1 files changed, 524 insertions, 0 deletions

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
new file mode 100644
index 000000000000..b7f5a468f076
--- /dev/null
+++ b/fs/quota/quota.c
@@ -0,0 +1,524 @@
+/*
+ * Quota code necessary even when VFS quota support is not compiled
+ * into the kernel.  The interesting stuff is over in dquot.c, here
+ * we have symbols for initial quotactl(2) handling, the sysctl(2)
+ * variables, etc - things needed even when quota support disabled.
+ */
+
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/slab.h>
+#include <asm/current.h>
+#include <asm/uaccess.h>
+#include <linux/compat.h>
+#include <linux/kernel.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/buffer_head.h>
+#include <linux/capability.h>
+#include <linux/quotaops.h>
+#include <linux/types.h>
+
+/* Check validity of generic quotactl commands */
+static int generic_quotactl_valid(struct super_block *sb, int type, int cmd,
+				  qid_t id)
+{
+	if (type >= MAXQUOTAS)
+		return -EINVAL;
+	if (!sb && cmd != Q_SYNC)
+		return -ENODEV;
+	/* Is operation supported? */
+	if (sb && !sb->s_qcop)
+		return -ENOSYS;
+
+	switch (cmd) {
+		case Q_GETFMT:
+			break;
+		case Q_QUOTAON:
+			if (!sb->s_qcop->quota_on)
+				return -ENOSYS;
+			break;
+		case Q_QUOTAOFF:
+			if (!sb->s_qcop->quota_off)
+				return -ENOSYS;
+			break;
+		case Q_SETINFO:
+			if (!sb->s_qcop->set_info)
+				return -ENOSYS;
+			break;
+		case Q_GETINFO:
+			if (!sb->s_qcop->get_info)
+				return -ENOSYS;
+			break;
+		case Q_SETQUOTA:
+			if (!sb->s_qcop->set_dqblk)
+				return -ENOSYS;
+			break;
+		case Q_GETQUOTA:
+			if (!sb->s_qcop->get_dqblk)
+				return -ENOSYS;
+			break;
+		case Q_SYNC:
+			if (sb && !sb->s_qcop->quota_sync)
+				return -ENOSYS;
+			break;
+		default:
+			return -EINVAL;
+	}
+
+	/* Is quota turned on for commands which need it? */
+	switch (cmd) {
+		case Q_GETFMT:
+		case Q_GETINFO:
+		case Q_SETINFO:
+		case Q_SETQUOTA:
+		case Q_GETQUOTA:
+			/* This is just an informative test so we are satisfied
+			 * without the lock */
+			if (!sb_has_quota_active(sb, type))
+				return -ESRCH;
+	}
+
+	/* Check privileges */
+	if (cmd == Q_GETQUOTA) {
+		if (((type == USRQUOTA && current_euid() != id) ||
+		     (type == GRPQUOTA && !in_egroup_p(id))) &&
+		    !capable(CAP_SYS_ADMIN))
+			return -EPERM;
+	}
+	else if (cmd != Q_GETFMT && cmd != Q_SYNC && cmd != Q_GETINFO)
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+	return 0;
+}
+
+/* Check validity of XFS Quota Manager commands */
+static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd,
+			      qid_t id)
+{
+	if (type >= XQM_MAXQUOTAS)
+		return -EINVAL;
+	if (!sb)
+		return -ENODEV;
+	if (!sb->s_qcop)
+		return -ENOSYS;
+
+	switch (cmd) {
+		case Q_XQUOTAON:
+		case Q_XQUOTAOFF:
+		case Q_XQUOTARM:
+			if (!sb->s_qcop->set_xstate)
+				return -ENOSYS;
+			break;
+		case Q_XGETQSTAT:
+			if (!sb->s_qcop->get_xstate)
+				return -ENOSYS;
+			break;
+		case Q_XSETQLIM:
+			if (!sb->s_qcop->set_xquota)
+				return -ENOSYS;
+			break;
+		case Q_XGETQUOTA:
+			if (!sb->s_qcop->get_xquota)
+				return -ENOSYS;
+			break;
+		case Q_XQUOTASYNC:
+			if (!sb->s_qcop->quota_sync)
+				return -ENOSYS;
+			break;
+		default:
+			return -EINVAL;
+	}
+
+	/* Check privileges */
+	if (cmd == Q_XGETQUOTA) {
+		if (((type == XQM_USRQUOTA && current_euid() != id) ||
+		     (type == XQM_GRPQUOTA && !in_egroup_p(id))) &&
+		     !capable(CAP_SYS_ADMIN))
+			return -EPERM;
+	} else if (cmd != Q_XGETQSTAT && cmd != Q_XQUOTASYNC) {
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+	}
+
+	return 0;
+}
+
+static int check_quotactl_valid(struct super_block *sb, int type, int cmd,
+				qid_t id)
+{
+	int error;
+
+	if (XQM_COMMAND(cmd))
+		error = xqm_quotactl_valid(sb, type, cmd, id);
+	else
+		error = generic_quotactl_valid(sb, type, cmd, id);
+	if (!error)
+		error = security_quotactl(cmd, type, id, sb);
+	return error;
+}
+
+static void quota_sync_sb(struct super_block *sb, int type)
+{
+	int cnt;
+
+	sb->s_qcop->quota_sync(sb, type);
+
+	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);
+}
+
+void sync_dquots(struct super_block *sb, int type)
+{
+	int cnt;
+
+	if (sb) {
+		if (sb->s_qcop->quota_sync)
+			quota_sync_sb(sb, type);
+		return;
+	}
+
+	spin_lock(&sb_lock);
+restart:
+	list_for_each_entry(sb, &super_blocks, s_list) {
+		/* This test just improves performance so it needn't be
+		 * reliable... */
+		for (cnt = 0; 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)
+			quota_sync_sb(sb, type);
+		up_read(&sb->s_umount);
+		spin_lock(&sb_lock);
+		if (__put_super_and_need_restart(sb))
+			goto restart;
+	}
+	spin_unlock(&sb_lock);
+}
+
+/* Copy parameters and call proper function */
+static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
+		       void __user *addr)
+{
+	int ret;
+
+	switch (cmd) {
+		case Q_QUOTAON: {
+			char *pathname;
+
+			pathname = getname(addr);
+			if (IS_ERR(pathname))
+				return PTR_ERR(pathname);
+			ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
+			putname(pathname);
+			return ret;
+		}
+		case Q_QUOTAOFF:
+			return sb->s_qcop->quota_off(sb, type, 0);
+
+		case Q_GETFMT: {
+			__u32 fmt;
+
+			down_read(&sb_dqopt(sb)->dqptr_sem);
+			if (!sb_has_quota_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;
+		}
+		case Q_GETINFO: {
+			struct if_dqinfo info;
+
+			ret = sb->s_qcop->get_info(sb, type, &info);
+			if (ret)
+				return ret;
+			if (copy_to_user(addr, &info, sizeof(info)))
+				return -EFAULT;
+			return 0;
+		}
+		case Q_SETINFO: {
+			struct if_dqinfo info;
+
+			if (copy_from_user(&info, addr, sizeof(info)))
+				return -EFAULT;
+			return sb->s_qcop->set_info(sb, type, &info);
+		}
+		case Q_GETQUOTA: {
+			struct if_dqblk idq;
+
+			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;
+		}
+		case Q_SETQUOTA: {
+			struct if_dqblk idq;
+
+			if (copy_from_user(&idq, addr, sizeof(idq)))
+				return -EFAULT;
+			return sb->s_qcop->set_dqblk(sb, type, id, &idq);
+		}
+		case Q_SYNC:
+			sync_dquots(sb, type);
+			return 0;
+
+		case Q_XQUOTAON:
+		case Q_XQUOTAOFF:
+		case Q_XQUOTARM: {
+			__u32 flags;
+
+			if (copy_from_user(&flags, addr, sizeof(flags)))
+				return -EFAULT;
+			return sb->s_qcop->set_xstate(sb, flags, cmd);
+		}
+		case Q_XGETQSTAT: {
+			struct fs_quota_stat fqs;
+		
+			if ((ret = sb->s_qcop->get_xstate(sb, &fqs)))
+				return ret;
+			if (copy_to_user(addr, &fqs, sizeof(fqs)))
+				return -EFAULT;
+			return 0;
+		}
+		case Q_XSETQLIM: {
+			struct fs_disk_quota fdq;
+
+			if (copy_from_user(&fdq, addr, sizeof(fdq)))
+				return -EFAULT;
+		       return sb->s_qcop->set_xquota(sb, type, id, &fdq);
+		}
+		case Q_XGETQUOTA: {
+			struct fs_disk_quota fdq;
+
+			ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
+			if (ret)
+				return ret;
+			if (copy_to_user(addr, &fdq, sizeof(fdq)))
+				return -EFAULT;
+			return 0;
+		}
+		case Q_XQUOTASYNC:
+			return sb->s_qcop->quota_sync(sb, type);
+		/* We never reach here unless validity check is broken */
+		default:
+			BUG();
+	}
+	return 0;
+}
+
+/*
+ * look up a superblock on which quota ops will be performed
+ * - use the name of a block device to find the superblock thereon
+ */
+static 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;
+
+	if (cmds != Q_SYNC || special) {
+		sb = quotactl_block(special);
+		if (IS_ERR(sb))
+			return PTR_ERR(sb);
+	}
+
+	ret = check_quotactl_valid(sb, type, cmds, id);
+	if (ret >= 0)
+		ret = do_quotactl(sb, type, cmds, id, addr);
+	if (sb)
+		drop_super(sb);
+
+	return ret;
+}
+
+#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
+/*
+ * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
+ * and is necessary due to alignment problems.
+ */
+struct compat_if_dqblk {
+	compat_u64 dqb_bhardlimit;
+	compat_u64 dqb_bsoftlimit;
+	compat_u64 dqb_curspace;
+	compat_u64 dqb_ihardlimit;
+	compat_u64 dqb_isoftlimit;
+	compat_u64 dqb_curinodes;
+	compat_u64 dqb_btime;
+	compat_u64 dqb_itime;
+	compat_uint_t dqb_valid;
+};
+
+/* XFS structures */
+struct compat_fs_qfilestat {
+	compat_u64 dqb_bhardlimit;
+	compat_u64 qfs_nblks;
+	compat_uint_t qfs_nextents;
+};
+
+struct compat_fs_quota_stat {
+	__s8		qs_version;
+	__u16		qs_flags;
+	__s8		qs_pad;
+	struct compat_fs_qfilestat	qs_uquota;
+	struct compat_fs_qfilestat	qs_gquota;
+	compat_uint_t	qs_incoredqs;
+	compat_int_t	qs_btimelimit;
+	compat_int_t	qs_itimelimit;
+	compat_int_t	qs_rtbtimelimit;
+	__u16		qs_bwarnlimit;
+	__u16		qs_iwarnlimit;
+};
+
+asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
+						qid_t id, void __user *addr)
+{
+	unsigned int cmds;
+	struct if_dqblk __user *dqblk;
+	struct compat_if_dqblk __user *compat_dqblk;
+	struct fs_quota_stat __user *fsqstat;
+	struct compat_fs_quota_stat __user *compat_fsqstat;
+	compat_uint_t data;
+	u16 xdata;
+	long ret;
+
+	cmds = cmd >> SUBCMDSHIFT;
+
+	switch (cmds) {
+	case Q_GETQUOTA:
+		dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
+		compat_dqblk = addr;
+		ret = sys_quotactl(cmd, special, id, dqblk);
+		if (ret)
+			break;
+		if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
+			get_user(data, &dqblk->dqb_valid) ||
+			put_user(data, &compat_dqblk->dqb_valid))
+			ret = -EFAULT;
+		break;
+	case Q_SETQUOTA:
+		dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
+		compat_dqblk = addr;
+		ret = -EFAULT;
+		if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) ||
+			get_user(data, &compat_dqblk->dqb_valid) ||
+			put_user(data, &dqblk->dqb_valid))
+			break;
+		ret = sys_quotactl(cmd, special, id, dqblk);
+		break;
+	case Q_XGETQSTAT:
+		fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
+		compat_fsqstat = addr;
+		ret = sys_quotactl(cmd, special, id, fsqstat);
+		if (ret)
+			break;
+		ret = -EFAULT;
+		/* Copying qs_version, qs_flags, qs_pad */
+		if (copy_in_user(compat_fsqstat, fsqstat,
+			offsetof(struct compat_fs_quota_stat, qs_uquota)))
+			break;
+		/* Copying qs_uquota */
+		if (copy_in_user(&compat_fsqstat->qs_uquota,
+			&fsqstat->qs_uquota,
+			sizeof(compat_fsqstat->qs_uquota)) ||
+			get_user(data, &fsqstat->qs_uquota.qfs_nextents) ||
+			put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
+			break;
+		/* Copying qs_gquota */
+		if (copy_in_user(&compat_fsqstat->qs_gquota,
+			&fsqstat->qs_gquota,
+			sizeof(compat_fsqstat->qs_gquota)) ||
+			get_user(data, &fsqstat->qs_gquota.qfs_nextents) ||
+			put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
+			break;
+		/* Copying the rest */
+		if (copy_in_user(&compat_fsqstat->qs_incoredqs,
+			&fsqstat->qs_incoredqs,
+			sizeof(struct compat_fs_quota_stat) -
+			offsetof(struct compat_fs_quota_stat, qs_incoredqs)) ||
+			get_user(xdata, &fsqstat->qs_iwarnlimit) ||
+			put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
+			break;
+		ret = 0;
+		break;
+	default:
+		ret = sys_quotactl(cmd, special, id, addr);
+	}
+	return ret;
+}
+#endif