block: Correct handling of bottom device misaligment

The top device misalignment flag would not be set if the added bottom device was already misaligned as opposed to causing a stacking failure. Also massage the reporting so that an error is only returned if adding the bottom device caused the misalignment. I.e. don't return an error if the top is already flagged as misaligned. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block: Correct handling of bottom device misaligment
The top device misalignment flag would not be set if the added bottom device was already misaligned as opposed to causing a stacking failure. Also massage the reporting so that an error is only returned if adding the bottom device caused the misalignment. I.e. don't return an error if the top is already flagged as misaligned. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Martin K. Petersen · Jens Axboe
1 parent c1152949bb
Showing 1 changed file with 13 additions and 4 deletions Side-by-side Diff
block/blk-settings.c
@@ -528,7 +528,7 @@
 		     sector_t offset)
 {
 	sector_t alignment;
-	unsigned int top, bottom;
+	unsigned int top, bottom, ret = 0;
  
 	t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
 	t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
@@ -546,6 +546,8 @@
 	t->max_segment_size = min_not_zero(t->max_segment_size,
 					   b->max_segment_size);
  
+	t->misaligned |= b->misaligned;
+
 	alignment = queue_limit_alignment_offset(b, offset);
  
 	/* Bottom device has different alignment.  Check that it is
  
@@ -558,8 +560,10 @@
 		bottom = max(b->physical_block_size, b->io_min) + alignment;
  
 		/* Verify that top and bottom intervals line up */
-		if (max(top, bottom) & (min(top, bottom) - 1))
+		if (max(top, bottom) & (min(top, bottom) - 1)) {
 			t->misaligned = 1;
+			ret = -1;
+		}
 	}
  
 	t->logical_block_size = max(t->logical_block_size,
  
  
@@ -578,18 +582,21 @@
 	if (t->physical_block_size & (t->logical_block_size - 1)) {
 		t->physical_block_size = t->logical_block_size;
 		t->misaligned = 1;
+		ret = -1;
 	}
  
 	/* Minimum I/O a multiple of the physical block size? */
 	if (t->io_min & (t->physical_block_size - 1)) {
 		t->io_min = t->physical_block_size;
 		t->misaligned = 1;
+		ret = -1;
 	}
  
 	/* Optimal I/O a multiple of the physical block size? */
 	if (t->io_opt & (t->physical_block_size - 1)) {
 		t->io_opt = 0;
 		t->misaligned = 1;
+		ret = -1;
 	}
  
 	/* Find lowest common alignment_offset */
  
@@ -597,8 +604,10 @@
 		& (max(t->physical_block_size, t->io_min) - 1);
  
 	/* Verify that new alignment_offset is on a logical block boundary */
-	if (t->alignment_offset & (t->logical_block_size - 1))
+	if (t->alignment_offset & (t->logical_block_size - 1)) {
 		t->misaligned = 1;
+		ret = -1;
+	}
  
 	/* Discard alignment and granularity */
 	if (b->discard_granularity) {
@@ -626,7 +635,7 @@
 			(t->discard_granularity - 1);
 	}
  
-	return t->misaligned ? -1 : 0;
+	return ret;
 }
 EXPORT_SYMBOL(blk_stack_limits);
...	...	@@ -528,7 +528,7 @@
528	528	sector_t offset)
529	529	{
530	530	sector_t alignment;
531		- unsigned int top, bottom;
	531	+ unsigned int top, bottom, ret = 0;
532	532
533	533	t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
534	534	t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
...	...	@@ -546,6 +546,8 @@
546	546	t->max_segment_size = min_not_zero(t->max_segment_size,
547	547	b->max_segment_size);
548	548
	549	+ t->misaligned \|= b->misaligned;
	550	+
549	551	alignment = queue_limit_alignment_offset(b, offset);
550	552
551	553	/* Bottom device has different alignment. Check that it is
552	554
...	...	@@ -558,8 +560,10 @@
558	560	bottom = max(b->physical_block_size, b->io_min) + alignment;
559	561
560	562	/* Verify that top and bottom intervals line up */
561		- if (max(top, bottom) & (min(top, bottom) - 1))
	563	+ if (max(top, bottom) & (min(top, bottom) - 1)) {
562	564	t->misaligned = 1;
	565	+ ret = -1;
	566	+ }
563	567	}
564	568
565	569	t->logical_block_size = max(t->logical_block_size,
566	570
567	571
...	...	@@ -578,18 +582,21 @@
578	582	if (t->physical_block_size & (t->logical_block_size - 1)) {
579	583	t->physical_block_size = t->logical_block_size;
580	584	t->misaligned = 1;
	585	+ ret = -1;
581	586	}
582	587
583	588	/* Minimum I/O a multiple of the physical block size? */
584	589	if (t->io_min & (t->physical_block_size - 1)) {
585	590	t->io_min = t->physical_block_size;
586	591	t->misaligned = 1;
	592	+ ret = -1;
587	593	}
588	594
589	595	/* Optimal I/O a multiple of the physical block size? */
590	596	if (t->io_opt & (t->physical_block_size - 1)) {
591	597	t->io_opt = 0;
592	598	t->misaligned = 1;
	599	+ ret = -1;
593	600	}
594	601
595	602	/* Find lowest common alignment_offset */
596	603
...	...	@@ -597,8 +604,10 @@
597	604	& (max(t->physical_block_size, t->io_min) - 1);
598	605
599	606	/* Verify that new alignment_offset is on a logical block boundary */
600		- if (t->alignment_offset & (t->logical_block_size - 1))
	607	+ if (t->alignment_offset & (t->logical_block_size - 1)) {
601	608	t->misaligned = 1;
	609	+ ret = -1;
	610	+ }
602	611
603	612	/* Discard alignment and granularity */
604	613	if (b->discard_granularity) {
...	...	@@ -626,7 +635,7 @@
626	635	(t->discard_granularity - 1);
627	636	}
628	637
629		- return t->misaligned ? -1 : 0;
	638	+ return ret;
630	639	}
631	640	EXPORT_SYMBOL(blk_stack_limits);
632	641