On Mon, 2009-04-20 at 18:14 +0530, Chauhan, Vijay wrote:
> This patch resolves the following issue. Please give your comment.
>
> > I am having issue with scsi_io_completion routine. During
> > device discovery, READ CAPACITY is failing with 02/04/01. It
> > has been retried 5 times(with NEED_RETRY) but when retry gets
> > exhausted ,scsi_io_completion simply ends the request without
> > trying with delay retry.
> >
> > Here scsi_io_completion routine checks for deferred sense and if
> > not found, it sets error with -EIO, which eventually ends the
> > request and doesnot allow for any more retries. I am seeing
> > deffered error being checked only for REQ_TYPE_BLOCK_PC
> > command type. Does it meant that command with cmd_type
> > REQ_TYPE_BLOCK_PC having current error sense should not be
> > retried in scsi_io_completion? If yes, then would it be
> > better to retry in rdac device handler in that case.
> >
> >
> > On Tues, 2009-03-10 at 15:47, James Bottomley wrote:
> > > > + if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
> > > > + /* LUN Not Ready - Logical Unit Not
> > > Ready and is in
> > > > + * the process of becoming ready
> > > > + * Just retry.
> > > > + */
> > > > + return ADD_TO_MLQUEUE;
> > > > + if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x04)
> > > > + /* LUN Not Ready - Format In Progress
> > > > + *
> > > > + * Just retry.
> > > > + */
> > > > + return ADD_TO_MLQUEUE;
> > > > + if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x07)
> > > > + /* LUN Not Ready - Storage controller
> > > cannot respond
> > > > + * immediately to a PRIN or PROUT command.
> > > > + * Just retry.
> > > > + */
> > > > + return ADD_TO_MLQUEUE;
> > >
> > > For all of these ... along with a few other not ready types,
> > > we already
> > > do a delayed retry at the mid-layer (in
> > scsi_io_completion). Is there
> > > some problem that causes this to need to be handled here as well?
>
> Thanks,
> Vijay
>
> ---
> During device discovery read capacity fails with 0x020401 and sets the device size to 0. As a reason any I/O submitted to this path gets killed at sd_prep_fn with BLKPREP_KILL. This patch is to retry for 0x020401. NEED_RETRY in scsi_decide_disposition does not give sufficient time for the device to become ready.
>
> Signed-off-by: Vijay Chauhan <vijay.chauhan@xxxxxxx>
Acked-by: Chandra Seetahraman <sekharan@xxxxxxxxxx>
> ---
> --- linux-2.6.30-rc2/drivers/scsi/device_handler/scsi_dh_rdac.c.orig 2009-04-20 23:07:14.000000000 +0530
> +++ linux-2.6.30-rc2/drivers/scsi/device_handler/scsi_dh_rdac.c 2009-04-20 23:11:27.000000000 +0530
> @@ -561,6 +561,12 @@ static int rdac_check_sense(struct scsi_
> struct rdac_dh_data *h = get_rdac_data(sdev);
> switch (sense_hdr->sense_key) {
> case NOT_READY:
> + if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
> + /* LUN Not Ready - Logical Unit Not Ready and is in
> + * the process of becoming ready
> + * Just retry.
> + */
> + return ADD_TO_MLQUEUE;
> if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
> /* LUN Not Ready - Storage firmware incompatible
> * Manual code synchonisation required.
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