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>
diff --git a/block/blk-settings.c b/block/blk-settings.c
index d52d4ad..127f825 100644
--- a/block/blk-settings.c
+++ b/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);