[PATCH 2/9] SQUASHME: pmem: Request from fdisk 4k alignment

[Boaz Harrosh <boaz@plexistor.com>]

From: Boaz Harrosh <boaz@plexistor.com>

Because of the direct_access() API which returns a PFN. partitions
better start on 4K boundary, else offset ZERO of a partition will
not be aligned and blk_direct_access() will fail the call.

By setting blk_queue_physical_block_size(PAGE_SIZE) we can communicate
this to fdisk and friends.
Note that blk_queue_physical_block_size() also trashes io_min, but
we can leave this one to be 512.

Signed-off-by: Boaz Harrosh <boaz@plexistor.com>
---
 drivers/block/pmem.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c
index 8b0b9b0..499536c 100644
--- a/drivers/block/pmem.c
+++ b/drivers/block/pmem.c
@@ -258,6 +258,12 @@ static struct pmem_device *pmem_alloc(int i)
 	blk_queue_max_hw_sectors(pmem->pmem_queue, 1024);
 	blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
 
+	/* This is so fdisk will align partitions on 4k, because of
+	 * direct_access API needing 4k alignment, returning a PFN
+	 */
+	blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE);
+	pmem->pmem_queue->limits.io_min = 512; /* Don't use the accessor */
+
 	disk = pmem->pmem_disk = alloc_disk(0);
 	if (!disk)
 		goto out_free_queue;
-- 
1.9.3