linux/fs/xfs/libxfs/xfs_dquot_buf.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * Copyright (c) 2013 Red Hat, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_quota.h"
#include "xfs_trans.h"
#include "xfs_qm.h"
#include "xfs_error.h"
#include "xfs_health.h"
#include "xfs_metadir.h"
#include "xfs_metafile.h"

int
xfs_calc_dquots_per_chunk(
	unsigned int		nbblks)	/* basic block units */
{
	ASSERT(nbblks > 0);
	return BBTOB(nbblks) / sizeof(struct xfs_dqblk);
}

/*
 * Do some primitive error checking on ondisk dquot data structures.
 *
 * The xfs_dqblk structure /contains/ the xfs_disk_dquot structure;
 * we verify them separately because at some points we have only the
 * smaller xfs_disk_dquot structure available.
 */

xfs_failaddr_t
xfs_dquot_verify(
	struct xfs_mount	*mp,
	struct xfs_disk_dquot	*ddq,
	xfs_dqid_t		id)	/* used only during quotacheck */
{
	__u8			ddq_type;

	/*
	 * We can encounter an uninitialized dquot buffer for 2 reasons:
	 * 1. If we crash while deleting the quotainode(s), and those blks got
	 *    used for user data. This is because we take the path of regular
	 *    file deletion; however, the size field of quotainodes is never
	 *    updated, so all the tricks that we play in itruncate_finish
	 *    don't quite matter.
	 *
	 * 2. We don't play the quota buffers when there's a quotaoff logitem.
	 *    But the allocation will be replayed so we'll end up with an
	 *    uninitialized quota block.
	 *
	 * This is all fine; things are still consistent, and we haven't lost
	 * any quota information. Just don't complain about bad dquot blks.
	 */
	if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
		return __this_address;
	if (ddq->d_version != XFS_DQUOT_VERSION)
		return __this_address;

	if (ddq->d_type & ~XFS_DQTYPE_ANY)
		return __this_address;
	ddq_type = ddq->d_type & XFS_DQTYPE_REC_MASK;
	if (ddq_type != XFS_DQTYPE_USER &&
	    ddq_type != XFS_DQTYPE_PROJ &&
	    ddq_type != XFS_DQTYPE_GROUP)
		return __this_address;

	if ((ddq->d_type & XFS_DQTYPE_BIGTIME) &&
	    !xfs_has_bigtime(mp))
		return __this_address;

	if ((ddq->d_type & XFS_DQTYPE_BIGTIME) && !ddq->d_id)
		return __this_address;

	if (id != -1 && id != be32_to_cpu(ddq->d_id))
		return __this_address;

	if (!ddq->d_id)
		return NULL;

	if (ddq->d_blk_softlimit &&
	    be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
	    !ddq->d_btimer)
		return __this_address;

	if (ddq->d_ino_softlimit &&
	    be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
	    !ddq->d_itimer)
		return __this_address;

	if (ddq->d_rtb_softlimit &&
	    be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
	    !ddq->d_rtbtimer)
		return __this_address;

	return NULL;
}

xfs_failaddr_t
xfs_dqblk_verify(
	struct xfs_mount	*mp,
	struct xfs_dqblk	*dqb,
	xfs_dqid_t		id)	/* used only during quotacheck */
{
	if (xfs_has_crc(mp) &&
	    !uuid_equal(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid))
		return __this_address;

	return xfs_dquot_verify(mp, &dqb->dd_diskdq, id);
}

/*
 * Do some primitive error checking on ondisk dquot data structures.
 */
void
xfs_dqblk_repair(
	struct xfs_mount	*mp,
	struct xfs_dqblk	*dqb,
	xfs_dqid_t		id,
	xfs_dqtype_t		type)
{
	/*
	 * Typically, a repair is only requested by quotacheck.
	 */
	ASSERT(id != -1);
	memset(dqb, 0, sizeof(struct xfs_dqblk));

	dqb->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
	dqb->dd_diskdq.d_version = XFS_DQUOT_VERSION;
	dqb->dd_diskdq.d_type = type;
	dqb->dd_diskdq.d_id = cpu_to_be32(id);

	if (xfs_has_crc(mp)) {
		uuid_copy(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid);
		xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
				 XFS_DQUOT_CRC_OFF);
	}
}

STATIC bool
xfs_dquot_buf_verify_crc(
	struct xfs_mount	*mp,
	struct xfs_buf		*bp,
	bool			readahead)
{
	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
	int			ndquots;
	int			i;

	if (!xfs_has_crc(mp))
		return true;

	/*
	 * if we are in log recovery, the quota subsystem has not been
	 * initialised so we have no quotainfo structure. In that case, we need
	 * to manually calculate the number of dquots in the buffer.
	 */
	if (mp->m_quotainfo)
		ndquots = mp->m_quotainfo->qi_dqperchunk;
	else
		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);

	for (i = 0; i < ndquots; i++, d++) {
		if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
				 XFS_DQUOT_CRC_OFF)) {
			if (!readahead)
				xfs_buf_verifier_error(bp, -EFSBADCRC, __func__,
					d, sizeof(*d), __this_address);
			return false;
		}
	}
	return true;
}

STATIC xfs_failaddr_t
xfs_dquot_buf_verify(
	struct xfs_mount	*mp,
	struct xfs_buf		*bp,
	bool			readahead)
{
	struct xfs_dqblk	*dqb = bp->b_addr;
	xfs_failaddr_t		fa;
	xfs_dqid_t		id = 0;
	int			ndquots;
	int			i;

	/*
	 * if we are in log recovery, the quota subsystem has not been
	 * initialised so we have no quotainfo structure. In that case, we need
	 * to manually calculate the number of dquots in the buffer.
	 */
	if (mp->m_quotainfo)
		ndquots = mp->m_quotainfo->qi_dqperchunk;
	else
		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);

	/*
	 * On the first read of the buffer, verify that each dquot is valid.
	 * We don't know what the id of the dquot is supposed to be, just that
	 * they should be increasing monotonically within the buffer. If the
	 * first id is corrupt, then it will fail on the second dquot in the
	 * buffer so corruptions could point to the wrong dquot in this case.
	 */
	for (i = 0; i < ndquots; i++) {
		struct xfs_disk_dquot	*ddq;

		ddq = &dqb[i].dd_diskdq;

		if (i == 0)
			id = be32_to_cpu(ddq->d_id);

		fa = xfs_dqblk_verify(mp, &dqb[i], id + i);
		if (fa) {
			if (!readahead)
				xfs_buf_verifier_error(bp, -EFSCORRUPTED,
					__func__, &dqb[i],
					sizeof(struct xfs_dqblk), fa);
			return fa;
		}
	}

	return NULL;
}

static xfs_failaddr_t
xfs_dquot_buf_verify_struct(
	struct xfs_buf		*bp)
{
	struct xfs_mount	*mp = bp->b_mount;

	return xfs_dquot_buf_verify(mp, bp, false);
}

static void
xfs_dquot_buf_read_verify(
	struct xfs_buf		*bp)
{
	struct xfs_mount	*mp = bp->b_mount;

	if (!xfs_dquot_buf_verify_crc(mp, bp, false))
		return;
	xfs_dquot_buf_verify(mp, bp, false);
}

/*
 * readahead errors are silent and simply leave the buffer as !done so a real
 * read will then be run with the xfs_dquot_buf_ops verifier. See
 * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
 * reporting the failure.
 */
static void
xfs_dquot_buf_readahead_verify(
	struct xfs_buf	*bp)
{
	struct xfs_mount	*mp = bp->b_mount;

	if (!xfs_dquot_buf_verify_crc(mp, bp, true) ||
	    xfs_dquot_buf_verify(mp, bp, true) != NULL) {
		xfs_buf_ioerror(bp, -EIO);
		bp->b_flags &= ~XBF_DONE;
	}
}

/*
 * we don't calculate the CRC here as that is done when the dquot is flushed to
 * the buffer after the update is done. This ensures that the dquot in the
 * buffer always has an up-to-date CRC value.
 */
static void
xfs_dquot_buf_write_verify(
	struct xfs_buf		*bp)
{
	struct xfs_mount	*mp = bp->b_mount;

	xfs_dquot_buf_verify(mp, bp, false);
}

const struct xfs_buf_ops xfs_dquot_buf_ops = {
	.name = "xfs_dquot",
	.magic16 = { cpu_to_be16(XFS_DQUOT_MAGIC),
		     cpu_to_be16(XFS_DQUOT_MAGIC) },
	.verify_read = xfs_dquot_buf_read_verify,
	.verify_write = xfs_dquot_buf_write_verify,
	.verify_struct = xfs_dquot_buf_verify_struct,
};

const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
	.name = "xfs_dquot_ra",
	.magic16 = { cpu_to_be16(XFS_DQUOT_MAGIC),
		     cpu_to_be16(XFS_DQUOT_MAGIC) },
	.verify_read = xfs_dquot_buf_readahead_verify,
	.verify_write = xfs_dquot_buf_write_verify,
};

/* Convert an on-disk timer value into an incore timer value. */
time64_t
xfs_dquot_from_disk_ts(
	struct xfs_disk_dquot	*ddq,
	__be32			dtimer)
{
	uint32_t		t = be32_to_cpu(dtimer);

	if (t != 0 && (ddq->d_type & XFS_DQTYPE_BIGTIME))
		return xfs_dq_bigtime_to_unix(t);

	return t;
}

/* Convert an incore timer value into an on-disk timer value. */
__be32
xfs_dquot_to_disk_ts(
	struct xfs_dquot	*dqp,
	time64_t		timer)
{
	uint32_t		t = timer;

	if (timer != 0 && (dqp->q_type & XFS_DQTYPE_BIGTIME))
		t = xfs_dq_unix_to_bigtime(timer);

	return cpu_to_be32(t);
}

inline unsigned int
xfs_dqinode_sick_mask(xfs_dqtype_t type)
{
	switch (type) {
	case XFS_DQTYPE_USER:
		return XFS_SICK_FS_UQUOTA;
	case XFS_DQTYPE_GROUP:
		return XFS_SICK_FS_GQUOTA;
	case XFS_DQTYPE_PROJ:
		return XFS_SICK_FS_PQUOTA;
	}

	ASSERT(0);
	return 0;
}

/*
 * Load the inode for a given type of quota, assuming that the sb fields have
 * been sorted out.  This is not true when switching quota types on a V4
 * filesystem, so do not use this function for that.  If metadir is enabled,
 * @dp must be the /quota metadir.
 *
 * Returns -ENOENT if the quota inode field is NULLFSINO; 0 and an inode on
 * success; or a negative errno.
 */
int
xfs_dqinode_load(
	struct xfs_trans	*tp,
	struct xfs_inode	*dp,
	xfs_dqtype_t		type,
	struct xfs_inode	**ipp)
{
	struct xfs_mount	*mp = tp->t_mountp;
	struct xfs_inode	*ip;
	enum xfs_metafile_type	metafile_type = xfs_dqinode_metafile_type(type);
	int			error;

	if (!xfs_has_metadir(mp)) {
		xfs_ino_t	ino;

		switch (type) {
		case XFS_DQTYPE_USER:
			ino = mp->m_sb.sb_uquotino;
			break;
		case XFS_DQTYPE_GROUP:
			ino = mp->m_sb.sb_gquotino;
			break;
		case XFS_DQTYPE_PROJ:
			ino = mp->m_sb.sb_pquotino;
			break;
		default:
			ASSERT(0);
			return -EFSCORRUPTED;
		}

		/* Should have set 0 to NULLFSINO when loading superblock */
		if (ino == NULLFSINO)
			return -ENOENT;

		error = xfs_trans_metafile_iget(tp, ino, metafile_type, &ip);
	} else {
		error = xfs_metadir_load(tp, dp, xfs_dqinode_path(type),
				metafile_type, &ip);
		if (error == -ENOENT)
			return error;
	}
	if (error) {
		if (xfs_metadata_is_sick(error))
			xfs_fs_mark_sick(mp, xfs_dqinode_sick_mask(type));
		return error;
	}

	if (XFS_IS_CORRUPT(mp, ip->i_df.if_format != XFS_DINODE_FMT_EXTENTS &&
			       ip->i_df.if_format != XFS_DINODE_FMT_BTREE)) {
		xfs_irele(ip);
		xfs_fs_mark_sick(mp, xfs_dqinode_sick_mask(type));
		return -EFSCORRUPTED;
	}

	if (XFS_IS_CORRUPT(mp, ip->i_projid != 0)) {
		xfs_irele(ip);
		xfs_fs_mark_sick(mp, xfs_dqinode_sick_mask(type));
		return -EFSCORRUPTED;
	}

	*ipp = ip;
	return 0;
}

/* Create a metadata directory quota inode. */
int
xfs_dqinode_metadir_create(
	struct xfs_inode		*dp,
	xfs_dqtype_t			type,
	struct xfs_inode		**ipp)
{
	struct xfs_metadir_update	upd = {
		.dp			= dp,
		.metafile_type		= xfs_dqinode_metafile_type(type),
		.path			= xfs_dqinode_path(type),
	};
	int				error;

	error = xfs_metadir_start_create(&upd);
	if (error)
		return error;

	error = xfs_metadir_create(&upd, S_IFREG);
	if (error)
		return error;

	xfs_trans_log_inode(upd.tp, upd.ip, XFS_ILOG_CORE);

	error = xfs_metadir_commit(&upd);
	if (error)
		return error;

	xfs_finish_inode_setup(upd.ip);
	*ipp = upd.ip;
	return 0;
}

#ifndef __KERNEL__
/* Link a metadata directory quota inode. */
int
xfs_dqinode_metadir_link(
	struct xfs_inode		*dp,
	xfs_dqtype_t			type,
	struct xfs_inode		*ip)
{
	struct xfs_metadir_update	upd = {
		.dp			= dp,
		.metafile_type		= xfs_dqinode_metafile_type(type),
		.path			= xfs_dqinode_path(type),
		.ip			= ip,
	};
	int				error;

	error = xfs_metadir_start_link(&upd);
	if (error)
		return error;

	error = xfs_metadir_link(&upd);
	if (error)
		return error;

	xfs_trans_log_inode(upd.tp, upd.ip, XFS_ILOG_CORE);

	return xfs_metadir_commit(&upd);
}
#endif /* __KERNEL__ */

/* Create the parent directory for all quota inodes and load it. */
int
xfs_dqinode_mkdir_parent(
	struct xfs_mount	*mp,
	struct xfs_inode	**dpp)
{
	if (!mp->m_metadirip) {
		xfs_fs_mark_sick(mp, XFS_SICK_FS_METADIR);
		return -EFSCORRUPTED;
	}

	return xfs_metadir_mkdir(mp->m_metadirip, "quota", dpp);
}

/*
 * Load the parent directory of all quota inodes.  Pass the inode to the caller
 * because quota functions (e.g. QUOTARM) can be called on the quota files even
 * if quotas are not enabled.
 */
int
xfs_dqinode_load_parent(
	struct xfs_trans	*tp,
	struct xfs_inode	**dpp)
{
	struct xfs_mount	*mp = tp->t_mountp;

	if (!mp->m_metadirip) {
		xfs_fs_mark_sick(mp, XFS_SICK_FS_METADIR);
		return -EFSCORRUPTED;
	}

	return xfs_metadir_load(tp, mp->m_metadirip, "quota", XFS_METAFILE_DIR,
			dpp);
}