The current medium access timeout counter will be increased for
each command, so if there are enough failed commands we'll hit
the medium access timeout for even a single failure.
Fix this by making the timeout per EH run, ie the counter will
only be increased once per device and EH run.
Cc: Ewan Milne <emi...@redhat.com>
Cc: Lawrence Oberman <lober...@redhat.com>
Cc: Benjamin Block <bbl...@linux.vnet.ibm.vom>
Cc: Steffen Maier <ma...@de.ibm.com>
Signed-off-by: Hannes Reinecke <h...@suse.com>
---
drivers/scsi/scsi_error.c | 2 ++
drivers/scsi/sd.c | 16 ++++++++++++++--
drivers/scsi/sd.h | 1 +
include/scsi/scsi.h | 1 +
4 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index f2cafae..481ea1b 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -58,6 +58,7 @@
static int scsi_eh_try_stu(struct scsi_cmnd *scmd);
static int scsi_try_to_abort_cmd(struct scsi_host_template *,
struct scsi_cmnd *);
+static int scsi_eh_action(struct scsi_cmnd *scmd, int rtn);
/* called with shost->host_lock held */
void scsi_eh_wakeup(struct Scsi_Host *shost)
@@ -249,6 +250,7 @@ int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
eh_flag &= ~SCSI_EH_CANCEL_CMD;
scmd->eh_eflags |= eh_flag;
+ scsi_eh_action(scmd, NEEDS_RESET);
list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
shost->host_failed++;
scsi_eh_wakeup(shost);
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index be535d4..cd9f290 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1696,12 +1696,21 @@ static int sd_pr_clear(struct block_device *bdev, u64
key)
* the eh command is passed in eh_disp. We're looking for devices that
* fail medium access commands but are OK with non access commands like
* test unit ready (so wrongly see the device as having a successful
- * recovery)
+ * recovery).
+ * We have to be careful to count a medium access failure only once
+ * per SCSI EH run; there might be several timed out commands which
+ * will cause the 'max_medium_access_timeouts' counter to trigger
+ * after the first SCSI EH run already and set the device to offline.
**/
static int sd_eh_action(struct scsi_cmnd *scmd, int eh_disp)
{
struct scsi_disk *sdkp = scsi_disk(scmd->request->rq_disk);
+ if (eh_disp == NEEDS_RESET) {
+ /* New SCSI EH run, reset gate variable */
+ sdkp->medium_access_reset = 0;
+ return eh_disp;
+ }
if (!scsi_device_online(scmd->device) ||
!scsi_medium_access_command(scmd) ||
host_byte(scmd->result) != DID_TIME_OUT ||
@@ -1715,7 +1724,10 @@ static int sd_eh_action(struct scsi_cmnd *scmd, int
eh_disp)
* process of recovering or has it suffered an internal failure
* that prevents access to the storage medium.
*/
- sdkp->medium_access_timed_out++;
+ if (!sdkp->medium_access_reset) {
+ sdkp->medium_access_timed_out++;
+ sdkp->medium_access_reset++;
+ }
/*
* If the device keeps failing read/write commands but TEST UNIT
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 4dac35e..19e0bab 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -85,6 +85,7 @@ struct scsi_disk {
unsigned int physical_block_size;
unsigned int max_medium_access_timeouts;
unsigned int medium_access_timed_out;
+ unsigned int medium_access_reset;
u8 media_present;
u8 write_prot;
u8 protection_type;/* Data Integrity Field */
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index a1e1930..b6c750f 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -185,6 +185,7 @@ static inline int scsi_is_wlun(u64 lun)
#define TIMEOUT_ERROR 0x2007
#define SCSI_RETURN_NOT_HANDLED 0x2008
#define FAST_IO_FAIL 0x2009
+#define NEEDS_RESET 0x2010
/*
* Midlevel queue return values.
--
1.8.5.6
