From: Omar Sandoval <osandov@fb.com>
Date: Thu, 24 Aug 2017 07:03:42 +0000 (-0700)
Subject: loop: set physical block size to PAGE_SIZE
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6c6b6f28b3335fd85ec833ee0005d9c9dca6c003;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

loop: set physical block size to PAGE_SIZE

The physical block size is "the lowest possible sector size that the
hardware can operate on without reverting to read-modify-write
operations" (from the comment on blk_queue_physical_block_size()). Since
loop does buffered I/O on the backing file by default, the RMW unit is a
page. This isn't the case for direct I/O mode, but let's keep it simple.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index efad2d46a018..e3f190016d4f 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1764,6 +1764,8 @@ static int loop_add(struct loop_device **l, int i)
 	}
 	lo->lo_queue->queuedata = lo;
 
+	blk_queue_physical_block_size(lo->lo_queue, PAGE_SIZE);
+
 	/*
 	 * It doesn't make sense to enable merge because the I/O
 	 * submitted to backing file is handled page by page.