[PATCH v3 3/3] block: improve detail in I/O error messages

[Mike Snitzer <snitzer@redhat.com>]

Classify severity of I/O errors for target and transport errors.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@suse.de>
---
 block/blk-core.c |   20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

Index: linux-2.6/block/blk-core.c
===================================================================
--- linux-2.6.orig/block/blk-core.c
+++ linux-2.6/block/blk-core.c
@@ -2044,9 +2044,23 @@ bool blk_update_request(struct request *
 
 	if (error && req->cmd_type == REQ_TYPE_FS &&
 	    !(req->cmd_flags & REQ_QUIET)) {
-		printk(KERN_ERR "end_request: I/O error, dev %s, sector %llu\n",
-				req->rq_disk ? req->rq_disk->disk_name : "?",
-				(unsigned long long)blk_rq_pos(req));
+		char *error_type;
+
+		switch (error) {
+		case -ENOLINK:
+			error_type = "recoverable transport";
+			break;
+		case -EREMOTEIO:
+			error_type = "critical target";
+			break;
+		case -EIO:
+		default:
+			error_type = "I/O";
+			break;
+		}
+		printk(KERN_ERR "end_request: %s error, dev %s, sector %llu\n",
+		       error_type, req->rq_disk ? req->rq_disk->disk_name : "?",
+		       (unsigned long long)blk_rq_pos(req));
 	}
 
 	blk_account_io_completion(req, nr_bytes);