block: check for max_hw_sectors underflow

The logical block size need to be smaller than the max_hw_sector setting, otherwise we can't even transfer a single LBA.

Signed-off-by Hannes Reinecke <[email protected]>

---
  block/blk-settings.c | 8 ++++++--
  1 file changed, 6 insertions(+), 2 deletions(-)

block/blk-settings.c +1 -0

index d2731843f2fc..030afb597183 100644
@@ -104,6 +104,7 @@ static int blk_validate_zoned_limits(struct queue_limits *lim)
  static int blk_validate_limits(struct queue_limits *lim)
  {
  	unsigned int max_hw_sectors;
+	unsigned int logical_block_sectors;
 
  	/*
  	 * Unless otherwise specified, default to 512 byte logical blocks and a

block/blk-settings.c +2 -2

-			lim->logical_block_size >> SECTOR_SHIFT);
+			logical_block_sectors);
 
  	/*
  	 * The actual max_sectors value is a complex beast and also takes the

@@ -153,7 +157,7 @@ static int blk_validate_limits(struct queue_limits *lim)
  		lim->max_sectors = min(max_hw_sectors, BLK_DEF_MAX_SECTORS_CAP);
  	}
  	lim->max_sectors = round_down(lim->max_sectors,
-			lim->logical_block_size >> SECTOR_SHIFT);
+			logical_block_sectors);
 
  	/*
  	 * Random default for the maximum number of segments.  Driver should not

I don't think that we ever check if lim->logical_block_size is a power-of-2
- but that's a given, right?

Quoted 2 lines · John Garry

I don't think that we ever check if lim->logical_block_size is a power-of-2
- but that's a given, right?

It has to be for the block stack to work. That being said now that we do have a single good place for sanity checks it's probably worth to add this check explicitly.