[GitHub/mt8127/android_kernel_alcatel_ttab.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>

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);
}

#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)
{
	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;
		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 = 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	23
c988afb5 CH	24	static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
c988afb5 CH	25	qid_t id)
1da177e4	26	{
c988afb5 CH	27	switch (cmd) {
	28	/* these commands do not require any special privilegues */
	29	case Q_GETFMT:
	30	case Q_SYNC:
	31	case Q_GETINFO:
	32	case Q_XGETQSTAT:
	33	case Q_XQUOTASYNC:
	34	break;
	35	/* allow to query information for dquots we "own" */
	36	case Q_GETQUOTA:
	37	case Q_XGETQUOTA:
	38	if ((type == USRQUOTA && current_euid() == id) \|\|
	39	(type == GRPQUOTA && in_egroup_p(id)))
	40	break;
	41	/FALLTHROUGH/
	42	default:
1da177e4 LT	43	if (!capable(CAP_SYS_ADMIN))
	44	return -EPERM;
	45	}
	46
c988afb5	47	return security_quotactl(cmd, type, id, sb);
1da177e4 LT	48	}
1da177e4 LT	49
850b201b CH	50	#ifdef CONFIG_QUOTA
850b201b CH	51	void sync_quota_sb(struct super_block *sb, int type)
1da177e4 LT	52	{
1da177e4 LT	53	int cnt;
1da177e4	54
850b201b CH	55	if (!sb->s_qcop->quota_sync)
	56	return;
	57
1da177e4	58	sb->s_qcop->quota_sync(sb, type);
ca785ec6 JK	59
	60	if (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)
	61	return;
1da177e4 LT	62	/* This is not very clever (and fast) but currently I don't know about
	63	* any other simple way of getting quota data to disk and we must get
	64	* them there for userspace to be visible... */
	65	if (sb->s_op->sync_fs)
	66	sb->s_op->sync_fs(sb, 1);
	67	sync_blockdev(sb->s_bdev);
	68
7925409e JK	69	/*
	70	* Now when everything is written we can discard the pagecache so
	71	* that userspace sees the changes.
	72	*/
d3be915f	73	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
1da177e4	74	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1da177e4 LT	75	if (type != -1 && cnt != type)
1da177e4 LT	76	continue;
f55abc0f	77	if (!sb_has_quota_active(sb, cnt))
1da177e4	78	continue;
268157ba JK	79	mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex,
268157ba JK	80	I_MUTEX_QUOTA);
7925409e JK	81	truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
7925409e JK	82	mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
1da177e4	83	}
d3be915f	84	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1da177e4	85	}
850b201b	86	#endif
1da177e4	87
6ae09575	88	static int quota_sync_all(int type)
1da177e4	89	{
850b201b	90	struct super_block *sb;
02a55ca8	91	int cnt;
6ae09575 CH	92	int ret;
	93
	94	if (type >= MAXQUOTAS)
	95	return -EINVAL;
	96	ret = security_quotactl(Q_SYNC, type, 0, NULL);
	97	if (ret)
	98	return ret;
618f0636	99
618f0636 KK	100	spin_lock(&sb_lock);
	101	restart:
	102	list_for_each_entry(sb, &super_blocks, s_list) {
268157ba JK	103	/* This test just improves performance so it needn't be
268157ba JK	104	* reliable... */
02a55ca8 JK	105	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
	106	if (type != -1 && type != cnt)
	107	continue;
f55abc0f	108	if (!sb_has_quota_active(sb, cnt))
02a55ca8 JK	109	continue;
02a55ca8 JK	110	if (!info_dirty(&sb_dqopt(sb)->info[cnt]) &&
268157ba	111	list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list))
02a55ca8 JK	112	continue;
	113	break;
	114	}
	115	if (cnt == MAXQUOTAS)
618f0636 KK	116	continue;
	117	sb->s_count++;
	118	spin_unlock(&sb_lock);
	119	down_read(&sb->s_umount);
850b201b CH	120	if (sb->s_root)
850b201b CH	121	sync_quota_sb(sb, type);
618f0636 KK	122	up_read(&sb->s_umount);
	123	spin_lock(&sb_lock);
	124	if (__put_super_and_need_restart(sb))
	125	goto restart;
1da177e4	126	}
618f0636	127	spin_unlock(&sb_lock);
6ae09575 CH	128
6ae09575 CH	129	return 0;
1da177e4 LT	130	}
1da177e4 LT	131
c411e5f6 CH	132	static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
c411e5f6 CH	133	void __user *addr)
1da177e4	134	{
c411e5f6	135	char *pathname;
f450d4fe	136	int ret = -ENOSYS;
1da177e4	137
c411e5f6 CH	138	pathname = getname(addr);
	139	if (IS_ERR(pathname))
	140	return PTR_ERR(pathname);
f450d4fe CH	141	if (sb->s_qcop->quota_on)
f450d4fe CH	142	ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
c411e5f6 CH	143	putname(pathname);
	144	return ret;
	145	}
1da177e4	146
c411e5f6 CH	147	static int quota_getfmt(struct super_block sb, int type, void __user addr)
	148	{
	149	__u32 fmt;
1da177e4	150
c411e5f6 CH	151	down_read(&sb_dqopt(sb)->dqptr_sem);
	152	if (!sb_has_quota_active(sb, type)) {
	153	up_read(&sb_dqopt(sb)->dqptr_sem);
	154	return -ESRCH;
	155	}
	156	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
	157	up_read(&sb_dqopt(sb)->dqptr_sem);
	158	if (copy_to_user(addr, &fmt, sizeof(fmt)))
	159	return -EFAULT;
	160	return 0;
	161	}
1da177e4	162
c411e5f6 CH	163	static int quota_getinfo(struct super_block sb, int type, void __user addr)
	164	{
	165	struct if_dqinfo info;
	166	int ret;
1da177e4	167
f450d4fe CH	168	if (!sb_has_quota_active(sb, type))
	169	return -ESRCH;
	170	if (!sb->s_qcop->get_info)
	171	return -ENOSYS;
c411e5f6 CH	172	ret = sb->s_qcop->get_info(sb, type, &info);
	173	if (!ret && copy_to_user(addr, &info, sizeof(info)))
	174	return -EFAULT;
	175	return ret;
	176	}
1da177e4	177
c411e5f6 CH	178	static int quota_setinfo(struct super_block sb, int type, void __user addr)
	179	{
	180	struct if_dqinfo info;
1da177e4	181
c411e5f6 CH	182	if (copy_from_user(&info, addr, sizeof(info)))
c411e5f6 CH	183	return -EFAULT;
f450d4fe CH	184	if (!sb_has_quota_active(sb, type))
	185	return -ESRCH;
	186	if (!sb->s_qcop->set_info)
	187	return -ENOSYS;
c411e5f6 CH	188	return sb->s_qcop->set_info(sb, type, &info);
	189	}
	190
	191	static int quota_getquota(struct super_block *sb, int type, qid_t id,
	192	void __user *addr)
	193	{
	194	struct if_dqblk idq;
	195	int ret;
	196
f450d4fe CH	197	if (!sb_has_quota_active(sb, type))
	198	return -ESRCH;
	199	if (!sb->s_qcop->get_dqblk)
	200	return -ENOSYS;
c411e5f6 CH	201	ret = sb->s_qcop->get_dqblk(sb, type, id, &idq);
	202	if (ret)
	203	return ret;
	204	if (copy_to_user(addr, &idq, sizeof(idq)))
	205	return -EFAULT;
	206	return 0;
	207	}
	208
	209	static int quota_setquota(struct super_block *sb, int type, qid_t id,
	210	void __user *addr)
	211	{
	212	struct if_dqblk idq;
	213
	214	if (copy_from_user(&idq, addr, sizeof(idq)))
	215	return -EFAULT;
f450d4fe CH	216	if (!sb_has_quota_active(sb, type))
	217	return -ESRCH;
	218	if (!sb->s_qcop->set_dqblk)
	219	return -ENOSYS;
c411e5f6 CH	220	return sb->s_qcop->set_dqblk(sb, type, id, &idq);
	221	}
	222
	223	static int quota_setxstate(struct super_block sb, int cmd, void __user addr)
	224	{
	225	__u32 flags;
	226
	227	if (copy_from_user(&flags, addr, sizeof(flags)))
	228	return -EFAULT;
f450d4fe CH	229	if (!sb->s_qcop->set_xstate)
f450d4fe CH	230	return -ENOSYS;
c411e5f6 CH	231	return sb->s_qcop->set_xstate(sb, flags, cmd);
	232	}
	233
	234	static int quota_getxstate(struct super_block sb, void __user addr)
	235	{
	236	struct fs_quota_stat fqs;
	237	int ret;
f450d4fe CH	238
	239	if (!sb->s_qcop->get_xstate)
	240	return -ENOSYS;
c411e5f6 CH	241	ret = sb->s_qcop->get_xstate(sb, &fqs);
	242	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
	243	return -EFAULT;
	244	return ret;
	245	}
1da177e4	246
c411e5f6 CH	247	static int quota_setxquota(struct super_block *sb, int type, qid_t id,
	248	void __user *addr)
	249	{
	250	struct fs_disk_quota fdq;
	251
	252	if (copy_from_user(&fdq, addr, sizeof(fdq)))
	253	return -EFAULT;
f450d4fe CH	254	if (!sb->s_qcop->set_xquota)
f450d4fe CH	255	return -ENOSYS;
c411e5f6 CH	256	return sb->s_qcop->set_xquota(sb, type, id, &fdq);
	257	}
	258
	259	static int quota_getxquota(struct super_block *sb, int type, qid_t id,
	260	void __user *addr)
	261	{
	262	struct fs_disk_quota fdq;
	263	int ret;
	264
f450d4fe CH	265	if (!sb->s_qcop->get_xquota)
f450d4fe CH	266	return -ENOSYS;
c411e5f6 CH	267	ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
	268	if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
	269	return -EFAULT;
	270	return ret;
	271	}
	272
	273	/* Copy parameters and call proper function */
	274	static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
	275	void __user *addr)
	276	{
c988afb5 CH	277	int ret;
	278
	279	if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
	280	return -EINVAL;
	281	if (!sb->s_qcop)
	282	return -ENOSYS;
	283
	284	ret = check_quotactl_permission(sb, type, cmd, id);
	285	if (ret < 0)
	286	return ret;
	287
c411e5f6 CH	288	switch (cmd) {
	289	case Q_QUOTAON:
	290	return quota_quotaon(sb, type, cmd, id, addr);
	291	case Q_QUOTAOFF:
f450d4fe CH	292	if (!sb->s_qcop->quota_off)
f450d4fe CH	293	return -ENOSYS;
c411e5f6 CH	294	return sb->s_qcop->quota_off(sb, type, 0);
	295	case Q_GETFMT:
	296	return quota_getfmt(sb, type, addr);
	297	case Q_GETINFO:
	298	return quota_getinfo(sb, type, addr);
	299	case Q_SETINFO:
	300	return quota_setinfo(sb, type, addr);
	301	case Q_GETQUOTA:
	302	return quota_getquota(sb, type, id, addr);
	303	case Q_SETQUOTA:
	304	return quota_setquota(sb, type, id, addr);
	305	case Q_SYNC:
6ae09575 CH	306	if (!sb->s_qcop->quota_sync)
	307	return -ENOSYS;
	308	sync_quota_sb(sb, type);
c411e5f6 CH	309	return 0;
	310	case Q_XQUOTAON:
	311	case Q_XQUOTAOFF:
	312	case Q_XQUOTARM:
	313	return quota_setxstate(sb, cmd, addr);
	314	case Q_XGETQSTAT:
	315	return quota_getxstate(sb, addr);
	316	case Q_XSETQLIM:
	317	return quota_setxquota(sb, type, id, addr);
	318	case Q_XGETQUOTA:
	319	return quota_getxquota(sb, type, id, addr);
	320	case Q_XQUOTASYNC:
f450d4fe CH	321	if (!sb->s_qcop->quota_sync)
f450d4fe CH	322	return -ENOSYS;
c411e5f6	323	return sb->s_qcop->quota_sync(sb, type);
c411e5f6	324	default:
f450d4fe	325	return -EINVAL;
1da177e4	326	}
1da177e4 LT	327	}
1da177e4 LT	328
9361401e DH	329	/*
	330	* look up a superblock on which quota ops will be performed
	331	* - use the name of a block device to find the superblock thereon
	332	*/
7a2435d8	333	static struct super_block quotactl_block(const char __user special)
9361401e DH	334	{
	335	#ifdef CONFIG_BLOCK
	336	struct block_device *bdev;
	337	struct super_block *sb;
	338	char *tmp = getname(special);
	339
	340	if (IS_ERR(tmp))
e231c2ee	341	return ERR_CAST(tmp);
9361401e DH	342	bdev = lookup_bdev(tmp);
	343	putname(tmp);
	344	if (IS_ERR(bdev))
e231c2ee	345	return ERR_CAST(bdev);
9361401e DH	346	sb = get_super(bdev);
	347	bdput(bdev);
	348	if (!sb)
	349	return ERR_PTR(-ENODEV);
	350
	351	return sb;
	352	#else
	353	return ERR_PTR(-ENODEV);
	354	#endif
	355	}
	356
1da177e4 LT	357	/*
	358	* This is the system call interface. This communicates with
	359	* the user-level programs. Currently this only supports diskquota
	360	* calls. Maybe we need to add the process quotas etc. in the future,
	361	* but we probably should use rlimits for that.
	362	*/
3cdad428 HC	363	SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
3cdad428 HC	364	qid_t, id, void __user *, addr)
1da177e4 LT	365	{
	366	uint cmds, type;
	367	struct super_block *sb = NULL;
1da177e4 LT	368	int ret;
	369
	370	cmds = cmd >> SUBCMDSHIFT;
	371	type = cmd & SUBCMDMASK;
	372
6ae09575 CH	373	/*
	374	* As a special case Q_SYNC can be called without a specific device.
	375	* It will iterate all superblocks that have quota enabled and call
	376	* the sync action on each of them.
	377	*/
	378	if (!special) {
	379	if (cmds == Q_SYNC)
	380	return quota_sync_all(type);
	381	return -ENODEV;
1da177e4 LT	382	}
1da177e4 LT	383
6ae09575 CH	384	sb = quotactl_block(special);
	385	if (IS_ERR(sb))
	386	return PTR_ERR(sb);
	387
c988afb5	388	ret = do_quotactl(sb, type, cmds, id, addr);
1da177e4	389
6ae09575	390	drop_super(sb);
1da177e4 LT	391	return ret;
1da177e4 LT	392	}
b716395e	393
7a6c8135	394	#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
b716395e VT	395	/*
	396	* This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
	397	* and is necessary due to alignment problems.
	398	*/
	399	struct compat_if_dqblk {
	400	compat_u64 dqb_bhardlimit;
	401	compat_u64 dqb_bsoftlimit;
	402	compat_u64 dqb_curspace;
	403	compat_u64 dqb_ihardlimit;
	404	compat_u64 dqb_isoftlimit;
	405	compat_u64 dqb_curinodes;
	406	compat_u64 dqb_btime;
	407	compat_u64 dqb_itime;
	408	compat_uint_t dqb_valid;
	409	};
	410
	411	/* XFS structures */
	412	struct compat_fs_qfilestat {
	413	compat_u64 dqb_bhardlimit;
	414	compat_u64 qfs_nblks;
	415	compat_uint_t qfs_nextents;
	416	};
	417
	418	struct compat_fs_quota_stat {
	419	__s8 qs_version;
	420	__u16 qs_flags;
	421	__s8 qs_pad;
	422	struct compat_fs_qfilestat qs_uquota;
	423	struct compat_fs_qfilestat qs_gquota;
	424	compat_uint_t qs_incoredqs;
	425	compat_int_t qs_btimelimit;
	426	compat_int_t qs_itimelimit;
	427	compat_int_t qs_rtbtimelimit;
	428	__u16 qs_bwarnlimit;
	429	__u16 qs_iwarnlimit;
	430	};
	431
	432	asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
	433	qid_t id, void __user *addr)
	434	{
	435	unsigned int cmds;
	436	struct if_dqblk __user *dqblk;
	437	struct compat_if_dqblk __user *compat_dqblk;
	438	struct fs_quota_stat __user *fsqstat;
	439	struct compat_fs_quota_stat __user *compat_fsqstat;
	440	compat_uint_t data;
	441	u16 xdata;
	442	long ret;
	443
	444	cmds = cmd >> SUBCMDSHIFT;
	445
	446	switch (cmds) {
	447	case Q_GETQUOTA:
	448	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
	449	compat_dqblk = addr;
	450	ret = sys_quotactl(cmd, special, id, dqblk);
	451	if (ret)
	452	break;
	453	if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) \|\|
	454	get_user(data, &dqblk->dqb_valid) \|\|
	455	put_user(data, &compat_dqblk->dqb_valid))
	456	ret = -EFAULT;
	457	break;
	458	case Q_SETQUOTA:
459	dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
460	compat_dqblk = addr;
461	ret = -EFAULT;
462	if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) \|\|
463	get_user(data, &compat_dqblk->dqb_valid) \|\|
464	put_user(data, &dqblk->dqb_valid))
465	break;
466	ret = sys_quotactl(cmd, special, id, dqblk);
467	break;
468	case Q_XGETQSTAT:
469	fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
470	compat_fsqstat = addr;
471	ret = sys_quotactl(cmd, special, id, fsqstat);
472	if (ret)
473	break;
474	ret = -EFAULT;
475	/* Copying qs_version, qs_flags, qs_pad */
476	if (copy_in_user(compat_fsqstat, fsqstat,
477	offsetof(struct compat_fs_quota_stat, qs_uquota)))
478	break;
479	/* Copying qs_uquota */
480	if (copy_in_user(&compat_fsqstat->qs_uquota,
481	&fsqstat->qs_uquota,
482	sizeof(compat_fsqstat->qs_uquota)) \|\|
483	get_user(data, &fsqstat->qs_uquota.qfs_nextents) \|\|
484	put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
485	break;
486	/* Copying qs_gquota */
487	if (copy_in_user(&compat_fsqstat->qs_gquota,
488	&fsqstat->qs_gquota,
489	sizeof(compat_fsqstat->qs_gquota)) \|\|
490	get_user(data, &fsqstat->qs_gquota.qfs_nextents) \|\|
491	put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
492	break;
493	/* Copying the rest */
494	if (copy_in_user(&compat_fsqstat->qs_incoredqs,
495	&fsqstat->qs_incoredqs,
496	sizeof(struct compat_fs_quota_stat) -
497	offsetof(struct compat_fs_quota_stat, qs_incoredqs)) \|\|
498	get_user(xdata, &fsqstat->qs_iwarnlimit) \|\|
499	put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
500	break;
501	ret = 0;
502	break;
503	default:
504	ret = sys_quotactl(cmd, special, id, addr);
505	}
506	return ret;
507	}
508	#endif
86e931a3 SW	509
	510
	511	#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
	512
	513	/* Netlink family structure for quota */
	514	static struct genl_family quota_genl_family = {
	515	.id = GENL_ID_GENERATE,
	516	.hdrsize = 0,
	517	.name = "VFS_DQUOT",
	518	.version = 1,
	519	.maxattr = QUOTA_NL_A_MAX,
	520	};
	521
	522	/**
	523	* quota_send_warning - Send warning to userspace about exceeded quota
	524	* @type: The quota type: USRQQUOTA, GRPQUOTA,...
	525	* @id: The user or group id of the quota that was exceeded
	526	* @dev: The device on which the fs is mounted (sb->s_dev)
	527	* @warntype: The type of the warning: QUOTA_NL_...
	528	*
	529	* This can be used by filesystems (including those which don't use
	530	* dquot) to send a message to userspace relating to quota limits.
	531	*
	532	*/
	533
	534	void quota_send_warning(short type, unsigned int id, dev_t dev,
	535	const char warntype)
	536	{
	537	static atomic_t seq;
	538	struct sk_buff *skb;
	539	void *msg_head;
	540	int ret;
	541	int msg_size = 4 * nla_total_size(sizeof(u32)) +
	542	2 * nla_total_size(sizeof(u64));
	543
	544	/* We have to allocate using GFP_NOFS as we are called from a
	545	* filesystem performing write and thus further recursion into
	546	* the fs to free some data could cause deadlocks. */
	547	skb = genlmsg_new(msg_size, GFP_NOFS);
	548	if (!skb) {
	549	printk(KERN_ERR
	550	"VFS: Not enough memory to send quota warning.\n");
	551	return;
	552	}
	553	msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
	554	&quota_genl_family, 0, QUOTA_NL_C_WARNING);
	555	if (!msg_head) {
	556	printk(KERN_ERR
	557	"VFS: Cannot store netlink header in quota warning.\n");
	558	goto err_out;
	559	}
	560	ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type);
	561	if (ret)
	562	goto attr_err_out;
	563	ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id);
	564	if (ret)
	565	goto attr_err_out;
	566	ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
	567	if (ret)
	568	goto attr_err_out;
	569	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev));
	570	if (ret)
	571	goto attr_err_out;
	572	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
573	if (ret)
574	goto attr_err_out;
575	ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
576	if (ret)
577	goto attr_err_out;
578	genlmsg_end(skb, msg_head);
579
580	genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
581	return;
582	attr_err_out:
583	printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
584	err_out:
585	kfree_skb(skb);
586	}
587	EXPORT_SYMBOL(quota_send_warning);
588
589	static int __init quota_init(void)
590	{
591	if (genl_register_family(&quota_genl_family) != 0)
592	printk(KERN_ERR
593	"VFS: Failed to create quota netlink interface.\n");
594	return 0;
595	};
596
597	module_init(quota_init);
598	#endif
599