[PATCH] libata: implement ata_scsi_timed_out()
Implement ata_scsi_timed_out(), to be used as
scsi_host_template->eh_timed_out callback for all libata drivers.
Without this function, the following race exists.
If a qc completes after SCSI timer expires but before libata EH kicks
in, the qc gets completed but the scsicmd still gets passed to libata
EH resulting in ->eng_timeout invocation with NULL qc, which none is
handling properly.
This patch makes sure that scmd and qc share the same lifetime.
Original idea from Jeff Garzik <jgarzik@pobox.com>.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 5c70a57..c1e1986 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -509,6 +509,7 @@
extern int ata_scsi_detect(struct scsi_host_template *sht);
extern int ata_scsi_ioctl(struct scsi_device *dev, int cmd, void __user *arg);
extern int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *));
+extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
extern int ata_scsi_error(struct Scsi_Host *host);
extern void ata_eh_qc_complete(struct ata_queued_cmd *qc);
extern void ata_eh_qc_retry(struct ata_queued_cmd *qc);