blk_end_request: changing ide-cd (take 4)

This patch converts ide-cd (cdrom_newpc_intr()) to use blk_end_request
interfaces.  Related 'uptodate' arguments are converted to 'error'.

In PIO mode, ide-cd (cdrom_newpc_intr()) needs to defer
end_that_request_last() until the device clears DRQ_STAT and raises
an interrupt after end_that_request_first().
So blk_end_request() has to return without completing request
even if no leftover in the request.

ide-cd uses blk_end_request_callback() and a dummy callback function,
which just returns value '1', to tell blk_end_request_callback()
about that.

Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 282f1580fca915bde7ea84edb35c68d97c69e138..74c6087ada38a99714011f84f18a0c05f9b69666 100644 (file)
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1647,6 +1647,17 @@ static int cdrom_write_check_ireason(ide_drive_t *drive, int len, int ireason)
        return 1;
 }
 
+/*
+ * Called from blk_end_request_callback() after the data of the request
+ * is completed and before the request is completed.
+ * By returning value '1', blk_end_request_callback() returns immediately
+ * without completing the request.
+ */
+static int cdrom_newpc_intr_dummy_cb(struct request *rq)
+{
+       return 1;
+}
+
 typedef void (xfer_func_t)(ide_drive_t *, void *, u32);
 
 /*
@@ -1685,9 +1696,13 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
                        return ide_error(drive, "dma error", stat);
                }
 
-               end_that_request_chunk(rq, 1, rq->data_len);
-               rq->data_len = 0;
-               goto end_request;
+               spin_lock_irqsave(&ide_lock, flags);
+               if (__blk_end_request(rq, 0, rq->data_len))
+                       BUG();
+               HWGROUP(drive)->rq = NULL;
+               spin_unlock_irqrestore(&ide_lock, flags);
+
+               return ide_stopped;
        }
 
        /*
@@ -1705,8 +1720,15 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
        /*
         * If DRQ is clear, the command has completed.
         */
-       if ((stat & DRQ_STAT) == 0)
-               goto end_request;
+       if ((stat & DRQ_STAT) == 0) {
+               spin_lock_irqsave(&ide_lock, flags);
+               if (__blk_end_request(rq, 0, 0))
+                       BUG();
+               HWGROUP(drive)->rq = NULL;
+               spin_unlock_irqrestore(&ide_lock, flags);
+
+               return ide_stopped;
+       }
 
        /*
         * check which way to transfer data
@@ -1759,7 +1781,14 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
                rq->data_len -= blen;
 
                if (rq->bio)
-                       end_that_request_chunk(rq, 1, blen);
+                       /*
+                        * The request can't be completed until DRQ is cleared.
+                        * So complete the data, but don't complete the request
+                        * using the dummy function for the callback feature
+                        * of blk_end_request_callback().
+                        */
+                       blk_end_request_callback(rq, 0, blen,
+                                                cdrom_newpc_intr_dummy_cb);
                else
                        rq->data += blen;
        }
@@ -1780,14 +1809,6 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
 
        ide_set_handler(drive, cdrom_newpc_intr, rq->timeout, NULL);
        return ide_started;
-
-end_request:
-       spin_lock_irqsave(&ide_lock, flags);
-       blkdev_dequeue_request(rq);
-       end_that_request_last(rq, 1);
-       HWGROUP(drive)->rq = NULL;
-       spin_unlock_irqrestore(&ide_lock, flags);
-       return ide_stopped;
 }
 
 static ide_startstop_t cdrom_write_intr(ide_drive_t *drive)