xfs: clean up bmap intent item recovery checking

The bmap intent item checking code in xfs_bui_item_recover is spread all
over the function.  We should check the recovered log item at the top
before we allocate any resources or do anything else, so do that.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/xfs_bmap_item.c

@@ -437,8 +437,6 @@ xfs_bui_item_recover(
 	xfs_fsblock_t			inode_fsb;
 	xfs_filblks_t			count;
 	xfs_exntst_t			state;
-	enum xfs_bmap_intent_type	type;
-	bool				op_ok;
 	unsigned int			bui_type;
 	int				whichfork;
 	int				error = 0;
@@ -456,16 +454,19 @@ xfs_bui_item_recover(
 			   XFS_FSB_TO_DADDR(mp, bmap->me_startblock));
 	inode_fsb = XFS_BB_TO_FSB(mp, XFS_FSB_TO_DADDR(mp,
 			XFS_INO_TO_FSB(mp, bmap->me_owner)));
-	switch (bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK) {
+	state = (bmap->me_flags & XFS_BMAP_EXTENT_UNWRITTEN) ?
+			XFS_EXT_UNWRITTEN : XFS_EXT_NORM;
+	whichfork = (bmap->me_flags & XFS_BMAP_EXTENT_ATTR_FORK) ?
+			XFS_ATTR_FORK : XFS_DATA_FORK;
+	bui_type = bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK;
+	switch (bui_type) {
 	case XFS_BMAP_MAP:
 	case XFS_BMAP_UNMAP:
-		op_ok = true;
 		break;
 	default:
-		op_ok = false;
-		break;
+		return -EFSCORRUPTED;
 	}
-	if (!op_ok || startblock_fsb == 0 ||
+	if (startblock_fsb == 0 ||
 	    bmap->me_len == 0 ||
 	    inode_fsb == 0 ||
 	    startblock_fsb >= mp->m_sb.sb_dblocks ||
@@ -493,32 +494,17 @@ xfs_bui_item_recover(
 	if (VFS_I(ip)->i_nlink == 0)
 		xfs_iflags_set(ip, XFS_IRECOVERY);
 
-	/* Process deferred bmap item. */
-	state = (bmap->me_flags & XFS_BMAP_EXTENT_UNWRITTEN) ?
-			XFS_EXT_UNWRITTEN : XFS_EXT_NORM;
-	whichfork = (bmap->me_flags & XFS_BMAP_EXTENT_ATTR_FORK) ?
-			XFS_ATTR_FORK : XFS_DATA_FORK;
-	bui_type = bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK;
-	switch (bui_type) {
-	case XFS_BMAP_MAP:
-	case XFS_BMAP_UNMAP:
-		type = bui_type;
-		break;
-	default:
-		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
-		error = -EFSCORRUPTED;
-		goto err_inode;
-	}
 	xfs_trans_ijoin(tp, ip, 0);
 
 	count = bmap->me_len;
-	error = xfs_trans_log_finish_bmap_update(tp, budp, type, ip, whichfork,
-			bmap->me_startoff, bmap->me_startblock, &count, state);
+	error = xfs_trans_log_finish_bmap_update(tp, budp, bui_type, ip,
+			whichfork, bmap->me_startoff, bmap->me_startblock,
+			&count, state);
 	if (error)
 		goto err_inode;
 
 	if (count > 0) {
-		ASSERT(type == XFS_BMAP_UNMAP);
+		ASSERT(bui_type == XFS_BMAP_UNMAP);
 		irec.br_startblock = bmap->me_startblock;
 		irec.br_blockcount = count;
 		irec.br_startoff = bmap->me_startoff;