[dm-devel] [PATCH] fix default IO restrictions

[Mike Christie <michaelc cs wisc edu>]

Becuase dm-table combines low against the default values, if all the 
devices in the table had IO restriction values greater than what is set 
in set_default_limits, the table's, target's, and DM queue's values will 
never get updated.

The attached patch fixes this by setting the initial defaults to 
unrealistic values, so the first added device will reset them.

The patch was made against 2.6.0-udm5.

Mike
--- linux-2.6.0-udm5.orig/drivers/md/dm-table.c	2004-01-22 20:22:55.000000000 -0800
+++ linux-2.6.0-udm5/drivers/md/dm-table.c	2004-01-22 20:27:01.041078794 -0800
@@ -633,11 +633,11 @@ static int split_args(int *argc, char **
 
 static void set_default_limits(struct io_restrictions *rs)
 {
-	rs->max_sectors = MAX_SECTORS;
-	rs->max_phys_segments = MAX_PHYS_SEGMENTS;
-	rs->max_hw_segments = MAX_HW_SEGMENTS;
-	rs->hardsect_size = 1 << SECTOR_SHIFT;
-	rs->max_segment_size = MAX_SEGMENT_SIZE;
+	rs->max_sectors = -1;
+	rs->max_phys_segments = -1;
+	rs->max_hw_segments = -1;
+	rs->hardsect_size = -1;
+	rs->max_segment_size = -1;
 	rs->seg_boundary_mask = -1;
 }