linux_dsm_epyc7002/drivers/s390/block
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
..
dasd_3990_erp.c [S390] dasd: message cleanup 2009-03-26 15:24:05 +01:00
dasd_alias.c [S390] dasd: message cleanup 2009-03-26 15:24:05 +01:00
dasd_devmap.c [S390] dasd: message cleanup 2009-03-26 15:24:05 +01:00
dasd_diag.c block: convert to pos and nr_sectors accessors 2009-05-11 09:50:54 +02:00
dasd_diag.h [S390] dasd whitespace and other cosmetics. 2006-06-29 14:58:12 +02:00
dasd_eckd.c block: convert to pos and nr_sectors accessors 2009-05-11 09:50:54 +02:00
dasd_eckd.h [S390] dasd: add High Performance FICON support 2009-03-26 15:24:05 +01:00
dasd_eer.c [S390] dasd: message cleanup 2009-03-26 15:24:05 +01:00
dasd_erp.c [S390] dasd: message cleanup 2009-03-26 15:24:05 +01:00
dasd_fba.c block: convert to pos and nr_sectors accessors 2009-05-11 09:50:54 +02:00
dasd_fba.h [S390] dasd whitespace and other cosmetics. 2006-06-29 14:58:12 +02:00
dasd_genhd.c [S390] dasd: message cleanup 2009-03-26 15:24:05 +01:00
dasd_int.h [S390] dasd: message cleanup 2009-03-26 15:24:05 +01:00
dasd_ioctl.c [S390] dasd: message cleanup 2009-03-26 15:24:05 +01:00
dasd_proc.c proc 2/2: remove struct proc_dir_entry::owner 2009-03-31 01:14:44 +04:00
dasd.c block: implement and enforce request peek/start/fetch 2009-05-11 09:52:18 +02:00
dcssblk.c s390: remove s390_root_dev_*() 2009-01-06 10:44:34 -08:00
Kconfig [S390] dasd: fix double elevator_exit call when deadline iosched fails to load 2008-04-17 07:46:55 +02:00
Makefile [S390] dasd: add hyper PAV support to DASD device driver, part 1 2008-01-26 14:11:28 +01:00
xpram.c [S390] convert xpram printks to pr_xxx macros. 2008-12-25 13:39:18 +01:00