block: Convert fifo_time from ulong to u64

Currently rq->fifo_time is unsigned long but CFQ stores nanosecond
timestamp in it which would overflow on 32-bit archs. Convert it to u64
to avoid the overflow. Since the rq->fifo_time is unioned with struct
call_single_data(), this does not change the size of struct request in
any way.

We have to slightly fixup block/deadline-iosched.c so that comparison
happens in the right types.

Fixes: 9a7f38c42c2b92391d9dabaf9f51df7cfe5608e4
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

2 files changed, 4 insertions, 3 deletions

diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index d0dd7882d8c7..26a9d3c8057a 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -173,7 +173,8 @@ deadline_merged_requests(struct request_queue *q, struct request *req,
          * and move into next position (next will be deleted) in fifo
          */
         if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
-                if (time_before(next->fifo_time, req->fifo_time)) {
+                if (time_before((unsigned long)next->fifo_time,
+                                (unsigned long)req->fifo_time)) {
                         list_move(&req->queuelist, &next->queuelist);
                         req->fifo_time = next->fifo_time;
                 }
@@ -227,7 +228,7 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
         /*
          * rq is expired!
          */
-        if (time_after_eq(jiffies, rq->fifo_time))
+        if (time_after_eq(jiffies, (unsigned long)rq->fifo_time))
                 return 1;
 
         return 0;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9746d223494c..d116d3b52c73 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -90,7 +90,7 @@ struct request {
         struct list_head queuelist;
         union {
                 struct call_single_data csd;
-                unsigned long fifo_time;
+                u64 fifo_time;
         };
 
         struct request_queue *q;