From 22aac0896b1b0b8cabaf00714c55dd12f25d5738 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 8 Aug 2006 14:08:59 +0900 Subject: [PATCH] libata: clear sdev->locked on door lock failure SCSI EH locks door if sdev->locked is set. Sometimes door lock command fails continuously (e.g. when medium is not present) and as libata uses EH to acquire sense data, this easily creates a loop where a failed lock door invokes EH and EH issues lock door on completion. This patch clears sdev->locked on door lock failure to break this loop. This problem has been spotted and diagnosed by Unicorn Chang . Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik --- drivers/scsi/libata-scsi.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c index 7ced41ecde86..e92c31d698ff 100644 --- a/drivers/scsi/libata-scsi.c +++ b/drivers/scsi/libata-scsi.c @@ -2353,6 +2353,19 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc) ata_gen_ata_desc_sense(qc); } + /* SCSI EH automatically locks door if sdev->locked is + * set. Sometimes door lock request continues to + * fail, for example, when no media is present. This + * creates a loop - SCSI EH issues door lock which + * fails and gets invoked again to acquire sense data + * for the failed command. + * + * If door lock fails, always clear sdev->locked to + * avoid this infinite loop. + */ + if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL) + qc->dev->sdev->locked = 0; + qc->scsicmd->result = SAM_STAT_CHECK_CONDITION; qc->scsidone(cmd); ata_qc_free(qc); -- cgit v1.2.2