block: ensure that completion error gets properly traced

We normally just use the BIO_UPTODATE flag to signal 0/-EIO. If
we have more information available, we should pass that along to
the trace output.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index fab31af..153562d 100644 (file)
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -758,54 +758,58 @@ static void blk_add_trace_rq_complete(void *ignore,
  * @q:         queue the io is for
  * @bio:       the source bio
  * @what:      the action
+ * @error:     error, if any
  *
  * Description:
  *     Records an action against a bio. Will log the bio offset + size.
  *
  **/
 static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
-                                    u32 what)
+                             u32 what, int error)
 {
        struct blk_trace *bt = q->blk_trace;
 
        if (likely(!bt))
                return;
 
+       if (!error && !bio_flagged(bio, BIO_UPTODATE))
+               error = EIO;
+
        __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what,
-                       !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
+                       error, 0, NULL);
 }
 
 static void blk_add_trace_bio_bounce(void *ignore,
                                     struct request_queue *q, struct bio *bio)
 {
-       blk_add_trace_bio(q, bio, BLK_TA_BOUNCE);
+       blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0);
 }
 
 static void blk_add_trace_bio_complete(void *ignore,
                                       struct request_queue *q, struct bio *bio,
                                       int error)
 {
-       blk_add_trace_bio(q, bio, BLK_TA_COMPLETE);
+       blk_add_trace_bio(q, bio, BLK_TA_COMPLETE, error);
 }
 
 static void blk_add_trace_bio_backmerge(void *ignore,
                                        struct request_queue *q,
                                        struct bio *bio)
 {
-       blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
+       blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0);
 }
 
 static void blk_add_trace_bio_frontmerge(void *ignore,
                                         struct request_queue *q,
                                         struct bio *bio)
 {
-       blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
+       blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0);
 }
 
 static void blk_add_trace_bio_queue(void *ignore,
                                    struct request_queue *q, struct bio *bio)
 {
-       blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
+       blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0);
 }
 
 static void blk_add_trace_getrq(void *ignore,
@@ -813,7 +817,7 @@ static void blk_add_trace_getrq(void *ignore,
                                struct bio *bio, int rw)
 {
        if (bio)
-               blk_add_trace_bio(q, bio, BLK_TA_GETRQ);
+               blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0);
        else {
                struct blk_trace *bt = q->blk_trace;
 
@@ -828,7 +832,7 @@ static void blk_add_trace_sleeprq(void *ignore,
                                  struct bio *bio, int rw)
 {
        if (bio)
-               blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ);
+               blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 0);
        else {
                struct blk_trace *bt = q->blk_trace;