block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()

Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests.  Deprecate barrier.  All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().

blk_queue_flush() takes combinations of REQ_FLUSH and FUA.  If a
device has write cache and can flush it, it should set REQ_FLUSH.  If
the device can handle FUA writes, it should also set REQ_FUA.

All blk_queue_ordered() users are converted.

* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Tejun Heo
2010-09-03 11:56:16 +02:00
committed by Jens Axboe
parent 6958f14545
commit 4913efe456
15 changed files with 67 additions and 102 deletions

View File

@@ -516,10 +516,10 @@ static int ide_do_setfeature(ide_drive_t *drive, u8 feature, u8 nsect)
return ide_no_data_taskfile(drive, &cmd);
}
static void update_ordered(ide_drive_t *drive)
static void update_flush(ide_drive_t *drive)
{
u16 *id = drive->id;
unsigned ordered = QUEUE_ORDERED_NONE;
unsigned flush = 0;
if (drive->dev_flags & IDE_DFLAG_WCACHE) {
unsigned long long capacity;
@@ -543,13 +543,12 @@ static void update_ordered(ide_drive_t *drive)
drive->name, barrier ? "" : "not ");
if (barrier) {
ordered = QUEUE_ORDERED_DRAIN_FLUSH;
flush = REQ_FLUSH;
blk_queue_prep_rq(drive->queue, idedisk_prep_fn);
}
} else
ordered = QUEUE_ORDERED_DRAIN;
}
blk_queue_ordered(drive->queue, ordered);
blk_queue_flush(drive->queue, flush);
}
ide_devset_get_flag(wcache, IDE_DFLAG_WCACHE);
@@ -572,7 +571,7 @@ static int set_wcache(ide_drive_t *drive, int arg)
}
}
update_ordered(drive);
update_flush(drive);
return err;
}