[deliverable/linux.git] / fs / quota / quota.c

/*
 * 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 <asm/uaccess.h>
#include <linux/compat.h>
#include <linux/kernel.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/buffer_head.h>
#include <linux/capability.h>
#include <linux/quotaops.h>
#include <linux/types.h>
#include <linux/writeback.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_XQUOTASYNC:
		break;
	/* allow to query information for dquots we "own" */
	case Q_GETQUOTA:
	case Q_XGETQUOTA:
		if ((type == USRQUOTA && current_euid() == id) ||
		    (type == GRPQUOTA && in_egroup_p(id)))
			break;
		/*FALLTHROUGH*/
	default:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
	}

	return security_quotactl(cmd, type, id, sb);
}

static int quota_sync_all(int type)
{
	struct super_block *sb;
	int ret;

	if (type >= MAXQUOTAS)
		return -EINVAL;
	ret = security_quotactl(Q_SYNC, type, 0, NULL);
	if (ret)
		return ret;

	spin_lock(&sb_lock);
restart:
	list_for_each_entry(sb, &super_blocks, s_list) {
		if (!sb->s_qcop || !sb->s_qcop->quota_sync)
			continue;

		sb->s_count++;
		spin_unlock(&sb_lock);
		down_read(&sb->s_umount);
		if (sb->s_root)
			sb->s_qcop->quota_sync(sb, type, 1);
		up_read(&sb->s_umount);
		spin_lock(&sb_lock);
		if (__put_super_and_need_restart(sb))
			goto restart;
	}
	spin_unlock(&sb_lock);

	return 0;
}

static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
		         void __user *addr)
{
	char *pathname;
	int ret = -ENOSYS;

	pathname = getname(addr);
	if (IS_ERR(pathname))
		return PTR_ERR(pathname);
	if (sb->s_qcop->quota_on)
		ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
	putname(pathname);
	return ret;
}

static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
{
	__u32 fmt;

	down_read(&sb_dqopt(sb)->dqptr_sem);
	if (!sb_has_quota_active(sb, type)) {
		up_read(&sb_dqopt(sb)->dqptr_sem);
		return -ESRCH;
	}
	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
	up_read(&sb_dqopt(sb)->dqptr_sem);
	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 if_dqinfo info;
	int ret;

	if (!sb_has_quota_active(sb, type))
		return -ESRCH;
	if (!sb->s_qcop->get_info)
		return -ENOSYS;
	ret = sb->s_qcop->get_info(sb, type, &info);
	if (!ret && copy_to_user(addr, &info, sizeof(info)))
		return -EFAULT;
	return ret;
}

static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
{
	struct if_dqinfo info;

	if (copy_from_user(&info, addr, sizeof(info)))
		return -EFAULT;
	if (!sb_has_quota_active(sb, type))
		return -ESRCH;
	if (!sb->s_qcop->set_info)
		return -ENOSYS;
	return sb->s_qcop->set_info(sb, type, &info);
}

static int quota_getquota(struct super_block *sb, int type, qid_t id,
			  void __user *addr)
{
	struct if_dqblk idq;
	int ret;

	if (!sb_has_quota_active(sb, type))
		return -ESRCH;
	if (!sb->s_qcop->get_dqblk)
		return -ENOSYS;
	ret = sb->s_qcop->get_dqblk(sb, type, id, &idq);
	if (ret)
		return ret;
	if (copy_to_user(addr, &idq, sizeof(idq)))
		return -EFAULT;
	return 0;
}

static int quota_setquota(struct super_block *sb, int type, qid_t id,
			  void __user *addr)
{
	struct if_dqblk idq;

	if (copy_from_user(&idq, addr, sizeof(idq)))
		return -EFAULT;
	if (!sb_has_quota_active(sb, type))
		return -ESRCH;
	if (!sb->s_qcop->set_dqblk)
		return -ENOSYS;
	return sb->s_qcop->set_dqblk(sb, type, id, &idq);
}

static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
{
	__u32 flags;

	if (copy_from_user(&flags, addr, sizeof(flags)))
		return -EFAULT;
	if (!sb->s_qcop->set_xstate)
		return -ENOSYS;
	return sb->s_qcop->set_xstate(sb, flags, cmd);
}

static int quota_getxstate(struct super_block *sb, void __user *addr)
{
	struct fs_quota_stat fqs;
	int ret;

	if (!sb->s_qcop->get_xstate)
		return -ENOSYS;
	ret = sb->s_qcop->get_xstate(sb, &fqs);
	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
		return -EFAULT;
	return ret;
}

static int quota_setxquota(struct super_block *sb, int type, qid_t id,
			   void __user *addr)
{
	struct fs_disk_quota fdq;

	if (copy_from_user(&fdq, addr, sizeof(fdq)))
		return -EFAULT;
	if (!sb->s_qcop->set_xquota)
		return -ENOSYS;
	return sb->s_qcop->set_xquota(sb, type, id, &fdq);
}

static int quota_getxquota(struct super_block *sb, int type, qid_t id,
			   void __user *addr)
{
	struct fs_disk_quota fdq;
	int ret;

	if (!sb->s_qcop->get_xquota)
		return -ENOSYS;
	ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
	if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
		return -EFAULT;
	return ret;
}

/* Copy parameters and call proper function */
static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
		       void __user *addr)
{
	int ret;

	if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
		return -EINVAL;
	if (!sb->s_qcop)
		return -ENOSYS;

	ret = check_quotactl_permission(sb, type, cmd, id);
	if (ret < 0)
		return ret;

	switch (cmd) {
	case Q_QUOTAON:
		return quota_quotaon(sb, type, cmd, id, addr);
	case Q_QUOTAOFF:
		if (!sb->s_qcop->quota_off)
			return -ENOSYS;
		return sb->s_qcop->quota_off(sb, type, 0);
	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_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, 1);
	case Q_XQUOTAON:
	case Q_XQUOTAOFF:
	case Q_XQUOTARM:
		return quota_setxstate(sb, cmd, addr);
	case Q_XGETQSTAT:
		return quota_getxstate(sb, addr);
	case Q_XSETQLIM:
		return quota_setxquota(sb, type, id, addr);
	case Q_XGETQUOTA:
		return quota_getxquota(sb, type, id, addr);
	case Q_XQUOTASYNC:
		/* caller already holds s_umount */
		if (sb->s_flags & MS_RDONLY)
			return -EROFS;
		writeback_inodes_sb(sb);
		return 0;
	default:
		return -EINVAL;
	}
}

/*
 * 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)
{
#ifdef CONFIG_BLOCK
	struct block_device *bdev;
	struct super_block *sb;
	char *tmp = getname(special);

	if (IS_ERR(tmp))
		return ERR_CAST(tmp);
	bdev = lookup_bdev(tmp);
	putname(tmp);
	if (IS_ERR(bdev))
		return ERR_CAST(bdev);
	sb = get_super(bdev);
	bdput(bdev);
	if (!sb)
		return ERR_PTR(-ENODEV);

	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;
	int ret;

	cmds = cmd >> SUBCMDSHIFT;
	type = cmd & SUBCMDMASK;

	/*
	 * 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;
	}

	sb = quotactl_block(special);
	if (IS_ERR(sb))
		return PTR_ERR(sb);

	ret = do_quotactl(sb, type, cmds, id, addr);

	drop_super(sb);
	return ret;
}

#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
/*
 * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
 * and is necessary due to alignment problems.
 */
struct compat_if_dqblk {
	compat_u64 dqb_bhardlimit;
	compat_u64 dqb_bsoftlimit;
	compat_u64 dqb_curspace;
	compat_u64 dqb_ihardlimit;
	compat_u64 dqb_isoftlimit;
	compat_u64 dqb_curinodes;
	compat_u64 dqb_btime;
	compat_u64 dqb_itime;
	compat_uint_t dqb_valid;
};

/* XFS structures */
struct compat_fs_qfilestat {
	compat_u64 dqb_bhardlimit;
	compat_u64 qfs_nblks;
	compat_uint_t qfs_nextents;
};

struct compat_fs_quota_stat {
	__s8		qs_version;
	__u16		qs_flags;
	__s8		qs_pad;
	struct compat_fs_qfilestat	qs_uquota;
	struct compat_fs_qfilestat	qs_gquota;
	compat_uint_t	qs_incoredqs;
	compat_int_t	qs_btimelimit;
	compat_int_t	qs_itimelimit;
	compat_int_t	qs_rtbtimelimit;
	__u16		qs_bwarnlimit;
	__u16		qs_iwarnlimit;
};

asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
						qid_t id, void __user *addr)
{
	unsigned int cmds;
	struct if_dqblk __user *dqblk;
	struct compat_if_dqblk __user *compat_dqblk;
	struct fs_quota_stat __user *fsqstat;
	struct compat_fs_quota_stat __user *compat_fsqstat;
	compat_uint_t data;
	u16 xdata;
	long ret;

	cmds = cmd >> SUBCMDSHIFT;

	switch (cmds) {
	case Q_GETQUOTA:
		dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
		compat_dqblk = addr;
		ret = sys_quotactl(cmd, special, id, dqblk);
		if (ret)
			break;
		if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
			get_user(data, &dqblk->dqb_valid) ||
			put_user(data, &compat_dqblk->dqb_valid))
			ret = -EFAULT;
		break;
	case Q_SETQUOTA:
		dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
		compat_dqblk = addr;
		ret = -EFAULT;
		if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) ||
			get_user(data, &compat_dqblk->dqb_valid) ||
			put_user(data, &dqblk->dqb_valid))
			break;
		ret = sys_quotactl(cmd, special, id, dqblk);
		break;
	case Q_XGETQSTAT:
		fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
		compat_fsqstat = addr;
		ret = sys_quotactl(cmd, special, id, fsqstat);
		if (ret)
			break;
		ret = -EFAULT;
		/* Copying qs_version, qs_flags, qs_pad */
		if (copy_in_user(compat_fsqstat, fsqstat,
			offsetof(struct compat_fs_quota_stat, qs_uquota)))
			break;
		/* Copying qs_uquota */
		if (copy_in_user(&compat_fsqstat->qs_uquota,
			&fsqstat->qs_uquota,
			sizeof(compat_fsqstat->qs_uquota)) ||
			get_user(data, &fsqstat->qs_uquota.qfs_nextents) ||
			put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
			break;
		/* Copying qs_gquota */
		if (copy_in_user(&compat_fsqstat->qs_gquota,
			&fsqstat->qs_gquota,
			sizeof(compat_fsqstat->qs_gquota)) ||
			get_user(data, &fsqstat->qs_gquota.qfs_nextents) ||
			put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
			break;
		/* Copying the rest */
		if (copy_in_user(&compat_fsqstat->qs_incoredqs,
			&fsqstat->qs_incoredqs,
			sizeof(struct compat_fs_quota_stat) -
			offsetof(struct compat_fs_quota_stat, qs_incoredqs)) ||
			get_user(xdata, &fsqstat->qs_iwarnlimit) ||
			put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
			break;
		ret = 0;
		break;
	default:
		ret = sys_quotactl(cmd, special, id, addr);
	}
	return ret;
}
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Quota code necessary even when VFS quota support is not compiled
	3	* into the kernel. The interesting stuff is over in dquot.c, here
	4	* we have symbols for initial quotactl(2) handling, the sysctl(2)
	5	* variables, etc - things needed even when quota support disabled.
	6	*/
	7
	8	#include <linux/fs.h>
	9	#include <linux/namei.h>
	10	#include <linux/slab.h>
	11	#include <asm/current.h>
	12	#include <asm/uaccess.h>
b716395e	13	#include <linux/compat.h>
1da177e4	14	#include <linux/kernel.h>
1da177e4 LT	15	#include <linux/security.h>
	16	#include <linux/syscalls.h>
	17	#include <linux/buffer_head.h>
16f7e0fe	18	#include <linux/capability.h>
be586bab	19	#include <linux/quotaops.h>
b716395e	20	#include <linux/types.h>
8c4e4acd	21	#include <linux/writeback.h>
1da177e4	22
c988afb5 CH	23	static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
c988afb5 CH	24	qid_t id)
1da177e4	25	{
c988afb5 CH	26	switch (cmd) {
	27	/* these commands do not require any special privilegues */
	28	case Q_GETFMT:
	29	case Q_SYNC:
	30	case Q_GETINFO:
	31	case Q_XGETQSTAT:
	32	case Q_XQUOTASYNC:
	33	break;
	34	/* allow to query information for dquots we "own" */
	35	case Q_GETQUOTA:
	36	case Q_XGETQUOTA:
	37	if ((type == USRQUOTA && current_euid() == id) \|\|
	38	(type == GRPQUOTA && in_egroup_p(id)))
	39	break;
	40	/FALLTHROUGH/
	41	default:
1da177e4 LT	42	if (!capable(CAP_SYS_ADMIN))
	43	return -EPERM;
	44	}
	45
c988afb5	46	return security_quotactl(cmd, type, id, sb);
1da177e4 LT	47	}
1da177e4 LT	48
6ae09575	49	static int quota_sync_all(int type)
1da177e4	50	{
850b201b	51	struct super_block *sb;
6ae09575 CH	52	int ret;
	53
	54	if (type >= MAXQUOTAS)
	55	return -EINVAL;
	56	ret = security_quotactl(Q_SYNC, type, 0, NULL);
	57	if (ret)
	58	return ret;
618f0636	59
618f0636 KK	60	spin_lock(&sb_lock);
	61	restart:
	62	list_for_each_entry(sb, &super_blocks, s_list) {
5fb324ad CH	63	if (!sb->s_qcop \|\| !sb->s_qcop->quota_sync)
	64	continue;
	65
618f0636 KK	66	sb->s_count++;
	67	spin_unlock(&sb_lock);
	68	down_read(&sb->s_umount);
850b201b	69	if (sb->s_root)
5fb324ad	70	sb->s_qcop->quota_sync(sb, type, 1);
618f0636 KK	71	up_read(&sb->s_umount);
	72	spin_lock(&sb_lock);
	73	if (__put_super_and_need_restart(sb))
	74	goto restart;
1da177e4	75	}
618f0636	76	spin_unlock(&sb_lock);
6ae09575 CH	77
6ae09575 CH	78	return 0;
1da177e4 LT	79	}
1da177e4 LT	80
c411e5f6 CH	81	static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
c411e5f6 CH	82	void __user *addr)
1da177e4	83	{
c411e5f6	84	char *pathname;
f450d4fe	85	int ret = -ENOSYS;
1da177e4	86
c411e5f6 CH	87	pathname = getname(addr);
	88	if (IS_ERR(pathname))
	89	return PTR_ERR(pathname);
f450d4fe CH	90	if (sb->s_qcop->quota_on)
f450d4fe CH	91	ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
c411e5f6 CH	92	putname(pathname);
	93	return ret;
	94	}
1da177e4	95
c411e5f6 CH	96	static int quota_getfmt(struct super_block sb, int type, void __user addr)
	97	{
	98	__u32 fmt;
1da177e4	99
c411e5f6 CH	100	down_read(&sb_dqopt(sb)->dqptr_sem);
	101	if (!sb_has_quota_active(sb, type)) {
	102	up_read(&sb_dqopt(sb)->dqptr_sem);
	103	return -ESRCH;
	104	}
	105	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
	106	up_read(&sb_dqopt(sb)->dqptr_sem);
	107	if (copy_to_user(addr, &fmt, sizeof(fmt)))
	108	return -EFAULT;
	109	return 0;
	110	}
1da177e4	111
c411e5f6 CH	112	static int quota_getinfo(struct super_block sb, int type, void __user addr)
	113	{
	114	struct if_dqinfo info;
	115	int ret;
1da177e4	116
f450d4fe CH	117	if (!sb_has_quota_active(sb, type))
	118	return -ESRCH;
	119	if (!sb->s_qcop->get_info)
	120	return -ENOSYS;
c411e5f6 CH	121	ret = sb->s_qcop->get_info(sb, type, &info);
	122	if (!ret && copy_to_user(addr, &info, sizeof(info)))
	123	return -EFAULT;
	124	return ret;
	125	}
1da177e4	126
c411e5f6 CH	127	static int quota_setinfo(struct super_block sb, int type, void __user addr)
	128	{
	129	struct if_dqinfo info;
1da177e4	130
c411e5f6 CH	131	if (copy_from_user(&info, addr, sizeof(info)))
c411e5f6 CH	132	return -EFAULT;
f450d4fe CH	133	if (!sb_has_quota_active(sb, type))
	134	return -ESRCH;
	135	if (!sb->s_qcop->set_info)
	136	return -ENOSYS;
c411e5f6 CH	137	return sb->s_qcop->set_info(sb, type, &info);
	138	}
	139
	140	static int quota_getquota(struct super_block *sb, int type, qid_t id,
	141	void __user *addr)
	142	{
	143	struct if_dqblk idq;
	144	int ret;
	145
f450d4fe CH	146	if (!sb_has_quota_active(sb, type))
	147	return -ESRCH;
	148	if (!sb->s_qcop->get_dqblk)
	149	return -ENOSYS;
c411e5f6 CH	150	ret = sb->s_qcop->get_dqblk(sb, type, id, &idq);
	151	if (ret)
	152	return ret;
	153	if (copy_to_user(addr, &idq, sizeof(idq)))
	154	return -EFAULT;
	155	return 0;
	156	}
	157
	158	static int quota_setquota(struct super_block *sb, int type, qid_t id,
	159	void __user *addr)
	160	{
	161	struct if_dqblk idq;
	162
	163	if (copy_from_user(&idq, addr, sizeof(idq)))
	164	return -EFAULT;
f450d4fe CH	165	if (!sb_has_quota_active(sb, type))
	166	return -ESRCH;
	167	if (!sb->s_qcop->set_dqblk)
	168	return -ENOSYS;
c411e5f6 CH	169	return sb->s_qcop->set_dqblk(sb, type, id, &idq);
	170	}
	171
	172	static int quota_setxstate(struct super_block sb, int cmd, void __user addr)
	173	{
	174	__u32 flags;
	175
	176	if (copy_from_user(&flags, addr, sizeof(flags)))
	177	return -EFAULT;
f450d4fe CH	178	if (!sb->s_qcop->set_xstate)
f450d4fe CH	179	return -ENOSYS;
c411e5f6 CH	180	return sb->s_qcop->set_xstate(sb, flags, cmd);
	181	}
	182
	183	static int quota_getxstate(struct super_block sb, void __user addr)
	184	{
	185	struct fs_quota_stat fqs;
	186	int ret;
f450d4fe CH	187
	188	if (!sb->s_qcop->get_xstate)
	189	return -ENOSYS;
c411e5f6 CH	190	ret = sb->s_qcop->get_xstate(sb, &fqs);
	191	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
	192	return -EFAULT;
	193	return ret;
	194	}
1da177e4	195
c411e5f6 CH	196	static int quota_setxquota(struct super_block *sb, int type, qid_t id,
	197	void __user *addr)
	198	{
	199	struct fs_disk_quota fdq;
	200
	201	if (copy_from_user(&fdq, addr, sizeof(fdq)))
	202	return -EFAULT;
f450d4fe CH	203	if (!sb->s_qcop->set_xquota)
f450d4fe CH	204	return -ENOSYS;
c411e5f6 CH	205	return sb->s_qcop->set_xquota(sb, type, id, &fdq);
	206	}
	207
	208	static int quota_getxquota(struct super_block *sb, int type, qid_t id,
	209	void __user *addr)
	210	{
	211	struct fs_disk_quota fdq;
	212	int ret;
	213
f450d4fe CH	214	if (!sb->s_qcop->get_xquota)
f450d4fe CH	215	return -ENOSYS;
c411e5f6 CH	216	ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
	217	if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
	218	return -EFAULT;
	219	return ret;
	220	}
	221
	222	/* Copy parameters and call proper function */
	223	static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
	224	void __user *addr)
	225	{
c988afb5 CH	226	int ret;
	227
	228	if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
	229	return -EINVAL;
	230	if (!sb->s_qcop)
	231	return -ENOSYS;
	232
	233	ret = check_quotactl_permission(sb, type, cmd, id);
	234	if (ret < 0)
	235	return ret;
	236
c411e5f6 CH	237	switch (cmd) {
	238	case Q_QUOTAON:
	239	return quota_quotaon(sb, type, cmd, id, addr);
	240	case Q_QUOTAOFF:
f450d4fe CH	241	if (!sb->s_qcop->quota_off)
f450d4fe CH	242	return -ENOSYS;
c411e5f6 CH	243	return sb->s_qcop->quota_off(sb, type, 0);
	244	case Q_GETFMT:
	245	return quota_getfmt(sb, type, addr);
	246	case Q_GETINFO:
	247	return quota_getinfo(sb, type, addr);
	248	case Q_SETINFO:
	249	return quota_setinfo(sb, type, addr);
	250	case Q_GETQUOTA:
	251	return quota_getquota(sb, type, id, addr);
	252	case Q_SETQUOTA:
	253	return quota_setquota(sb, type, id, addr);
	254	case Q_SYNC:
6ae09575 CH	255	if (!sb->s_qcop->quota_sync)
6ae09575 CH	256	return -ENOSYS;
5fb324ad	257	return sb->s_qcop->quota_sync(sb, type, 1);
c411e5f6 CH	258	case Q_XQUOTAON:
	259	case Q_XQUOTAOFF:
	260	case Q_XQUOTARM:
	261	return quota_setxstate(sb, cmd, addr);
	262	case Q_XGETQSTAT:
	263	return quota_getxstate(sb, addr);
	264	case Q_XSETQLIM:
	265	return quota_setxquota(sb, type, id, addr);
	266	case Q_XGETQUOTA:
	267	return quota_getxquota(sb, type, id, addr);
	268	case Q_XQUOTASYNC:
8c4e4acd CH	269	/* caller already holds s_umount */
	270	if (sb->s_flags & MS_RDONLY)
	271	return -EROFS;
	272	writeback_inodes_sb(sb);
	273	return 0;
c411e5f6	274	default:
f450d4fe	275	return -EINVAL;
1da177e4	276	}
1da177e4 LT	277	}
1da177e4 LT	278
9361401e DH	279	/*
	280	* look up a superblock on which quota ops will be performed
	281	* - use the name of a block device to find the superblock thereon
	282	*/
7a2435d8	283	static struct super_block quotactl_block(const char __user special)
9361401e DH	284	{
	285	#ifdef CONFIG_BLOCK
	286	struct block_device *bdev;
	287	struct super_block *sb;
	288	char *tmp = getname(special);
	289
	290	if (IS_ERR(tmp))
e231c2ee	291	return ERR_CAST(tmp);
9361401e DH	292	bdev = lookup_bdev(tmp);
	293	putname(tmp);
	294	if (IS_ERR(bdev))
e231c2ee	295	return ERR_CAST(bdev);
9361401e DH	296	sb = get_super(bdev);
	297	bdput(bdev);
	298	if (!sb)
	299	return ERR_PTR(-ENODEV);
	300
	301	return sb;
	302	#else
	303	return ERR_PTR(-ENODEV);
	304	#endif
	305	}
	306
1da177e4 LT	307	/*
	308	* This is the system call interface. This communicates with
	309	* the user-level programs. Currently this only supports diskquota
	310	* calls. Maybe we need to add the process quotas etc. in the future,
	311	* but we probably should use rlimits for that.
	312	*/
3cdad428 HC	313	SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
3cdad428 HC	314	qid_t, id, void __user *, addr)
1da177e4 LT	315	{
	316	uint cmds, type;
	317	struct super_block *sb = NULL;
1da177e4 LT	318	int ret;
	319
	320	cmds = cmd >> SUBCMDSHIFT;
	321	type = cmd & SUBCMDMASK;
	322
6ae09575 CH	323	/*
	324	* As a special case Q_SYNC can be called without a specific device.
	325	* It will iterate all superblocks that have quota enabled and call
	326	* the sync action on each of them.
	327	*/
	328	if (!special) {
	329	if (cmds == Q_SYNC)
	330	return quota_sync_all(type);
	331	return -ENODEV;
1da177e4 LT	332	}
1da177e4 LT	333
6ae09575 CH	334	sb = quotactl_block(special);
	335	if (IS_ERR(sb))
	336	return PTR_ERR(sb);
	337
c988afb5	338	ret = do_quotactl(sb, type, cmds, id, addr);
1da177e4	339
6ae09575	340	drop_super(sb);
1da177e4 LT	341	return ret;
1da177e4 LT	342	}
b716395e	343
7a6c8135	344	#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
b716395e VT	345	/*
	346	* This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
	347	* and is necessary due to alignment problems.
	348	*/
	349	struct compat_if_dqblk {
	350	compat_u64 dqb_bhardlimit;
	351	compat_u64 dqb_bsoftlimit;
	352	compat_u64 dqb_curspace;
	353	compat_u64 dqb_ihardlimit;
	354	compat_u64 dqb_isoftlimit;
	355	compat_u64 dqb_curinodes;
	356	compat_u64 dqb_btime;
	357	compat_u64 dqb_itime;
	358	compat_uint_t dqb_valid;
	359	};
	360
	361	/* XFS structures */
	362	struct compat_fs_qfilestat {
	363	compat_u64 dqb_bhardlimit;
	364	compat_u64 qfs_nblks;
	365	compat_uint_t qfs_nextents;
	366	};
	367
	368	struct compat_fs_quota_stat {
	369	__s8 qs_version;
	370	__u16 qs_flags;
	371	__s8 qs_pad;
	372	struct compat_fs_qfilestat qs_uquota;
	373	struct compat_fs_qfilestat qs_gquota;
	374	compat_uint_t qs_incoredqs;
	375	compat_int_t qs_btimelimit;
	376	compat_int_t qs_itimelimit;
	377	compat_int_t qs_rtbtimelimit;
	378	__u16 qs_bwarnlimit;
	379	__u16 qs_iwarnlimit;
	380	};
	381
	382	asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
	383	qid_t id, void __user *addr)
	384	{
	385	unsigned int cmds;
	386	struct if_dqblk __user *dqblk;
	387	struct compat_if_dqblk __user *compat_dqblk;
	388	struct fs_quota_stat __user *fsqstat;
	389	struct compat_fs_quota_stat __user *compat_fsqstat;
	390	compat_uint_t data;
	391	u16 xdata;
	392	long ret;
	393
	394	cmds = cmd >> SUBCMDSHIFT;
	395
	396	switch (cmds) {
	397	case Q_GETQUOTA:
	398	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
	399	compat_dqblk = addr;
	400	ret = sys_quotactl(cmd, special, id, dqblk);
	401	if (ret)
	402	break;
	403	if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) \|\|
	404	get_user(data, &dqblk->dqb_valid) \|\|
	405	put_user(data, &compat_dqblk->dqb_valid))
	406	ret = -EFAULT;
	407	break;
	408	case Q_SETQUOTA:
409	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
410	compat_dqblk = addr;
411	ret = -EFAULT;
412	if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) \|\|
413	get_user(data, &compat_dqblk->dqb_valid) \|\|
414	put_user(data, &dqblk->dqb_valid))
415	break;
416	ret = sys_quotactl(cmd, special, id, dqblk);
417	break;
418	case Q_XGETQSTAT:
419	fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
420	compat_fsqstat = addr;
421	ret = sys_quotactl(cmd, special, id, fsqstat);
422	if (ret)
423	break;
424	ret = -EFAULT;
425	/* Copying qs_version, qs_flags, qs_pad */
426	if (copy_in_user(compat_fsqstat, fsqstat,
427	offsetof(struct compat_fs_quota_stat, qs_uquota)))
428	break;
429	/* Copying qs_uquota */
430	if (copy_in_user(&compat_fsqstat->qs_uquota,
431	&fsqstat->qs_uquota,
432	sizeof(compat_fsqstat->qs_uquota)) \|\|
433	get_user(data, &fsqstat->qs_uquota.qfs_nextents) \|\|
434	put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
435	break;
436	/* Copying qs_gquota */
437	if (copy_in_user(&compat_fsqstat->qs_gquota,
438	&fsqstat->qs_gquota,
439	sizeof(compat_fsqstat->qs_gquota)) \|\|
440	get_user(data, &fsqstat->qs_gquota.qfs_nextents) \|\|
441	put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
442	break;
443	/* Copying the rest */
444	if (copy_in_user(&compat_fsqstat->qs_incoredqs,
445	&fsqstat->qs_incoredqs,
446	sizeof(struct compat_fs_quota_stat) -
447	offsetof(struct compat_fs_quota_stat, qs_incoredqs)) \|\|
448	get_user(xdata, &fsqstat->qs_iwarnlimit) \|\|
449	put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
450	break;
451	ret = 0;
452	break;
453	default:
454	ret = sys_quotactl(cmd, special, id, addr);
455	}
456	return ret;
457	}
458	#endif