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linux-stable/fs/quota/quota.c
Jan Kara 64c2c2c62f quota: Change quotactl_path() systcall to an fd-based one 
Some users have pointed out that path-based syscalls are problematic in
some environments and at least directory fd argument and possibly also
resolve flags are desirable for such syscalls. Rather than
reimplementing all details of pathname lookup and following where it may
eventually evolve, let's go for full file descriptor based syscall
similar to how ioctl(2) works since the beginning. Managing of quotas
isn't performance sensitive so the extra overhead of open does not
matter and we are able to consume O_PATH descriptors as well which makes
open cheap anyway. Also for frequent operations (such as retrieving
usage information for all users) we can reuse single fd and in fact get
even better performance as well as avoiding races with possible remounts
etc.

Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-06-07 12:11:24 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Quota code necessary even when VFS quota support is not compiled
* into the kernel. The interesting stuff is over in dquot.c, here
* we have symbols for initial quotactl(2) handling, the sysctl(2)
* variables, etc - things needed even when quota support disabled.
*/
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <asm/current.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/capability.h>
#include <linux/quotaops.h>
#include <linux/types.h>
#include <linux/mount.h>
#include <linux/writeback.h>
#include <linux/nospec.h>
#include "compat.h"
#include "../internal.h"
static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
qid_t id)
{
switch (cmd) {
/* these commands do not require any special privilegues */
case Q_GETFMT:
case Q_SYNC:
case Q_GETINFO:
case Q_XGETQSTAT:
case Q_XGETQSTATV:
case Q_XQUOTASYNC:
break;
/* allow to query information for dquots we "own" */
case Q_GETQUOTA:
case Q_XGETQUOTA:
if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
(type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
break;
fallthrough;
default:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
}
return security_quotactl(cmd, type, id, sb);
}
static void quota_sync_one(struct super_block *sb, void *arg)
{
int type = *(int *)arg;
if (sb->s_qcop && sb->s_qcop->quota_sync &&
(sb->s_quota_types & (1 << type)))
sb->s_qcop->quota_sync(sb, type);
}
static int quota_sync_all(int type)
{
int ret;
ret = security_quotactl(Q_SYNC, type, 0, NULL);
if (!ret)
iterate_supers(quota_sync_one, &type);
return ret;
}
unsigned int qtype_enforce_flag(int type)
{
switch (type) {
case USRQUOTA:
return FS_QUOTA_UDQ_ENFD;
case GRPQUOTA:
return FS_QUOTA_GDQ_ENFD;
case PRJQUOTA:
return FS_QUOTA_PDQ_ENFD;
}
return 0;
}
static int quota_quotaon(struct super_block *sb, int type, qid_t id,
const struct path *path)
{
if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
return -ENOSYS;
if (sb->s_qcop->quota_enable)
return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
if (IS_ERR(path))
return PTR_ERR(path);
return sb->s_qcop->quota_on(sb, type, id, path);
}
static int quota_quotaoff(struct super_block *sb, int type)
{
if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
return -ENOSYS;
if (sb->s_qcop->quota_disable)
return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
return sb->s_qcop->quota_off(sb, type);
}
static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
{
__u32 fmt;
if (!sb_has_quota_active(sb, type))
return -ESRCH;
fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
if (copy_to_user(addr, &fmt, sizeof(fmt)))
return -EFAULT;
return 0;
}
static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
{
struct qc_state state;
struct qc_type_state *tstate;
struct if_dqinfo uinfo;
int ret;
if (!sb->s_qcop->get_state)
return -ENOSYS;
ret = sb->s_qcop->get_state(sb, &state);
if (ret)
return ret;
tstate = state.s_state + type;
if (!(tstate->flags & QCI_ACCT_ENABLED))
return -ESRCH;
memset(&uinfo, 0, sizeof(uinfo));
uinfo.dqi_bgrace = tstate->spc_timelimit;
uinfo.dqi_igrace = tstate->ino_timelimit;
if (tstate->flags & QCI_SYSFILE)
uinfo.dqi_flags |= DQF_SYS_FILE;
if (tstate->flags & QCI_ROOT_SQUASH)
uinfo.dqi_flags |= DQF_ROOT_SQUASH;
uinfo.dqi_valid = IIF_ALL;
if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
return -EFAULT;
return 0;
}
static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
{
struct if_dqinfo info;
struct qc_info qinfo;
if (copy_from_user(&info, addr, sizeof(info)))
return -EFAULT;
if (!sb->s_qcop->set_info)
return -ENOSYS;
if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
return -EINVAL;
memset(&qinfo, 0, sizeof(qinfo));
if (info.dqi_valid & IIF_FLAGS) {
if (info.dqi_flags & ~DQF_SETINFO_MASK)
return -EINVAL;
if (info.dqi_flags & DQF_ROOT_SQUASH)
qinfo.i_flags |= QCI_ROOT_SQUASH;
qinfo.i_fieldmask |= QC_FLAGS;
}
if (info.dqi_valid & IIF_BGRACE) {
qinfo.i_spc_timelimit = info.dqi_bgrace;
qinfo.i_fieldmask |= QC_SPC_TIMER;
}
if (info.dqi_valid & IIF_IGRACE) {
qinfo.i_ino_timelimit = info.dqi_igrace;
qinfo.i_fieldmask |= QC_INO_TIMER;
}
return sb->s_qcop->set_info(sb, type, &qinfo);
}
static inline qsize_t qbtos(qsize_t blocks)
{
return blocks << QIF_DQBLKSIZE_BITS;
}
static inline qsize_t stoqb(qsize_t space)
{
return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
}
static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
{
memset(dst, 0, sizeof(*dst));
dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
dst->dqb_curspace = src->d_space;
dst->dqb_ihardlimit = src->d_ino_hardlimit;
dst->dqb_isoftlimit = src->d_ino_softlimit;
dst->dqb_curinodes = src->d_ino_count;
dst->dqb_btime = src->d_spc_timer;
dst->dqb_itime = src->d_ino_timer;
dst->dqb_valid = QIF_ALL;
}
static int quota_getquota(struct super_block *sb, int type, qid_t id,
void __user *addr)
{
struct kqid qid;
struct qc_dqblk fdq;
struct if_dqblk idq;
int ret;
if (!sb->s_qcop->get_dqblk)
return -ENOSYS;
qid = make_kqid(current_user_ns(), type, id);
if (!qid_has_mapping(sb->s_user_ns, qid))
return -EINVAL;
ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
if (ret)
return ret;
copy_to_if_dqblk(&idq, &fdq);
if (compat_need_64bit_alignment_fixup()) {
struct compat_if_dqblk __user *compat_dqblk = addr;
if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
return -EFAULT;
if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
return -EFAULT;
} else {
if (copy_to_user(addr, &idq, sizeof(idq)))
return -EFAULT;
}
return 0;
}
/*
* Return quota for next active quota >= this id, if any exists,
* otherwise return -ENOENT via ->get_nextdqblk
*/
static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
void __user *addr)
{
struct kqid qid;
struct qc_dqblk fdq;
struct if_nextdqblk idq;
int ret;
if (!sb->s_qcop->get_nextdqblk)
return -ENOSYS;
qid = make_kqid(current_user_ns(), type, id);
if (!qid_has_mapping(sb->s_user_ns, qid))
return -EINVAL;
ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
if (ret)
return ret;
/* struct if_nextdqblk is a superset of struct if_dqblk */
copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
idq.dqb_id = from_kqid(current_user_ns(), qid);
if (copy_to_user(addr, &idq, sizeof(idq)))
return -EFAULT;
return 0;
}
static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
{
dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
dst->d_space = src->dqb_curspace;
dst->d_ino_hardlimit = src->dqb_ihardlimit;
dst->d_ino_softlimit = src->dqb_isoftlimit;
dst->d_ino_count = src->dqb_curinodes;
dst->d_spc_timer = src->dqb_btime;
dst->d_ino_timer = src->dqb_itime;
dst->d_fieldmask = 0;
if (src->dqb_valid & QIF_BLIMITS)
dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
if (src->dqb_valid & QIF_SPACE)
dst->d_fieldmask |= QC_SPACE;
if (src->dqb_valid & QIF_ILIMITS)
dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
if (src->dqb_valid & QIF_INODES)
dst->d_fieldmask |= QC_INO_COUNT;
if (src->dqb_valid & QIF_BTIME)
dst->d_fieldmask |= QC_SPC_TIMER;
if (src->dqb_valid & QIF_ITIME)
dst->d_fieldmask |= QC_INO_TIMER;
}
static int quota_setquota(struct super_block *sb, int type, qid_t id,
void __user *addr)
{
struct qc_dqblk fdq;
struct if_dqblk idq;
struct kqid qid;
if (compat_need_64bit_alignment_fixup()) {
struct compat_if_dqblk __user *compat_dqblk = addr;
if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
return -EFAULT;
} else {
if (copy_from_user(&idq, addr, sizeof(idq)))
return -EFAULT;
}
if (!sb->s_qcop->set_dqblk)
return -ENOSYS;
qid = make_kqid(current_user_ns(), type, id);
if (!qid_has_mapping(sb->s_user_ns, qid))
return -EINVAL;
copy_from_if_dqblk(&fdq, &idq);
return sb->s_qcop->set_dqblk(sb, qid, &fdq);
}
static int quota_enable(struct super_block *sb, void __user *addr)
{
__u32 flags;
if (copy_from_user(&flags, addr, sizeof(flags)))
return -EFAULT;
if (!sb->s_qcop->quota_enable)
return -ENOSYS;
return sb->s_qcop->quota_enable(sb, flags);
}
static int quota_disable(struct super_block *sb, void __user *addr)
{
__u32 flags;
if (copy_from_user(&flags, addr, sizeof(flags)))
return -EFAULT;
if (!sb->s_qcop->quota_disable)
return -ENOSYS;
return sb->s_qcop->quota_disable(sb, flags);
}
static int quota_state_to_flags(struct qc_state *state)
{
int flags = 0;
if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
flags |= FS_QUOTA_UDQ_ACCT;
if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
flags |= FS_QUOTA_UDQ_ENFD;
if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
flags |= FS_QUOTA_GDQ_ACCT;
if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
flags |= FS_QUOTA_GDQ_ENFD;
if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
flags |= FS_QUOTA_PDQ_ACCT;
if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
flags |= FS_QUOTA_PDQ_ENFD;
return flags;
}
static int quota_getstate(struct super_block *sb, int type,
struct fs_quota_stat *fqs)
{
struct qc_state state;
int ret;
memset(&state, 0, sizeof (struct qc_state));
ret = sb->s_qcop->get_state(sb, &state);
if (ret < 0)
return ret;
memset(fqs, 0, sizeof(*fqs));
fqs->qs_version = FS_QSTAT_VERSION;
fqs->qs_flags = quota_state_to_flags(&state);
/* No quota enabled? */
if (!fqs->qs_flags)
return -ENOSYS;
fqs->qs_incoredqs = state.s_incoredqs;
fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
/* Inodes may be allocated even if inactive; copy out if present */
if (state.s_state[USRQUOTA].ino) {
fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
}
if (state.s_state[GRPQUOTA].ino) {
fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
}
if (state.s_state[PRJQUOTA].ino) {
/*
* Q_XGETQSTAT doesn't have room for both group and project
* quotas. So, allow the project quota values to be copied out
* only if there is no group quota information available.
*/
if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
fqs->qs_gquota.qfs_nblks =
state.s_state[PRJQUOTA].blocks;
fqs->qs_gquota.qfs_nextents =
state.s_state[PRJQUOTA].nextents;
}
}
return 0;
}
static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
struct fs_qfilestat *from)
{
if (copy_to_user(to, from, sizeof(*to)) ||
put_user(from->qfs_nextents, &to->qfs_nextents))
return -EFAULT;
return 0;
}
static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
struct fs_quota_stat *from)
{
if (put_user(from->qs_version, &to->qs_version) ||
put_user(from->qs_flags, &to->qs_flags) ||
put_user(from->qs_pad, &to->qs_pad) ||
compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
return -EFAULT;
return 0;
}
static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
{
struct fs_quota_stat fqs;
int ret;
if (!sb->s_qcop->get_state)
return -ENOSYS;
ret = quota_getstate(sb, type, &fqs);
if (ret)
return ret;
if (compat_need_64bit_alignment_fixup())
return compat_copy_fs_quota_stat(addr, &fqs);
if (copy_to_user(addr, &fqs, sizeof(fqs)))
return -EFAULT;
return 0;
}
static int quota_getstatev(struct super_block *sb, int type,
struct fs_quota_statv *fqs)
{
struct qc_state state;
int ret;
memset(&state, 0, sizeof (struct qc_state));
ret = sb->s_qcop->get_state(sb, &state);
if (ret < 0)
return ret;
memset(fqs, 0, sizeof(*fqs));
fqs->qs_version = FS_QSTAT_VERSION;
fqs->qs_flags = quota_state_to_flags(&state);
/* No quota enabled? */
if (!fqs->qs_flags)
return -ENOSYS;
fqs->qs_incoredqs = state.s_incoredqs;
fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
fqs->qs_rtbwarnlimit = state.s_state[type].rt_spc_warnlimit;
/* Inodes may be allocated even if inactive; copy out if present */
if (state.s_state[USRQUOTA].ino) {
fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
}
if (state.s_state[GRPQUOTA].ino) {
fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
}
if (state.s_state[PRJQUOTA].ino) {
fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
}
return 0;
}
static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
{
struct fs_quota_statv fqs;
int ret;
if (!sb->s_qcop->get_state)
return -ENOSYS;
memset(&fqs, 0, sizeof(fqs));
if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
return -EFAULT;
/* If this kernel doesn't support user specified version, fail */
switch (fqs.qs_version) {
case FS_QSTATV_VERSION1:
break;
default:
return -EINVAL;
}
ret = quota_getstatev(sb, type, &fqs);
if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
return -EFAULT;
return ret;
}
/*
* XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
* out of there as xfsprogs rely on definitions being in that header file. So
* just define same functions here for quota purposes.
*/
#define XFS_BB_SHIFT 9
static inline u64 quota_bbtob(u64 blocks)
{
return blocks << XFS_BB_SHIFT;
}
static inline u64 quota_btobb(u64 bytes)
{
return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
}
static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
__s32 timer, __s8 timer_hi)
{
if (d->d_fieldmask & FS_DQ_BIGTIME)
return (u32)timer | (s64)timer_hi << 32;
return timer;
}
static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
{
dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
dst->d_ino_hardlimit = src->d_ino_hardlimit;
dst->d_ino_softlimit = src->d_ino_softlimit;
dst->d_space = quota_bbtob(src->d_bcount);
dst->d_ino_count = src->d_icount;
dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
src->d_itimer_hi);
dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
src->d_btimer_hi);
dst->d_ino_warns = src->d_iwarns;
dst->d_spc_warns = src->d_bwarns;
dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
dst->d_rt_space = quota_bbtob(src->d_rtbcount);
dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
src->d_rtbtimer_hi);
dst->d_rt_spc_warns = src->d_rtbwarns;
dst->d_fieldmask = 0;
if (src->d_fieldmask & FS_DQ_ISOFT)
dst->d_fieldmask |= QC_INO_SOFT;
if (src->d_fieldmask & FS_DQ_IHARD)
dst->d_fieldmask |= QC_INO_HARD;
if (src->d_fieldmask & FS_DQ_BSOFT)
dst->d_fieldmask |= QC_SPC_SOFT;
if (src->d_fieldmask & FS_DQ_BHARD)
dst->d_fieldmask |= QC_SPC_HARD;
if (src->d_fieldmask & FS_DQ_RTBSOFT)
dst->d_fieldmask |= QC_RT_SPC_SOFT;
if (src->d_fieldmask & FS_DQ_RTBHARD)
dst->d_fieldmask |= QC_RT_SPC_HARD;
if (src->d_fieldmask & FS_DQ_BTIMER)
dst->d_fieldmask |= QC_SPC_TIMER;
if (src->d_fieldmask & FS_DQ_ITIMER)
dst->d_fieldmask |= QC_INO_TIMER;
if (src->d_fieldmask & FS_DQ_RTBTIMER)
dst->d_fieldmask |= QC_RT_SPC_TIMER;
if (src->d_fieldmask & FS_DQ_BWARNS)
dst->d_fieldmask |= QC_SPC_WARNS;
if (src->d_fieldmask & FS_DQ_IWARNS)
dst->d_fieldmask |= QC_INO_WARNS;
if (src->d_fieldmask & FS_DQ_RTBWARNS)
dst->d_fieldmask |= QC_RT_SPC_WARNS;
if (src->d_fieldmask & FS_DQ_BCOUNT)
dst->d_fieldmask |= QC_SPACE;
if (src->d_fieldmask & FS_DQ_ICOUNT)
dst->d_fieldmask |= QC_INO_COUNT;
if (src->d_fieldmask & FS_DQ_RTBCOUNT)
dst->d_fieldmask |= QC_RT_SPACE;
}
static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
struct fs_disk_quota *src)
{
memset(dst, 0, sizeof(*dst));
dst->i_spc_timelimit = src->d_btimer;
dst->i_ino_timelimit = src->d_itimer;
dst->i_rt_spc_timelimit = src->d_rtbtimer;
dst->i_ino_warnlimit = src->d_iwarns;
dst->i_spc_warnlimit = src->d_bwarns;
dst->i_rt_spc_warnlimit = src->d_rtbwarns;
if (src->d_fieldmask & FS_DQ_BWARNS)
dst->i_fieldmask |= QC_SPC_WARNS;
if (src->d_fieldmask & FS_DQ_IWARNS)
dst->i_fieldmask |= QC_INO_WARNS;
if (src->d_fieldmask & FS_DQ_RTBWARNS)
dst->i_fieldmask |= QC_RT_SPC_WARNS;
if (src->d_fieldmask & FS_DQ_BTIMER)
dst->i_fieldmask |= QC_SPC_TIMER;
if (src->d_fieldmask & FS_DQ_ITIMER)
dst->i_fieldmask |= QC_INO_TIMER;
if (src->d_fieldmask & FS_DQ_RTBTIMER)
dst->i_fieldmask |= QC_RT_SPC_TIMER;
}
static int quota_setxquota(struct super_block *sb, int type, qid_t id,
void __user *addr)
{
struct fs_disk_quota fdq;
struct qc_dqblk qdq;
struct kqid qid;
if (copy_from_user(&fdq, addr, sizeof(fdq)))
return -EFAULT;
if (!sb->s_qcop->set_dqblk)
return -ENOSYS;
qid = make_kqid(current_user_ns(), type, id);
if (!qid_has_mapping(sb->s_user_ns, qid))
return -EINVAL;
/* Are we actually setting timer / warning limits for all users? */
if (from_kqid(sb->s_user_ns, qid) == 0 &&
fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
struct qc_info qinfo;
int ret;
if (!sb->s_qcop->set_info)
return -EINVAL;
copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
ret = sb->s_qcop->set_info(sb, type, &qinfo);
if (ret)
return ret;
/* These are already done */
fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
}
copy_from_xfs_dqblk(&qdq, &fdq);
return sb->s_qcop->set_dqblk(sb, qid, &qdq);
}
static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
__s32 *timer_lo, __s8 *timer_hi, s64 timer)
{
*timer_lo = timer;
if (d->d_fieldmask & FS_DQ_BIGTIME)
*timer_hi = timer >> 32;
}
static inline bool want_bigtime(s64 timer)
{
return timer > S32_MAX || timer < S32_MIN;
}
static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
int type, qid_t id)
{
memset(dst, 0, sizeof(*dst));
if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
want_bigtime(src->d_rt_spc_timer))
dst->d_fieldmask |= FS_DQ_BIGTIME;
dst->d_version = FS_DQUOT_VERSION;
dst->d_id = id;
if (type == USRQUOTA)
dst->d_flags = FS_USER_QUOTA;
else if (type == PRJQUOTA)
dst->d_flags = FS_PROJ_QUOTA;
else
dst->d_flags = FS_GROUP_QUOTA;
dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
dst->d_ino_hardlimit = src->d_ino_hardlimit;
dst->d_ino_softlimit = src->d_ino_softlimit;
dst->d_bcount = quota_btobb(src->d_space);
dst->d_icount = src->d_ino_count;
copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
src->d_ino_timer);
copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
src->d_spc_timer);
dst->d_iwarns = src->d_ino_warns;
dst->d_bwarns = src->d_spc_warns;
dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
dst->d_rtbcount = quota_btobb(src->d_rt_space);
copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
src->d_rt_spc_timer);
dst->d_rtbwarns = src->d_rt_spc_warns;
}
static int quota_getxquota(struct super_block *sb, int type, qid_t id,
void __user *addr)
{
struct fs_disk_quota fdq;
struct qc_dqblk qdq;
struct kqid qid;
int ret;
if (!sb->s_qcop->get_dqblk)
return -ENOSYS;
qid = make_kqid(current_user_ns(), type, id);
if (!qid_has_mapping(sb->s_user_ns, qid))
return -EINVAL;
ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
if (ret)
return ret;
copy_to_xfs_dqblk(&fdq, &qdq, type, id);
if (copy_to_user(addr, &fdq, sizeof(fdq)))
return -EFAULT;
return ret;
}
/*
* Return quota for next active quota >= this id, if any exists,
* otherwise return -ENOENT via ->get_nextdqblk.
*/
static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
void __user *addr)
{
struct fs_disk_quota fdq;
struct qc_dqblk qdq;
struct kqid qid;
qid_t id_out;
int ret;
if (!sb->s_qcop->get_nextdqblk)
return -ENOSYS;
qid = make_kqid(current_user_ns(), type, id);
if (!qid_has_mapping(sb->s_user_ns, qid))
return -EINVAL;
ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
if (ret)
return ret;
id_out = from_kqid(current_user_ns(), qid);
copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
if (copy_to_user(addr, &fdq, sizeof(fdq)))
return -EFAULT;
return ret;
}
static int quota_rmxquota(struct super_block *sb, void __user *addr)
{
__u32 flags;
if (copy_from_user(&flags, addr, sizeof(flags)))
return -EFAULT;
if (!sb->s_qcop->rm_xquota)
return -ENOSYS;
return sb->s_qcop->rm_xquota(sb, flags);
}
/* Copy parameters and call proper function */
static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
void __user *addr, const struct path *path)
{
int ret;
type = array_index_nospec(type, MAXQUOTAS);
/*
* Quota not supported on this fs? Check this before s_quota_types
* since they needn't be set if quota is not supported at all.
*/
if (!sb->s_qcop)
return -ENOSYS;
if (!(sb->s_quota_types & (1 << type)))
return -EINVAL;
ret = check_quotactl_permission(sb, type, cmd, id);
if (ret < 0)
return ret;
switch (cmd) {
case Q_QUOTAON:
return quota_quotaon(sb, type, id, path);
case Q_QUOTAOFF:
return quota_quotaoff(sb, type);
case Q_GETFMT:
return quota_getfmt(sb, type, addr);
case Q_GETINFO:
return quota_getinfo(sb, type, addr);
case Q_SETINFO:
return quota_setinfo(sb, type, addr);
case Q_GETQUOTA:
return quota_getquota(sb, type, id, addr);
case Q_GETNEXTQUOTA:
return quota_getnextquota(sb, type, id, addr);
case Q_SETQUOTA:
return quota_setquota(sb, type, id, addr);
case Q_SYNC:
if (!sb->s_qcop->quota_sync)
return -ENOSYS;
return sb->s_qcop->quota_sync(sb, type);
case Q_XQUOTAON:
return quota_enable(sb, addr);
case Q_XQUOTAOFF:
return quota_disable(sb, addr);
case Q_XQUOTARM:
return quota_rmxquota(sb, addr);
case Q_XGETQSTAT:
return quota_getxstate(sb, type, addr);
case Q_XGETQSTATV:
return quota_getxstatev(sb, type, addr);
case Q_XSETQLIM:
return quota_setxquota(sb, type, id, addr);
case Q_XGETQUOTA:
return quota_getxquota(sb, type, id, addr);
case Q_XGETNEXTQUOTA:
return quota_getnextxquota(sb, type, id, addr);
case Q_XQUOTASYNC:
if (sb_rdonly(sb))
return -EROFS;
/* XFS quotas are fully coherent now, making this call a noop */
return 0;
default:
return -EINVAL;
}
}
/* Return 1 if 'cmd' will block on frozen filesystem */
static int quotactl_cmd_write(int cmd)
{
/*
* We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
* as dquot_acquire() may allocate space for new structure and OCFS2
* needs to increment on-disk use count.
*/
switch (cmd) {
case Q_GETFMT:
case Q_GETINFO:
case Q_SYNC:
case Q_XGETQSTAT:
case Q_XGETQSTATV:
case Q_XGETQUOTA:
case Q_XGETNEXTQUOTA:
case Q_XQUOTASYNC:
return 0;
}
return 1;
}
/* Return true if quotactl command is manipulating quota on/off state */
static bool quotactl_cmd_onoff(int cmd)
{
return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
(cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
}
/*
* look up a superblock on which quota ops will be performed
* - use the name of a block device to find the superblock thereon
*/
static struct super_block *quotactl_block(const char __user *special, int cmd)
{
#ifdef CONFIG_BLOCK
struct super_block *sb;
struct filename *tmp = getname(special);
bool excl = false, thawed = false;
int error;
dev_t dev;
if (IS_ERR(tmp))
return ERR_CAST(tmp);
error = lookup_bdev(tmp->name, &dev);
putname(tmp);
if (error)
return ERR_PTR(error);
if (quotactl_cmd_onoff(cmd)) {
excl = true;
thawed = true;
} else if (quotactl_cmd_write(cmd)) {
thawed = true;
}
retry:
sb = user_get_super(dev, excl);
if (!sb)
return ERR_PTR(-ENODEV);
if (thawed && sb->s_writers.frozen != SB_UNFROZEN) {
if (excl)
up_write(&sb->s_umount);
else
up_read(&sb->s_umount);
wait_event(sb->s_writers.wait_unfrozen,
sb->s_writers.frozen == SB_UNFROZEN);
put_super(sb);
goto retry;
}
return sb;
#else
return ERR_PTR(-ENODEV);
#endif
}
/*
* This is the system call interface. This communicates with
* the user-level programs. Currently this only supports diskquota
* calls. Maybe we need to add the process quotas etc. in the future,
* but we probably should use rlimits for that.
*/
SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
qid_t, id, void __user *, addr)
{
uint cmds, type;
struct super_block *sb = NULL;
struct path path, *pathp = NULL;
int ret;
cmds = cmd >> SUBCMDSHIFT;
type = cmd & SUBCMDMASK;
if (type >= MAXQUOTAS)
return -EINVAL;
/*
* As a special case Q_SYNC can be called without a specific device.
* It will iterate all superblocks that have quota enabled and call
* the sync action on each of them.
*/
if (!special) {
if (cmds == Q_SYNC)
return quota_sync_all(type);
return -ENODEV;
}
/*
* Path for quotaon has to be resolved before grabbing superblock
* because that gets s_umount sem which is also possibly needed by path
* resolution (think about autofs) and thus deadlocks could arise.
*/
if (cmds == Q_QUOTAON) {
ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
if (ret)
pathp = ERR_PTR(ret);
else
pathp = &path;
}
sb = quotactl_block(special, cmds);
if (IS_ERR(sb)) {
ret = PTR_ERR(sb);
goto out;
}
ret = do_quotactl(sb, type, cmds, id, addr, pathp);
if (!quotactl_cmd_onoff(cmds))
drop_super(sb);
else
drop_super_exclusive(sb);
out:
if (pathp && !IS_ERR(pathp))
path_put(pathp);
return ret;
}
SYSCALL_DEFINE4(quotactl_fd, unsigned int, fd, unsigned int, cmd,
qid_t, id, void __user *, addr)
{
struct super_block *sb;
unsigned int cmds = cmd >> SUBCMDSHIFT;
unsigned int type = cmd & SUBCMDMASK;
struct fd f;
int ret;
f = fdget_raw(fd);
if (!f.file)
return -EBADF;
ret = -EINVAL;
if (type >= MAXQUOTAS)
goto out;
if (quotactl_cmd_write(cmds)) {
ret = mnt_want_write(f.file->f_path.mnt);
if (ret)
goto out;
}
sb = f.file->f_path.mnt->mnt_sb;
if (quotactl_cmd_onoff(cmds))
down_write(&sb->s_umount);
else
down_read(&sb->s_umount);
ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
if (quotactl_cmd_onoff(cmds))
up_write(&sb->s_umount);
else
up_read(&sb->s_umount);
if (quotactl_cmd_write(cmds))
mnt_drop_write(f.file->f_path.mnt);
out:
fdput(f);
return ret;
}
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