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

/*
 * Quota code necessary even when VFS quota support is not compiled
 * into the kernel.  The interesting stuff is over in dquot.c, here
 * we have symbols for initial quotactl(2) handling, the sysctl(2)
 * variables, etc - things needed even when quota support disabled.
 */

#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <asm/current.h>
#include <asm/uaccess.h>
#include <linux/compat.h>
#include <linux/kernel.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/buffer_head.h>
#include <linux/capability.h>
#include <linux/quotaops.h>
#include <linux/types.h>
#include <linux/writeback.h>
#include <net/netlink.h>
#include <net/genetlink.h>

static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
				     qid_t id)
{
	switch (cmd) {
	/* these commands do not require any special privilegues */
	case Q_GETFMT:
	case Q_SYNC:
	case Q_GETINFO:
	case Q_XGETQSTAT:
	case Q_XQUOTASYNC:
		break;
	/* allow to query information for dquots we "own" */
	case Q_GETQUOTA:
	case Q_XGETQUOTA:
		if ((type == USRQUOTA && current_euid() == id) ||
		    (type == GRPQUOTA && in_egroup_p(id)))
			break;
		/*FALLTHROUGH*/
	default:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
	}

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

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

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

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

		/* 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(sb, type, 1);
		up_read(&sb->s_umount);
		spin_lock(&sb_lock);
		if (__put_super_and_need_restart(sb))
			goto restart;
	}
	spin_unlock(&sb_lock);

	return 0;
}

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

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

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

	down_read(&sb_dqopt(sb)->dqptr_sem);
	if (!sb_has_quota_active(sb, type)) {
		up_read(&sb_dqopt(sb)->dqptr_sem);
		return -ESRCH;
	}
	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
	up_read(&sb_dqopt(sb)->dqptr_sem);
	if (copy_to_user(addr, &fmt, sizeof(fmt)))
		return -EFAULT;
	return 0;
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	switch (cmd) {
	case Q_QUOTAON:
		return quota_quotaon(sb, type, cmd, id, addr);
	case Q_QUOTAOFF:
		if (!sb->s_qcop->quota_off)
			return -ENOSYS;
		return sb->s_qcop->quota_off(sb, type, 0);
	case Q_GETFMT:
		return quota_getfmt(sb, type, addr);
	case Q_GETINFO:
		return quota_getinfo(sb, type, addr);
	case Q_SETINFO:
		return quota_setinfo(sb, type, addr);
	case Q_GETQUOTA:
		return quota_getquota(sb, type, id, addr);
	case Q_SETQUOTA:
		return quota_setquota(sb, type, id, addr);
	case Q_SYNC:
		if (!sb->s_qcop->quota_sync)
			return -ENOSYS;
		return sb->s_qcop->quota_sync(sb, type, 1);
	case Q_XQUOTAON:
	case Q_XQUOTAOFF:
	case Q_XQUOTARM:
		return quota_setxstate(sb, cmd, addr);
	case Q_XGETQSTAT:
		return quota_getxstate(sb, addr);
	case Q_XSETQLIM:
		return quota_setxquota(sb, type, id, addr);
	case Q_XGETQUOTA:
		return quota_getxquota(sb, type, id, addr);
	case Q_XQUOTASYNC:
		/* caller already holds s_umount */
		if (sb->s_flags & MS_RDONLY)
			return -EROFS;
		writeback_inodes_sb(sb);
		return 0;
	default:
		return -EINVAL;
	}
}

/*
 * look up a superblock on which quota ops will be performed
 * - use the name of a block device to find the superblock thereon
 */
static struct super_block *quotactl_block(const char __user *special)
{
#ifdef CONFIG_BLOCK
	struct block_device *bdev;
	struct super_block *sb;
	char *tmp = getname(special);

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

	return sb;
#else
	return ERR_PTR(-ENODEV);
#endif
}

/*
 * This is the system call interface. This communicates with
 * the user-level programs. Currently this only supports diskquota
 * calls. Maybe we need to add the process quotas etc. in the future,
 * but we probably should use rlimits for that.
 */
SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
		qid_t, id, void __user *, addr)
{
	uint cmds, type;
	struct super_block *sb = NULL;
	int ret;

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

	/*
	 * As a special case Q_SYNC can be called without a specific device.
	 * It will iterate all superblocks that have quota enabled and call
	 * the sync action on each of them.
	 */
	if (!special) {
		if (cmds == Q_SYNC)
			return quota_sync_all(type);
		return -ENODEV;
	}

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

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

	drop_super(sb);
	return ret;
}

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

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

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

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

	cmds = cmd >> SUBCMDSHIFT;

	switch (cmds) {
	case Q_GETQUOTA:
		dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
		compat_dqblk = addr;
		ret = sys_quotactl(cmd, special, id, dqblk);
		if (ret)
			break;
		if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
			get_user(data, &dqblk->dqb_valid) ||
			put_user(data, &compat_dqblk->dqb_valid))
			ret = -EFAULT;
		break;
	case Q_SETQUOTA:
		dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
		compat_dqblk = addr;
		ret = -EFAULT;
		if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) ||
			get_user(data, &compat_dqblk->dqb_valid) ||
			put_user(data, &dqblk->dqb_valid))
			break;
		ret = sys_quotactl(cmd, special, id, dqblk);
		break;
	case Q_XGETQSTAT:
		fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
		compat_fsqstat = addr;
		ret = sys_quotactl(cmd, special, id, fsqstat);
		if (ret)
			break;
		ret = -EFAULT;
		/* Copying qs_version, qs_flags, qs_pad */
		if (copy_in_user(compat_fsqstat, fsqstat,
			offsetof(struct compat_fs_quota_stat, qs_uquota)))
			break;
		/* Copying qs_uquota */
		if (copy_in_user(&compat_fsqstat->qs_uquota,
			&fsqstat->qs_uquota,
			sizeof(compat_fsqstat->qs_uquota)) ||
			get_user(data, &fsqstat->qs_uquota.qfs_nextents) ||
			put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
			break;
		/* Copying qs_gquota */
		if (copy_in_user(&compat_fsqstat->qs_gquota,
			&fsqstat->qs_gquota,
			sizeof(compat_fsqstat->qs_gquota)) ||
			get_user(data, &fsqstat->qs_gquota.qfs_nextents) ||
			put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
			break;
		/* Copying the rest */
		if (copy_in_user(&compat_fsqstat->qs_incoredqs,
			&fsqstat->qs_incoredqs,
			sizeof(struct compat_fs_quota_stat) -
			offsetof(struct compat_fs_quota_stat, qs_incoredqs)) ||
			get_user(xdata, &fsqstat->qs_iwarnlimit) ||
			put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
			break;
		ret = 0;
		break;
	default:
		ret = sys_quotactl(cmd, special, id, addr);
	}
	return ret;
}
#endif


#ifdef CONFIG_QUOTA_NETLINK_INTERFACE

/* Netlink family structure for quota */
static struct genl_family quota_genl_family = {
	.id = GENL_ID_GENERATE,
	.hdrsize = 0,
	.name = "VFS_DQUOT",
	.version = 1,
	.maxattr = QUOTA_NL_A_MAX,
};

/**
 * quota_send_warning - Send warning to userspace about exceeded quota
 * @type: The quota type: USRQQUOTA, GRPQUOTA,...
 * @id: The user or group id of the quota that was exceeded
 * @dev: The device on which the fs is mounted (sb->s_dev)
 * @warntype: The type of the warning: QUOTA_NL_...
 *
 * This can be used by filesystems (including those which don't use
 * dquot) to send a message to userspace relating to quota limits.
 *
 */

void quota_send_warning(short type, unsigned int id, dev_t dev,
			const char warntype)
{
	static atomic_t seq;
	struct sk_buff *skb;
	void *msg_head;
	int ret;
	int msg_size = 4 * nla_total_size(sizeof(u32)) +
		       2 * nla_total_size(sizeof(u64));

	/* We have to allocate using GFP_NOFS as we are called from a
	 * filesystem performing write and thus further recursion into
	 * the fs to free some data could cause deadlocks. */
	skb = genlmsg_new(msg_size, GFP_NOFS);
	if (!skb) {
		printk(KERN_ERR
		  "VFS: Not enough memory to send quota warning.\n");
		return;
	}
	msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
			&quota_genl_family, 0, QUOTA_NL_C_WARNING);
	if (!msg_head) {
		printk(KERN_ERR
		  "VFS: Cannot store netlink header in quota warning.\n");
		goto err_out;
	}
	ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type);
	if (ret)
		goto attr_err_out;
	ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id);
	if (ret)
		goto attr_err_out;
	ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
	if (ret)
		goto attr_err_out;
	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev));
	if (ret)
		goto attr_err_out;
	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
	if (ret)
		goto attr_err_out;
	ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
	if (ret)
		goto attr_err_out;
	genlmsg_end(skb, msg_head);

	genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
	return;
attr_err_out:
	printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
err_out:
	kfree_skb(skb);
}
EXPORT_SYMBOL(quota_send_warning);

static int __init quota_init(void)
{
	if (genl_register_family(&quota_genl_family) != 0)
		printk(KERN_ERR
		       "VFS: Failed to create quota netlink interface.\n");
	return 0;
};

module_init(quota_init);
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Quota code necessary even when VFS quota support is not compiled
	3	* into the kernel. The interesting stuff is over in dquot.c, here
	4	* we have symbols for initial quotactl(2) handling, the sysctl(2)
	5	* variables, etc - things needed even when quota support disabled.
	6	*/
	7
	8	#include <linux/fs.h>
	9	#include <linux/namei.h>
	10	#include <linux/slab.h>
	11	#include <asm/current.h>
	12	#include <asm/uaccess.h>
b716395e	13	#include <linux/compat.h>
1da177e4	14	#include <linux/kernel.h>
1da177e4 LT	15	#include <linux/security.h>
	16	#include <linux/syscalls.h>
	17	#include <linux/buffer_head.h>
16f7e0fe	18	#include <linux/capability.h>
be586bab	19	#include <linux/quotaops.h>
b716395e	20	#include <linux/types.h>
8c4e4acd	21	#include <linux/writeback.h>
86e931a3 SW	22	#include <net/netlink.h>
86e931a3 SW	23	#include <net/genetlink.h>
1da177e4	24
c988afb5 CH	25	static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
c988afb5 CH	26	qid_t id)
1da177e4	27	{
c988afb5 CH	28	switch (cmd) {
	29	/* these commands do not require any special privilegues */
	30	case Q_GETFMT:
	31	case Q_SYNC:
	32	case Q_GETINFO:
	33	case Q_XGETQSTAT:
	34	case Q_XQUOTASYNC:
	35	break;
	36	/* allow to query information for dquots we "own" */
	37	case Q_GETQUOTA:
	38	case Q_XGETQUOTA:
	39	if ((type == USRQUOTA && current_euid() == id) \|\|
	40	(type == GRPQUOTA && in_egroup_p(id)))
	41	break;
	42	/FALLTHROUGH/
	43	default:
1da177e4 LT	44	if (!capable(CAP_SYS_ADMIN))
	45	return -EPERM;
	46	}
	47
c988afb5	48	return security_quotactl(cmd, type, id, sb);
1da177e4 LT	49	}
1da177e4 LT	50
6ae09575	51	static int quota_sync_all(int type)
1da177e4	52	{
850b201b	53	struct super_block *sb;
02a55ca8	54	int cnt;
6ae09575 CH	55	int ret;
	56
	57	if (type >= MAXQUOTAS)
	58	return -EINVAL;
	59	ret = security_quotactl(Q_SYNC, type, 0, NULL);
	60	if (ret)
	61	return ret;
618f0636	62
618f0636 KK	63	spin_lock(&sb_lock);
	64	restart:
	65	list_for_each_entry(sb, &super_blocks, s_list) {
5fb324ad CH	66	if (!sb->s_qcop \|\| !sb->s_qcop->quota_sync)
	67	continue;
	68
268157ba JK	69	/* This test just improves performance so it needn't be
268157ba JK	70	* reliable... */
02a55ca8 JK	71	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
	72	if (type != -1 && type != cnt)
	73	continue;
f55abc0f	74	if (!sb_has_quota_active(sb, cnt))
02a55ca8 JK	75	continue;
02a55ca8 JK	76	if (!info_dirty(&sb_dqopt(sb)->info[cnt]) &&
268157ba	77	list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list))
02a55ca8 JK	78	continue;
	79	break;
	80	}
	81	if (cnt == MAXQUOTAS)
618f0636 KK	82	continue;
	83	sb->s_count++;
	84	spin_unlock(&sb_lock);
	85	down_read(&sb->s_umount);
850b201b	86	if (sb->s_root)
5fb324ad	87	sb->s_qcop->quota_sync(sb, type, 1);
618f0636 KK	88	up_read(&sb->s_umount);
	89	spin_lock(&sb_lock);
	90	if (__put_super_and_need_restart(sb))
	91	goto restart;
1da177e4	92	}
618f0636	93	spin_unlock(&sb_lock);
6ae09575 CH	94
6ae09575 CH	95	return 0;
1da177e4 LT	96	}
1da177e4 LT	97
c411e5f6 CH	98	static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
c411e5f6 CH	99	void __user *addr)
1da177e4	100	{
c411e5f6	101	char *pathname;
f450d4fe	102	int ret = -ENOSYS;
1da177e4	103
c411e5f6 CH	104	pathname = getname(addr);
	105	if (IS_ERR(pathname))
	106	return PTR_ERR(pathname);
f450d4fe CH	107	if (sb->s_qcop->quota_on)
f450d4fe CH	108	ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
c411e5f6 CH	109	putname(pathname);
	110	return ret;
	111	}
1da177e4	112
c411e5f6 CH	113	static int quota_getfmt(struct super_block sb, int type, void __user addr)
	114	{
	115	__u32 fmt;
1da177e4	116
c411e5f6 CH	117	down_read(&sb_dqopt(sb)->dqptr_sem);
	118	if (!sb_has_quota_active(sb, type)) {
	119	up_read(&sb_dqopt(sb)->dqptr_sem);
	120	return -ESRCH;
	121	}
	122	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
	123	up_read(&sb_dqopt(sb)->dqptr_sem);
	124	if (copy_to_user(addr, &fmt, sizeof(fmt)))
	125	return -EFAULT;
	126	return 0;
	127	}
1da177e4	128
c411e5f6 CH	129	static int quota_getinfo(struct super_block sb, int type, void __user addr)
	130	{
	131	struct if_dqinfo info;
	132	int ret;
1da177e4	133
f450d4fe CH	134	if (!sb_has_quota_active(sb, type))
	135	return -ESRCH;
	136	if (!sb->s_qcop->get_info)
	137	return -ENOSYS;
c411e5f6 CH	138	ret = sb->s_qcop->get_info(sb, type, &info);
	139	if (!ret && copy_to_user(addr, &info, sizeof(info)))
	140	return -EFAULT;
	141	return ret;
	142	}
1da177e4	143
c411e5f6 CH	144	static int quota_setinfo(struct super_block sb, int type, void __user addr)
	145	{
	146	struct if_dqinfo info;
1da177e4	147
c411e5f6 CH	148	if (copy_from_user(&info, addr, sizeof(info)))
c411e5f6 CH	149	return -EFAULT;
f450d4fe CH	150	if (!sb_has_quota_active(sb, type))
	151	return -ESRCH;
	152	if (!sb->s_qcop->set_info)
	153	return -ENOSYS;
c411e5f6 CH	154	return sb->s_qcop->set_info(sb, type, &info);
	155	}
	156
	157	static int quota_getquota(struct super_block *sb, int type, qid_t id,
	158	void __user *addr)
	159	{
	160	struct if_dqblk idq;
	161	int ret;
	162
f450d4fe CH	163	if (!sb_has_quota_active(sb, type))
	164	return -ESRCH;
	165	if (!sb->s_qcop->get_dqblk)
	166	return -ENOSYS;
c411e5f6 CH	167	ret = sb->s_qcop->get_dqblk(sb, type, id, &idq);
	168	if (ret)
	169	return ret;
	170	if (copy_to_user(addr, &idq, sizeof(idq)))
	171	return -EFAULT;
	172	return 0;
	173	}
	174
	175	static int quota_setquota(struct super_block *sb, int type, qid_t id,
	176	void __user *addr)
	177	{
	178	struct if_dqblk idq;
	179
	180	if (copy_from_user(&idq, addr, sizeof(idq)))
	181	return -EFAULT;
f450d4fe CH	182	if (!sb_has_quota_active(sb, type))
	183	return -ESRCH;
	184	if (!sb->s_qcop->set_dqblk)
	185	return -ENOSYS;
c411e5f6 CH	186	return sb->s_qcop->set_dqblk(sb, type, id, &idq);
	187	}
	188
	189	static int quota_setxstate(struct super_block sb, int cmd, void __user addr)
	190	{
	191	__u32 flags;
	192
	193	if (copy_from_user(&flags, addr, sizeof(flags)))
	194	return -EFAULT;
f450d4fe CH	195	if (!sb->s_qcop->set_xstate)
f450d4fe CH	196	return -ENOSYS;
c411e5f6 CH	197	return sb->s_qcop->set_xstate(sb, flags, cmd);
	198	}
	199
	200	static int quota_getxstate(struct super_block sb, void __user addr)
	201	{
	202	struct fs_quota_stat fqs;
	203	int ret;
f450d4fe CH	204
	205	if (!sb->s_qcop->get_xstate)
	206	return -ENOSYS;
c411e5f6 CH	207	ret = sb->s_qcop->get_xstate(sb, &fqs);
	208	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
	209	return -EFAULT;
	210	return ret;
	211	}
1da177e4	212
c411e5f6 CH	213	static int quota_setxquota(struct super_block *sb, int type, qid_t id,
	214	void __user *addr)
	215	{
	216	struct fs_disk_quota fdq;
	217
	218	if (copy_from_user(&fdq, addr, sizeof(fdq)))
	219	return -EFAULT;
f450d4fe CH	220	if (!sb->s_qcop->set_xquota)
f450d4fe CH	221	return -ENOSYS;
c411e5f6 CH	222	return sb->s_qcop->set_xquota(sb, type, id, &fdq);
	223	}
	224
	225	static int quota_getxquota(struct super_block *sb, int type, qid_t id,
	226	void __user *addr)
	227	{
	228	struct fs_disk_quota fdq;
	229	int ret;
	230
f450d4fe CH	231	if (!sb->s_qcop->get_xquota)
f450d4fe CH	232	return -ENOSYS;
c411e5f6 CH	233	ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
	234	if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
	235	return -EFAULT;
	236	return ret;
	237	}
	238
	239	/* Copy parameters and call proper function */
	240	static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
	241	void __user *addr)
	242	{
c988afb5 CH	243	int ret;
	244
	245	if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
	246	return -EINVAL;
	247	if (!sb->s_qcop)
	248	return -ENOSYS;
	249
	250	ret = check_quotactl_permission(sb, type, cmd, id);
	251	if (ret < 0)
	252	return ret;
	253
c411e5f6 CH	254	switch (cmd) {
	255	case Q_QUOTAON:
	256	return quota_quotaon(sb, type, cmd, id, addr);
	257	case Q_QUOTAOFF:
f450d4fe CH	258	if (!sb->s_qcop->quota_off)
f450d4fe CH	259	return -ENOSYS;
c411e5f6 CH	260	return sb->s_qcop->quota_off(sb, type, 0);
	261	case Q_GETFMT:
	262	return quota_getfmt(sb, type, addr);
	263	case Q_GETINFO:
	264	return quota_getinfo(sb, type, addr);
	265	case Q_SETINFO:
	266	return quota_setinfo(sb, type, addr);
	267	case Q_GETQUOTA:
	268	return quota_getquota(sb, type, id, addr);
	269	case Q_SETQUOTA:
	270	return quota_setquota(sb, type, id, addr);
	271	case Q_SYNC:
6ae09575 CH	272	if (!sb->s_qcop->quota_sync)
6ae09575 CH	273	return -ENOSYS;
5fb324ad	274	return sb->s_qcop->quota_sync(sb, type, 1);
c411e5f6 CH	275	case Q_XQUOTAON:
	276	case Q_XQUOTAOFF:
	277	case Q_XQUOTARM:
	278	return quota_setxstate(sb, cmd, addr);
	279	case Q_XGETQSTAT:
	280	return quota_getxstate(sb, addr);
	281	case Q_XSETQLIM:
	282	return quota_setxquota(sb, type, id, addr);
	283	case Q_XGETQUOTA:
	284	return quota_getxquota(sb, type, id, addr);
	285	case Q_XQUOTASYNC:
8c4e4acd CH	286	/* caller already holds s_umount */
	287	if (sb->s_flags & MS_RDONLY)
	288	return -EROFS;
	289	writeback_inodes_sb(sb);
	290	return 0;
c411e5f6	291	default:
f450d4fe	292	return -EINVAL;
1da177e4	293	}
1da177e4 LT	294	}
1da177e4 LT	295
9361401e DH	296	/*
	297	* look up a superblock on which quota ops will be performed
	298	* - use the name of a block device to find the superblock thereon
	299	*/
7a2435d8	300	static struct super_block quotactl_block(const char __user special)
9361401e DH	301	{
	302	#ifdef CONFIG_BLOCK
	303	struct block_device *bdev;
	304	struct super_block *sb;
	305	char *tmp = getname(special);
	306
	307	if (IS_ERR(tmp))
e231c2ee	308	return ERR_CAST(tmp);
9361401e DH	309	bdev = lookup_bdev(tmp);
	310	putname(tmp);
	311	if (IS_ERR(bdev))
e231c2ee	312	return ERR_CAST(bdev);
9361401e DH	313	sb = get_super(bdev);
	314	bdput(bdev);
	315	if (!sb)
	316	return ERR_PTR(-ENODEV);
	317
	318	return sb;
	319	#else
	320	return ERR_PTR(-ENODEV);
	321	#endif
	322	}
	323
1da177e4 LT	324	/*
	325	* This is the system call interface. This communicates with
	326	* the user-level programs. Currently this only supports diskquota
	327	* calls. Maybe we need to add the process quotas etc. in the future,
	328	* but we probably should use rlimits for that.
	329	*/
3cdad428 HC	330	SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
3cdad428 HC	331	qid_t, id, void __user *, addr)
1da177e4 LT	332	{
	333	uint cmds, type;
	334	struct super_block *sb = NULL;
1da177e4 LT	335	int ret;
	336
	337	cmds = cmd >> SUBCMDSHIFT;
	338	type = cmd & SUBCMDMASK;
	339
6ae09575 CH	340	/*
	341	* As a special case Q_SYNC can be called without a specific device.
	342	* It will iterate all superblocks that have quota enabled and call
	343	* the sync action on each of them.
	344	*/
	345	if (!special) {
	346	if (cmds == Q_SYNC)
	347	return quota_sync_all(type);
	348	return -ENODEV;
1da177e4 LT	349	}
1da177e4 LT	350
6ae09575 CH	351	sb = quotactl_block(special);
	352	if (IS_ERR(sb))
	353	return PTR_ERR(sb);
	354
c988afb5	355	ret = do_quotactl(sb, type, cmds, id, addr);
1da177e4	356
6ae09575	357	drop_super(sb);
1da177e4 LT	358	return ret;
1da177e4 LT	359	}
b716395e	360
7a6c8135	361	#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
b716395e VT	362	/*
	363	* This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
	364	* and is necessary due to alignment problems.
	365	*/
	366	struct compat_if_dqblk {
	367	compat_u64 dqb_bhardlimit;
	368	compat_u64 dqb_bsoftlimit;
	369	compat_u64 dqb_curspace;
	370	compat_u64 dqb_ihardlimit;
	371	compat_u64 dqb_isoftlimit;
	372	compat_u64 dqb_curinodes;
	373	compat_u64 dqb_btime;
	374	compat_u64 dqb_itime;
	375	compat_uint_t dqb_valid;
	376	};
	377
	378	/* XFS structures */
	379	struct compat_fs_qfilestat {
	380	compat_u64 dqb_bhardlimit;
	381	compat_u64 qfs_nblks;
	382	compat_uint_t qfs_nextents;
	383	};
	384
	385	struct compat_fs_quota_stat {
	386	__s8 qs_version;
	387	__u16 qs_flags;
	388	__s8 qs_pad;
	389	struct compat_fs_qfilestat qs_uquota;
	390	struct compat_fs_qfilestat qs_gquota;
	391	compat_uint_t qs_incoredqs;
	392	compat_int_t qs_btimelimit;
	393	compat_int_t qs_itimelimit;
	394	compat_int_t qs_rtbtimelimit;
	395	__u16 qs_bwarnlimit;
	396	__u16 qs_iwarnlimit;
	397	};
	398
	399	asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
	400	qid_t id, void __user *addr)
	401	{
	402	unsigned int cmds;
	403	struct if_dqblk __user *dqblk;
	404	struct compat_if_dqblk __user *compat_dqblk;
	405	struct fs_quota_stat __user *fsqstat;
	406	struct compat_fs_quota_stat __user *compat_fsqstat;
	407	compat_uint_t data;
	408	u16 xdata;
	409	long ret;
	410
	411	cmds = cmd >> SUBCMDSHIFT;
	412
	413	switch (cmds) {
	414	case Q_GETQUOTA:
	415	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
	416	compat_dqblk = addr;
	417	ret = sys_quotactl(cmd, special, id, dqblk);
	418	if (ret)
	419	break;
	420	if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) \|\|
	421	get_user(data, &dqblk->dqb_valid) \|\|
	422	put_user(data, &compat_dqblk->dqb_valid))
	423	ret = -EFAULT;
	424	break;
	425	case Q_SETQUOTA:
426	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
427	compat_dqblk = addr;
428	ret = -EFAULT;
429	if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) \|\|
430	get_user(data, &compat_dqblk->dqb_valid) \|\|
431	put_user(data, &dqblk->dqb_valid))
432	break;
433	ret = sys_quotactl(cmd, special, id, dqblk);
434	break;
435	case Q_XGETQSTAT:
436	fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
437	compat_fsqstat = addr;
438	ret = sys_quotactl(cmd, special, id, fsqstat);
439	if (ret)
440	break;
441	ret = -EFAULT;
442	/* Copying qs_version, qs_flags, qs_pad */
443	if (copy_in_user(compat_fsqstat, fsqstat,
444	offsetof(struct compat_fs_quota_stat, qs_uquota)))
445	break;
446	/* Copying qs_uquota */
447	if (copy_in_user(&compat_fsqstat->qs_uquota,
448	&fsqstat->qs_uquota,
449	sizeof(compat_fsqstat->qs_uquota)) \|\|
450	get_user(data, &fsqstat->qs_uquota.qfs_nextents) \|\|
451	put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
452	break;
453	/* Copying qs_gquota */
454	if (copy_in_user(&compat_fsqstat->qs_gquota,
455	&fsqstat->qs_gquota,
456	sizeof(compat_fsqstat->qs_gquota)) \|\|
457	get_user(data, &fsqstat->qs_gquota.qfs_nextents) \|\|
458	put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
459	break;
460	/* Copying the rest */
461	if (copy_in_user(&compat_fsqstat->qs_incoredqs,
462	&fsqstat->qs_incoredqs,
463	sizeof(struct compat_fs_quota_stat) -
464	offsetof(struct compat_fs_quota_stat, qs_incoredqs)) \|\|
465	get_user(xdata, &fsqstat->qs_iwarnlimit) \|\|
466	put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
467	break;
468	ret = 0;
469	break;
470	default:
471	ret = sys_quotactl(cmd, special, id, addr);
472	}
473	return ret;
474	}
475	#endif
86e931a3 SW	476
	477
	478	#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
	479
	480	/* Netlink family structure for quota */
	481	static struct genl_family quota_genl_family = {
	482	.id = GENL_ID_GENERATE,
	483	.hdrsize = 0,
	484	.name = "VFS_DQUOT",
	485	.version = 1,
	486	.maxattr = QUOTA_NL_A_MAX,
	487	};
	488
	489	/**
	490	* quota_send_warning - Send warning to userspace about exceeded quota
	491	* @type: The quota type: USRQQUOTA, GRPQUOTA,...
	492	* @id: The user or group id of the quota that was exceeded
	493	* @dev: The device on which the fs is mounted (sb->s_dev)
	494	* @warntype: The type of the warning: QUOTA_NL_...
	495	*
	496	* This can be used by filesystems (including those which don't use
	497	* dquot) to send a message to userspace relating to quota limits.
	498	*
	499	*/
	500
	501	void quota_send_warning(short type, unsigned int id, dev_t dev,
	502	const char warntype)
	503	{
	504	static atomic_t seq;
	505	struct sk_buff *skb;
	506	void *msg_head;
	507	int ret;
	508	int msg_size = 4 * nla_total_size(sizeof(u32)) +
	509	2 * nla_total_size(sizeof(u64));
	510
	511	/* We have to allocate using GFP_NOFS as we are called from a
	512	* filesystem performing write and thus further recursion into
	513	* the fs to free some data could cause deadlocks. */
	514	skb = genlmsg_new(msg_size, GFP_NOFS);
	515	if (!skb) {
	516	printk(KERN_ERR
	517	"VFS: Not enough memory to send quota warning.\n");
	518	return;
	519	}
	520	msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
	521	&quota_genl_family, 0, QUOTA_NL_C_WARNING);
	522	if (!msg_head) {
	523	printk(KERN_ERR
	524	"VFS: Cannot store netlink header in quota warning.\n");
	525	goto err_out;
	526	}
	527	ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type);
	528	if (ret)
	529	goto attr_err_out;
	530	ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id);
	531	if (ret)
	532	goto attr_err_out;
	533	ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
	534	if (ret)
	535	goto attr_err_out;
	536	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev));
	537	if (ret)
	538	goto attr_err_out;
	539	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
540	if (ret)
541	goto attr_err_out;
542	ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
543	if (ret)
544	goto attr_err_out;
545	genlmsg_end(skb, msg_head);
546
547	genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
548	return;
549	attr_err_out:
550	printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
551	err_out:
552	kfree_skb(skb);
553	}
554	EXPORT_SYMBOL(quota_send_warning);
555
556	static int __init quota_init(void)
557	{
558	if (genl_register_family(&quota_genl_family) != 0)
559	printk(KERN_ERR
560	"VFS: Failed to create quota netlink interface.\n");
561	return 0;
562	};
563
564	module_init(quota_init);
565	#endif
566