cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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quota.c (28287B)


      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_event(sb->s_writers.wait_unfrozen,
    899			   sb->s_writers.frozen == SB_UNFROZEN);
    900		put_super(sb);
    901		goto retry;
    902	}
    903	return sb;
    904
    905#else
    906	return ERR_PTR(-ENODEV);
    907#endif
    908}
    909
    910/*
    911 * This is the system call interface. This communicates with
    912 * the user-level programs. Currently this only supports diskquota
    913 * calls. Maybe we need to add the process quotas etc. in the future,
    914 * but we probably should use rlimits for that.
    915 */
    916SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
    917		qid_t, id, void __user *, addr)
    918{
    919	uint cmds, type;
    920	struct super_block *sb = NULL;
    921	struct path path, *pathp = NULL;
    922	int ret;
    923
    924	cmds = cmd >> SUBCMDSHIFT;
    925	type = cmd & SUBCMDMASK;
    926
    927	if (type >= MAXQUOTAS)
    928		return -EINVAL;
    929
    930	/*
    931	 * As a special case Q_SYNC can be called without a specific device.
    932	 * It will iterate all superblocks that have quota enabled and call
    933	 * the sync action on each of them.
    934	 */
    935	if (!special) {
    936		if (cmds == Q_SYNC)
    937			return quota_sync_all(type);
    938		return -ENODEV;
    939	}
    940
    941	/*
    942	 * Path for quotaon has to be resolved before grabbing superblock
    943	 * because that gets s_umount sem which is also possibly needed by path
    944	 * resolution (think about autofs) and thus deadlocks could arise.
    945	 */
    946	if (cmds == Q_QUOTAON) {
    947		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
    948		if (ret)
    949			pathp = ERR_PTR(ret);
    950		else
    951			pathp = &path;
    952	}
    953
    954	sb = quotactl_block(special, cmds);
    955	if (IS_ERR(sb)) {
    956		ret = PTR_ERR(sb);
    957		goto out;
    958	}
    959
    960	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
    961
    962	if (!quotactl_cmd_onoff(cmds))
    963		drop_super(sb);
    964	else
    965		drop_super_exclusive(sb);
    966out:
    967	if (pathp && !IS_ERR(pathp))
    968		path_put(pathp);
    969	return ret;
    970}
    971
    972SYSCALL_DEFINE4(quotactl_fd, unsigned int, fd, unsigned int, cmd,
    973		qid_t, id, void __user *, addr)
    974{
    975	struct super_block *sb;
    976	unsigned int cmds = cmd >> SUBCMDSHIFT;
    977	unsigned int type = cmd & SUBCMDMASK;
    978	struct fd f;
    979	int ret;
    980
    981	f = fdget_raw(fd);
    982	if (!f.file)
    983		return -EBADF;
    984
    985	ret = -EINVAL;
    986	if (type >= MAXQUOTAS)
    987		goto out;
    988
    989	if (quotactl_cmd_write(cmds)) {
    990		ret = mnt_want_write(f.file->f_path.mnt);
    991		if (ret)
    992			goto out;
    993	}
    994
    995	sb = f.file->f_path.mnt->mnt_sb;
    996	if (quotactl_cmd_onoff(cmds))
    997		down_write(&sb->s_umount);
    998	else
    999		down_read(&sb->s_umount);
   1000
   1001	ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
   1002
   1003	if (quotactl_cmd_onoff(cmds))
   1004		up_write(&sb->s_umount);
   1005	else
   1006		up_read(&sb->s_umount);
   1007
   1008	if (quotactl_cmd_write(cmds))
   1009		mnt_drop_write(f.file->f_path.mnt);
   1010out:
   1011	fdput(f);
   1012	return ret;
   1013}