xfs_qm_syscalls.c

linux-2.6.15.6

/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_alloc.h"
#include "xfs_dmapi.h"
#include "xfs_quota.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_ialloc.h"
#include "xfs_itable.h"
#include "xfs_bmap.h"
#include "xfs_btree.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_rw.h"
#include "xfs_acl.h"
#include "xfs_cap.h"
#include "xfs_mac.h"
#include "xfs_attr.h"
#include "xfs_buf_item.h"
#include "xfs_utils.h"
#include "xfs_qm.h"

#ifdef DEBUG
# define qdprintk(s, args...)	cmn_err(CE_DEBUG, s, ## args)
#else
# define qdprintk(s, args...)	do { } while (0)
#endif

STATIC int	xfs_qm_scall_trunc_qfiles(xfs_mount_t *, uint);
STATIC int	xfs_qm_scall_getquota(xfs_mount_t *, xfs_dqid_t, uint,
					fs_disk_quota_t *);
STATIC int	xfs_qm_scall_getqstat(xfs_mount_t *, fs_quota_stat_t *);
STATIC int	xfs_qm_scall_setqlim(xfs_mount_t *, xfs_dqid_t, uint,
					fs_disk_quota_t *);
STATIC int	xfs_qm_scall_quotaon(xfs_mount_t *, uint);
STATIC int	xfs_qm_scall_quotaoff(xfs_mount_t *, uint, boolean_t);
STATIC int	xfs_qm_log_quotaoff(xfs_mount_t *, xfs_qoff_logitem_t **, uint);
STATIC int	xfs_qm_log_quotaoff_end(xfs_mount_t *, xfs_qoff_logitem_t *,
					uint);
STATIC uint	xfs_qm_import_flags(uint);
STATIC uint	xfs_qm_export_flags(uint);
STATIC uint	xfs_qm_import_qtype_flags(uint);
STATIC uint	xfs_qm_export_qtype_flags(uint);
STATIC void	xfs_qm_export_dquot(xfs_mount_t *, xfs_disk_dquot_t *,
					fs_disk_quota_t *);


/*
 * The main distribution switch of all XFS quotactl system calls.
 */
int
xfs_qm_quotactl(
	struct bhv_desc *bdp,
	int		cmd,
	int		id,
	xfs_caddr_t	addr)
{
	xfs_mount_t	*mp;
	int		error;
	struct vfs	*vfsp;

	vfsp = bhvtovfs(bdp);
	mp = XFS_VFSTOM(vfsp);

	ASSERT(addr != NULL || cmd == Q_XQUOTASYNC);

	/*
	 * The following commands are valid even when quotaoff.
	 */
	switch (cmd) {
	case Q_XQUOTARM:
		/*
		 * Truncate quota files. quota must be off.
		 */
		if (XFS_IS_QUOTA_ON(mp))
			return XFS_ERROR(EINVAL);
		if (vfsp->vfs_flag & VFS_RDONLY)
			return XFS_ERROR(EROFS);
		return (xfs_qm_scall_trunc_qfiles(mp,
			       xfs_qm_import_qtype_flags(*(uint *)addr)));

	case Q_XGETQSTAT:
		/*
		 * Get quota status information.
		 */
		return (xfs_qm_scall_getqstat(mp, (fs_quota_stat_t *)addr));

	case Q_XQUOTAON:
		/*
		 * QUOTAON - enabling quota enforcement.
		 * Quota accounting must be turned on at mount time.
		 */
		if (vfsp->vfs_flag & VFS_RDONLY)
			return XFS_ERROR(EROFS);
		return (xfs_qm_scall_quotaon(mp,
					  xfs_qm_import_flags(*(uint *)addr)));

	case Q_XQUOTAOFF:
		if (vfsp->vfs_flag & VFS_RDONLY)
			return XFS_ERROR(EROFS);
		break;

	case Q_XQUOTASYNC:
		return (xfs_sync_inodes(mp, SYNC_DELWRI, 0, NULL));

	default:
		break;
	}

	if (! XFS_IS_QUOTA_ON(mp))
		return XFS_ERROR(ESRCH);

	switch (cmd) {
	case Q_XQUOTAOFF:
		if (vfsp->vfs_flag & VFS_RDONLY)
			return XFS_ERROR(EROFS);
		error = xfs_qm_scall_quotaoff(mp,
					    xfs_qm_import_flags(*(uint *)addr),
					    B_FALSE);
		break;

	case Q_XGETQUOTA:
		error = xfs_qm_scall_getquota(mp, (xfs_dqid_t)id, XFS_DQ_USER,
					(fs_disk_quota_t *)addr);
		break;
	case Q_XGETGQUOTA:
		error = xfs_qm_scall_getquota(mp, (xfs_dqid_t)id, XFS_DQ_GROUP,
					(fs_disk_quota_t *)addr);
		break;
	case Q_XGETPQUOTA:
		error = xfs_qm_scall_getquota(mp, (xfs_dqid_t)id, XFS_DQ_PROJ,
					(fs_disk_quota_t *)addr);
		break;

	case Q_XSETQLIM:
		if (vfsp->vfs_flag & VFS_RDONLY)
			return XFS_ERROR(EROFS);
		error = xfs_qm_scall_setqlim(mp, (xfs_dqid_t)id, XFS_DQ_USER,
					     (fs_disk_quota_t *)addr);
		break;
	case Q_XSETGQLIM:
		if (vfsp->vfs_flag & VFS_RDONLY)
			return XFS_ERROR(EROFS);
		error = xfs_qm_scall_setqlim(mp, (xfs_dqid_t)id, XFS_DQ_GROUP,
					     (fs_disk_quota_t *)addr);
		break;
	case Q_XSETPQLIM:
		if (vfsp->vfs_flag & VFS_RDONLY)
			return XFS_ERROR(EROFS);
		error = xfs_qm_scall_setqlim(mp, (xfs_dqid_t)id, XFS_DQ_PROJ,
					     (fs_disk_quota_t *)addr);
		break;

	default:
		error = XFS_ERROR(EINVAL);
		break;
	}

	return (error);
}

/*
 * Turn off quota accounting and/or enforcement for all udquots and/or
 * gdquots. Called only at unmount time.
 *
 * This assumes that there are no dquots of this file system cached
 * incore, and modifies the ondisk dquot directly. Therefore, for example,
 * it is an error to call this twice, without purging the cache.
 */
STATIC int
xfs_qm_scall_quotaoff(
	xfs_mount_t		*mp,
	uint			flags,
	boolean_t		force)
{
	uint			dqtype;
	unsigned long	s;
	int			error;
	uint			inactivate_flags;
	xfs_qoff_logitem_t	*qoffstart;
	int			nculprits;

	if (!force && !capable(CAP_SYS_ADMIN))
		return XFS_ERROR(EPERM);
	/*
	 * No file system can have quotas enabled on disk but not in core.
	 * Note that quota utilities (like quotaoff) _expect_
	 * errno == EEXIST here.
	 */
	if ((mp->m_qflags & flags) == 0)
		return XFS_ERROR(EEXIST);
	error = 0;

	flags &= (XFS_ALL_QUOTA_ACCT | XFS_ALL_QUOTA_ENFD);

	/*
	 * We don't want to deal with two quotaoffs messing up each other,
	 * so we're going to serialize it. quotaoff isn't exactly a performance
	 * critical thing.
	 * If quotaoff, then we must be dealing with the root filesystem.
	 */
	ASSERT(mp->m_quotainfo);
	if (mp->m_quotainfo)
		mutex_lock(&(XFS_QI_QOFFLOCK(mp)), PINOD);

	ASSERT(mp->m_quotainfo);

	/*
	 * If we're just turning off quota enforcement, change mp and go.
	 */
	if ((flags & XFS_ALL_QUOTA_ACCT) == 0) {
		mp->m_qflags &= ~(flags);

		s = XFS_SB_LOCK(mp);
		mp->m_sb.sb_qflags = mp->m_qflags;
		XFS_SB_UNLOCK(mp, s);
		mutex_unlock(&(XFS_QI_QOFFLOCK(mp)));

		/* XXX what to do if error ? Revert back to old vals incore ? */
		error = xfs_qm_write_sb_changes(mp, XFS_SB_QFLAGS);
		return (error);
	}

	dqtype = 0;
	inactivate_flags = 0;
	/*
	 * If accounting is off, we must turn enforcement off, clear the
	 * quota 'CHKD' certificate to make it known that we have to
	 * do a quotacheck the next time this quota is turned on.
	 */
	if (flags & XFS_UQUOTA_ACCT) {
		dqtype |= XFS_QMOPT_UQUOTA;
		flags |= (XFS_UQUOTA_CHKD | XFS_UQUOTA_ENFD);
		inactivate_flags |= XFS_UQUOTA_ACTIVE;
	}
	if (flags & XFS_GQUOTA_ACCT) {
		dqtype |= XFS_QMOPT_GQUOTA;
		flags |= (XFS_OQUOTA_CHKD | XFS_OQUOTA_ENFD);
		inactivate_flags |= XFS_GQUOTA_ACTIVE;
	} else if (flags & XFS_PQUOTA_ACCT) {
		dqtype |= XFS_QMOPT_PQUOTA;
		flags |= (XFS_OQUOTA_CHKD | XFS_OQUOTA_ENFD);
		inactivate_flags |= XFS_PQUOTA_ACTIVE;
	}

	/*
	 * Nothing to do?  Don't complain. This happens when we're just
	 * turning off quota enforcement.
	 */
	if ((mp->m_qflags & flags) == 0) {
		mutex_unlock(&(XFS_QI_QOFFLOCK(mp)));
		return (0);
	}

	/*
	 * Write the LI_QUOTAOFF log record, and do SB changes atomically,
	 * and synchronously.
	 */
	xfs_qm_log_quotaoff(mp, &qoffstart, flags);

	/*
	 * Next we clear the XFS_MOUNT_*DQ_ACTIVE bit(s) in the mount struct
	 * to take care of the race between dqget and quotaoff. We don't take
	 * any special locks to reset these bits. All processes need to check
	 * these bits *after* taking inode lock(s) to see if the particular
	 * quota type is in the process of being turned off. If *ACTIVE, it is
	 * guaranteed that all dquot structures and all quotainode ptrs will all
	 * stay valid as long as that inode is kept locked.
	 *
	 * There is no turning back after this.
	 */
	mp->m_qflags &= ~inactivate_flags;

	/*
	 * Give back all the dquot reference(s) held by inodes.
	 * Here we go thru every single incore inode in this file system, and
	 * do a dqrele on the i_udquot/i_gdquot that it may have.
	 * Essentially, as long as somebody has an inode locked, this guarantees
	 * that quotas will not be turned off. This is handy because in a
	 * transaction once we lock the inode(s) and check for quotaon, we can
	 * depend on the quota inodes (and other things) being valid as long as
	 * we keep the lock(s).
	 */
	xfs_qm_dqrele_all_inodes(mp, flags);

	/*
	 * Next we make the changes in the quota flag in the mount struct.
	 * This isn't protected by a particular lock directly, because we
	 * don't want to take a mrlock everytime we depend on quotas being on.
	 */
	mp->m_qflags &= ~(flags);

	/*
	 * Go through all the dquots of this file system and purge them,
	 * according to what was turned off. We may not be able to get rid
	 * of all dquots, because dquots can have temporary references that
	 * are not attached to inodes. eg. xfs_setattr, xfs_create.
	 * So, if we couldn't purge all the dquots from the filesystem,
	 * we can't get rid of the incore data structures.
	 */
	while ((nculprits = xfs_qm_dqpurge_all(mp, dqtype|XFS_QMOPT_QUOTAOFF)))
		delay(10 * nculprits);

	/*
	 * Transactions that had started before ACTIVE state bit was cleared
	 * could have logged many dquots, so they'd have higher LSNs than
	 * the first QUOTAOFF log record does. If we happen to crash when
	 * the tail of the log has gone past the QUOTAOFF record, but
	 * before the last dquot modification, those dquots __will__
	 * recover, and that's not good.
	 *
	 * So, we have QUOTAOFF start and end logitems; the start
	 * logitem won't get overwritten until the end logitem appears...
	 */
	xfs_qm_log_quotaoff_end(mp, qoffstart, flags);

	/*
	 * If quotas is completely disabled, close shop.
	 */
	if (((flags & XFS_MOUNT_QUOTA_ALL) == XFS_MOUNT_QUOTA_SET1) ||
	    ((flags & XFS_MOUNT_QUOTA_ALL) == XFS_MOUNT_QUOTA_SET2)) {
		mutex_unlock(&(XFS_QI_QOFFLOCK(mp)));
		xfs_qm_destroy_quotainfo(mp);
		return (0);
	}

	/*
	 * Release our quotainode references, and vn_purge them,
	 * if we don't need them anymore.
	 */
	if ((dqtype & XFS_QMOPT_UQUOTA) && XFS_QI_UQIP(mp)) {
		XFS_PURGE_INODE(XFS_QI_UQIP(mp));
		XFS_QI_UQIP(mp) = NULL;
	}
	if ((dqtype & (XFS_QMOPT_GQUOTA|XFS_QMOPT_PQUOTA)) && XFS_QI_GQIP(mp)) {
		XFS_PURGE_INODE(XFS_QI_GQIP(mp));
		XFS_QI_GQIP(mp) = NULL;
	}
	mutex_unlock(&(XFS_QI_QOFFLOCK(mp)));

	return (error);
}

STATIC int
xfs_qm_scall_trunc_qfiles(
	xfs_mount_t	*mp,
	uint		flags)
{
	int		error;
	xfs_inode_t	*qip;

	if (!capable(CAP_SYS_ADMIN))
		return XFS_ERROR(EPERM);
	error = 0;
	if (!XFS_SB_VERSION_HASQUOTA(&mp->m_sb) || flags == 0) {
		qdprintk("qtrunc flags=%x m_qflags=%x\n", flags, mp->m_qflags);
		return XFS_ERROR(EINVAL);
	}

	if ((flags & XFS_DQ_USER) && mp->m_sb.sb_uquotino != NULLFSINO) {
		error = xfs_iget(mp, NULL, mp->m_sb.sb_uquotino, 0, 0, &qip, 0);
		if (! error) {
			(void) xfs_truncate_file(mp, qip);
			VN_RELE(XFS_ITOV(qip));
		}
	}

	if ((flags & (XFS_DQ_GROUP|XFS_DQ_PROJ)) &&
	    mp->m_sb.sb_gquotino != NULLFSINO) {
		error = xfs_iget(mp, NULL, mp->m_sb.sb_gquotino, 0, 0, &qip, 0);
		if (! error) {
			(void) xfs_truncate_file(mp, qip);
			VN_RELE(XFS_ITOV(qip));
		}
	}

	return (error);
}


/*
 * Switch on (a given) quota enforcement for a filesystem.  This takes
 * effect immediately.
 * (Switching on quota accounting must be done at mount time.)
 */
STATIC int
xfs_qm_scall_quotaon(
	xfs_mount_t	*mp,
	uint		flags)
{
	int		error;
	unsigned long	s;
	uint		qf;
	uint		accflags;
	__int64_t	sbflags;

	if (!capable(CAP_SYS_ADMIN))
		return XFS_ERROR(EPERM);

	flags &= (XFS_ALL_QUOTA_ACCT | XFS_ALL_QUOTA_ENFD);
	/*
	 * Switching on quota accounting must be done at mount time.
	 */
	accflags = flags & XFS_ALL_QUOTA_ACCT;
	flags &= ~(XFS_ALL_QUOTA_ACCT);

	sbflags = 0;

	if (flags == 0) {
		qdprintk("quotaon: zero flags, m_qflags=%x\n", mp->m_qflags);
		return XFS_ERROR(EINVAL);
	}

	/* No fs can turn on quotas with a delayed effect */
	ASSERT((flags & XFS_ALL_QUOTA_ACCT) == 0);

	/*
	 * Can't enforce without accounting. We check the superblock
	 * qflags here instead of m_qflags because rootfs can have
	 * quota acct on ondisk without m_qflags' knowing.
	 */
	if (((flags & XFS_UQUOTA_ACCT) == 0 &&
	    (mp->m_sb.sb_qflags & XFS_UQUOTA_ACCT) == 0 &&
	    (flags & XFS_UQUOTA_ENFD))
	    ||
	    ((flags & XFS_PQUOTA_ACCT) == 0 &&
	    (mp->m_sb.sb_qflags & XFS_PQUOTA_ACCT) == 0 &&
	    (flags & XFS_OQUOTA_ENFD))
	    ||
	    ((flags & XFS_GQUOTA_ACCT) == 0 &&
	    (mp->m_sb.sb_qflags & XFS_GQUOTA_ACCT) == 0 &&
	    (flags & XFS_OQUOTA_ENFD))) {
		qdprintk("Can't enforce without acct, flags=%x sbflags=%x\n",
			flags, mp->m_sb.sb_qflags);
		return XFS_ERROR(EINVAL);
	}
	/*
	 * If everything's upto-date incore, then don't waste time.
	 */
	if ((mp->m_qflags & flags) == flags)
		return XFS_ERROR(EEXIST);

	/*
	 * Change sb_qflags on disk but not incore mp->qflags
	 * if this is the root filesystem.
	 */
	s = XFS_SB_LOCK(mp);
	qf = mp->m_sb.sb_qflags;
	mp->m_sb.sb_qflags = qf | flags;
	XFS_SB_UNLOCK(mp, s);

	/*
	 * There's nothing to change if it's the same.
	 */
	if ((qf & flags) == flags && sbflags == 0)
		return XFS_ERROR(EEXIST);
	sbflags |= XFS_SB_QFLAGS;

	if ((error = xfs_qm_write_sb_changes(mp, sbflags)))
		return (error);
	/*
	 * If we aren't trying to switch on quota enforcement, we are done.