Commit 23ffa52c authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: refactor unlinked list search and mapping to a separate function 



There's a loop that searches an unlinked bucket list to find the inode
that points to a given inode.  Hoist this into a separate function;
later we'll use our iunlink backref cache to bypass the slow list
operation.  No functional changes.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
parent f2fc16a3

fs/xfs/xfs_inode.c

+96 −38
Original line number Original line Diff line number Diff line
@@ -2082,6 +2082,97 @@ xfs_iunlink( 
	return xfs_iunlink_update_bucket(tp, agno, agibp, bucket_index, agino);

	return xfs_iunlink_update_bucket(tp, agno, agibp, bucket_index, agino);

}

}





/* Return the imap, dinode pointer, and buffer for an inode. */

STATIC int

xfs_iunlink_map_ino(

	struct xfs_trans	*tp,

	xfs_agnumber_t		agno,

	xfs_agino_t		agino,

	struct xfs_imap		*imap,

	struct xfs_dinode	**dipp,

	struct xfs_buf		**bpp)

{

	struct xfs_mount	*mp = tp->t_mountp;

	int			error;



	imap->im_blkno = 0;

	error = xfs_imap(mp, tp, XFS_AGINO_TO_INO(mp, agno, agino), imap, 0);

	if (error) {

		xfs_warn(mp, "%s: xfs_imap returned error %d.",

				__func__, error);

		return error;

	}



	error = xfs_imap_to_bp(mp, tp, imap, dipp, bpp, 0, 0);

	if (error) {

		xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",

				__func__, error);

		return error;

	}



	return 0;

}



/*

 * Walk the unlinked chain from @head_agino until we find the inode that

 * points to @target_agino.  Return the inode number, map, dinode pointer,

 * and inode cluster buffer of that inode as @agino, @imap, @dipp, and @bpp.

 *

 * @tp, @pag, @head_agino, and @target_agino are input parameters.

 * @agino, @imap, @dipp, and @bpp are all output parameters.

 *

 * Do not call this function if @target_agino is the head of the list.

 */

STATIC int

xfs_iunlink_map_prev(

	struct xfs_trans	*tp,

	xfs_agnumber_t		agno,

	xfs_agino_t		head_agino,

	xfs_agino_t		target_agino,

	xfs_agino_t		*agino,

	struct xfs_imap		*imap,

	struct xfs_dinode	**dipp,

	struct xfs_buf		**bpp)

{

	struct xfs_mount	*mp = tp->t_mountp;

	xfs_agino_t		next_agino;

	int			error;



	ASSERT(head_agino != target_agino);

	*bpp = NULL;



	next_agino = head_agino;

	while (next_agino != target_agino) {

		xfs_agino_t	unlinked_agino;



		if (*bpp)

			xfs_trans_brelse(tp, *bpp);



		*agino = next_agino;

		error = xfs_iunlink_map_ino(tp, agno, next_agino, imap, dipp,

				bpp);

		if (error)

			return error;



		unlinked_agino = be32_to_cpu((*dipp)->di_next_unlinked);

		/*

		 * Make sure this pointer is valid and isn't an obvious

		 * infinite loop.

		 */

		if (!xfs_verify_agino(mp, agno, unlinked_agino) ||

		    next_agino == unlinked_agino) {

			XFS_CORRUPTION_ERROR(__func__,

					XFS_ERRLEVEL_LOW, mp,

					*dipp, sizeof(**dipp));

			error = -EFSCORRUPTED;

			return error;

		}

		next_agino = unlinked_agino;

	}



	return 0;

}



/*

/*

 * Pull the on-disk inode from the AGI unlinked list.

 * Pull the on-disk inode from the AGI unlinked list.

 */

 */
@@ -2095,7 +2186,6 @@ xfs_iunlink_remove( 
	struct xfs_buf		*agibp;

	struct xfs_buf		*agibp;

	struct xfs_buf		*last_ibp;

	struct xfs_buf		*last_ibp;

	struct xfs_dinode	*last_dip = NULL;

	struct xfs_dinode	*last_dip = NULL;

	xfs_ino_t		next_ino;

	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, ip->i_ino);

	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, ip->i_ino);

	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, ip->i_ino);

	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, ip->i_ino);

	xfs_agino_t		next_agino;

	xfs_agino_t		next_agino;
@@ -2138,43 +2228,11 @@ xfs_iunlink_remove( 
		struct xfs_imap	imap;

		struct xfs_imap	imap;

		xfs_agino_t	prev_agino;

		xfs_agino_t	prev_agino;





		/*

		/* We need to search the list for the inode being freed. */

		 * We need to search the list for the inode being freed.

		error = xfs_iunlink_map_prev(tp, agno, next_agino, agino,

		 */

				&prev_agino, &imap, &last_dip, &last_ibp);

		last_ibp = NULL;

		if (error)

		while (next_agino != agino) {

			if (last_ibp)

				xfs_trans_brelse(tp, last_ibp);



			imap.im_blkno = 0;

			next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);



			error = xfs_imap(mp, tp, next_ino, &imap, 0);

			if (error) {

				xfs_warn(mp,

	"%s: xfs_imap returned error %d.",

					 __func__, error);

				return error;

			}



			error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,

					       &last_ibp, 0, 0);

			if (error) {

				xfs_warn(mp,

	"%s: xfs_imap_to_bp returned error %d.",

					__func__, error);

			return error;

			return error;

			}



			prev_agino = next_agino;

			next_agino = be32_to_cpu(last_dip->di_next_unlinked);

			if (!xfs_verify_agino(mp, agno, next_agino)) {

				XFS_CORRUPTION_ERROR(__func__,

						XFS_ERRLEVEL_LOW, mp,

						last_dip, sizeof(*last_dip));

				return -EFSCORRUPTED;

			}

		}





		/*

		/*

		 * Now last_ibp points to the buffer previous to us on the

		 * Now last_ibp points to the buffer previous to us on the