block/dasd: detailed I/O errors

The DASD driver is using FASTFAIL as an equivalent to the
transport errors in SCSI. And the 'steal lock' function maps
roughly to a reservation error. So we should be returning the
appropriate error codes when completing a request.

Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/block/blk-core.c b/block/blk-core.c
index d5745b5..3214432 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2315,6 +2315,9 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
                case -EBADE:
                        error_type = "critical nexus";
                        break;
+               case -ETIMEDOUT:
+                       error_type = "timeout";
+                       break;
                case -EIO:
                default:
                        error_type = "I/O";

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 87478be..b97624b 100644 (file)
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2183,7 +2183,7 @@ static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
                    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
                    (!dasd_eer_enabled(device))) {
                        cqr->status = DASD_CQR_FAILED;
-                       cqr->intrc = -EAGAIN;
+                       cqr->intrc = -ENOLINK;
                        continue;
                }
                /* Don't try to start requests if device is stopped */
@@ -2590,8 +2590,17 @@ static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
        req = (struct request *) cqr->callback_data;
        dasd_profile_end(cqr->block, cqr, req);
        status = cqr->block->base->discipline->free_cp(cqr, req);
-       if (status <= 0)
-               error = status ? status : -EIO;
+       if (status < 0)
+               error = status;
+       else if (status == 0) {
+               if (cqr->intrc == -EPERM)
+                       error = -EBADE;
+               else if (cqr->intrc == -ENOLINK ||
+                        cqr->intrc == -ETIMEDOUT)
+                       error = cqr->intrc;
+               else
+                       error = -EIO;
+       }
        __blk_end_request_all(req, error);
 }
 
@@ -2692,6 +2701,7 @@ static void __dasd_block_start_head(struct dasd_block *block)
                    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
                    (!dasd_eer_enabled(block->base))) {
                        cqr->status = DASD_CQR_FAILED;
+                       cqr->intrc = -ENOLINK;
                        dasd_schedule_block_bh(block);
                        continue;
                }