linux/arch/um
Tejun Heo 9934c8c045 block: implement and enforce request peek/start/fetch
Till now block layer allowed two separate modes of request execution.
A request is always acquired from the request queue via
elv_next_request().  After that, drivers are free to either dequeue it
or process it without dequeueing.  Dequeue allows elv_next_request()
to return the next request so that multiple requests can be in flight.

Executing requests without dequeueing has its merits mostly in
allowing drivers for simpler devices which can't do sg to deal with
segments only without considering request boundary.  However, the
benefit this brings is dubious and declining while the cost of the API
ambiguity is increasing.  Segment based drivers are usually for very
old or limited devices and as converting to dequeueing model isn't
difficult, it doesn't justify the API overhead it puts on block layer
and its more modern users.

Previous patches converted all block low level drivers to dequeueing
model.  This patch completes the API transition by...

* renaming elv_next_request() to blk_peek_request()

* renaming blkdev_dequeue_request() to blk_start_request()

* adding blk_fetch_request() which is combination of peek and start

* disallowing completion of queued (not started) requests

* applying new API to all LLDs

Renamings are for consistency and to break out of tree code so that
it's apparent that out of tree drivers need updating.

[ Impact: block request issue API cleanup, no functional change ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: unsik Kim <donari75@gmail.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Laurent Vivier <Laurent@lvivier.info>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:52:18 +02:00
..
drivers block: implement and enforce request peek/start/fetch 2009-05-11 09:52:18 +02:00
include Merge branch 'tracing/core-v2' into tracing-for-linus 2009-04-02 00:49:02 +02:00
kernel clocksource: pass clocksource to read() callback 2009-04-21 13:41:47 -07:00
os-Linux uml: improve error messages 2009-04-01 08:59:16 -07:00
scripts uml: throw out CONFIG_MODE_TT 2007-10-16 09:43:05 -07:00
sys-i386 uml: fix link error from prefixing of i386 syscalls with ptregs_ 2009-04-02 19:04:50 -07:00
sys-ia64 uml: remove useless comments 2009-04-01 08:59:17 -07:00
sys-ppc uml: remove useless comments 2009-04-01 08:59:17 -07:00
sys-x86_64 uml: remove useless comments 2009-04-01 08:59:17 -07:00
defconfig UML: update defconfig 2008-02-23 17:12:13 -08:00
Kconfig.char sound: make OSS sound core optional 2008-08-29 10:06:21 +02:00
Kconfig.common x86, um: get rid of arch/um/Kconfig.arch 2008-10-22 22:55:23 -07:00
Kconfig.debug uml: GPROF needs to depend on FRAME_POINTER 2008-02-05 09:44:25 -08:00
Kconfig.net uml: fix URLs in Kconfig and help strings 2008-02-05 09:44:25 -08:00
Kconfig.rest uml: kill a kconfig warning 2009-04-21 13:41:50 -07:00
Kconfig.um x86, um: get rid of arch/um/Kconfig.arch 2008-10-22 22:55:23 -07:00
Kconfig.x86 x86, um: get rid of arch/um/Kconfig.arch 2008-10-22 22:55:23 -07:00
Makefile get rid of the last symlink in uml build 2009-01-05 17:41:45 -08:00
Makefile-i386 [UML] fix gcc ICEs and unresolved externs 2008-07-07 10:53:10 -07:00
Makefile-ia64 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-os-Linux x86, um: get rid of arch/um/os symlink 2008-10-22 22:55:22 -07:00
Makefile-ppc Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-skas [PATCH] uml makefiles sanitized 2005-09-29 08:46:26 -07:00
Makefile-x86_64 [UML] fix gcc ICEs and unresolved externs 2008-07-07 10:53:10 -07:00