Gwendal Grignou wrote:
> Send a Read/Write command to a locked disk triggers the error handler.
> Given the disk returns a generic device error code, the error handler can come
> to the conclusion of reducing the link speed, which is bad.
> Also, if drives are still locked at boot, this fix speeds up the boot process
> by returning errors without invoquing the error handler thread.
>
> Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxx>
> ---
> drivers/ata/libata-core.c | 2 ++
> drivers/ata/libata-scsi.c | 6 ++++++
> include/linux/ata.h | 3 +++
> 3 files changed, 11 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 072ba5e..3f80570 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -5023,6 +5023,8 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
> qc->tf.feature != SETFEATURES_WC_OFF)
> break;
> /* fall through */
> + case ATA_CMD_SEC_UNLOCK: /* Read/Write access now work */
> + case ATA_CMD_SEC_ERASE_UNIT: /* Read/Write access now work */
> case ATA_CMD_INIT_DEV_PARAMS: /* CHS translation changed */
> case ATA_CMD_SET_MULTI: /* multi_count changed */
> /* revalidate device */
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index d0dfeef..8a41767 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -1658,6 +1658,12 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)
> u32 n_block;
> int rc;
>
> + if (unlikely(ata_id_locked(qc->dev->id))) {
> + /* Terminate RW commands early when the disk is locked */
> + ata_scsi_set_sense(scmd, ABORTED_COMMAND, 0, 0);
> + return 1;
> + }
> +
> if (cdb[0] == WRITE_10 || cdb[0] == WRITE_6 || cdb[0] == WRITE_16)
> tf_flags |= ATA_TFLAG_WRITE;
Hmmm... how sure are we that there aren't some braindead devices which
incorrectly would trigger the ata_id_locked() condition? I think it
would be safer to have an extra DFLAG, say ATA_DFLAG_LOCKED which gets
set when EH detects unknown device error && ata_id_locked(); then, in
the issue path, we can do
if (ATA_DFLAG_LOCKED is set) {
if (ata_id_locked())
Terminate early;
else
Clear ATA_DFLAG_LOCKED;
}
Thanks.
--
tejun
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