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/blkdev.h>
  14#include <linux/uaccess.h>
  15#include <linux/kernel.h>
  16#include <linux/security.h>
  17#include <linux/syscalls.h>
  18#include <linux/capability.h>
  19#include <linux/quotaops.h>
  20#include <linux/types.h>
  21#include <linux/mount.h>
  22#include <linux/writeback.h>
  23#include <linux/nospec.h>
  24#include "compat.h"
  25#include "../internal.h"
  26
  27static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  28				     qid_t id)
  29{
  30	switch (cmd) {
  31	/* these commands do not require any special privilegues */
  32	case Q_GETFMT:
  33	case Q_SYNC:
  34	case Q_GETINFO:
  35	case Q_XGETQSTAT:
  36	case Q_XGETQSTATV:
  37	case Q_XQUOTASYNC:
  38		break;
  39	/* allow to query information for dquots we "own" */
  40	case Q_GETQUOTA:
  41	case Q_XGETQUOTA:
  42		if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  43		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
  44			break;
  45		fallthrough;
  46	default:
  47		if (!capable(CAP_SYS_ADMIN))
  48			return -EPERM;
  49	}
  50
  51	return security_quotactl(cmd, type, id, sb);
  52}
  53
  54static void quota_sync_one(struct super_block *sb, void *arg)
  55{
  56	int type = *(int *)arg;
  57
  58	if (sb->s_qcop && sb->s_qcop->quota_sync &&
  59	    (sb->s_quota_types & (1 << type)))
  60		sb->s_qcop->quota_sync(sb, type);
  61}
  62
  63static int quota_sync_all(int type)
  64{
  65	int ret;
  66
  67	ret = security_quotactl(Q_SYNC, type, 0, NULL);
  68	if (!ret)
  69		iterate_supers(quota_sync_one, &type);
  70	return ret;
  71}
  72
  73unsigned int qtype_enforce_flag(int type)
  74{
  75	switch (type) {
  76	case USRQUOTA:
  77		return FS_QUOTA_UDQ_ENFD;
  78	case GRPQUOTA:
  79		return FS_QUOTA_GDQ_ENFD;
  80	case PRJQUOTA:
  81		return FS_QUOTA_PDQ_ENFD;
  82	}
  83	return 0;
  84}
  85
  86static int quota_quotaon(struct super_block *sb, int type, qid_t id,
  87		         const struct path *path)
  88{
  89	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
  90		return -ENOSYS;
  91	if (sb->s_qcop->quota_enable)
  92		return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
  93	if (IS_ERR(path))
  94		return PTR_ERR(path);
  95	return sb->s_qcop->quota_on(sb, type, id, path);
  96}
  97
  98static int quota_quotaoff(struct super_block *sb, int type)
  99{
 100	if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
 101		return -ENOSYS;
 102	if (sb->s_qcop->quota_disable)
 103		return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
 104	return sb->s_qcop->quota_off(sb, type);
 105}
 106
 107static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 108{
 109	__u32 fmt;
 110
 111	if (!sb_has_quota_active(sb, type))
 112		return -ESRCH;
 113	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
 114	if (copy_to_user(addr, &fmt, sizeof(fmt)))
 115		return -EFAULT;
 116	return 0;
 117}
 118
 119static 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	if (!sb->s_qcop->get_state)
 127		return -ENOSYS;
 128	ret = sb->s_qcop->get_state(sb, &state);
 129	if (ret)
 130		return ret;
 131	tstate = state.s_state + type;
 132	if (!(tstate->flags & QCI_ACCT_ENABLED))
 133		return -ESRCH;
 134	memset(&uinfo, 0, sizeof(uinfo));
 135	uinfo.dqi_bgrace = tstate->spc_timelimit;
 136	uinfo.dqi_igrace = tstate->ino_timelimit;
 137	if (tstate->flags & QCI_SYSFILE)
 138		uinfo.dqi_flags |= DQF_SYS_FILE;
 139	if (tstate->flags & QCI_ROOT_SQUASH)
 140		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
 141	uinfo.dqi_valid = IIF_ALL;
 142	if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
 143		return -EFAULT;
 144	return 0;
 145}
 146
 147static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 148{
 149	struct if_dqinfo info;
 150	struct qc_info qinfo;
 151
 152	if (copy_from_user(&info, addr, sizeof(info)))
 153		return -EFAULT;
 154	if (!sb->s_qcop->set_info)
 155		return -ENOSYS;
 156	if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
 157		return -EINVAL;
 158	memset(&qinfo, 0, sizeof(qinfo));
 159	if (info.dqi_valid & IIF_FLAGS) {
 160		if (info.dqi_flags & ~DQF_SETINFO_MASK)
 161			return -EINVAL;
 162		if (info.dqi_flags & DQF_ROOT_SQUASH)
 163			qinfo.i_flags |= QCI_ROOT_SQUASH;
 164		qinfo.i_fieldmask |= QC_FLAGS;
 165	}
 166	if (info.dqi_valid & IIF_BGRACE) {
 167		qinfo.i_spc_timelimit = info.dqi_bgrace;
 168		qinfo.i_fieldmask |= QC_SPC_TIMER;
 169	}
 170	if (info.dqi_valid & IIF_IGRACE) {
 171		qinfo.i_ino_timelimit = info.dqi_igrace;
 172		qinfo.i_fieldmask |= QC_INO_TIMER;
 173	}
 174	return sb->s_qcop->set_info(sb, type, &qinfo);
 175}
 176
 177static inline qsize_t qbtos(qsize_t blocks)
 178{
 179	return blocks << QIF_DQBLKSIZE_BITS;
 180}
 181
 182static inline qsize_t stoqb(qsize_t space)
 183{
 184	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
 185}
 186
 187static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
 188{
 189	memset(dst, 0, sizeof(*dst));
 190	dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
 191	dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
 192	dst->dqb_curspace = src->d_space;
 193	dst->dqb_ihardlimit = src->d_ino_hardlimit;
 194	dst->dqb_isoftlimit = src->d_ino_softlimit;
 195	dst->dqb_curinodes = src->d_ino_count;
 196	dst->dqb_btime = src->d_spc_timer;
 197	dst->dqb_itime = src->d_ino_timer;
 198	dst->dqb_valid = QIF_ALL;
 199}
 200
 201static int quota_getquota(struct super_block *sb, int type, qid_t id,
 202			  void __user *addr)
 203{
 204	struct kqid qid;
 205	struct qc_dqblk fdq;
 206	struct if_dqblk idq;
 207	int ret;
 208
 209	if (!sb->s_qcop->get_dqblk)
 210		return -ENOSYS;
 211	qid = make_kqid(current_user_ns(), type, id);
 212	if (!qid_has_mapping(sb->s_user_ns, qid))
 213		return -EINVAL;
 214	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 215	if (ret)
 216		return ret;
 217	copy_to_if_dqblk(&idq, &fdq);
 218
 219	if (compat_need_64bit_alignment_fixup()) {
 220		struct compat_if_dqblk __user *compat_dqblk = addr;
 221
 222		if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
 223			return -EFAULT;
 224		if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 225			return -EFAULT;
 226	} else {
 227		if (copy_to_user(addr, &idq, sizeof(idq)))
 228			return -EFAULT;
 229	}
 230	return 0;
 231}
 232
 233/*
 234 * Return quota for next active quota >= this id, if any exists,
 235 * otherwise return -ENOENT via ->get_nextdqblk
 236 */
 237static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
 238			  void __user *addr)
 239{
 240	struct kqid qid;
 241	struct qc_dqblk fdq;
 242	struct if_nextdqblk idq;
 243	int ret;
 244
 245	if (!sb->s_qcop->get_nextdqblk)
 246		return -ENOSYS;
 247	qid = make_kqid(current_user_ns(), type, id);
 248	if (!qid_has_mapping(sb->s_user_ns, qid))
 249		return -EINVAL;
 250	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
 251	if (ret)
 252		return ret;
 253	/* struct if_nextdqblk is a superset of struct if_dqblk */
 254	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
 255	idq.dqb_id = from_kqid(current_user_ns(), qid);
 256	if (copy_to_user(addr, &idq, sizeof(idq)))
 257		return -EFAULT;
 258	return 0;
 259}
 260
 261static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 262{
 263	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
 264	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
 265	dst->d_space = src->dqb_curspace;
 266	dst->d_ino_hardlimit = src->dqb_ihardlimit;
 267	dst->d_ino_softlimit = src->dqb_isoftlimit;
 268	dst->d_ino_count = src->dqb_curinodes;
 269	dst->d_spc_timer = src->dqb_btime;
 270	dst->d_ino_timer = src->dqb_itime;
 271
 272	dst->d_fieldmask = 0;
 273	if (src->dqb_valid & QIF_BLIMITS)
 274		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
 275	if (src->dqb_valid & QIF_SPACE)
 276		dst->d_fieldmask |= QC_SPACE;
 277	if (src->dqb_valid & QIF_ILIMITS)
 278		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
 279	if (src->dqb_valid & QIF_INODES)
 280		dst->d_fieldmask |= QC_INO_COUNT;
 281	if (src->dqb_valid & QIF_BTIME)
 282		dst->d_fieldmask |= QC_SPC_TIMER;
 283	if (src->dqb_valid & QIF_ITIME)
 284		dst->d_fieldmask |= QC_INO_TIMER;
 285}
 286
 287static int quota_setquota(struct super_block *sb, int type, qid_t id,
 288			  void __user *addr)
 289{
 290	struct qc_dqblk fdq;
 291	struct if_dqblk idq;
 292	struct kqid qid;
 293
 294	if (compat_need_64bit_alignment_fixup()) {
 295		struct compat_if_dqblk __user *compat_dqblk = addr;
 296
 297		if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
 298		    get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
 299			return -EFAULT;
 300	} else {
 301		if (copy_from_user(&idq, addr, sizeof(idq)))
 302			return -EFAULT;
 303	}
 304	if (!sb->s_qcop->set_dqblk)
 305		return -ENOSYS;
 306	qid = make_kqid(current_user_ns(), type, id);
 307	if (!qid_has_mapping(sb->s_user_ns, qid))
 308		return -EINVAL;
 309	copy_from_if_dqblk(&fdq, &idq);
 310	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 311}
 312
 313static int quota_enable(struct super_block *sb, void __user *addr)
 314{
 315	__u32 flags;
 316
 317	if (copy_from_user(&flags, addr, sizeof(flags)))
 318		return -EFAULT;
 319	if (!sb->s_qcop->quota_enable)
 320		return -ENOSYS;
 321	return sb->s_qcop->quota_enable(sb, flags);
 322}
 323
 324static int quota_disable(struct super_block *sb, void __user *addr)
 325{
 326	__u32 flags;
 327
 328	if (copy_from_user(&flags, addr, sizeof(flags)))
 329		return -EFAULT;
 330	if (!sb->s_qcop->quota_disable)
 331		return -ENOSYS;
 332	return sb->s_qcop->quota_disable(sb, flags);
 333}
 334
 335static int quota_state_to_flags(struct qc_state *state)
 336{
 337	int flags = 0;
 338
 339	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
 340		flags |= FS_QUOTA_UDQ_ACCT;
 341	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
 342		flags |= FS_QUOTA_UDQ_ENFD;
 343	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
 344		flags |= FS_QUOTA_GDQ_ACCT;
 345	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
 346		flags |= FS_QUOTA_GDQ_ENFD;
 347	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
 348		flags |= FS_QUOTA_PDQ_ACCT;
 349	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
 350		flags |= FS_QUOTA_PDQ_ENFD;
 351	return flags;
 352}
 353
 354static int quota_getstate(struct super_block *sb, int type,
 355			  struct fs_quota_stat *fqs)
 356{
 357	struct qc_state state;
 358	int ret;
 359
 360	memset(&state, 0, sizeof (struct qc_state));
 361	ret = sb->s_qcop->get_state(sb, &state);
 362	if (ret < 0)
 363		return ret;
 364
 365	memset(fqs, 0, sizeof(*fqs));
 366	fqs->qs_version = FS_QSTAT_VERSION;
 367	fqs->qs_flags = quota_state_to_flags(&state);
 368	/* No quota enabled? */
 369	if (!fqs->qs_flags)
 370		return -ENOSYS;
 371	fqs->qs_incoredqs = state.s_incoredqs;
 372
 373	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 374	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 375	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 376	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 377	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 378
 379	/* Inodes may be allocated even if inactive; copy out if present */
 380	if (state.s_state[USRQUOTA].ino) {
 381		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 382		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 383		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 384	}
 385	if (state.s_state[GRPQUOTA].ino) {
 386		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 387		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 388		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 389	}
 390	if (state.s_state[PRJQUOTA].ino) {
 391		/*
 392		 * Q_XGETQSTAT doesn't have room for both group and project
 393		 * quotas.  So, allow the project quota values to be copied out
 394		 * only if there is no group quota information available.
 395		 */
 396		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
 397			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 398			fqs->qs_gquota.qfs_nblks =
 399					state.s_state[PRJQUOTA].blocks;
 400			fqs->qs_gquota.qfs_nextents =
 401					state.s_state[PRJQUOTA].nextents;
 402		}
 403	}
 404	return 0;
 405}
 406
 407static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
 408		struct fs_qfilestat *from)
 409{
 410	if (copy_to_user(to, from, sizeof(*to)) ||
 411	    put_user(from->qfs_nextents, &to->qfs_nextents))
 412		return -EFAULT;
 413	return 0;
 414}
 415
 416static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
 417		struct fs_quota_stat *from)
 418{
 419	if (put_user(from->qs_version, &to->qs_version) ||
 420	    put_user(from->qs_flags, &to->qs_flags) ||
 421	    put_user(from->qs_pad, &to->qs_pad) ||
 422	    compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
 423	    compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
 424	    put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
 425	    put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
 426	    put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
 427	    put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
 428	    put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
 429	    put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
 430		return -EFAULT;
 431	return 0;
 432}
 433
 434static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
 435{
 436	struct fs_quota_stat fqs;
 437	int ret;
 438
 439	if (!sb->s_qcop->get_state)
 440		return -ENOSYS;
 441	ret = quota_getstate(sb, type, &fqs);
 442	if (ret)
 443		return ret;
 444
 445	if (compat_need_64bit_alignment_fixup())
 446		return compat_copy_fs_quota_stat(addr, &fqs);
 447	if (copy_to_user(addr, &fqs, sizeof(fqs)))
 448		return -EFAULT;
 449	return 0;
 450}
 451
 452static int quota_getstatev(struct super_block *sb, int type,
 453			   struct fs_quota_statv *fqs)
 454{
 455	struct qc_state state;
 456	int ret;
 457
 458	memset(&state, 0, sizeof (struct qc_state));
 459	ret = sb->s_qcop->get_state(sb, &state);
 460	if (ret < 0)
 461		return ret;
 462
 463	memset(fqs, 0, sizeof(*fqs));
 464	fqs->qs_version = FS_QSTAT_VERSION;
 465	fqs->qs_flags = quota_state_to_flags(&state);
 466	/* No quota enabled? */
 467	if (!fqs->qs_flags)
 468		return -ENOSYS;
 469	fqs->qs_incoredqs = state.s_incoredqs;
 470
 471	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
 472	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
 473	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
 474	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
 475	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
 476	fqs->qs_rtbwarnlimit = state.s_state[type].rt_spc_warnlimit;
 477
 478	/* Inodes may be allocated even if inactive; copy out if present */
 479	if (state.s_state[USRQUOTA].ino) {
 480		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
 481		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
 482		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
 483	}
 484	if (state.s_state[GRPQUOTA].ino) {
 485		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
 486		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
 487		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
 488	}
 489	if (state.s_state[PRJQUOTA].ino) {
 490		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
 491		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
 492		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
 493	}
 494	return 0;
 495}
 496
 497static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
 498{
 499	struct fs_quota_statv fqs;
 500	int ret;
 501
 502	if (!sb->s_qcop->get_state)
 503		return -ENOSYS;
 504
 505	memset(&fqs, 0, sizeof(fqs));
 506	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
 507		return -EFAULT;
 508
 509	/* If this kernel doesn't support user specified version, fail */
 510	switch (fqs.qs_version) {
 511	case FS_QSTATV_VERSION1:
 512		break;
 513	default:
 514		return -EINVAL;
 515	}
 516	ret = quota_getstatev(sb, type, &fqs);
 517	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
 518		return -EFAULT;
 519	return ret;
 520}
 521
 522/*
 523 * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
 524 * out of there as xfsprogs rely on definitions being in that header file. So
 525 * just define same functions here for quota purposes.
 526 */
 527#define XFS_BB_SHIFT 9
 528
 529static inline u64 quota_bbtob(u64 blocks)
 530{
 531	return blocks << XFS_BB_SHIFT;
 532}
 533
 534static inline u64 quota_btobb(u64 bytes)
 535{
 536	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 537}
 538
 539static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
 540		__s32 timer, __s8 timer_hi)
 541{
 542	if (d->d_fieldmask & FS_DQ_BIGTIME)
 543		return (u32)timer | (s64)timer_hi << 32;
 544	return timer;
 545}
 546
 547static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 548{
 549	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
 550	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
 551	dst->d_ino_hardlimit = src->d_ino_hardlimit;
 552	dst->d_ino_softlimit = src->d_ino_softlimit;
 553	dst->d_space = quota_bbtob(src->d_bcount);
 554	dst->d_ino_count = src->d_icount;
 555	dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
 556						  src->d_itimer_hi);
 557	dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
 558						  src->d_btimer_hi);
 559	dst->d_ino_warns = src->d_iwarns;
 560	dst->d_spc_warns = src->d_bwarns;
 561	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 562	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 563	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
 564	dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
 565						     src->d_rtbtimer_hi);
 566	dst->d_rt_spc_warns = src->d_rtbwarns;
 567	dst->d_fieldmask = 0;
 568	if (src->d_fieldmask & FS_DQ_ISOFT)
 569		dst->d_fieldmask |= QC_INO_SOFT;
 570	if (src->d_fieldmask & FS_DQ_IHARD)
 571		dst->d_fieldmask |= QC_INO_HARD;
 572	if (src->d_fieldmask & FS_DQ_BSOFT)
 573		dst->d_fieldmask |= QC_SPC_SOFT;
 574	if (src->d_fieldmask & FS_DQ_BHARD)
 575		dst->d_fieldmask |= QC_SPC_HARD;
 576	if (src->d_fieldmask & FS_DQ_RTBSOFT)
 577		dst->d_fieldmask |= QC_RT_SPC_SOFT;
 578	if (src->d_fieldmask & FS_DQ_RTBHARD)
 579		dst->d_fieldmask |= QC_RT_SPC_HARD;
 580	if (src->d_fieldmask & FS_DQ_BTIMER)
 581		dst->d_fieldmask |= QC_SPC_TIMER;
 582	if (src->d_fieldmask & FS_DQ_ITIMER)
 583		dst->d_fieldmask |= QC_INO_TIMER;
 584	if (src->d_fieldmask & FS_DQ_RTBTIMER)
 585		dst->d_fieldmask |= QC_RT_SPC_TIMER;
 586	if (src->d_fieldmask & FS_DQ_BWARNS)
 587		dst->d_fieldmask |= QC_SPC_WARNS;
 588	if (src->d_fieldmask & FS_DQ_IWARNS)
 589		dst->d_fieldmask |= QC_INO_WARNS;
 590	if (src->d_fieldmask & FS_DQ_RTBWARNS)
 591		dst->d_fieldmask |= QC_RT_SPC_WARNS;
 592	if (src->d_fieldmask & FS_DQ_BCOUNT)
 593		dst->d_fieldmask |= QC_SPACE;
 594	if (src->d_fieldmask & FS_DQ_ICOUNT)
 595		dst->d_fieldmask |= QC_INO_COUNT;
 596	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
 597		dst->d_fieldmask |= QC_RT_SPACE;
 598}
 599
 600static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
 601				       struct fs_disk_quota *src)
 602{
 603	memset(dst, 0, sizeof(*dst));
 604	dst->i_spc_timelimit = src->d_btimer;
 605	dst->i_ino_timelimit = src->d_itimer;
 606	dst->i_rt_spc_timelimit = src->d_rtbtimer;
 607	dst->i_ino_warnlimit = src->d_iwarns;
 608	dst->i_spc_warnlimit = src->d_bwarns;
 609	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
 610	if (src->d_fieldmask & FS_DQ_BWARNS)
 611		dst->i_fieldmask |= QC_SPC_WARNS;
 612	if (src->d_fieldmask & FS_DQ_IWARNS)
 613		dst->i_fieldmask |= QC_INO_WARNS;
 614	if (src->d_fieldmask & FS_DQ_RTBWARNS)
 615		dst->i_fieldmask |= QC_RT_SPC_WARNS;
 616	if (src->d_fieldmask & FS_DQ_BTIMER)
 617		dst->i_fieldmask |= QC_SPC_TIMER;
 618	if (src->d_fieldmask & FS_DQ_ITIMER)
 619		dst->i_fieldmask |= QC_INO_TIMER;
 620	if (src->d_fieldmask & FS_DQ_RTBTIMER)
 621		dst->i_fieldmask |= QC_RT_SPC_TIMER;
 622}
 623
 624static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 625			   void __user *addr)
 626{
 627	struct fs_disk_quota fdq;
 628	struct qc_dqblk qdq;
 629	struct kqid qid;
 630
 631	if (copy_from_user(&fdq, addr, sizeof(fdq)))
 632		return -EFAULT;
 633	if (!sb->s_qcop->set_dqblk)
 634		return -ENOSYS;
 635	qid = make_kqid(current_user_ns(), type, id);
 636	if (!qid_has_mapping(sb->s_user_ns, qid))
 637		return -EINVAL;
 638	/* Are we actually setting timer / warning limits for all users? */
 639	if (from_kqid(sb->s_user_ns, qid) == 0 &&
 640	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
 641		struct qc_info qinfo;
 642		int ret;
 643
 644		if (!sb->s_qcop->set_info)
 645			return -EINVAL;
 646		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
 647		ret = sb->s_qcop->set_info(sb, type, &qinfo);
 648		if (ret)
 649			return ret;
 650		/* These are already done */
 651		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
 652	}
 653	copy_from_xfs_dqblk(&qdq, &fdq);
 654	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 655}
 656
 657static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
 658		__s32 *timer_lo, __s8 *timer_hi, s64 timer)
 659{
 660	*timer_lo = timer;
 661	if (d->d_fieldmask & FS_DQ_BIGTIME)
 662		*timer_hi = timer >> 32;
 663}
 664
 665static inline bool want_bigtime(s64 timer)
 666{
 667	return timer > S32_MAX || timer < S32_MIN;
 668}
 669
 670static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 671			      int type, qid_t id)
 672{
 673	memset(dst, 0, sizeof(*dst));
 674	if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
 675	    want_bigtime(src->d_rt_spc_timer))
 676		dst->d_fieldmask |= FS_DQ_BIGTIME;
 677	dst->d_version = FS_DQUOT_VERSION;
 678	dst->d_id = id;
 679	if (type == USRQUOTA)
 680		dst->d_flags = FS_USER_QUOTA;
 681	else if (type == PRJQUOTA)
 682		dst->d_flags = FS_PROJ_QUOTA;
 683	else
 684		dst->d_flags = FS_GROUP_QUOTA;
 685	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
 686	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
 687	dst->d_ino_hardlimit = src->d_ino_hardlimit;
 688	dst->d_ino_softlimit = src->d_ino_softlimit;
 689	dst->d_bcount = quota_btobb(src->d_space);
 690	dst->d_icount = src->d_ino_count;
 691	copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
 692			     src->d_ino_timer);
 693	copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
 694			     src->d_spc_timer);
 695	dst->d_iwarns = src->d_ino_warns;
 696	dst->d_bwarns = src->d_spc_warns;
 697	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 698	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 699	dst->d_rtbcount = quota_btobb(src->d_rt_space);
 700	copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
 701			     src->d_rt_spc_timer);
 702	dst->d_rtbwarns = src->d_rt_spc_warns;
 703}
 704
 705static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 706			   void __user *addr)
 707{
 708	struct fs_disk_quota fdq;
 709	struct qc_dqblk qdq;
 710	struct kqid qid;
 711	int ret;
 712
 713	if (!sb->s_qcop->get_dqblk)
 714		return -ENOSYS;
 715	qid = make_kqid(current_user_ns(), type, id);
 716	if (!qid_has_mapping(sb->s_user_ns, qid))
 717		return -EINVAL;
 718	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
 719	if (ret)
 720		return ret;
 721	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
 722	if (copy_to_user(addr, &fdq, sizeof(fdq)))
 723		return -EFAULT;
 724	return ret;
 725}
 726
 727/*
 728 * Return quota for next active quota >= this id, if any exists,
 729 * otherwise return -ENOENT via ->get_nextdqblk.
 730 */
 731static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
 732			    void __user *addr)
 733{
 734	struct fs_disk_quota fdq;
 735	struct qc_dqblk qdq;
 736	struct kqid qid;
 737	qid_t id_out;
 738	int ret;
 739
 740	if (!sb->s_qcop->get_nextdqblk)
 741		return -ENOSYS;
 742	qid = make_kqid(current_user_ns(), type, id);
 743	if (!qid_has_mapping(sb->s_user_ns, qid))
 744		return -EINVAL;
 745	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
 746	if (ret)
 747		return ret;
 748	id_out = from_kqid(current_user_ns(), qid);
 749	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
 750	if (copy_to_user(addr, &fdq, sizeof(fdq)))
 751		return -EFAULT;
 752	return ret;
 753}
 754
 755static int quota_rmxquota(struct super_block *sb, void __user *addr)
 756{
 757	__u32 flags;
 758
 759	if (copy_from_user(&flags, addr, sizeof(flags)))
 760		return -EFAULT;
 761	if (!sb->s_qcop->rm_xquota)
 762		return -ENOSYS;
 763	return sb->s_qcop->rm_xquota(sb, flags);
 764}
 765
 766/* Copy parameters and call proper function */
 767static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 768		       void __user *addr, const struct path *path)
 769{
 770	int ret;
 771
 772	type = array_index_nospec(type, MAXQUOTAS);
 773	/*
 774	 * Quota not supported on this fs? Check this before s_quota_types
 775	 * since they needn't be set if quota is not supported at all.
 776	 */
 777	if (!sb->s_qcop)
 778		return -ENOSYS;
 779	if (!(sb->s_quota_types & (1 << type)))
 780		return -EINVAL;
 781
 782	ret = check_quotactl_permission(sb, type, cmd, id);
 783	if (ret < 0)
 784		return ret;
 785
 786	switch (cmd) {
 787	case Q_QUOTAON:
 788		return quota_quotaon(sb, type, id, path);
 789	case Q_QUOTAOFF:
 790		return quota_quotaoff(sb, type);
 791	case Q_GETFMT:
 792		return quota_getfmt(sb, type, addr);
 793	case Q_GETINFO:
 794		return quota_getinfo(sb, type, addr);
 795	case Q_SETINFO:
 796		return quota_setinfo(sb, type, addr);
 797	case Q_GETQUOTA:
 798		return quota_getquota(sb, type, id, addr);
 799	case Q_GETNEXTQUOTA:
 800		return quota_getnextquota(sb, type, id, addr);
 801	case Q_SETQUOTA:
 802		return quota_setquota(sb, type, id, addr);
 803	case Q_SYNC:
 804		if (!sb->s_qcop->quota_sync)
 805			return -ENOSYS;
 806		return sb->s_qcop->quota_sync(sb, type);
 807	case Q_XQUOTAON:
 808		return quota_enable(sb, addr);
 809	case Q_XQUOTAOFF:
 810		return quota_disable(sb, addr);
 811	case Q_XQUOTARM:
 812		return quota_rmxquota(sb, addr);
 813	case Q_XGETQSTAT:
 814		return quota_getxstate(sb, type, addr);
 815	case Q_XGETQSTATV:
 816		return quota_getxstatev(sb, type, addr);
 817	case Q_XSETQLIM:
 818		return quota_setxquota(sb, type, id, addr);
 819	case Q_XGETQUOTA:
 820		return quota_getxquota(sb, type, id, addr);
 821	case Q_XGETNEXTQUOTA:
 822		return quota_getnextxquota(sb, type, id, addr);
 823	case Q_XQUOTASYNC:
 824		if (sb_rdonly(sb))
 825			return -EROFS;
 826		/* XFS quotas are fully coherent now, making this call a noop */
 827		return 0;
 828	default:
 829		return -EINVAL;
 830	}
 831}
 832
 833/* Return 1 if 'cmd' will block on frozen filesystem */
 834static int quotactl_cmd_write(int cmd)
 835{
 836	/*
 837	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
 838	 * as dquot_acquire() may allocate space for new structure and OCFS2
 839	 * needs to increment on-disk use count.
 840	 */
 841	switch (cmd) {
 842	case Q_GETFMT:
 843	case Q_GETINFO:
 844	case Q_SYNC:
 845	case Q_XGETQSTAT:
 846	case Q_XGETQSTATV:
 847	case Q_XGETQUOTA:
 848	case Q_XGETNEXTQUOTA:
 849	case Q_XQUOTASYNC:
 850		return 0;
 851	}
 852	return 1;
 853}
 854
 855/* Return true if quotactl command is manipulating quota on/off state */
 856static 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 */
 866static struct super_block *quotactl_block(const char __user *special, int cmd)
 867{
 868#ifdef CONFIG_BLOCK
 869	struct super_block *sb;
 870	struct filename *tmp = getname(special);
 871	bool excl = false, thawed = false;
 872	int error;
 873	dev_t dev;
 874
 875	if (IS_ERR(tmp))
 876		return ERR_CAST(tmp);
 877	error = lookup_bdev(tmp->name, &dev);
 878	putname(tmp);
 879	if (error)
 880		return ERR_PTR(error);
 881
 882	if (quotactl_cmd_onoff(cmd)) {
 883		excl = true;
 884		thawed = true;
 885	} else if (quotactl_cmd_write(cmd)) {
 886		thawed = true;
 887	}
 888
 889retry:
 890	sb = user_get_super(dev, excl);
 891	if (!sb)
 892		return ERR_PTR(-ENODEV);
 893	if (thawed && sb->s_writers.frozen != SB_UNFROZEN) {
 894		if (excl)
 895			up_write(&sb->s_umount);
 896		else
 897			up_read(&sb->s_umount);
 898		/* Wait for sb to unfreeze */
 899		sb_start_write(sb);
 900		sb_end_write(sb);
 901		put_super(sb);
 902		goto retry;
 903	}
 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 */
 917SYSCALL_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);
 967out:
 968	if (pathp && !IS_ERR(pathp))
 969		path_put(pathp);
 970	return ret;
 971}
 972
 973SYSCALL_DEFINE4(quotactl_fd, unsigned int, fd, unsigned int, cmd,
 974		qid_t, id, void __user *, addr)
 975{
 976	struct super_block *sb;
 977	unsigned int cmds = cmd >> SUBCMDSHIFT;
 978	unsigned int type = cmd & SUBCMDMASK;
 979	struct fd f;
 980	int ret;
 981
 982	f = fdget_raw(fd);
 983	if (!f.file)
 984		return -EBADF;
 985
 986	ret = -EINVAL;
 987	if (type >= MAXQUOTAS)
 988		goto out;
 989
 990	if (quotactl_cmd_write(cmds)) {
 991		ret = mnt_want_write(f.file->f_path.mnt);
 992		if (ret)
 993			goto out;
 994	}
 995
 996	sb = f.file->f_path.mnt->mnt_sb;
 997	if (quotactl_cmd_onoff(cmds))
 998		down_write(&sb->s_umount);
 999	else
1000		down_read(&sb->s_umount);
1001
1002	ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
1003
1004	if (quotactl_cmd_onoff(cmds))
1005		up_write(&sb->s_umount);
1006	else
1007		up_read(&sb->s_umount);
1008
1009	if (quotactl_cmd_write(cmds))
1010		mnt_drop_write(f.file->f_path.mnt);
1011out:
1012	fdput(f);
1013	return ret;
1014}