[IDE] Use the block layer deferred softirq request completion

This patch makes IDE use the new blk_complete_request() interface.
There's still room for improvement, as __ide_end_request() really
could drop the lock after getting HWGROUP->rq (why does it need to
hold it in the first place? If ->rq access isn't serialized, we are
screwed anyways).

Signed-off-by: Jens Axboe <axboe@suse.de>

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index b5dc6df8e67ddc8858527b95a875a2429392eee4..dea2d4dcc6981848222eb97ea0b47478dcc9df4c 100644 (file)
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -55,9 +55,22 @@
 #include <asm/io.h>
 #include <asm/bitops.h>
 
+void ide_softirq_done(struct request *rq)
+{
+       request_queue_t *q = rq->q;
+
+       add_disk_randomness(rq->rq_disk);
+       end_that_request_chunk(rq, rq->errors, rq->data_len);
+
+       spin_lock_irq(q->queue_lock);
+       end_that_request_last(rq, rq->errors);
+       spin_unlock_irq(q->queue_lock);
+}
+
 int __ide_end_request(ide_drive_t *drive, struct request *rq, int uptodate,
                      int nr_sectors)
 {
+       unsigned int nbytes;
        int ret = 1;
 
        BUG_ON(!(rq->flags & REQ_STARTED));
@@ -81,17 +94,28 @@ int __ide_end_request(ide_drive_t *drive, struct request *rq, int uptodate,
                HWGROUP(drive)->hwif->ide_dma_on(drive);
        }
 
-       if (!end_that_request_first(rq, uptodate, nr_sectors)) {
-               add_disk_randomness(rq->rq_disk);
-
-               if (blk_rq_tagged(rq))
-                       blk_queue_end_tag(drive->queue, rq);
-
+       /*
+        * For partial completions (or non fs/pc requests), use the regular
+        * direct completion path.
+        */
+       nbytes = nr_sectors << 9;
+       if (rq_all_done(rq, nbytes)) {
+               rq->errors = uptodate;
+               rq->data_len = nbytes;
                blkdev_dequeue_request(rq);
                HWGROUP(drive)->rq = NULL;
-               end_that_request_last(rq, uptodate);
+               blk_complete_request(rq);
                ret = 0;
+       } else {
+               if (!end_that_request_first(rq, uptodate, nr_sectors)) {
+                       add_disk_randomness(rq->rq_disk);
+                       blkdev_dequeue_request(rq);
+                       HWGROUP(drive)->rq = NULL;
+                       end_that_request_last(rq, uptodate);
+                       ret = 0;
+               }
        }
+
        return ret;
 }
 EXPORT_SYMBOL(__ide_end_request);
@@ -113,6 +137,10 @@ int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
        unsigned long flags;
        int ret = 1;
 
+       /*
+        * room for locking improvements here, the calls below don't
+        * need the queue lock held at all
+        */
        spin_lock_irqsave(&ide_lock, flags);
        rq = HWGROUP(drive)->rq;
 

diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 02167a5b751dbe40a0b1be304766903fceb43c52..1ddaa71a8f45c7dbd525035c017a99c2469d23f3 100644 (file)
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1011,6 +1011,8 @@ static int ide_init_queue(ide_drive_t *drive)
        blk_queue_max_hw_segments(q, max_sg_entries);
        blk_queue_max_phys_segments(q, max_sg_entries);
 
+       blk_queue_softirq_done(q, ide_softirq_done);
+
        /* assign drive queue */
        drive->queue = q;
 

diff --git a/include/linux/ide.h b/include/linux/ide.h
index 4dd6694963c0b76d46e5c931f8ceb0062ac781b6..ef8d0cbb832f14496b0687600b5500e79e77cd99 100644 (file)
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1001,6 +1001,7 @@ extern int noautodma;
 
 extern int ide_end_request (ide_drive_t *drive, int uptodate, int nrsecs);
 extern int __ide_end_request (ide_drive_t *drive, struct request *rq, int uptodate, int nrsecs);
+extern void ide_softirq_done(struct request *rq);
 
 /*
  * This is used on exit from the driver to designate the next irq handler