block: fix oops in blk_queue_io_stat()

Some initial probe requests don't have disk->queue mapped yet, so we
can't rely on a non-NULL queue in blk_queue_io_stat(). Wrap it in
blk_do_io_stat().

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 11 insertions, 3 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index ca69f3d94100..29bcfac6c688 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -69,7 +69,7 @@ static void drive_stat_acct(struct request *rq, int new_io)
         int rw = rq_data_dir(rq);
         int cpu;
 
-        if (!blk_fs_request(rq) || !disk || !blk_queue_io_stat(disk->queue))
+        if (!blk_fs_request(rq) || !disk || !blk_do_io_stat(disk->queue))
                 return;
 
         cpu = part_stat_lock();
@@ -1667,7 +1667,7 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
 {
         struct gendisk *disk = req->rq_disk;
 
-        if (!disk || !blk_queue_io_stat(disk->queue))
+        if (!disk || !blk_do_io_stat(disk->queue))
                 return;
 
         if (blk_fs_request(req)) {
@@ -1686,7 +1686,7 @@ static void blk_account_io_done(struct request *req)
 {
         struct gendisk *disk = req->rq_disk;
 
-        if (!disk || !blk_queue_io_stat(disk->queue))
+        if (!disk || !blk_do_io_stat(disk->queue))
                 return;
 
         /*
diff --git a/block/blk.h b/block/blk.h
index 6e1ed40534e9..0dce92c37496 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -108,4 +108,12 @@ static inline int blk_cpu_to_group(int cpu)
 #endif
 }
 
+static inline int blk_do_io_stat(struct request_queue *q)
+{
+        if (q)
+                return blk_queue_io_stat(q);
+
+        return 0;
+}
+
 #endif