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>

1 files changed, 35 insertions, 14 deletions

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 282f1580fca9..74c6087ada38 100644
--- 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)