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-rw-r--r--block/ll_rw_blk.c72
1 files changed, 66 insertions, 6 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index fb95119..919e4ba 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -3825,10 +3825,14 @@ static void complete_request(struct request *rq, int error)
}
/**
- * blk_end_request - Helper function for drivers to complete the request.
- * @rq: the request being processed
- * @error: 0 for success, < 0 for error
- * @nr_bytes: number of bytes to complete
+ * blk_end_io - Generic end_io function to complete a request.
+ * @rq: the request being processed
+ * @error: 0 for success, < 0 for error
+ * @nr_bytes: number of bytes to complete
+ * @drv_callback: function called between completion of bios in the request
+ * and completion of the request.
+ * If the callback returns non 0, this helper returns without
+ * completion of the request.
*
* Description:
* Ends I/O on a number of bytes attached to @rq.
@@ -3836,9 +3840,10 @@ static void complete_request(struct request *rq, int error)
*
* Return:
* 0 - we are done with this request
- * 1 - still buffers pending for this request
+ * 1 - this request is not freed yet, it still has pending buffers.
**/
-int blk_end_request(struct request *rq, int error, int nr_bytes)
+static int blk_end_io(struct request *rq, int error, int nr_bytes,
+ int (drv_callback)(struct request *))
{
struct request_queue *q = rq->q;
unsigned long flags = 0UL;
@@ -3855,6 +3860,10 @@ int blk_end_request(struct request *rq, int error, int nr_bytes)
return 1;
}
+ /* Special feature for tricky drivers */
+ if (drv_callback && drv_callback(rq))
+ return 1;
+
add_disk_randomness(rq->rq_disk);
spin_lock_irqsave(q->queue_lock, flags);
@@ -3863,6 +3872,25 @@ int blk_end_request(struct request *rq, int error, int nr_bytes)
return 0;
}
+
+/**
+ * blk_end_request - Helper function for drivers to complete the request.
+ * @rq: the request being processed
+ * @error: 0 for success, < 0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ * Ends I/O on a number of bytes attached to @rq.
+ * If @rq has leftover, sets it up for the next range of segments.
+ *
+ * Return:
+ * 0 - we are done with this request
+ * 1 - still buffers pending for this request
+ **/
+int blk_end_request(struct request *rq, int error, int nr_bytes)
+{
+ return blk_end_io(rq, error, nr_bytes, NULL);
+}
EXPORT_SYMBOL_GPL(blk_end_request);
/**
@@ -3901,6 +3929,38 @@ int __blk_end_request(struct request *rq, int error, int nr_bytes)
}
EXPORT_SYMBOL_GPL(__blk_end_request);
+/**
+ * blk_end_request_callback - Special helper function for tricky drivers
+ * @rq: the request being processed
+ * @error: 0 for success, < 0 for error
+ * @nr_bytes: number of bytes to complete
+ * @drv_callback: function called between completion of bios in the request
+ * and completion of the request.
+ * If the callback returns non 0, this helper returns without
+ * completion of the request.
+ *
+ * Description:
+ * Ends I/O on a number of bytes attached to @rq.
+ * If @rq has leftover, sets it up for the next range of segments.
+ *
+ * This special helper function is used only for existing tricky drivers.
+ * (e.g. cdrom_newpc_intr() of ide-cd)
+ * This interface will be removed when such drivers are rewritten.
+ * Don't use this interface in other places anymore.
+ *
+ * Return:
+ * 0 - we are done with this request
+ * 1 - this request is not freed yet.
+ * this request still has pending buffers or
+ * the driver doesn't want to finish this request yet.
+ **/
+int blk_end_request_callback(struct request *rq, int error, int nr_bytes,
+ int (drv_callback)(struct request *))
+{
+ return blk_end_io(rq, error, nr_bytes, drv_callback);
+}
+EXPORT_SYMBOL_GPL(blk_end_request_callback);
+
static void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio)
{