[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_QUOTAOFF:
		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);
			putname(pathname);
			return ret;
		}
		case Q_QUOTAOFF:
			return sb->s_qcop->quota_off(sb, type);

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