[net-next-2.6.git] / fs / 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 informative test so we are satisfied without a lock */
			if (!sb_has_quota_enabled(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);
	/* 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_enabled(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_enabled(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;

			if (IS_ERR(pathname = getname(addr)))
				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_enabled(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;

			if ((ret = sb->s_qcop->get_info(sb, type, &info)))
				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;

			if ((ret = sb->s_qcop->get_dqblk(sb, type, id, &idq)))
				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;

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