block: Set max_sectors correctly for stacking devices

The topology changes unintentionally caused SAFE_MAX_SECTORS to be set
for stacking devices.  Set the default limit to BLK_DEF_MAX_SECTORS and
provide SAFE_MAX_SECTORS in blk_queue_make_request() for legacy hw
drivers that depend on the old behavior.

Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 83413ff..cd9b730 100644 (file)
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -111,7 +111,7 @@ void blk_set_default_limits(struct queue_limits *lim)
        lim->max_hw_segments = MAX_HW_SEGMENTS;
        lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
        lim->max_segment_size = MAX_SEGMENT_SIZE;
-       lim->max_sectors = lim->max_hw_sectors = SAFE_MAX_SECTORS;
+       lim->max_sectors = lim->max_hw_sectors = BLK_DEF_MAX_SECTORS;
        lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
        lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
        lim->alignment_offset = 0;
@@ -164,6 +164,7 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
        q->unplug_timer.data = (unsigned long)q;
 
        blk_set_default_limits(&q->limits);
+       blk_queue_max_sectors(q, SAFE_MAX_SECTORS);
 
        /*
         * If the caller didn't supply a lock, fall back to our embedded