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-rw-r--r--drivers/md/dm-mpath-hp-sw.c64
1 files changed, 53 insertions, 11 deletions
diff --git a/drivers/md/dm-mpath-hp-sw.c b/drivers/md/dm-mpath-hp-sw.c
index 57531703..204bf42 100644
--- a/drivers/md/dm-mpath-hp-sw.c
+++ b/drivers/md/dm-mpath-hp-sw.c
@@ -18,19 +18,54 @@
#include <linux/types.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_dbg.h>
#include "dm.h"
#include "dm-hw-handler.h"
#define DM_MSG_PREFIX "multipath hp-sw"
#define DM_HP_HWH_NAME "hp-sw"
-#define DM_HP_HWH_VER "0.0.3"
+#define DM_HP_HWH_VER "1.0.0"
struct hp_sw_context {
unsigned char sense[SCSI_SENSE_BUFFERSIZE];
};
/*
+ * hp_sw_error_is_retryable - Is an HP-specific check condition retryable?
+ * @req: path activation request
+ *
+ * Examine error codes of request and determine whether the error is retryable.
+ * Some error codes are already retried by scsi-ml (see
+ * scsi_decide_disposition), but some HP specific codes are not.
+ * The intent of this routine is to supply the logic for the HP specific
+ * check conditions.
+ *
+ * Returns:
+ * 1 - command completed with retryable error
+ * 0 - command completed with non-retryable error
+ *
+ * Possible optimizations
+ * 1. More hardware-specific error codes
+ */
+static int hp_sw_error_is_retryable(struct request *req)
+{
+ /*
+ * NOT_READY is known to be retryable
+ * For now we just dump out the sense data and call it retryable
+ */
+ if (status_byte(req->errors) == CHECK_CONDITION)
+ __scsi_print_sense(DM_HP_HWH_NAME, req->sense, req->sense_len);
+
+ /*
+ * At this point we don't have complete information about all the error
+ * codes from this hardware, so we are just conservative and retry
+ * when in doubt.
+ */
+ return 1;
+}
+
+/*
* hp_sw_end_io - Completion handler for HP path activation.
* @req: path activation request
* @error: scsi-ml error
@@ -40,23 +75,30 @@ struct hp_sw_context {
*
* Context: scsi-ml softirq
*
- * Possible optimizations
- * 1. Actually check sense data for retryable error (e.g. NOT_READY)
*/
static void hp_sw_end_io(struct request *req, int error)
{
struct dm_path *path = req->end_io_data;
unsigned err_flags = 0;
- if (!error)
+ if (!error) {
DMDEBUG("%s path activation command - success",
path->dev->name);
- else {
- DMWARN("%s path activation command - error=0x%x",
- path->dev->name, error);
- err_flags = MP_FAIL_PATH;
+ goto out;
}
+ if (hp_sw_error_is_retryable(req)) {
+ DMDEBUG("%s path activation command - retry",
+ path->dev->name);
+ err_flags = MP_RETRY;
+ goto out;
+ }
+
+ DMWARN("%s path activation fail - error=0x%x",
+ path->dev->name, error);
+ err_flags = MP_FAIL_PATH;
+
+out:
req->end_io_data = NULL;
__blk_put_request(req->q, req);
dm_pg_init_complete(path, err_flags);
@@ -135,7 +177,7 @@ static void hp_sw_pg_init(struct hw_handler *hwh, unsigned bypassed,
if (!req) {
DMERR("%s path activation command - allocation fail",
path->dev->name);
- goto fail;
+ goto retry;
}
DMDEBUG("%s path activation command - sent", path->dev->name);
@@ -143,8 +185,8 @@ static void hp_sw_pg_init(struct hw_handler *hwh, unsigned bypassed,
blk_execute_rq_nowait(req->q, NULL, req, 1, hp_sw_end_io);
return;
-fail:
- dm_pg_init_complete(path, MP_FAIL_PATH);
+retry:
+ dm_pg_init_complete(path, MP_RETRY);
}
static int hp_sw_create(struct hw_handler *hwh, unsigned argc, char **argv)
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