[BLOCK] add @uptodate to end_that_request_last() and @error to rq_end_io_fn()

add @uptodate argument to end_that_request_last() and @error
to rq_end_io_fn().  there's no generic way to pass error code
to request completion function, making generic error handling
of non-fs request difficult (rq->errors is driver-specific and
each driver uses it differently).  this patch adds @uptodate
to end_that_request_last() and @error to rq_end_io_fn().

for fs requests, this doesn't really matter, so just using the
same uptodate argument used in the last call to
end_that_request_first() should suffice.  imho, this can also
help the generic command-carrying request jens is working on.

Signed-off-by: tejun heo <htejun@gmail.com>
Signed-Off-By: Jens Axboe <axboe@suse.de>

2 files changed, 16 insertions, 8 deletions

diff --git a/block/elevator.c b/block/elevator.c
index 6c3fc8a10bf..85a11cee7d1 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -498,7 +498,7 @@ struct request *elv_next_request(request_queue_t *q)
                         blkdev_dequeue_request(rq);
                         rq->flags |= REQ_QUIET;
                         end_that_request_chunk(rq, 0, nr_bytes);
-                        end_that_request_last(rq);
+                        end_that_request_last(rq, 0);
                 } else {
                         printk(KERN_ERR "%s: bad return=%d\n", __FUNCTION__,
                                                                 ret);
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index e02c88ca8fb..8b1ae69bc5a 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -344,7 +344,7 @@ EXPORT_SYMBOL(blk_queue_issue_flush_fn);
 /*
  * Cache flushing for ordered writes handling
  */
-static void blk_pre_flush_end_io(struct request *flush_rq)
+static void blk_pre_flush_end_io(struct request *flush_rq, int error)
 {
         struct request *rq = flush_rq->end_io_data;
         request_queue_t *q = rq->q;
@@ -362,7 +362,7 @@ static void blk_pre_flush_end_io(struct request *flush_rq)
         }
 }
 
-static void blk_post_flush_end_io(struct request *flush_rq)
+static void blk_post_flush_end_io(struct request *flush_rq, int error)
 {
         struct request *rq = flush_rq->end_io_data;
         request_queue_t *q = rq->q;
@@ -2317,7 +2317,7 @@ EXPORT_SYMBOL(blk_rq_map_kern);
  */
 void blk_execute_rq_nowait(request_queue_t *q, struct gendisk *bd_disk,
                            struct request *rq, int at_head,
-                           void (*done)(struct request *))
+                           rq_end_io_fn *done)
 {
         int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
 
@@ -2521,7 +2521,7 @@ EXPORT_SYMBOL(blk_put_request);
  * blk_end_sync_rq - executes a completion event on a request
  * @rq: request to complete
  */
-void blk_end_sync_rq(struct request *rq)
+void blk_end_sync_rq(struct request *rq, int error)
 {
         struct completion *waiting = rq->waiting;
 
@@ -3183,9 +3183,17 @@ EXPORT_SYMBOL(end_that_request_chunk);
 /*
  * queue lock must be held
  */
-void end_that_request_last(struct request *req)
+void end_that_request_last(struct request *req, int uptodate)
 {
         struct gendisk *disk = req->rq_disk;
+        int error;
+
+        /*
+         * extend uptodate bool to allow < 0 value to be direct io error
+         */
+        error = 0;
+        if (end_io_error(uptodate))
+                error = !uptodate ? -EIO : uptodate;
 
         if (unlikely(laptop_mode) && blk_fs_request(req))
                 laptop_io_completion();
@@ -3200,7 +3208,7 @@ void end_that_request_last(struct request *req)
                 disk->in_flight--;
         }
         if (req->end_io)
-                req->end_io(req);
+                req->end_io(req, error);
         else
                 __blk_put_request(req->q, req);
 }
@@ -3212,7 +3220,7 @@ void end_request(struct request *req, int uptodate)
         if (!end_that_request_first(req, uptodate, req->hard_cur_sectors)) {
                 add_disk_randomness(req->rq_disk);
                 blkdev_dequeue_request(req);
-                end_that_request_last(req);
+                end_that_request_last(req, uptodate);
         }
 }