Re: [PATCH] barrier patch set

["Mika Penttilä" <mika.penttila@kolumbus.fi>]

Jens Axboe wrote:

>Hi,
>
>A first release of a collected barrier patchset for 2.6.5-rc1-mm2. I
>have a few changes planned to support dm/md + sata, I'll do those
>changes over the weekend.
>
>Reiser has the best barrier support, ext3 works but only if things don't
>go wrong. So only attempt to use the barrier feature on ext3 if on ide
>drives, not SCSI nor SATA.
>
>  
>
What are these brutal pieces...?


+static int ide_transform_pc_req(ide_drive_t *drive, struct request *rq)
+{
+ if (rq->cmd[0] != 0x35) {
+ ide_end_request(drive, 0, 0);
+ return 1;
+ }
+
+ if (!drive->wcache) {
+ ide_end_request(drive, 1, 0);
+ return 1;
+ }
+
+ ide_fill_flush_cmd(drive, rq);
+ return 0;
+}


/*
+ * basic transformation support for scsi -> ata commands
+ */
+ if (blk_pc_request(rq)) {
+ if (drive->media != ide_disk)
+ goto kill_rq;
+ if (ide_transform_pc_req(drive, rq))
+ return ide_stopped;
+ }
+



--Mika