tree d31987b15d57429bd40843c02b2283b8e2d90cb0
parent 75e5584c89d213d6089f64f22cd899fb172e4c95
author Jeff Dike <jdike@addtoit.com> 1125788266 -0700
committer Linus Torvalds <torvalds@evo.osdl.org> 1125903983 -0700

[PATCH] uml: add host AIO support to block driver

This adds AIO support to the ubd driver.

The driver breaks a struct request into IO requests to the host, based on the
hardware segments in the request and on any COW blocks covered by the request.

The ubd IO thread is gone, since there is now an equivalent thread in the AIO
module.

There is provision for multiple outstanding requests now.  Requests aren't
retired until all pieces of it have been completed.  The AIO requests have a
shared count, which is decremented as IO operations come in until it reaches
0.  This can be possibly moved to the request struct - haven't looked at this
yet.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>