loop: set physical block size to PAGE_SIZE
authorOmar Sandoval <osandov@fb.com>
Thu, 24 Aug 2017 07:03:42 +0000 (00:03 -0700)
committerJens Axboe <axboe@kernel.dk>
Thu, 31 Aug 2017 19:51:12 +0000 (13:51 -0600)
commit6c6b6f28b3335fd85ec833ee0005d9c9dca6c003
tree47c20664f91ebd3591628a8ec52ca06b7dbbef76
parent8a0740c4109d646d8697d359962edea47301c652
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>
drivers/block/loop.c