[linux-2.6-block.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>

/* Check validity of generic quotactl commands */
static int generic_quotactl_valid(struct super_block *sb, int type, int cmd,
				  qid_t id)
{
	if (type >= MAXQUOTAS)
		return -EINVAL;
	if (!sb && cmd != Q_SYNC)
		return -ENODEV;
	/* Is operation supported? */
	if (sb && !sb->s_qcop)
		return -ENOSYS;

	switch (cmd) {
		case Q_GETFMT:
			break;
		case Q_QUOTAON:
			if (!sb->s_qcop->quota_on)
				return -ENOSYS;
			break;
		case Q_QUOTAOFF:
			if (!sb->s_qcop->quota_off)
				return -ENOSYS;
			break;
		case Q_SETINFO:
			if (!sb->s_qcop->set_info)
				return -ENOSYS;
			break;
		case Q_GETINFO:
			if (!sb->s_qcop->get_info)
				return -ENOSYS;
			break;
		case Q_SETQUOTA:
			if (!sb->s_qcop->set_dqblk)
				return -ENOSYS;
			break;
		case Q_GETQUOTA:
			if (!sb->s_qcop->get_dqblk)
				return -ENOSYS;
			break;
		case Q_SYNC:
			if (sb && !sb->s_qcop->quota_sync)
				return -ENOSYS;
			break;
		default:
			return -EINVAL;
	}

	/* Is quota turned on for commands which need it? */
	switch (cmd) {
		case Q_GETFMT:
		case Q_GETINFO:
		case Q_SETINFO:
		case Q_SETQUOTA:
		case Q_GETQUOTA:
			/* This is just an informative test so we are satisfied
			 * without the lock */
			if (!sb_has_quota_active(sb, type))
				return -ESRCH;
	}

	/* Check privileges */
	if (cmd == Q_GETQUOTA) {
		if (((type == USRQUOTA && current_euid() != id) ||
		     (type == GRPQUOTA && !in_egroup_p(id))) &&
		    !capable(CAP_SYS_ADMIN))
			return -EPERM;
	}
	else if (cmd != Q_GETFMT && cmd != Q_SYNC && cmd != Q_GETINFO)
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;

	return 0;
}

/* Check validity of XFS Quota Manager commands */
static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd,
			      qid_t id)
{
	if (type >= XQM_MAXQUOTAS)
		return -EINVAL;
	if (!sb)
		return -ENODEV;
	if (!sb->s_qcop)
		return -ENOSYS;

	switch (cmd) {
		case Q_XQUOTAON:
		case Q_XQUOTAOFF:
		case Q_XQUOTARM:
			if (!sb->s_qcop->set_xstate)
				return -ENOSYS;
			break;
		case Q_XGETQSTAT:
			if (!sb->s_qcop->get_xstate)
				return -ENOSYS;
			break;
		case Q_XSETQLIM:
			if (!sb->s_qcop->set_xquota)
				return -ENOSYS;
			break;
		case Q_XGETQUOTA:
			if (!sb->s_qcop->get_xquota)
				return -ENOSYS;
			break;
		case Q_XQUOTASYNC:
			if (!sb->s_qcop->quota_sync)
				return -ENOSYS;
			break;
		default:
			return -EINVAL;
	}

	/* Check privileges */
	if (cmd == Q_XGETQUOTA) {
		if (((type == XQM_USRQUOTA && current_euid() != id) ||
		     (type == XQM_GRPQUOTA && !in_egroup_p(id))) &&
		     !capable(CAP_SYS_ADMIN))
			return -EPERM;
	} else if (cmd != Q_XGETQSTAT && cmd != Q_XQUOTASYNC) {
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
	}

	return 0;
}

static int check_quotactl_valid(struct super_block *sb, int type, int cmd,
				qid_t id)
{
	int error;

	if (XQM_COMMAND(cmd))
		error = xqm_quotactl_valid(sb, type, cmd, id);
	else
		error = generic_quotactl_valid(sb, type, cmd, id);
	if (!error)
		error = security_quotactl(cmd, type, id, sb);
	return error;
}

static void quota_sync_sb(struct super_block *sb, int type)
{
	int cnt;

	sb->s_qcop->quota_sync(sb, type);

	if (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)
		return;
	/* This is not very clever (and fast) but currently I don't know about
	 * any other simple way of getting quota data to disk and we must get
	 * them there for userspace to be visible... */
	if (sb->s_op->sync_fs)
		sb->s_op->sync_fs(sb, 1);
	sync_blockdev(sb->s_bdev);

	/*
	 * Now when everything is written we can discard the pagecache so
	 * that userspace sees the changes.
	 */
	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
		if (type != -1 && cnt != type)
			continue;
		if (!sb_has_quota_active(sb, cnt))
			continue;
		mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex,
				  I_MUTEX_QUOTA);
		truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
		mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
	}
	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
}

void sync_dquots(struct super_block *sb, int type)
{
	int cnt;

	if (sb) {
		if (sb->s_qcop->quota_sync)
			quota_sync_sb(sb, type);
		return;
	}

	spin_lock(&sb_lock);
restart:
	list_for_each_entry(sb, &super_blocks, s_list) {
		/* This test just improves performance so it needn't be
		 * reliable... */
		for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
			if (type != -1 && type != cnt)
				continue;
			if (!sb_has_quota_active(sb, cnt))
				continue;
			if (!info_dirty(&sb_dqopt(sb)->info[cnt]) &&
			   list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list))
				continue;
			break;
		}
		if (cnt == MAXQUOTAS)
			continue;
		sb->s_count++;
		spin_unlock(&sb_lock);
		down_read(&sb->s_umount);
		if (sb->s_root && sb->s_qcop->quota_sync)
			quota_sync_sb(sb, type);
		up_read(&sb->s_umount);
		spin_lock(&sb_lock);
		if (__put_super_and_need_restart(sb))
			goto restart;
	}
	spin_unlock(&sb_lock);
}

/* 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;

	switch (cmd) {
		case Q_QUOTAON: {
			char *pathname;

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

		case Q_GETFMT: {
			__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;
		}
		case Q_GETINFO: {
			struct if_dqinfo info;

			ret = sb->s_qcop->get_info(sb, type, &info);
			if (ret)
				return ret;
			if (copy_to_user(addr, &info, sizeof(info)))
				return -EFAULT;
			return 0;
		}
		case Q_SETINFO: {
			struct if_dqinfo info;

			if (copy_from_user(&info, addr, sizeof(info)))
				return -EFAULT;
			return sb->s_qcop->set_info(sb, type, &info);
		}
		case Q_GETQUOTA: {
			struct if_dqblk idq;

			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;
		}
		case Q_SETQUOTA: {
			struct if_dqblk idq;

			if (copy_from_user(&idq, addr, sizeof(idq)))
				return -EFAULT;
			return sb->s_qcop->set_dqblk(sb, type, id, &idq);
		}
		case Q_SYNC:
			sync_dquots(sb, type);
			return 0;

		case Q_XQUOTAON:
		case Q_XQUOTAOFF:
		case Q_XQUOTARM: {
			__u32 flags;

			if (copy_from_user(&flags, addr, sizeof(flags)))
				return -EFAULT;
			return sb->s_qcop->set_xstate(sb, flags, cmd);
		}
		case Q_XGETQSTAT: {
			struct fs_quota_stat fqs;
		
			if ((ret = sb->s_qcop->get_xstate(sb, &fqs)))
				return ret;
			if (copy_to_user(addr, &fqs, sizeof(fqs)))
				return -EFAULT;
			return 0;
		}
		case Q_XSETQLIM: {
			struct fs_disk_quota fdq;

			if (copy_from_user(&fdq, addr, sizeof(fdq)))
				return -EFAULT;
		       return sb->s_qcop->set_xquota(sb, type, id, &fdq);
		}
		case Q_XGETQUOTA: {
			struct fs_disk_quota fdq;

			ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
			if (ret)
				return ret;
			if (copy_to_user(addr, &fdq, sizeof(fdq)))
				return -EFAULT;
			return 0;
		}
		case Q_XQUOTASYNC:
			return sb->s_qcop->quota_sync(sb, type);
		/* We never reach here unless validity check is broken */
		default:
			BUG();
	}
	return 0;
}

/*
 * 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;

	if (cmds != Q_SYNC || special) {
		sb = quotactl_block(special);
		if (IS_ERR(sb))
			return PTR_ERR(sb);
	}

	ret = check_quotactl_valid(sb, type, cmds, id);
	if (ret >= 0)
		ret = do_quotactl(sb, type, cmds, id, addr);
	if (sb)
		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>
1da177e4 LT	21
1da177e4 LT	22	/* Check validity of generic quotactl commands */
268157ba JK	23	static int generic_quotactl_valid(struct super_block *sb, int type, int cmd,
268157ba JK	24	qid_t id)
1da177e4 LT	25	{
	26	if (type >= MAXQUOTAS)
	27	return -EINVAL;
	28	if (!sb && cmd != Q_SYNC)
	29	return -ENODEV;
	30	/* Is operation supported? */
	31	if (sb && !sb->s_qcop)
	32	return -ENOSYS;
	33
	34	switch (cmd) {
	35	case Q_GETFMT:
	36	break;
	37	case Q_QUOTAON:
	38	if (!sb->s_qcop->quota_on)
	39	return -ENOSYS;
	40	break;
	41	case Q_QUOTAOFF:
	42	if (!sb->s_qcop->quota_off)
	43	return -ENOSYS;
	44	break;
	45	case Q_SETINFO:
	46	if (!sb->s_qcop->set_info)
	47	return -ENOSYS;
	48	break;
	49	case Q_GETINFO:
	50	if (!sb->s_qcop->get_info)
	51	return -ENOSYS;
	52	break;
	53	case Q_SETQUOTA:
	54	if (!sb->s_qcop->set_dqblk)
	55	return -ENOSYS;
	56	break;
	57	case Q_GETQUOTA:
	58	if (!sb->s_qcop->get_dqblk)
	59	return -ENOSYS;
	60	break;
	61	case Q_SYNC:
	62	if (sb && !sb->s_qcop->quota_sync)
	63	return -ENOSYS;
	64	break;
	65	default:
	66	return -EINVAL;
	67	}
	68
	69	/* Is quota turned on for commands which need it? */
	70	switch (cmd) {
	71	case Q_GETFMT:
	72	case Q_GETINFO:
1da177e4 LT	73	case Q_SETINFO:
	74	case Q_SETQUOTA:
	75	case Q_GETQUOTA:
268157ba JK	76	/* This is just an informative test so we are satisfied
268157ba JK	77	* without the lock */
f55abc0f	78	if (!sb_has_quota_active(sb, type))
1da177e4 LT	79	return -ESRCH;
	80	}
	81
	82	/* Check privileges */
	83	if (cmd == Q_GETQUOTA) {
da9592ed	84	if (((type == USRQUOTA && current_euid() != id) \|\|
1da177e4 LT	85	(type == GRPQUOTA && !in_egroup_p(id))) &&
	86	!capable(CAP_SYS_ADMIN))
	87	return -EPERM;
	88	}
	89	else if (cmd != Q_GETFMT && cmd != Q_SYNC && cmd != Q_GETINFO)
	90	if (!capable(CAP_SYS_ADMIN))
	91	return -EPERM;
	92
	93	return 0;
	94	}
	95
	96	/* Check validity of XFS Quota Manager commands */
268157ba JK	97	static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd,
268157ba JK	98	qid_t id)
1da177e4 LT	99	{
	100	if (type >= XQM_MAXQUOTAS)
	101	return -EINVAL;
	102	if (!sb)
	103	return -ENODEV;
	104	if (!sb->s_qcop)
	105	return -ENOSYS;
	106
	107	switch (cmd) {
	108	case Q_XQUOTAON:
	109	case Q_XQUOTAOFF:
	110	case Q_XQUOTARM:
	111	if (!sb->s_qcop->set_xstate)
	112	return -ENOSYS;
	113	break;
	114	case Q_XGETQSTAT:
	115	if (!sb->s_qcop->get_xstate)
	116	return -ENOSYS;
	117	break;
	118	case Q_XSETQLIM:
	119	if (!sb->s_qcop->set_xquota)
	120	return -ENOSYS;
	121	break;
	122	case Q_XGETQUOTA:
	123	if (!sb->s_qcop->get_xquota)
	124	return -ENOSYS;
	125	break;
de69e5f4 NS	126	case Q_XQUOTASYNC:
	127	if (!sb->s_qcop->quota_sync)
	128	return -ENOSYS;
	129	break;
1da177e4 LT	130	default:
	131	return -EINVAL;
	132	}
	133
	134	/* Check privileges */
	135	if (cmd == Q_XGETQUOTA) {
da9592ed	136	if (((type == XQM_USRQUOTA && current_euid() != id) \|\|
1da177e4 LT	137	(type == XQM_GRPQUOTA && !in_egroup_p(id))) &&
	138	!capable(CAP_SYS_ADMIN))
	139	return -EPERM;
de69e5f4	140	} else if (cmd != Q_XGETQSTAT && cmd != Q_XQUOTASYNC) {
1da177e4 LT	141	if (!capable(CAP_SYS_ADMIN))
	142	return -EPERM;
	143	}
	144
	145	return 0;
	146	}
	147
268157ba JK	148	static int check_quotactl_valid(struct super_block *sb, int type, int cmd,
268157ba JK	149	qid_t id)
1da177e4 LT	150	{
	151	int error;
	152
	153	if (XQM_COMMAND(cmd))
	154	error = xqm_quotactl_valid(sb, type, cmd, id);
	155	else
	156	error = generic_quotactl_valid(sb, type, cmd, id);
	157	if (!error)
	158	error = security_quotactl(cmd, type, id, sb);
	159	return error;
	160	}
	161
1da177e4 LT	162	static void quota_sync_sb(struct super_block *sb, int type)
	163	{
	164	int cnt;
1da177e4 LT	165
1da177e4 LT	166	sb->s_qcop->quota_sync(sb, type);
ca785ec6 JK	167
	168	if (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)
	169	return;
1da177e4 LT	170	/* This is not very clever (and fast) but currently I don't know about
	171	* any other simple way of getting quota data to disk and we must get
	172	* them there for userspace to be visible... */
	173	if (sb->s_op->sync_fs)
	174	sb->s_op->sync_fs(sb, 1);
	175	sync_blockdev(sb->s_bdev);
	176
7925409e JK	177	/*
	178	* Now when everything is written we can discard the pagecache so
	179	* that userspace sees the changes.
	180	*/
d3be915f	181	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
1da177e4	182	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1da177e4 LT	183	if (type != -1 && cnt != type)
1da177e4 LT	184	continue;
f55abc0f	185	if (!sb_has_quota_active(sb, cnt))
1da177e4	186	continue;
268157ba JK	187	mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex,
268157ba JK	188	I_MUTEX_QUOTA);
7925409e JK	189	truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
7925409e JK	190	mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
1da177e4	191	}
d3be915f	192	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1da177e4 LT	193	}
	194
	195	void sync_dquots(struct super_block *sb, int type)
	196	{
02a55ca8	197	int cnt;
618f0636	198
1da177e4 LT	199	if (sb) {
	200	if (sb->s_qcop->quota_sync)
	201	quota_sync_sb(sb, type);
618f0636	202	return;
1da177e4	203	}
618f0636 KK	204
	205	spin_lock(&sb_lock);
	206	restart:
	207	list_for_each_entry(sb, &super_blocks, s_list) {
268157ba JK	208	/* This test just improves performance so it needn't be
268157ba JK	209	* reliable... */
02a55ca8 JK	210	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
	211	if (type != -1 && type != cnt)
	212	continue;
f55abc0f	213	if (!sb_has_quota_active(sb, cnt))
02a55ca8 JK	214	continue;
02a55ca8 JK	215	if (!info_dirty(&sb_dqopt(sb)->info[cnt]) &&
268157ba	216	list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list))
02a55ca8 JK	217	continue;
	218	break;
	219	}
	220	if (cnt == MAXQUOTAS)
618f0636 KK	221	continue;
	222	sb->s_count++;
	223	spin_unlock(&sb_lock);
	224	down_read(&sb->s_umount);
	225	if (sb->s_root && sb->s_qcop->quota_sync)
	226	quota_sync_sb(sb, type);
	227	up_read(&sb->s_umount);
	228	spin_lock(&sb_lock);
	229	if (__put_super_and_need_restart(sb))
	230	goto restart;
1da177e4	231	}
618f0636	232	spin_unlock(&sb_lock);
1da177e4 LT	233	}
	234
	235	/* Copy parameters and call proper function */
268157ba JK	236	static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
268157ba JK	237	void __user *addr)
1da177e4 LT	238	{
	239	int ret;
	240
	241	switch (cmd) {
	242	case Q_QUOTAON: {
	243	char *pathname;
	244
268157ba JK	245	pathname = getname(addr);
268157ba JK	246	if (IS_ERR(pathname))
1da177e4	247	return PTR_ERR(pathname);
0ff5af83	248	ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
1da177e4 LT	249	putname(pathname);
	250	return ret;
	251	}
	252	case Q_QUOTAOFF:
0ff5af83	253	return sb->s_qcop->quota_off(sb, type, 0);
1da177e4 LT	254
	255	case Q_GETFMT: {
	256	__u32 fmt;
	257
	258	down_read(&sb_dqopt(sb)->dqptr_sem);
f55abc0f	259	if (!sb_has_quota_active(sb, type)) {
1da177e4 LT	260	up_read(&sb_dqopt(sb)->dqptr_sem);
	261	return -ESRCH;
	262	}
	263	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
	264	up_read(&sb_dqopt(sb)->dqptr_sem);
	265	if (copy_to_user(addr, &fmt, sizeof(fmt)))
	266	return -EFAULT;
	267	return 0;
	268	}
	269	case Q_GETINFO: {
	270	struct if_dqinfo info;
	271
268157ba JK	272	ret = sb->s_qcop->get_info(sb, type, &info);
268157ba JK	273	if (ret)
1da177e4 LT	274	return ret;
	275	if (copy_to_user(addr, &info, sizeof(info)))
	276	return -EFAULT;
	277	return 0;
	278	}
	279	case Q_SETINFO: {
	280	struct if_dqinfo info;
	281
	282	if (copy_from_user(&info, addr, sizeof(info)))
	283	return -EFAULT;
	284	return sb->s_qcop->set_info(sb, type, &info);
	285	}
	286	case Q_GETQUOTA: {
	287	struct if_dqblk idq;
	288
268157ba JK	289	ret = sb->s_qcop->get_dqblk(sb, type, id, &idq);
268157ba JK	290	if (ret)
1da177e4 LT	291	return ret;
	292	if (copy_to_user(addr, &idq, sizeof(idq)))
	293	return -EFAULT;
	294	return 0;
	295	}
	296	case Q_SETQUOTA: {
	297	struct if_dqblk idq;
	298
	299	if (copy_from_user(&idq, addr, sizeof(idq)))
	300	return -EFAULT;
	301	return sb->s_qcop->set_dqblk(sb, type, id, &idq);
	302	}
	303	case Q_SYNC:
	304	sync_dquots(sb, type);
	305	return 0;
	306
	307	case Q_XQUOTAON:
	308	case Q_XQUOTAOFF:
	309	case Q_XQUOTARM: {
	310	__u32 flags;
	311
	312	if (copy_from_user(&flags, addr, sizeof(flags)))
	313	return -EFAULT;
	314	return sb->s_qcop->set_xstate(sb, flags, cmd);
	315	}
	316	case Q_XGETQSTAT: {
	317	struct fs_quota_stat fqs;
	318
	319	if ((ret = sb->s_qcop->get_xstate(sb, &fqs)))
	320	return ret;
	321	if (copy_to_user(addr, &fqs, sizeof(fqs)))
	322	return -EFAULT;
	323	return 0;
	324	}
	325	case Q_XSETQLIM: {
	326	struct fs_disk_quota fdq;
	327
	328	if (copy_from_user(&fdq, addr, sizeof(fdq)))
	329	return -EFAULT;
	330	return sb->s_qcop->set_xquota(sb, type, id, &fdq);
	331	}
	332	case Q_XGETQUOTA: {
	333	struct fs_disk_quota fdq;
	334
268157ba JK	335	ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
268157ba JK	336	if (ret)
1da177e4 LT	337	return ret;
	338	if (copy_to_user(addr, &fdq, sizeof(fdq)))
	339	return -EFAULT;
	340	return 0;
	341	}
de69e5f4 NS	342	case Q_XQUOTASYNC:
de69e5f4 NS	343	return sb->s_qcop->quota_sync(sb, type);
1da177e4 LT	344	/* We never reach here unless validity check is broken */
	345	default:
	346	BUG();
	347	}
	348	return 0;
	349	}
	350
9361401e DH	351	/*
	352	* look up a superblock on which quota ops will be performed
	353	* - use the name of a block device to find the superblock thereon
	354	*/
7a2435d8	355	static struct super_block quotactl_block(const char __user special)
9361401e DH	356	{
	357	#ifdef CONFIG_BLOCK
	358	struct block_device *bdev;
	359	struct super_block *sb;
	360	char *tmp = getname(special);
	361
	362	if (IS_ERR(tmp))
e231c2ee	363	return ERR_CAST(tmp);
9361401e DH	364	bdev = lookup_bdev(tmp);
	365	putname(tmp);
	366	if (IS_ERR(bdev))
e231c2ee	367	return ERR_CAST(bdev);
9361401e DH	368	sb = get_super(bdev);
	369	bdput(bdev);
	370	if (!sb)
	371	return ERR_PTR(-ENODEV);
	372
	373	return sb;
	374	#else
	375	return ERR_PTR(-ENODEV);
	376	#endif
	377	}
	378
1da177e4 LT	379	/*
	380	* This is the system call interface. This communicates with
	381	* the user-level programs. Currently this only supports diskquota
	382	* calls. Maybe we need to add the process quotas etc. in the future,
	383	* but we probably should use rlimits for that.
	384	*/
3cdad428 HC	385	SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
3cdad428 HC	386	qid_t, id, void __user *, addr)
1da177e4 LT	387	{
	388	uint cmds, type;
	389	struct super_block *sb = NULL;
1da177e4 LT	390	int ret;
	391
	392	cmds = cmd >> SUBCMDSHIFT;
	393	type = cmd & SUBCMDMASK;
	394
	395	if (cmds != Q_SYNC \|\| special) {
9361401e DH	396	sb = quotactl_block(special);
	397	if (IS_ERR(sb))
	398	return PTR_ERR(sb);
1da177e4 LT	399	}
	400
	401	ret = check_quotactl_valid(sb, type, cmds, id);
	402	if (ret >= 0)
	403	ret = do_quotactl(sb, type, cmds, id, addr);
	404	if (sb)
	405	drop_super(sb);
	406
	407	return ret;
	408	}
b716395e	409
7a6c8135	410	#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
b716395e VT	411	/*
	412	* This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
	413	* and is necessary due to alignment problems.
	414	*/
	415	struct compat_if_dqblk {
	416	compat_u64 dqb_bhardlimit;
	417	compat_u64 dqb_bsoftlimit;
	418	compat_u64 dqb_curspace;
	419	compat_u64 dqb_ihardlimit;
	420	compat_u64 dqb_isoftlimit;
	421	compat_u64 dqb_curinodes;
	422	compat_u64 dqb_btime;
	423	compat_u64 dqb_itime;
	424	compat_uint_t dqb_valid;
	425	};
	426
	427	/* XFS structures */
	428	struct compat_fs_qfilestat {
	429	compat_u64 dqb_bhardlimit;
	430	compat_u64 qfs_nblks;
	431	compat_uint_t qfs_nextents;
	432	};
	433
	434	struct compat_fs_quota_stat {
	435	__s8 qs_version;
	436	__u16 qs_flags;
	437	__s8 qs_pad;
	438	struct compat_fs_qfilestat qs_uquota;
	439	struct compat_fs_qfilestat qs_gquota;
	440	compat_uint_t qs_incoredqs;
	441	compat_int_t qs_btimelimit;
	442	compat_int_t qs_itimelimit;
	443	compat_int_t qs_rtbtimelimit;
	444	__u16 qs_bwarnlimit;
	445	__u16 qs_iwarnlimit;
	446	};
	447
	448	asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
	449	qid_t id, void __user *addr)
	450	{
	451	unsigned int cmds;
	452	struct if_dqblk __user *dqblk;
	453	struct compat_if_dqblk __user *compat_dqblk;
	454	struct fs_quota_stat __user *fsqstat;
	455	struct compat_fs_quota_stat __user *compat_fsqstat;
	456	compat_uint_t data;
	457	u16 xdata;
	458	long ret;
	459
	460	cmds = cmd >> SUBCMDSHIFT;
	461
	462	switch (cmds) {
	463	case Q_GETQUOTA:
	464	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
	465	compat_dqblk = addr;
	466	ret = sys_quotactl(cmd, special, id, dqblk);
	467	if (ret)
	468	break;
	469	if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) \|\|
	470	get_user(data, &dqblk->dqb_valid) \|\|
	471	put_user(data, &compat_dqblk->dqb_valid))
	472	ret = -EFAULT;
	473	break;
	474	case Q_SETQUOTA:
475	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
476	compat_dqblk = addr;
477	ret = -EFAULT;
478	if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) \|\|
479	get_user(data, &compat_dqblk->dqb_valid) \|\|
480	put_user(data, &dqblk->dqb_valid))
481	break;
482	ret = sys_quotactl(cmd, special, id, dqblk);
483	break;
484	case Q_XGETQSTAT:
485	fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
486	compat_fsqstat = addr;
487	ret = sys_quotactl(cmd, special, id, fsqstat);
488	if (ret)
489	break;
490	ret = -EFAULT;
491	/* Copying qs_version, qs_flags, qs_pad */
492	if (copy_in_user(compat_fsqstat, fsqstat,
493	offsetof(struct compat_fs_quota_stat, qs_uquota)))
494	break;
495	/* Copying qs_uquota */
496	if (copy_in_user(&compat_fsqstat->qs_uquota,
497	&fsqstat->qs_uquota,
498	sizeof(compat_fsqstat->qs_uquota)) \|\|
499	get_user(data, &fsqstat->qs_uquota.qfs_nextents) \|\|
500	put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
501	break;
502	/* Copying qs_gquota */
503	if (copy_in_user(&compat_fsqstat->qs_gquota,
504	&fsqstat->qs_gquota,
505	sizeof(compat_fsqstat->qs_gquota)) \|\|
506	get_user(data, &fsqstat->qs_gquota.qfs_nextents) \|\|
507	put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
508	break;
509	/* Copying the rest */
510	if (copy_in_user(&compat_fsqstat->qs_incoredqs,
511	&fsqstat->qs_incoredqs,
512	sizeof(struct compat_fs_quota_stat) -
513	offsetof(struct compat_fs_quota_stat, qs_incoredqs)) \|\|
514	get_user(xdata, &fsqstat->qs_iwarnlimit) \|\|
515	put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
516	break;
517	ret = 0;
518	break;
519	default:
520	ret = sys_quotactl(cmd, special, id, addr);
521	}
522	return ret;
523	}
524	#endif