[linux.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, dirty;

	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, dirty = 0; cnt < MAXQUOTAS; cnt++)
			if ((type == cnt || type == -1) && sb_has_quota_enabled(sb, cnt)
			    && info_any_dirty(&sb_dqopt(sb)->info[cnt]))
				dirty = 1;
		if (!dirty)
			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	{
618f0636 KK	189	int cnt, dirty;
618f0636 KK	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... */
	201	for (cnt = 0, dirty = 0; cnt < MAXQUOTAS; cnt++)
	202	if ((type == cnt \|\| type == -1) && sb_has_quota_enabled(sb, cnt)
	203	&& info_any_dirty(&sb_dqopt(sb)->info[cnt]))
	204	dirty = 1;
	205	if (!dirty)
	206	continue;
	207	sb->s_count++;
	208	spin_unlock(&sb_lock);
	209	down_read(&sb->s_umount);
	210	if (sb->s_root && sb->s_qcop->quota_sync)
	211	quota_sync_sb(sb, type);
	212	up_read(&sb->s_umount);
	213	spin_lock(&sb_lock);
	214	if (__put_super_and_need_restart(sb))
	215	goto restart;
1da177e4	216	}
618f0636	217	spin_unlock(&sb_lock);
1da177e4 LT	218	}
	219
	220	/* Copy parameters and call proper function */
	221	static int do_quotactl(struct super_block sb, int type, int cmd, qid_t id, void __user addr)
	222	{
	223	int ret;
	224
	225	switch (cmd) {
	226	case Q_QUOTAON: {
	227	char *pathname;
	228
	229	if (IS_ERR(pathname = getname(addr)))
	230	return PTR_ERR(pathname);
0ff5af83	231	ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
1da177e4 LT	232	putname(pathname);
	233	return ret;
	234	}
	235	case Q_QUOTAOFF:
0ff5af83	236	return sb->s_qcop->quota_off(sb, type, 0);
1da177e4 LT	237
	238	case Q_GETFMT: {
	239	__u32 fmt;
	240
	241	down_read(&sb_dqopt(sb)->dqptr_sem);
	242	if (!sb_has_quota_enabled(sb, type)) {
	243	up_read(&sb_dqopt(sb)->dqptr_sem);
	244	return -ESRCH;
	245	}
	246	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
	247	up_read(&sb_dqopt(sb)->dqptr_sem);
	248	if (copy_to_user(addr, &fmt, sizeof(fmt)))
	249	return -EFAULT;
	250	return 0;
	251	}
	252	case Q_GETINFO: {
	253	struct if_dqinfo info;
	254
	255	if ((ret = sb->s_qcop->get_info(sb, type, &info)))
	256	return ret;
	257	if (copy_to_user(addr, &info, sizeof(info)))
	258	return -EFAULT;
	259	return 0;
	260	}
	261	case Q_SETINFO: {
	262	struct if_dqinfo info;
	263
	264	if (copy_from_user(&info, addr, sizeof(info)))
	265	return -EFAULT;
	266	return sb->s_qcop->set_info(sb, type, &info);
	267	}
	268	case Q_GETQUOTA: {
	269	struct if_dqblk idq;
	270
	271	if ((ret = sb->s_qcop->get_dqblk(sb, type, id, &idq)))
	272	return ret;
	273	if (copy_to_user(addr, &idq, sizeof(idq)))
	274	return -EFAULT;
	275	return 0;
	276	}
	277	case Q_SETQUOTA: {
	278	struct if_dqblk idq;
	279
	280	if (copy_from_user(&idq, addr, sizeof(idq)))
	281	return -EFAULT;
	282	return sb->s_qcop->set_dqblk(sb, type, id, &idq);
	283	}
	284	case Q_SYNC:
	285	sync_dquots(sb, type);
	286	return 0;
	287
	288	case Q_XQUOTAON:
	289	case Q_XQUOTAOFF:
	290	case Q_XQUOTARM: {
	291	__u32 flags;
	292
	293	if (copy_from_user(&flags, addr, sizeof(flags)))
	294	return -EFAULT;
	295	return sb->s_qcop->set_xstate(sb, flags, cmd);
	296	}
	297	case Q_XGETQSTAT: {
	298	struct fs_quota_stat fqs;
	299
	300	if ((ret = sb->s_qcop->get_xstate(sb, &fqs)))
301	return ret;
302	if (copy_to_user(addr, &fqs, sizeof(fqs)))
303	return -EFAULT;
304	return 0;
305	}
306	case Q_XSETQLIM: {
307	struct fs_disk_quota fdq;
308
309	if (copy_from_user(&fdq, addr, sizeof(fdq)))
310	return -EFAULT;
311	return sb->s_qcop->set_xquota(sb, type, id, &fdq);
312	}
313	case Q_XGETQUOTA: {
314	struct fs_disk_quota fdq;
315
316	if ((ret = sb->s_qcop->get_xquota(sb, type, id, &fdq)))
317	return ret;
318	if (copy_to_user(addr, &fdq, sizeof(fdq)))
319	return -EFAULT;
320	return 0;
321	}
de69e5f4 NS	322	case Q_XQUOTASYNC:
de69e5f4 NS	323	return sb->s_qcop->quota_sync(sb, type);
1da177e4 LT	324	/* We never reach here unless validity check is broken */
	325	default:
	326	BUG();
	327	}
	328	return 0;
	329	}
	330
9361401e DH	331	/*
	332	* look up a superblock on which quota ops will be performed
	333	* - use the name of a block device to find the superblock thereon
	334	*/
	335	static inline struct super_block quotactl_block(const char __user special)
	336	{
	337	#ifdef CONFIG_BLOCK
	338	struct block_device *bdev;
	339	struct super_block *sb;
	340	char *tmp = getname(special);
	341
	342	if (IS_ERR(tmp))
e231c2ee	343	return ERR_CAST(tmp);
9361401e DH	344	bdev = lookup_bdev(tmp);
	345	putname(tmp);
	346	if (IS_ERR(bdev))
e231c2ee	347	return ERR_CAST(bdev);
9361401e DH	348	sb = get_super(bdev);
	349	bdput(bdev);
	350	if (!sb)
	351	return ERR_PTR(-ENODEV);
	352
	353	return sb;
	354	#else
	355	return ERR_PTR(-ENODEV);
	356	#endif
	357	}
	358
1da177e4 LT	359	/*
	360	* This is the system call interface. This communicates with
	361	* the user-level programs. Currently this only supports diskquota
	362	* calls. Maybe we need to add the process quotas etc. in the future,
	363	* but we probably should use rlimits for that.
	364	*/
	365	asmlinkage long sys_quotactl(unsigned int cmd, const char __user special, qid_t id, void __user addr)
	366	{
	367	uint cmds, type;
	368	struct super_block *sb = NULL;
1da177e4 LT	369	int ret;
	370
	371	cmds = cmd >> SUBCMDSHIFT;
	372	type = cmd & SUBCMDMASK;
	373
	374	if (cmds != Q_SYNC \|\| special) {
9361401e DH	375	sb = quotactl_block(special);
	376	if (IS_ERR(sb))
	377	return PTR_ERR(sb);
1da177e4 LT	378	}
	379
	380	ret = check_quotactl_valid(sb, type, cmds, id);
	381	if (ret >= 0)
	382	ret = do_quotactl(sb, type, cmds, id, addr);
	383	if (sb)
	384	drop_super(sb);
	385
	386	return ret;
	387	}
b716395e	388
7a6c8135	389	#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
b716395e VT	390	/*
	391	* This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
	392	* and is necessary due to alignment problems.
	393	*/
	394	struct compat_if_dqblk {
	395	compat_u64 dqb_bhardlimit;
	396	compat_u64 dqb_bsoftlimit;
	397	compat_u64 dqb_curspace;
	398	compat_u64 dqb_ihardlimit;
	399	compat_u64 dqb_isoftlimit;
	400	compat_u64 dqb_curinodes;
	401	compat_u64 dqb_btime;
	402	compat_u64 dqb_itime;
	403	compat_uint_t dqb_valid;
	404	};
	405
	406	/* XFS structures */
	407	struct compat_fs_qfilestat {
	408	compat_u64 dqb_bhardlimit;
	409	compat_u64 qfs_nblks;
	410	compat_uint_t qfs_nextents;
	411	};
	412
	413	struct compat_fs_quota_stat {
	414	__s8 qs_version;
	415	__u16 qs_flags;
	416	__s8 qs_pad;
	417	struct compat_fs_qfilestat qs_uquota;
	418	struct compat_fs_qfilestat qs_gquota;
	419	compat_uint_t qs_incoredqs;
	420	compat_int_t qs_btimelimit;
	421	compat_int_t qs_itimelimit;
	422	compat_int_t qs_rtbtimelimit;
	423	__u16 qs_bwarnlimit;
	424	__u16 qs_iwarnlimit;
	425	};
	426
	427	asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
	428	qid_t id, void __user *addr)
	429	{
	430	unsigned int cmds;
	431	struct if_dqblk __user *dqblk;
	432	struct compat_if_dqblk __user *compat_dqblk;
	433	struct fs_quota_stat __user *fsqstat;
	434	struct compat_fs_quota_stat __user *compat_fsqstat;
	435	compat_uint_t data;
	436	u16 xdata;
	437	long ret;
	438
	439	cmds = cmd >> SUBCMDSHIFT;
	440
	441	switch (cmds) {
	442	case Q_GETQUOTA:
	443	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
	444	compat_dqblk = addr;
	445	ret = sys_quotactl(cmd, special, id, dqblk);
	446	if (ret)
	447	break;
	448	if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) \|\|
	449	get_user(data, &dqblk->dqb_valid) \|\|
	450	put_user(data, &compat_dqblk->dqb_valid))
	451	ret = -EFAULT;
	452	break;
	453	case Q_SETQUOTA:
454	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
455	compat_dqblk = addr;
456	ret = -EFAULT;
457	if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) \|\|
458	get_user(data, &compat_dqblk->dqb_valid) \|\|
459	put_user(data, &dqblk->dqb_valid))
460	break;
461	ret = sys_quotactl(cmd, special, id, dqblk);
462	break;
463	case Q_XGETQSTAT:
464	fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
465	compat_fsqstat = addr;
466	ret = sys_quotactl(cmd, special, id, fsqstat);
467	if (ret)
468	break;
469	ret = -EFAULT;
470	/* Copying qs_version, qs_flags, qs_pad */
471	if (copy_in_user(compat_fsqstat, fsqstat,
472	offsetof(struct compat_fs_quota_stat, qs_uquota)))
473	break;
474	/* Copying qs_uquota */
475	if (copy_in_user(&compat_fsqstat->qs_uquota,
476	&fsqstat->qs_uquota,
477	sizeof(compat_fsqstat->qs_uquota)) \|\|
478	get_user(data, &fsqstat->qs_uquota.qfs_nextents) \|\|
479	put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
480	break;
481	/* Copying qs_gquota */
482	if (copy_in_user(&compat_fsqstat->qs_gquota,
483	&fsqstat->qs_gquota,
484	sizeof(compat_fsqstat->qs_gquota)) \|\|
485	get_user(data, &fsqstat->qs_gquota.qfs_nextents) \|\|
486	put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
487	break;
488	/* Copying the rest */
489	if (copy_in_user(&compat_fsqstat->qs_incoredqs,
490	&fsqstat->qs_incoredqs,
491	sizeof(struct compat_fs_quota_stat) -
492	offsetof(struct compat_fs_quota_stat, qs_incoredqs)) \|\|
493	get_user(xdata, &fsqstat->qs_iwarnlimit) \|\|
494	put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
495	break;
496	ret = 0;
497	break;
498	default:
499	ret = sys_quotactl(cmd, special, id, addr);
500	}
501	return ret;
502	}
503	#endif