block: remove request ref_count

This reference count has been around since before git history, but the only
place where it's used is in blk_execute_rq, and ther it is entirely useless
as it is incremented before submitting the request and decremented in the
end_io handler before waking up the submitter thread.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-core.c b/block/blk-core.c
index 213e9f0..18faa7e 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -145,7 +145,6 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
        rq->cmd = rq->__cmd;
        rq->cmd_len = BLK_MAX_CDB;
        rq->tag = -1;
-       rq->ref_count = 1;
        rq->start_time = jiffies;
        set_start_time_ns(rq);
        rq->part = NULL;
@@ -1272,8 +1271,6 @@ void __blk_put_request(struct request_queue *q, struct request *req)
 {
        if (unlikely(!q))
                return;
-       if (unlikely(--req->ref_count))
-               return;
 
        blk_pm_put_request(req);
 

diff --git a/block/blk-exec.c b/block/blk-exec.c
index ae4f27d..6b18d82 100644 (file)
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -24,7 +24,6 @@ static void blk_end_sync_rq(struct request *rq, int error)
        struct completion *waiting = rq->end_io_data;
 
        rq->end_io_data = NULL;
-       __blk_put_request(rq->q, rq);
 
        /*
         * complete last, if this is a stack request the process (and thus
@@ -103,12 +102,6 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
        int err = 0;
        unsigned long hang_check;
 
-       /*
-        * we need an extra reference to the request, so we can look at
-        * it after io completion
-        */
-       rq->ref_count++;
-
        if (!rq->sense) {
                memset(sense, 0, sizeof(sense));
                rq->sense = sense;

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f5c7596..0a8da96 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -160,8 +160,6 @@ struct request {
 
        unsigned short ioprio;
 
-       int ref_count;
-
        void *special;          /* opaque pointer available for LLD use */
        char *buffer;           /* kaddr of the current segment if available */