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authorMike Christie <michaelc@cs.wisc.edu>2008-08-19 18:45:31 -0500
committerJames Bottomley <James.Bottomley@HansenPartnership.com>2008-10-13 09:28:52 -0400
commit4a27446f3e39b06c28d1c8e31d33a5340826ed5c (patch)
treee55c982632ab6e0a8484f8267fce8f159b6f78dc
parent6000a368cd8e6da1caf101411bdb494cd6fb8b09 (diff)
[SCSI] modify scsi to handle new fail fast flags.
This checks the errors the scsi-ml determined were retryable and returns if we should fast fail it based on the request fail fast flags. Without the patch, drivers like lpfc, qla2xxx and fcoe would return DID_ERROR for what it determines is a temporary communication problem. There is no loss of connectivity at that time and the driver thinks that it would be fast to retry at the driver level. SCSI-ml will however sees fast fail on the request and DID_ERROR and will fast fail the io. This will then cause dm-multipath to fail the path and possibley switch target controllers when we should be retrying at the scsi layer. We also were fast failing device errors to dm multiapth when unless the scsi_dh modules think otherwis we want to retry at the scsi layer because multipath can only retry the IO like scsi should have done. multipath is a little dumber though because it does not what the error was for and assumes that it should fail the paths. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
-rw-r--r--drivers/scsi/scsi_error.c38
-rw-r--r--drivers/scsi/scsi_lib.c2
-rw-r--r--drivers/scsi/scsi_priv.h1
3 files changed, 38 insertions, 3 deletions
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 5bf8be21a16..ad019ece213 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1219,6 +1219,40 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q,
}
/**
+ * scsi_noretry_cmd - determinte if command should be failed fast
+ * @scmd: SCSI cmd to examine.
+ */
+int scsi_noretry_cmd(struct scsi_cmnd *scmd)
+{
+ switch (host_byte(scmd->result)) {
+ case DID_OK:
+ break;
+ case DID_BUS_BUSY:
+ return blk_failfast_transport(scmd->request);
+ case DID_PARITY:
+ return blk_failfast_dev(scmd->request);
+ case DID_ERROR:
+ if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
+ status_byte(scmd->result) == RESERVATION_CONFLICT)
+ return 0;
+ /* fall through */
+ case DID_SOFT_ERROR:
+ return blk_failfast_driver(scmd->request);
+ }
+
+ switch (status_byte(scmd->result)) {
+ case CHECK_CONDITION:
+ /*
+ * assume caller has checked sense and determinted
+ * the check condition was retryable.
+ */
+ return blk_failfast_dev(scmd->request);
+ }
+
+ return 0;
+}
+
+/**
* scsi_decide_disposition - Disposition a cmd on return from LLD.
* @scmd: SCSI cmd to examine.
*
@@ -1396,7 +1430,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
* even if the request is marked fast fail, we still requeue
* for queue congestion conditions (QUEUE_FULL or BUSY) */
if ((++scmd->retries) <= scmd->allowed
- && !blk_noretry_request(scmd->request)) {
+ && !scsi_noretry_cmd(scmd)) {
return NEEDS_RETRY;
} else {
/*
@@ -1521,7 +1555,7 @@ void scsi_eh_flush_done_q(struct list_head *done_q)
list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
list_del_init(&scmd->eh_entry);
if (scsi_device_online(scmd->device) &&
- !blk_noretry_request(scmd->request) &&
+ !scsi_noretry_cmd(scmd) &&
(++scmd->retries <= scmd->allowed)) {
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
" retry cmd: %p\n",
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 91c74c55aa5..e5a9526d203 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -706,7 +706,7 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
leftover = req->data_len;
/* kill remainder if no retrys */
- if (error && blk_noretry_request(req))
+ if (error && scsi_noretry_cmd(cmd))
blk_end_request(req, error, leftover);
else {
if (requeue) {
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 6cddd5dd323..e1850904ff7 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -59,6 +59,7 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost,
struct list_head *done_q);
int scsi_eh_get_sense(struct list_head *work_q,
struct list_head *done_q);
+int scsi_noretry_cmd(struct scsi_cmnd *scmd);
/* scsi_lib.c */
extern int scsi_maybe_unblock_host(struct scsi_device *sdev);