alistair23-linux/fs/xfs/xfs_inode_item_recover.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2006 Silicon Graphics, 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_trans.h"
#include "xfs_inode_item.h"
#include "xfs_trace.h"
#include "xfs_trans_priv.h"
#include "xfs_buf_item.h"
#include "xfs_log.h"
#include "xfs_error.h"
#include "xfs_log_priv.h"
#include "xfs_log_recover.h"
#include "xfs_icache.h"
#include "xfs_bmap_btree.h"

STATIC void
xlog_recover_inode_ra_pass2(
	struct xlog                     *log,
	struct xlog_recover_item        *item)
{
	if (item->ri_buf[0].i_len == sizeof(struct xfs_inode_log_format)) {
		struct xfs_inode_log_format	*ilfp = item->ri_buf[0].i_addr;

		xlog_buf_readahead(log, ilfp->ilf_blkno, ilfp->ilf_len,
				   &xfs_inode_buf_ra_ops);
	} else {
		struct xfs_inode_log_format_32	*ilfp = item->ri_buf[0].i_addr;

		xlog_buf_readahead(log, ilfp->ilf_blkno, ilfp->ilf_len,
				   &xfs_inode_buf_ra_ops);
	}
}

/*
 * Inode fork owner changes
 *
 * If we have been told that we have to reparent the inode fork, it's because an
 * extent swap operation on a CRC enabled filesystem has been done and we are
 * replaying it. We need to walk the BMBT of the appropriate fork and change the
 * owners of it.
 *
 * The complexity here is that we don't have an inode context to work with, so
 * after we've replayed the inode we need to instantiate one.  This is where the
 * fun begins.
 *
 * We are in the middle of log recovery, so we can't run transactions. That
 * means we cannot use cache coherent inode instantiation via xfs_iget(), as
 * that will result in the corresponding iput() running the inode through
 * xfs_inactive(). If we've just replayed an inode core that changes the link
 * count to zero (i.e. it's been unlinked), then xfs_inactive() will run
 * transactions (bad!).
 *
 * So, to avoid this, we instantiate an inode directly from the inode core we've
 * just recovered. We have the buffer still locked, and all we really need to
 * instantiate is the inode core and the forks being modified. We can do this
 * manually, then run the inode btree owner change, and then tear down the
 * xfs_inode without having to run any transactions at all.
 *
 * Also, because we don't have a transaction context available here but need to
 * gather all the buffers we modify for writeback so we pass the buffer_list
 * instead for the operation to use.
 */

STATIC int
xfs_recover_inode_owner_change(
	struct xfs_mount	*mp,
	struct xfs_dinode	*dip,
	struct xfs_inode_log_format *in_f,
	struct list_head	*buffer_list)
{
	struct xfs_inode	*ip;
	int			error;

	ASSERT(in_f->ilf_fields & (XFS_ILOG_DOWNER|XFS_ILOG_AOWNER));

	ip = xfs_inode_alloc(mp, in_f->ilf_ino);
	if (!ip)
		return -ENOMEM;

	/* instantiate the inode */
	ASSERT(dip->di_version >= 3);

	error = xfs_inode_from_disk(ip, dip);
	if (error)
		goto out_free_ip;

	if (in_f->ilf_fields & XFS_ILOG_DOWNER) {
		ASSERT(in_f->ilf_fields & XFS_ILOG_DBROOT);
		error = xfs_bmbt_change_owner(NULL, ip, XFS_DATA_FORK,
					      ip->i_ino, buffer_list);
		if (error)
			goto out_free_ip;
	}

	if (in_f->ilf_fields & XFS_ILOG_AOWNER) {
		ASSERT(in_f->ilf_fields & XFS_ILOG_ABROOT);
		error = xfs_bmbt_change_owner(NULL, ip, XFS_ATTR_FORK,
					      ip->i_ino, buffer_list);
		if (error)
			goto out_free_ip;
	}

out_free_ip:
	xfs_inode_free(ip);
	return error;
}

STATIC int
xlog_recover_inode_commit_pass2(
	struct xlog			*log,
	struct list_head		*buffer_list,
	struct xlog_recover_item	*item,
	xfs_lsn_t			current_lsn)
{
	struct xfs_inode_log_format	*in_f;
	struct xfs_mount		*mp = log->l_mp;
	struct xfs_buf			*bp;
	struct xfs_dinode		*dip;
	int				len;
	char				*src;
	char				*dest;
	int				error;
	int				attr_index;
	uint				fields;
	struct xfs_log_dinode		*ldip;
	uint				isize;
	int				need_free = 0;

	if (item->ri_buf[0].i_len == sizeof(struct xfs_inode_log_format)) {
		in_f = item->ri_buf[0].i_addr;
	} else {
		in_f = kmem_alloc(sizeof(struct xfs_inode_log_format), 0);
		need_free = 1;
		error = xfs_inode_item_format_convert(&item->ri_buf[0], in_f);
		if (error)
			goto error;
	}

	/*
	 * Inode buffers can be freed, look out for it,
	 * and do not replay the inode.
	 */
	if (xlog_is_buffer_cancelled(log, in_f->ilf_blkno, in_f->ilf_len)) {
		error = 0;
		trace_xfs_log_recover_inode_cancel(log, in_f);
		goto error;
	}
	trace_xfs_log_recover_inode_recover(log, in_f);

	error = xfs_buf_read(mp->m_ddev_targp, in_f->ilf_blkno, in_f->ilf_len,
			0, &bp, &xfs_inode_buf_ops);
	if (error)
		goto error;
	ASSERT(in_f->ilf_fields & XFS_ILOG_CORE);
	dip = xfs_buf_offset(bp, in_f->ilf_boffset);

	/*
	 * Make sure the place we're flushing out to really looks
	 * like an inode!
	 */
	if (XFS_IS_CORRUPT(mp, !xfs_verify_magic16(bp, dip->di_magic))) {
		xfs_alert(mp,
	"%s: Bad inode magic number, dip = "PTR_FMT", dino bp = "PTR_FMT", ino = %Ld",
			__func__, dip, bp, in_f->ilf_ino);
		error = -EFSCORRUPTED;
		goto out_release;
	}
	ldip = item->ri_buf[1].i_addr;
	if (XFS_IS_CORRUPT(mp, ldip->di_magic != XFS_DINODE_MAGIC)) {
		xfs_alert(mp,
			"%s: Bad inode log record, rec ptr "PTR_FMT", ino %Ld",
			__func__, item, in_f->ilf_ino);
		error = -EFSCORRUPTED;
		goto out_release;
	}

	/*
	 * If the inode has an LSN in it, recover the inode only if it's less
	 * than the lsn of the transaction we are replaying. Note: we still
	 * need to replay an owner change even though the inode is more recent
	 * than the transaction as there is no guarantee that all the btree
	 * blocks are more recent than this transaction, too.
	 */
	if (dip->di_version >= 3) {
		xfs_lsn_t	lsn = be64_to_cpu(dip->di_lsn);

		if (lsn && lsn != -1 && XFS_LSN_CMP(lsn, current_lsn) >= 0) {
			trace_xfs_log_recover_inode_skip(log, in_f);
			error = 0;
			goto out_owner_change;
		}
	}

	/*
	 * di_flushiter is only valid for v1/2 inodes. All changes for v3 inodes
	 * are transactional and if ordering is necessary we can determine that
	 * more accurately by the LSN field in the V3 inode core. Don't trust
	 * the inode versions we might be changing them here - use the
	 * superblock flag to determine whether we need to look at di_flushiter
	 * to skip replay when the on disk inode is newer than the log one
	 */
	if (!xfs_sb_version_has_v3inode(&mp->m_sb) &&
	    ldip->di_flushiter < be16_to_cpu(dip->di_flushiter)) {
		/*
		 * Deal with the wrap case, DI_MAX_FLUSH is less
		 * than smaller numbers
		 */
		if (be16_to_cpu(dip->di_flushiter) == DI_MAX_FLUSH &&
		    ldip->di_flushiter < (DI_MAX_FLUSH >> 1)) {
			/* do nothing */
		} else {
			trace_xfs_log_recover_inode_skip(log, in_f);
			error = 0;
			goto out_release;
		}
	}

	/* Take the opportunity to reset the flush iteration count */
	ldip->di_flushiter = 0;

	if (unlikely(S_ISREG(ldip->di_mode))) {
		if ((ldip->di_format != XFS_DINODE_FMT_EXTENTS) &&
		    (ldip->di_format != XFS_DINODE_FMT_BTREE)) {
			XFS_CORRUPTION_ERROR("xlog_recover_inode_pass2(3)",
					 XFS_ERRLEVEL_LOW, mp, ldip,
					 sizeof(*ldip));
			xfs_alert(mp,
		"%s: Bad regular inode log record, rec ptr "PTR_FMT", "
		"ino ptr = "PTR_FMT", ino bp = "PTR_FMT", ino %Ld",
				__func__, item, dip, bp, in_f->ilf_ino);
			error = -EFSCORRUPTED;
			goto out_release;
		}
	} else if (unlikely(S_ISDIR(ldip->di_mode))) {
		if ((ldip->di_format != XFS_DINODE_FMT_EXTENTS) &&
		    (ldip->di_format != XFS_DINODE_FMT_BTREE) &&
		    (ldip->di_format != XFS_DINODE_FMT_LOCAL)) {
			XFS_CORRUPTION_ERROR("xlog_recover_inode_pass2(4)",
					     XFS_ERRLEVEL_LOW, mp, ldip,
					     sizeof(*ldip));
			xfs_alert(mp,
		"%s: Bad dir inode log record, rec ptr "PTR_FMT", "
		"ino ptr = "PTR_FMT", ino bp = "PTR_FMT", ino %Ld",
				__func__, item, dip, bp, in_f->ilf_ino);
			error = -EFSCORRUPTED;
			goto out_release;
		}
	}
	if (unlikely(ldip->di_nextents + ldip->di_anextents > ldip->di_nblocks)){
		XFS_CORRUPTION_ERROR("xlog_recover_inode_pass2(5)",
				     XFS_ERRLEVEL_LOW, mp, ldip,
				     sizeof(*ldip));
		xfs_alert(mp,
	"%s: Bad inode log record, rec ptr "PTR_FMT", dino ptr "PTR_FMT", "
	"dino bp "PTR_FMT", ino %Ld, total extents = %d, nblocks = %Ld",
			__func__, item, dip, bp, in_f->ilf_ino,
			ldip->di_nextents + ldip->di_anextents,
			ldip->di_nblocks);
		error = -EFSCORRUPTED;
		goto out_release;
	}
	if (unlikely(ldip->di_forkoff > mp->m_sb.sb_inodesize)) {
		XFS_CORRUPTION_ERROR("xlog_recover_inode_pass2(6)",
				     XFS_ERRLEVEL_LOW, mp, ldip,
				     sizeof(*ldip));
		xfs_alert(mp,
	"%s: Bad inode log record, rec ptr "PTR_FMT", dino ptr "PTR_FMT", "
	"dino bp "PTR_FMT", ino %Ld, forkoff 0x%x", __func__,
			item, dip, bp, in_f->ilf_ino, ldip->di_forkoff);
		error = -EFSCORRUPTED;
		goto out_release;
	}
	isize = xfs_log_dinode_size(mp);
	if (unlikely(item->ri_buf[1].i_len > isize)) {
		XFS_CORRUPTION_ERROR("xlog_recover_inode_pass2(7)",
				     XFS_ERRLEVEL_LOW, mp, ldip,
				     sizeof(*ldip));
		xfs_alert(mp,
			"%s: Bad inode log record length %d, rec ptr "PTR_FMT,
			__func__, item->ri_buf[1].i_len, item);
		error = -EFSCORRUPTED;
		goto out_release;
	}

	/* recover the log dinode inode into the on disk inode */
	xfs_log_dinode_to_disk(ldip, dip);

	fields = in_f->ilf_fields;
	if (fields & XFS_ILOG_DEV)
		xfs_dinode_put_rdev(dip, in_f->ilf_u.ilfu_rdev);

	if (in_f->ilf_size == 2)
		goto out_owner_change;
	len = item->ri_buf[2].i_len;
	src = item->ri_buf[2].i_addr;
	ASSERT(in_f->ilf_size <= 4);
	ASSERT((in_f->ilf_size == 3) || (fields & XFS_ILOG_AFORK));
	ASSERT(!(fields & XFS_ILOG_DFORK) ||
	       (len == in_f->ilf_dsize));

	switch (fields & XFS_ILOG_DFORK) {
	case XFS_ILOG_DDATA:
	case XFS_ILOG_DEXT:
		memcpy(XFS_DFORK_DPTR(dip), src, len);
		break;

	case XFS_ILOG_DBROOT:
		xfs_bmbt_to_bmdr(mp, (struct xfs_btree_block *)src, len,
				 (struct xfs_bmdr_block *)XFS_DFORK_DPTR(dip),
				 XFS_DFORK_DSIZE(dip, mp));
		break;

	default:
		/*
		 * There are no data fork flags set.
		 */
		ASSERT((fields & XFS_ILOG_DFORK) == 0);
		break;
	}

	/*
	 * If we logged any attribute data, recover it.  There may or
	 * may not have been any other non-core data logged in this
	 * transaction.
	 */
	if (in_f->ilf_fields & XFS_ILOG_AFORK) {
		if (in_f->ilf_fields & XFS_ILOG_DFORK) {
			attr_index = 3;
		} else {
			attr_index = 2;
		}
		len = item->ri_buf[attr_index].i_len;
		src = item->ri_buf[attr_index].i_addr;
		ASSERT(len == in_f->ilf_asize);

		switch (in_f->ilf_fields & XFS_ILOG_AFORK) {
		case XFS_ILOG_ADATA:
		case XFS_ILOG_AEXT:
			dest = XFS_DFORK_APTR(dip);
			ASSERT(len <= XFS_DFORK_ASIZE(dip, mp));
			memcpy(dest, src, len);
			break;

		case XFS_ILOG_ABROOT:
			dest = XFS_DFORK_APTR(dip);
			xfs_bmbt_to_bmdr(mp, (struct xfs_btree_block *)src,
					 len, (struct xfs_bmdr_block *)dest,
					 XFS_DFORK_ASIZE(dip, mp));
			break;

		default:
			xfs_warn(log->l_mp, "%s: Invalid flag", __func__);
			ASSERT(0);
			error = -EFSCORRUPTED;
			goto out_release;
		}
	}

out_owner_change:
	/* Recover the swapext owner change unless inode has been deleted */
	if ((in_f->ilf_fields & (XFS_ILOG_DOWNER|XFS_ILOG_AOWNER)) &&
	    (dip->di_mode != 0))
		error = xfs_recover_inode_owner_change(mp, dip, in_f,
						       buffer_list);
	/* re-generate the checksum. */
	xfs_dinode_calc_crc(log->l_mp, dip);

	ASSERT(bp->b_mount == mp);
	bp->b_flags |= _XBF_LOGRECOVERY;
	xfs_buf_delwri_queue(bp, buffer_list);

out_release:
	xfs_buf_relse(bp);
error:
	if (need_free)
		kmem_free(in_f);
	return error;
}

const struct xlog_recover_item_ops xlog_inode_item_ops = {
	.item_type		= XFS_LI_INODE,
	.ra_pass2		= xlog_recover_inode_ra_pass2,
	.commit_pass2		= xlog_recover_inode_commit_pass2,
};