Commit 39aff5fd authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: refactor swapext code 



Refactor the swapext function to pull out the fork swapping piece
into a separate function.  In the next patch we'll add in the bit
we need to make it work with rmap filesystems.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent e06259aa

fs/xfs/xfs_bmap_util.c

+144 −131
Original line number Diff line number Diff line
@@ -1649,127 +1649,37 @@ xfs_swap_extent_flush( 
	return 0;

}



int

xfs_swap_extents(

	struct xfs_inode	*ip,	/* target inode */

	struct xfs_inode	*tip,	/* tmp inode */

	struct xfs_swapext	*sxp)

/* Swap the extents of two files by swapping data forks. */

STATIC int

xfs_swap_extent_forks(

	struct xfs_trans	*tp,

	struct xfs_inode	*ip,

	struct xfs_inode	*tip,

	int			*src_log_flags,

	int			*target_log_flags)

{

	struct xfs_mount	*mp = ip->i_mount;

	struct xfs_trans	*tp;

	struct xfs_bstat	*sbp = &sxp->sx_stat;

	struct xfs_ifork	*tempifp, *ifp, *tifp;

	int			src_log_flags, target_log_flags;

	int			error = 0;

	struct xfs_ifork	tempifp, *ifp, *tifp;

	int			aforkblks = 0;

	int			taforkblks = 0;

	__uint64_t		tmp;

	int			lock_flags;

	struct xfs_ifork	*cowfp;

	__uint64_t		f;



	/* XXX: we can't do this with rmap, will fix later */

	if (xfs_sb_version_hasrmapbt(&mp->m_sb))

		return -EOPNOTSUPP;



	tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);

	if (!tempifp) {

		error = -ENOMEM;

		goto out;

	}



	/*

	 * Lock the inodes against other IO, page faults and truncate to

	 * begin with.  Then we can ensure the inodes are flushed and have no

	 * page cache safely. Once we have done this we can take the ilocks and

	 * do the rest of the checks.

	 */

	lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;

	xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);

	xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL);



	/* Verify that both files have the same format */

	if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {

		error = -EINVAL;

		goto out_unlock;

	}



	/* Verify both files are either real-time or non-realtime */

	if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {

		error = -EINVAL;

		goto out_unlock;

	}



	error = xfs_swap_extent_flush(ip);

	if (error)

		goto out_unlock;

	error = xfs_swap_extent_flush(tip);

	if (error)

		goto out_unlock;



	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);

	if (error)

		goto out_unlock;



	/*

	 * Lock and join the inodes to the tansaction so that transaction commit

	 * or cancel will unlock the inodes from this point onwards.

	 */

	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);

	lock_flags |= XFS_ILOCK_EXCL;

	xfs_trans_ijoin(tp, ip, lock_flags);

	xfs_trans_ijoin(tp, tip, lock_flags);





	/* Verify all data are being swapped */

	if (sxp->sx_offset != 0 ||

	    sxp->sx_length != ip->i_d.di_size ||

	    sxp->sx_length != tip->i_d.di_size) {

		error = -EFAULT;

		goto out_trans_cancel;

	}



	trace_xfs_swap_extent_before(ip, 0);

	trace_xfs_swap_extent_before(tip, 1);



	/* check inode formats now that data is flushed */

	error = xfs_swap_extents_check_format(ip, tip);

	if (error) {

		xfs_notice(mp,

		    "%s: inode 0x%llx format is incompatible for exchanging.",

				__func__, ip->i_ino);

		goto out_trans_cancel;

	}

	int			error;



	/*

	 * Compare the current change & modify times with that

	 * passed in.  If they differ, we abort this swap.

	 * This is the mechanism used to ensure the calling

	 * process that the file was not changed out from

	 * under it.

	 */

	if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||

	    (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||

	    (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||

	    (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {

		error = -EBUSY;

		goto out_trans_cancel;

	}

	/*

	 * Count the number of extended attribute blocks

	 */

	if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&

	     (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {

		error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);

		error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK,

				&aforkblks);

		if (error)

			goto out_trans_cancel;

			return error;

	}

	if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&

	     (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {

		error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,

				&taforkblks);

		if (error)

			goto out_trans_cancel;

			return error;

	}



	/*
@@ -1778,31 +1688,23 @@ xfs_swap_extents( 
	 * buffers, and so the validation done on read will expect the owner

	 * field to be correctly set. Once we change the owners, we can swap the

	 * inode forks.

	 *

	 * Note the trickiness in setting the log flags - we set the owner log

	 * flag on the opposite inode (i.e. the inode we are setting the new

	 * owner to be) because once we swap the forks and log that, log

	 * recovery is going to see the fork as owned by the swapped inode,

	 * not the pre-swapped inodes.

	 */

	src_log_flags = XFS_ILOG_CORE;

	target_log_flags = XFS_ILOG_CORE;

	if (ip->i_d.di_version == 3 &&

	    ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {

		target_log_flags |= XFS_ILOG_DOWNER;

		(*target_log_flags) |= XFS_ILOG_DOWNER;

		error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK,

					      tip->i_ino, NULL);

		if (error)

			goto out_trans_cancel;

			return error;

	}



	if (tip->i_d.di_version == 3 &&

	    tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {

		src_log_flags |= XFS_ILOG_DOWNER;

		(*src_log_flags) |= XFS_ILOG_DOWNER;

		error = xfs_bmbt_change_owner(tp, tip, XFS_DATA_FORK,

					      ip->i_ino, NULL);

		if (error)

			goto out_trans_cancel;

			return error;

	}



	/*
@@ -1810,9 +1712,9 @@ xfs_swap_extents( 
	 */

	ifp = &ip->i_df;

	tifp = &tip->i_df;

	*tempifp = *ifp;	/* struct copy */

	tempifp = *ifp;		/* struct copy */

	*ifp = *tifp;		/* struct copy */

	*tifp = *tempifp;	/* struct copy */

	*tifp = tempifp;	/* struct copy */



	/*

	 * Fix the on-disk inode values
@@ -1852,12 +1754,12 @@ xfs_swap_extents( 
			ifp->if_u1.if_extents =

				ifp->if_u2.if_inline_ext;

		}

		src_log_flags |= XFS_ILOG_DEXT;

		(*src_log_flags) |= XFS_ILOG_DEXT;

		break;

	case XFS_DINODE_FMT_BTREE:

		ASSERT(ip->i_d.di_version < 3 ||

		       (src_log_flags & XFS_ILOG_DOWNER));

		src_log_flags |= XFS_ILOG_DBROOT;

		       (*src_log_flags & XFS_ILOG_DOWNER));

		(*src_log_flags) |= XFS_ILOG_DBROOT;

		break;

	}
@@ -1871,15 +1773,126 @@ xfs_swap_extents( 
			tifp->if_u1.if_extents =

				tifp->if_u2.if_inline_ext;

		}

		target_log_flags |= XFS_ILOG_DEXT;

		(*target_log_flags) |= XFS_ILOG_DEXT;

		break;

	case XFS_DINODE_FMT_BTREE:

		target_log_flags |= XFS_ILOG_DBROOT;

		(*target_log_flags) |= XFS_ILOG_DBROOT;

		ASSERT(tip->i_d.di_version < 3 ||

		       (target_log_flags & XFS_ILOG_DOWNER));

		       (*target_log_flags & XFS_ILOG_DOWNER));

		break;

	}



	return 0;

}



int

xfs_swap_extents(

	struct xfs_inode	*ip,	/* target inode */

	struct xfs_inode	*tip,	/* tmp inode */

	struct xfs_swapext	*sxp)

{

	struct xfs_mount	*mp = ip->i_mount;

	struct xfs_trans	*tp;

	struct xfs_bstat	*sbp = &sxp->sx_stat;

	int			src_log_flags, target_log_flags;

	int			error = 0;

	int			lock_flags;

	struct xfs_ifork	*cowfp;

	__uint64_t		f;



	/*

	 * Lock the inodes against other IO, page faults and truncate to

	 * begin with.  Then we can ensure the inodes are flushed and have no

	 * page cache safely. Once we have done this we can take the ilocks and

	 * do the rest of the checks.

	 */

	lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;

	xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);

	xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL);



	/* Verify that both files have the same format */

	if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {

		error = -EINVAL;

		goto out_unlock;

	}



	/* Verify both files are either real-time or non-realtime */

	if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {

		error = -EINVAL;

		goto out_unlock;

	}



	error = xfs_swap_extent_flush(ip);

	if (error)

		goto out_unlock;

	error = xfs_swap_extent_flush(tip);

	if (error)

		goto out_unlock;



	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);

	if (error)

		goto out_unlock;



	/*

	 * Lock and join the inodes to the tansaction so that transaction commit

	 * or cancel will unlock the inodes from this point onwards.

	 */

	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);

	lock_flags |= XFS_ILOCK_EXCL;

	xfs_trans_ijoin(tp, ip, 0);

	xfs_trans_ijoin(tp, tip, 0);





	/* Verify all data are being swapped */

	if (sxp->sx_offset != 0 ||

	    sxp->sx_length != ip->i_d.di_size ||

	    sxp->sx_length != tip->i_d.di_size) {

		error = -EFAULT;

		goto out_trans_cancel;

	}



	trace_xfs_swap_extent_before(ip, 0);

	trace_xfs_swap_extent_before(tip, 1);



	/* check inode formats now that data is flushed */

	error = xfs_swap_extents_check_format(ip, tip);

	if (error) {

		xfs_notice(mp,

		    "%s: inode 0x%llx format is incompatible for exchanging.",

				__func__, ip->i_ino);

		goto out_trans_cancel;

	}



	/*

	 * Compare the current change & modify times with that

	 * passed in.  If they differ, we abort this swap.

	 * This is the mechanism used to ensure the calling

	 * process that the file was not changed out from

	 * under it.

	 */

	if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||

	    (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||

	    (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||

	    (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {

		error = -EBUSY;

		goto out_trans_cancel;

	}



	/*

	 * Note the trickiness in setting the log flags - we set the owner log

	 * flag on the opposite inode (i.e. the inode we are setting the new

	 * owner to be) because once we swap the forks and log that, log

	 * recovery is going to see the fork as owned by the swapped inode,

	 * not the pre-swapped inodes.

	 */

	src_log_flags = XFS_ILOG_CORE;

	target_log_flags = XFS_ILOG_CORE;



	error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags,

			&target_log_flags);

	if (error)

		goto out_trans_cancel;



	/* Do we have to swap reflink flags? */

	if ((ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK) ^

	    (tip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK)) {
@@ -1909,16 +1922,16 @@ xfs_swap_extents( 


	trace_xfs_swap_extent_after(ip, 0);

	trace_xfs_swap_extent_after(tip, 1);

out:

	kmem_free(tempifp);

	return error;



out_unlock:

	xfs_iunlock(ip, lock_flags);

	xfs_iunlock(tip, lock_flags);

	goto out;

	return error;



out_trans_cancel:

	xfs_trans_cancel(tp);

	goto out;



out_unlock:

	xfs_iunlock(ip, lock_flags);

	xfs_iunlock(tip, lock_flags);

	return error;

}

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