tree 0edf941f787dd10dd674111cfefbde5004348ef4
parent 4929630901100fdbfa19186ecf5ea2706f57719b
author Mikulas Patocka <mpatocka@redhat.com> 1343398083 +0100
committer Alasdair G Kergon <agk@redhat.com> 1343398083 +0100

dm thin: optimize power of two block size

dm-thin will be most likely used with a block size that is a power of
two. So it should be optimized for this case.

This patch changes division and modulo operations to shifts and bit
masks if block size is a power of two.

A test that bi_sector is divisible by a block size is removed from
io_overlaps_block. Device mapper never sends bios that span a block
boundary. Consequently, if we tested that bi_size is equivalent to block
size, bi_sector must already be on a block boundary.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>