[mirror_ubuntu-hirsute-kernel.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 <net/netlink.h>
#include <net/genetlink.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;

	/* 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;

	/* 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;
}

#ifdef CONFIG_QUOTA
void sync_quota_sb(struct super_block *sb, int type)
{
	int cnt;

	if (!sb->s_qcop->quota_sync)
		return;

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

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

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

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) {
		/* 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)
			sync_quota_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);

	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)
{
	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;
		sync_quota_sb(sb, type);
		return 0;
	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:
		if (!sb->s_qcop->quota_sync)
			return -ENOSYS;
		return sb->s_qcop->quota_sync(sb, type);
	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 = check_quotactl_valid(sb, type, cmds, id);
	if (ret >= 0)
		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>
86e931a3 SW	21	#include <net/netlink.h>
86e931a3 SW	22	#include <net/genetlink.h>
1da177e4 LT	23
1da177e4 LT	24	/* Check validity of generic quotactl commands */
268157ba JK	25	static int generic_quotactl_valid(struct super_block *sb, int type, int cmd,
268157ba JK	26	qid_t id)
1da177e4 LT	27	{
	28	if (type >= MAXQUOTAS)
	29	return -EINVAL;
	30	if (!sb && cmd != Q_SYNC)
	31	return -ENODEV;
	32	/* Is operation supported? */
	33	if (sb && !sb->s_qcop)
	34	return -ENOSYS;
	35
1da177e4 LT	36	/* Check privileges */
1da177e4 LT	37	if (cmd == Q_GETQUOTA) {
da9592ed	38	if (((type == USRQUOTA && current_euid() != id) \|\|
1da177e4 LT	39	(type == GRPQUOTA && !in_egroup_p(id))) &&
	40	!capable(CAP_SYS_ADMIN))
	41	return -EPERM;
	42	}
	43	else if (cmd != Q_GETFMT && cmd != Q_SYNC && cmd != Q_GETINFO)
	44	if (!capable(CAP_SYS_ADMIN))
	45	return -EPERM;
	46
	47	return 0;
	48	}
	49
	50	/* Check validity of XFS Quota Manager commands */
268157ba JK	51	static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd,
268157ba JK	52	qid_t id)
1da177e4 LT	53	{
	54	if (type >= XQM_MAXQUOTAS)
	55	return -EINVAL;
	56	if (!sb)
	57	return -ENODEV;
	58	if (!sb->s_qcop)
	59	return -ENOSYS;
	60
1da177e4 LT	61	/* Check privileges */
1da177e4 LT	62	if (cmd == Q_XGETQUOTA) {
da9592ed	63	if (((type == XQM_USRQUOTA && current_euid() != id) \|\|
1da177e4 LT	64	(type == XQM_GRPQUOTA && !in_egroup_p(id))) &&
	65	!capable(CAP_SYS_ADMIN))
	66	return -EPERM;
de69e5f4	67	} else if (cmd != Q_XGETQSTAT && cmd != Q_XQUOTASYNC) {
1da177e4 LT	68	if (!capable(CAP_SYS_ADMIN))
	69	return -EPERM;
	70	}
	71
	72	return 0;
	73	}
	74
268157ba JK	75	static int check_quotactl_valid(struct super_block *sb, int type, int cmd,
268157ba JK	76	qid_t id)
1da177e4 LT	77	{
	78	int error;
	79
	80	if (XQM_COMMAND(cmd))
	81	error = xqm_quotactl_valid(sb, type, cmd, id);
	82	else
	83	error = generic_quotactl_valid(sb, type, cmd, id);
	84	if (!error)
	85	error = security_quotactl(cmd, type, id, sb);
	86	return error;
	87	}
	88
850b201b CH	89	#ifdef CONFIG_QUOTA
850b201b CH	90	void sync_quota_sb(struct super_block *sb, int type)
1da177e4 LT	91	{
1da177e4 LT	92	int cnt;
1da177e4	93
850b201b CH	94	if (!sb->s_qcop->quota_sync)
	95	return;
	96
1da177e4	97	sb->s_qcop->quota_sync(sb, type);
ca785ec6 JK	98
	99	if (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)
	100	return;
1da177e4 LT	101	/* This is not very clever (and fast) but currently I don't know about
	102	* any other simple way of getting quota data to disk and we must get
	103	* them there for userspace to be visible... */
	104	if (sb->s_op->sync_fs)
	105	sb->s_op->sync_fs(sb, 1);
	106	sync_blockdev(sb->s_bdev);
	107
7925409e JK	108	/*
	109	* Now when everything is written we can discard the pagecache so
	110	* that userspace sees the changes.
	111	*/
d3be915f	112	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
1da177e4	113	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1da177e4 LT	114	if (type != -1 && cnt != type)
1da177e4 LT	115	continue;
f55abc0f	116	if (!sb_has_quota_active(sb, cnt))
1da177e4	117	continue;
268157ba JK	118	mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex,
268157ba JK	119	I_MUTEX_QUOTA);
7925409e JK	120	truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
7925409e JK	121	mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
1da177e4	122	}
d3be915f	123	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1da177e4	124	}
850b201b	125	#endif
1da177e4	126
6ae09575	127	static int quota_sync_all(int type)
1da177e4	128	{
850b201b	129	struct super_block *sb;
02a55ca8	130	int cnt;
6ae09575 CH	131	int ret;
	132
	133	if (type >= MAXQUOTAS)
	134	return -EINVAL;
	135	ret = security_quotactl(Q_SYNC, type, 0, NULL);
	136	if (ret)
	137	return ret;
618f0636	138
618f0636 KK	139	spin_lock(&sb_lock);
	140	restart:
	141	list_for_each_entry(sb, &super_blocks, s_list) {
268157ba JK	142	/* This test just improves performance so it needn't be
268157ba JK	143	* reliable... */
02a55ca8 JK	144	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
	145	if (type != -1 && type != cnt)
	146	continue;
f55abc0f	147	if (!sb_has_quota_active(sb, cnt))
02a55ca8 JK	148	continue;
02a55ca8 JK	149	if (!info_dirty(&sb_dqopt(sb)->info[cnt]) &&
268157ba	150	list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list))
02a55ca8 JK	151	continue;
	152	break;
	153	}
	154	if (cnt == MAXQUOTAS)
618f0636 KK	155	continue;
	156	sb->s_count++;
	157	spin_unlock(&sb_lock);
	158	down_read(&sb->s_umount);
850b201b CH	159	if (sb->s_root)
850b201b CH	160	sync_quota_sb(sb, type);
618f0636 KK	161	up_read(&sb->s_umount);
	162	spin_lock(&sb_lock);
	163	if (__put_super_and_need_restart(sb))
	164	goto restart;
1da177e4	165	}
618f0636	166	spin_unlock(&sb_lock);
6ae09575 CH	167
6ae09575 CH	168	return 0;
1da177e4 LT	169	}
1da177e4 LT	170
c411e5f6 CH	171	static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
c411e5f6 CH	172	void __user *addr)
1da177e4	173	{
c411e5f6	174	char *pathname;
f450d4fe	175	int ret = -ENOSYS;
1da177e4	176
c411e5f6 CH	177	pathname = getname(addr);
	178	if (IS_ERR(pathname))
	179	return PTR_ERR(pathname);
f450d4fe CH	180	if (sb->s_qcop->quota_on)
f450d4fe CH	181	ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
c411e5f6 CH	182	putname(pathname);
	183	return ret;
	184	}
1da177e4	185
c411e5f6 CH	186	static int quota_getfmt(struct super_block sb, int type, void __user addr)
	187	{
	188	__u32 fmt;
1da177e4	189
c411e5f6 CH	190	down_read(&sb_dqopt(sb)->dqptr_sem);
	191	if (!sb_has_quota_active(sb, type)) {
	192	up_read(&sb_dqopt(sb)->dqptr_sem);
	193	return -ESRCH;
	194	}
	195	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
	196	up_read(&sb_dqopt(sb)->dqptr_sem);
	197	if (copy_to_user(addr, &fmt, sizeof(fmt)))
	198	return -EFAULT;
	199	return 0;
	200	}
1da177e4	201
c411e5f6 CH	202	static int quota_getinfo(struct super_block sb, int type, void __user addr)
	203	{
	204	struct if_dqinfo info;
	205	int ret;
1da177e4	206
f450d4fe CH	207	if (!sb_has_quota_active(sb, type))
	208	return -ESRCH;
	209	if (!sb->s_qcop->get_info)
	210	return -ENOSYS;
c411e5f6 CH	211	ret = sb->s_qcop->get_info(sb, type, &info);
	212	if (!ret && copy_to_user(addr, &info, sizeof(info)))
	213	return -EFAULT;
	214	return ret;
	215	}
1da177e4	216
c411e5f6 CH	217	static int quota_setinfo(struct super_block sb, int type, void __user addr)
	218	{
	219	struct if_dqinfo info;
1da177e4	220
c411e5f6 CH	221	if (copy_from_user(&info, addr, sizeof(info)))
c411e5f6 CH	222	return -EFAULT;
f450d4fe CH	223	if (!sb_has_quota_active(sb, type))
	224	return -ESRCH;
	225	if (!sb->s_qcop->set_info)
	226	return -ENOSYS;
c411e5f6 CH	227	return sb->s_qcop->set_info(sb, type, &info);
	228	}
	229
	230	static int quota_getquota(struct super_block *sb, int type, qid_t id,
	231	void __user *addr)
	232	{
	233	struct if_dqblk idq;
	234	int ret;
	235
f450d4fe CH	236	if (!sb_has_quota_active(sb, type))
	237	return -ESRCH;
	238	if (!sb->s_qcop->get_dqblk)
	239	return -ENOSYS;
c411e5f6 CH	240	ret = sb->s_qcop->get_dqblk(sb, type, id, &idq);
	241	if (ret)
	242	return ret;
	243	if (copy_to_user(addr, &idq, sizeof(idq)))
	244	return -EFAULT;
	245	return 0;
	246	}
	247
	248	static int quota_setquota(struct super_block *sb, int type, qid_t id,
	249	void __user *addr)
	250	{
	251	struct if_dqblk idq;
	252
	253	if (copy_from_user(&idq, addr, sizeof(idq)))
	254	return -EFAULT;
f450d4fe CH	255	if (!sb_has_quota_active(sb, type))
	256	return -ESRCH;
	257	if (!sb->s_qcop->set_dqblk)
	258	return -ENOSYS;
c411e5f6 CH	259	return sb->s_qcop->set_dqblk(sb, type, id, &idq);
	260	}
	261
	262	static int quota_setxstate(struct super_block sb, int cmd, void __user addr)
	263	{
	264	__u32 flags;
	265
	266	if (copy_from_user(&flags, addr, sizeof(flags)))
	267	return -EFAULT;
f450d4fe CH	268	if (!sb->s_qcop->set_xstate)
f450d4fe CH	269	return -ENOSYS;
c411e5f6 CH	270	return sb->s_qcop->set_xstate(sb, flags, cmd);
	271	}
	272
	273	static int quota_getxstate(struct super_block sb, void __user addr)
	274	{
	275	struct fs_quota_stat fqs;
	276	int ret;
f450d4fe CH	277
	278	if (!sb->s_qcop->get_xstate)
	279	return -ENOSYS;
c411e5f6 CH	280	ret = sb->s_qcop->get_xstate(sb, &fqs);
	281	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
	282	return -EFAULT;
	283	return ret;
	284	}
1da177e4	285
c411e5f6 CH	286	static int quota_setxquota(struct super_block *sb, int type, qid_t id,
	287	void __user *addr)
	288	{
	289	struct fs_disk_quota fdq;
	290
	291	if (copy_from_user(&fdq, addr, sizeof(fdq)))
	292	return -EFAULT;
f450d4fe CH	293	if (!sb->s_qcop->set_xquota)
f450d4fe CH	294	return -ENOSYS;
c411e5f6 CH	295	return sb->s_qcop->set_xquota(sb, type, id, &fdq);
	296	}
	297
	298	static int quota_getxquota(struct super_block *sb, int type, qid_t id,
	299	void __user *addr)
	300	{
	301	struct fs_disk_quota fdq;
	302	int ret;
	303
f450d4fe CH	304	if (!sb->s_qcop->get_xquota)
f450d4fe CH	305	return -ENOSYS;
c411e5f6 CH	306	ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
	307	if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
	308	return -EFAULT;
	309	return ret;
	310	}
	311
	312	/* Copy parameters and call proper function */
	313	static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
	314	void __user *addr)
	315	{
	316	switch (cmd) {
	317	case Q_QUOTAON:
	318	return quota_quotaon(sb, type, cmd, id, addr);
	319	case Q_QUOTAOFF:
f450d4fe CH	320	if (!sb->s_qcop->quota_off)
f450d4fe CH	321	return -ENOSYS;
c411e5f6 CH	322	return sb->s_qcop->quota_off(sb, type, 0);
	323	case Q_GETFMT:
	324	return quota_getfmt(sb, type, addr);
	325	case Q_GETINFO:
	326	return quota_getinfo(sb, type, addr);
	327	case Q_SETINFO:
	328	return quota_setinfo(sb, type, addr);
	329	case Q_GETQUOTA:
	330	return quota_getquota(sb, type, id, addr);
	331	case Q_SETQUOTA:
	332	return quota_setquota(sb, type, id, addr);
	333	case Q_SYNC:
6ae09575 CH	334	if (!sb->s_qcop->quota_sync)
	335	return -ENOSYS;
	336	sync_quota_sb(sb, type);
c411e5f6 CH	337	return 0;
	338	case Q_XQUOTAON:
	339	case Q_XQUOTAOFF:
	340	case Q_XQUOTARM:
	341	return quota_setxstate(sb, cmd, addr);
	342	case Q_XGETQSTAT:
	343	return quota_getxstate(sb, addr);
	344	case Q_XSETQLIM:
	345	return quota_setxquota(sb, type, id, addr);
	346	case Q_XGETQUOTA:
	347	return quota_getxquota(sb, type, id, addr);
	348	case Q_XQUOTASYNC:
f450d4fe CH	349	if (!sb->s_qcop->quota_sync)
f450d4fe CH	350	return -ENOSYS;
c411e5f6	351	return sb->s_qcop->quota_sync(sb, type);
c411e5f6	352	default:
f450d4fe	353	return -EINVAL;
1da177e4	354	}
1da177e4 LT	355	}
1da177e4 LT	356
9361401e DH	357	/*
	358	* look up a superblock on which quota ops will be performed
	359	* - use the name of a block device to find the superblock thereon
	360	*/
7a2435d8	361	static struct super_block quotactl_block(const char __user special)
9361401e DH	362	{
	363	#ifdef CONFIG_BLOCK
	364	struct block_device *bdev;
	365	struct super_block *sb;
	366	char *tmp = getname(special);
	367
	368	if (IS_ERR(tmp))
e231c2ee	369	return ERR_CAST(tmp);
9361401e DH	370	bdev = lookup_bdev(tmp);
	371	putname(tmp);
	372	if (IS_ERR(bdev))
e231c2ee	373	return ERR_CAST(bdev);
9361401e DH	374	sb = get_super(bdev);
	375	bdput(bdev);
	376	if (!sb)
	377	return ERR_PTR(-ENODEV);
	378
	379	return sb;
	380	#else
	381	return ERR_PTR(-ENODEV);
	382	#endif
	383	}
	384
1da177e4 LT	385	/*
	386	* This is the system call interface. This communicates with
	387	* the user-level programs. Currently this only supports diskquota
	388	* calls. Maybe we need to add the process quotas etc. in the future,
	389	* but we probably should use rlimits for that.
	390	*/
3cdad428 HC	391	SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
3cdad428 HC	392	qid_t, id, void __user *, addr)
1da177e4 LT	393	{
	394	uint cmds, type;
	395	struct super_block *sb = NULL;
1da177e4 LT	396	int ret;
	397
	398	cmds = cmd >> SUBCMDSHIFT;
	399	type = cmd & SUBCMDMASK;
	400
6ae09575 CH	401	/*
	402	* As a special case Q_SYNC can be called without a specific device.
	403	* It will iterate all superblocks that have quota enabled and call
	404	* the sync action on each of them.
	405	*/
	406	if (!special) {
	407	if (cmds == Q_SYNC)
	408	return quota_sync_all(type);
	409	return -ENODEV;
1da177e4 LT	410	}
1da177e4 LT	411
6ae09575 CH	412	sb = quotactl_block(special);
	413	if (IS_ERR(sb))
	414	return PTR_ERR(sb);
	415
1da177e4 LT	416	ret = check_quotactl_valid(sb, type, cmds, id);
	417	if (ret >= 0)
	418	ret = do_quotactl(sb, type, cmds, id, addr);
1da177e4	419
6ae09575	420	drop_super(sb);
1da177e4 LT	421	return ret;
1da177e4 LT	422	}
b716395e	423
7a6c8135	424	#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
b716395e VT	425	/*
	426	* This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
	427	* and is necessary due to alignment problems.
	428	*/
	429	struct compat_if_dqblk {
	430	compat_u64 dqb_bhardlimit;
	431	compat_u64 dqb_bsoftlimit;
	432	compat_u64 dqb_curspace;
	433	compat_u64 dqb_ihardlimit;
	434	compat_u64 dqb_isoftlimit;
	435	compat_u64 dqb_curinodes;
	436	compat_u64 dqb_btime;
	437	compat_u64 dqb_itime;
	438	compat_uint_t dqb_valid;
	439	};
	440
	441	/* XFS structures */
	442	struct compat_fs_qfilestat {
	443	compat_u64 dqb_bhardlimit;
	444	compat_u64 qfs_nblks;
	445	compat_uint_t qfs_nextents;
	446	};
	447
	448	struct compat_fs_quota_stat {
	449	__s8 qs_version;
	450	__u16 qs_flags;
	451	__s8 qs_pad;
	452	struct compat_fs_qfilestat qs_uquota;
	453	struct compat_fs_qfilestat qs_gquota;
	454	compat_uint_t qs_incoredqs;
	455	compat_int_t qs_btimelimit;
	456	compat_int_t qs_itimelimit;
	457	compat_int_t qs_rtbtimelimit;
	458	__u16 qs_bwarnlimit;
	459	__u16 qs_iwarnlimit;
	460	};
	461
	462	asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
	463	qid_t id, void __user *addr)
	464	{
	465	unsigned int cmds;
	466	struct if_dqblk __user *dqblk;
	467	struct compat_if_dqblk __user *compat_dqblk;
	468	struct fs_quota_stat __user *fsqstat;
	469	struct compat_fs_quota_stat __user *compat_fsqstat;
	470	compat_uint_t data;
	471	u16 xdata;
	472	long ret;
	473
	474	cmds = cmd >> SUBCMDSHIFT;
	475
	476	switch (cmds) {
	477	case Q_GETQUOTA:
	478	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
	479	compat_dqblk = addr;
	480	ret = sys_quotactl(cmd, special, id, dqblk);
	481	if (ret)
	482	break;
	483	if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) \|\|
	484	get_user(data, &dqblk->dqb_valid) \|\|
	485	put_user(data, &compat_dqblk->dqb_valid))
	486	ret = -EFAULT;
	487	break;
	488	case Q_SETQUOTA:
489	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
490	compat_dqblk = addr;
491	ret = -EFAULT;
492	if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) \|\|
493	get_user(data, &compat_dqblk->dqb_valid) \|\|
494	put_user(data, &dqblk->dqb_valid))
495	break;
496	ret = sys_quotactl(cmd, special, id, dqblk);
497	break;
498	case Q_XGETQSTAT:
499	fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
500	compat_fsqstat = addr;
501	ret = sys_quotactl(cmd, special, id, fsqstat);
502	if (ret)
503	break;
504	ret = -EFAULT;
505	/* Copying qs_version, qs_flags, qs_pad */
506	if (copy_in_user(compat_fsqstat, fsqstat,
507	offsetof(struct compat_fs_quota_stat, qs_uquota)))
508	break;
509	/* Copying qs_uquota */
510	if (copy_in_user(&compat_fsqstat->qs_uquota,
511	&fsqstat->qs_uquota,
512	sizeof(compat_fsqstat->qs_uquota)) \|\|
513	get_user(data, &fsqstat->qs_uquota.qfs_nextents) \|\|
514	put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
515	break;
516	/* Copying qs_gquota */
517	if (copy_in_user(&compat_fsqstat->qs_gquota,
518	&fsqstat->qs_gquota,
519	sizeof(compat_fsqstat->qs_gquota)) \|\|
520	get_user(data, &fsqstat->qs_gquota.qfs_nextents) \|\|
521	put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
522	break;
523	/* Copying the rest */
524	if (copy_in_user(&compat_fsqstat->qs_incoredqs,
525	&fsqstat->qs_incoredqs,
526	sizeof(struct compat_fs_quota_stat) -
527	offsetof(struct compat_fs_quota_stat, qs_incoredqs)) \|\|
528	get_user(xdata, &fsqstat->qs_iwarnlimit) \|\|
529	put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
530	break;
531	ret = 0;
532	break;
533	default:
534	ret = sys_quotactl(cmd, special, id, addr);
535	}
536	return ret;
537	}
538	#endif
86e931a3 SW	539
	540
	541	#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
	542
	543	/* Netlink family structure for quota */
	544	static struct genl_family quota_genl_family = {
	545	.id = GENL_ID_GENERATE,
	546	.hdrsize = 0,
	547	.name = "VFS_DQUOT",
	548	.version = 1,
	549	.maxattr = QUOTA_NL_A_MAX,
	550	};
	551
	552	/**
	553	* quota_send_warning - Send warning to userspace about exceeded quota
	554	* @type: The quota type: USRQQUOTA, GRPQUOTA,...
	555	* @id: The user or group id of the quota that was exceeded
	556	* @dev: The device on which the fs is mounted (sb->s_dev)
	557	* @warntype: The type of the warning: QUOTA_NL_...
	558	*
	559	* This can be used by filesystems (including those which don't use
	560	* dquot) to send a message to userspace relating to quota limits.
	561	*
	562	*/
	563
	564	void quota_send_warning(short type, unsigned int id, dev_t dev,
	565	const char warntype)
	566	{
	567	static atomic_t seq;
	568	struct sk_buff *skb;
	569	void *msg_head;
	570	int ret;
	571	int msg_size = 4 * nla_total_size(sizeof(u32)) +
	572	2 * nla_total_size(sizeof(u64));
	573
	574	/* We have to allocate using GFP_NOFS as we are called from a
	575	* filesystem performing write and thus further recursion into
	576	* the fs to free some data could cause deadlocks. */
	577	skb = genlmsg_new(msg_size, GFP_NOFS);
	578	if (!skb) {
	579	printk(KERN_ERR
	580	"VFS: Not enough memory to send quota warning.\n");
	581	return;
	582	}
	583	msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
	584	&quota_genl_family, 0, QUOTA_NL_C_WARNING);
	585	if (!msg_head) {
	586	printk(KERN_ERR
	587	"VFS: Cannot store netlink header in quota warning.\n");
	588	goto err_out;
	589	}
	590	ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type);
	591	if (ret)
	592	goto attr_err_out;
	593	ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id);
	594	if (ret)
	595	goto attr_err_out;
	596	ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
	597	if (ret)
	598	goto attr_err_out;
	599	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev));
	600	if (ret)
	601	goto attr_err_out;
	602	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
603	if (ret)
604	goto attr_err_out;
605	ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
606	if (ret)
607	goto attr_err_out;
608	genlmsg_end(skb, msg_head);
609
610	genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
611	return;
612	attr_err_out:
613	printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
614	err_out:
615	kfree_skb(skb);
616	}
617	EXPORT_SYMBOL(quota_send_warning);
618
619	static int __init quota_init(void)
620	{
621	if (genl_register_family(&quota_genl_family) != 0)
622	printk(KERN_ERR
623	"VFS: Failed to create quota netlink interface.\n");
624	return 0;
625	};
626
627	module_init(quota_init);
628	#endif
629