are fully coherent now, making this call a noop */
 826                return 0;
 827        default:
 828                return -EINVAL;
 829        }
 830}
 831
 832/* Return 1 if 'cmd' will block on frozen filesystem */
 833static 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
 854/* Return true if quotactl command is manipulating quota on/off state */
 855static bool quotactl_cmd_onoff(int cmd)
 856{
 857        return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
 858                 (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
 859}
 860
 861/*
 862 * look up a superblock on which quota ops will be performed
 863 * - use the name of a block device to find the superblock thereon
 864 */
 865static struct super_block *quotactl_block(const char __user *special, int cmd)
 866{
 867#ifdef CONFIG_BLOCK
 868        struct super_block *sb;
 869        struct filename *tmp = getname(special);
 870        bool excl = false, thawed = false;
 871        int error;
 872        dev_t dev;
 873
 874        if (IS_ERR(tmp))
 875                return ERR_CAST(tmp);
 876        error = lookup_bdev(tmp->name, &dev);
 877        putname(tmp);
 878        if (error)
 879                return ERR_PTR(error);
 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
 888retry:
 889        sb = user_get_super(dev, excl);
 890        if (!sb)
 891                return ERR_PTR(-ENODEV);
 892        if (thawed && sb->s_writers.frozen != SB_UNFROZEN) {
 893                if (excl)
 894                        up_write(&sb->s_umount);
 895                else
 896                        up_read(&sb->s_umount);
 897                wait_event(sb->s_writers.wait_unfrozen,
 898                           sb->s_writers.frozen == SB_UNFROZEN);
 899                put_super(sb);
 900                goto retry;
 901        }
 902        return sb;
 903
 904#else
 905        return ERR_PTR(-ENODEV);
 906#endif
 907}
 908
 909/*
 910 * This is the system call interface. This communicates with
 911 * the user-level programs. Currently this only supports diskquota
 912 * calls. Maybe we need to add the process quotas etc. in the future,
 913 * but we probably should use rlimits for that.
 914 */
 915SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 916                qid_t, id, void __user *, addr)
 917{
 918        uint cmds, type;
 919        struct super_block *sb = NULL;
 920        struct path path, *pathp = NULL;
 921        int ret;
 922
 923        cmds = cmd >> SUBCMDSHIFT;
 924        type = cmd & SUBCMDMASK;
 925
 926        if (type >= MAXQUOTAS)
 927                return -EINVAL;
 928
 929        /*
 930         * As a special case Q_SYNC can be called without a specific device.
 931         * It will iterate all superblocks that have quota enabled and call
 932         * the sync action on each of them.
 933         */
 934        if (!special) {
 935                if (cmds == Q_SYNC)
 936                        return quota_sync_all(type);
 937                return -ENODEV;
 938        }
 939
 940        /*
 941         * Path for quotaon has to be resolved before grabbing superblock
 942         * because that gets s_umount sem which is also possibly needed by path
 943         * resolution (think about autofs) and thus deadlocks could arise.
 944         */
 945        if (cmds == Q_QUOTAON) {
 946                ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
 947                if (ret)
 948                        pathp = ERR_PTR(ret);
 949                else
 950                        pathp = &path;
 951        }
 952
 953        sb = quotactl_block(special, cmds);
 954        if (IS_ERR(sb)) {
 955                ret = PTR_ERR(sb);
 956                goto out;
 957        }
 958
 959        ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 960
 961        if (!quotactl_cmd_onoff(cmds))
 962                drop_super(sb);
 963        else
 964                drop_super_exclusive(sb);
 965out:
 966        if (pathp && !IS_ERR(pathp))
 967                path_put(pathp);
 968        return ret;
 969}
 970
 971SYSCALL_DEFINE4(quotactl_fd, unsigned int, fd, unsigned int, cmd,
 972                qid_t, id, void __user *, addr)
 973{
 974        struct super_block *sb;
 975        unsigned int cmds = cmd >> SUBCMDSHIFT;
 976        unsigned int type = cmd & SUBCMDMASK;
 977        struct fd f;
 978        int ret;
 979
 980        f = fdget_raw(fd);
 981        if (!f.file)
 982                return -EBADF;
 983
 984        ret = -EINVAL;
 985        if (type >= MAXQUOTAS)
 986                goto out;
 987
 988        if (quotactl_cmd_write(cmds)) {
 989                ret = mnt_want_write(f.file->f_path.mnt);
 990                if (ret)
 991                        goto out;
 992        }
 993
 994        sb = f.file->f_path.mnt->mnt_sb;
 995        if (quotactl_cmd_onoff(cmds))
 996                down_write(&sb->s_umount);
 997        else
 998                down_read(&sb->s_umount);
 999
1000        ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
1001
1002        if (quotactl_cmd_onoff(cmds))
1003                up_write(&sb->s_umount);
1004        else
1005                up_read(&sb->s_umount);
1006
1007        if (quotactl_cmd_write(cmds))
1008                mnt_drop_write(f.file->f_path.mnt);
1009out:
1010        fdput(f);
1011        return ret;
1012}
1013