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authorOmar Sandoval <osandov@fb.com>2017-08-24 00:03:42 -0700
committerJens Axboe <axboe@kernel.dk>2017-08-31 13:51:12 -0600
commit6c6b6f28b3335fd85ec833ee0005d9c9dca6c003 (patch)
tree47c20664f91ebd3591628a8ec52ca06b7dbbef76 /drivers/block
parent8a0740c4109d646d8697d359962edea47301c652 (diff)
downloadlinux-6c6b6f28b3335fd85ec833ee0005d9c9dca6c003.tar.bz2
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>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/loop.c2
1 files changed, 2 insertions, 0 deletions
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.