- patches.suse/dm-mpath-evaluate-request-result-and-sense:

  multipath: Evaluate request result and sense code
  (FATE#303695,bnc#433920,bnc#442001).

suse-commit: 411d58510d662f5ff5571559af47ef1dabc1705b

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index be68d14..11b8621 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -19,6 +19,7 @@
 #include <linux/time.h>
 #include <linux/workqueue.h>
 #include <scsi/scsi_dh.h>
+#include <scsi/scsi_eh.h>
 #include <asm/atomic.h>
 
 #define DM_MSG_PREFIX "multipath"
@@ -101,6 +102,7 @@ struct multipath {
 struct dm_mpath_io {
        struct pgpath *pgpath;
        size_t nr_bytes;
+       char sense[SCSI_SENSE_BUFFERSIZE];
 };
 
 typedef int (*action_fn) (struct pgpath *pgpath);
@@ -911,6 +913,9 @@ static int multipath_map(struct dm_target *ti, struct request *clone,
 
        map_context->ptr = mpio;
        clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
+       /* Always attach a sense buffer */
+       if (!clone->sense)
+               clone->sense = mpio->sense;
        r = map_io(m, clone, mpio, 0);
        if (r < 0 || r == DM_MAPIO_REQUEUE)
                mempool_free(mpio, m->mpio_pool);
@@ -1190,6 +1195,42 @@ static void activate_path(struct work_struct *work)
 }
 
 /*
+ * Evaluate scsi return code
+ */
+static int eval_scsi_error(int result, char *sense, int sense_len)
+{
+       struct scsi_sense_hdr sshdr;
+       int r = DM_ENDIO_REQUEUE;
+
+       if (host_byte(result) != DID_OK)
+               return r;
+
+       if (msg_byte(result) != COMMAND_COMPLETE)
+               return r;
+
+       if (status_byte(result) == RESERVATION_CONFLICT)
+               /* Do not retry here, possible data corruption */
+               return -EIO;
+
+       if (status_byte(result) == CHECK_CONDITION &&
+           !scsi_normalize_sense(sense, sense_len, &sshdr)) {
+
+               switch (sshdr.sense_key) {
+               case MEDIUM_ERROR:
+               case DATA_PROTECT:
+               case BLANK_CHECK:
+               case COPY_ABORTED:
+               case VOLUME_OVERFLOW:
+               case MISCOMPARE:
+                       r = -EIO;
+                       break;
+               }
+       }
+
+       return r;
+}
+
+/*
  * end_io handling
  */
 static int do_end_io(struct multipath *m, struct request *clone,
@@ -1215,6 +1256,10 @@ static int do_end_io(struct multipath *m, struct request *clone,
        if (error == -EOPNOTSUPP)
                return error;
 
+       r = eval_scsi_error(clone->errors, clone->sense, clone->sense_len);
+       if (r != DM_ENDIO_REQUEUE)
+               return r;
+
        if (mpio->pgpath)
                fail_path(mpio->pgpath);
 
@@ -1241,6 +1286,10 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone,
                if (ps->type->end_io)
                        ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes);
        }
+       if (clone->sense == mpio->sense) {
+               clone->sense = NULL;
+               clone->sense_len = 0;
+       }
        mempool_free(mpio, m->mpio_pool);
 
        return r;

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d8fcb80..550fa68 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -722,23 +722,19 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                        sense_deferred = scsi_sense_is_deferred(&sshdr);
        }
 
-       if (blk_pc_request(req)) { /* SG_IO ioctl from block level */
-               req->errors = result;
-               if (result) {
-                       if (sense_valid && req->sense) {
-                               /*
-                                * SG_IO wants current and deferred errors
-                                */
-                               int len = 8 + cmd->sense_buffer[7];
+       req->errors = result;
+       if (sense_valid && req->sense) {
+               int len = 8 + cmd->sense_buffer[7];
+
+               if (len > SCSI_SENSE_BUFFERSIZE)
+                       len = SCSI_SENSE_BUFFERSIZE;
+               memcpy(req->sense, cmd->sense_buffer,  len);
+               req->sense_len = len;
+       }
 
-                               if (len > SCSI_SENSE_BUFFERSIZE)
-                                       len = SCSI_SENSE_BUFFERSIZE;
-                               memcpy(req->sense, cmd->sense_buffer,  len);
-                               req->sense_len = len;
-                       }
-                       if (!sense_deferred)
-                               error = -EIO;
-               }
+       if (blk_pc_request(req)) { /* SG_IO ioctl from block level */
+               if ((result) && (!sense_deferred))
+                       error = -EIO;
 
                req->resid_len = scsi_get_resid(cmd);