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authorKiyoshi Ueda <k-ueda@ct.jp.nec.com>2007-12-11 22:51:46 (GMT)
committerJens Axboe <jens.axboe@oracle.com>2008-01-28 09:37:08 (GMT)
commite3a04fe34a3ec81ddeddb6c73fb7299716cffbb0 (patch)
tree080d1ec1cc3d78b3aef4e95f5334f5b4c3da3498 /block
parentaaa04c28cb9a1efd42541fdb7ab648231c2a2263 (diff)
downloadlinux-e3a04fe34a3ec81ddeddb6c73fb7299716cffbb0.tar.xz
blk_end_request: add bidi completion interface (take 4)
This patch adds a variant of the interface, blk_end_bidi_request(), which completes a bidi request. Bidi request must be completed as a whole, both rq and rq->next_rq at once. So the interface has 2 arguments for completion size. As for ->end_io, only rq->end_io is called (rq->next_rq->end_io is not called). So if special completion handling is needed, the handler must be set to rq->end_io. And the handler must take care of freeing next_rq too, since the interface doesn't care of it if rq->end_io is not NULL. Cc: Boaz Harrosh <bharrosh@panasas.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>
Diffstat (limited to 'block')
-rw-r--r--block/ll_rw_blk.c40
1 files changed, 35 insertions, 5 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 919e4ba..4889f7a 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -3821,6 +3821,9 @@ static void complete_request(struct request *rq, int error)
if (blk_queued_rq(rq))
blkdev_dequeue_request(rq);
+ if (blk_bidi_rq(rq) && !rq->end_io)
+ __blk_put_request(rq->next_rq->q, rq->next_rq);
+
end_that_request_last(rq, uptodate);
}
@@ -3828,14 +3831,15 @@ static void complete_request(struct request *rq, int error)
* 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
+ * @nr_bytes: number of bytes to complete @rq
+ * @bidi_bytes: number of bytes to complete @rq->next_rq
* @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.
+ * Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
* If @rq has leftover, sets it up for the next range of segments.
*
* Return:
@@ -3843,7 +3847,7 @@ static void complete_request(struct request *rq, int error)
* 1 - this request is not freed yet, it still has pending buffers.
**/
static int blk_end_io(struct request *rq, int error, int nr_bytes,
- int (drv_callback)(struct request *))
+ int bidi_bytes, int (drv_callback)(struct request *))
{
struct request_queue *q = rq->q;
unsigned long flags = 0UL;
@@ -3858,6 +3862,11 @@ static int blk_end_io(struct request *rq, int error, int nr_bytes,
if (blk_fs_request(rq) || blk_pc_request(rq)) {
if (__end_that_request_first(rq, uptodate, nr_bytes))
return 1;
+
+ /* Bidi request must be completed as a whole */
+ if (blk_bidi_rq(rq) &&
+ __end_that_request_first(rq->next_rq, uptodate, bidi_bytes))
+ return 1;
}
/* Special feature for tricky drivers */
@@ -3889,7 +3898,7 @@ static int blk_end_io(struct request *rq, int error, int nr_bytes,
**/
int blk_end_request(struct request *rq, int error, int nr_bytes)
{
- return blk_end_io(rq, error, nr_bytes, NULL);
+ return blk_end_io(rq, error, nr_bytes, 0, NULL);
}
EXPORT_SYMBOL_GPL(blk_end_request);
@@ -3930,6 +3939,27 @@ int __blk_end_request(struct request *rq, int error, int nr_bytes)
EXPORT_SYMBOL_GPL(__blk_end_request);
/**
+ * blk_end_bidi_request - Helper function for drivers to complete bidi request.
+ * @rq: the bidi request being processed
+ * @error: 0 for success, < 0 for error
+ * @nr_bytes: number of bytes to complete @rq
+ * @bidi_bytes: number of bytes to complete @rq->next_rq
+ *
+ * Description:
+ * Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
+ *
+ * Return:
+ * 0 - we are done with this request
+ * 1 - still buffers pending for this request
+ **/
+int blk_end_bidi_request(struct request *rq, int error, int nr_bytes,
+ int bidi_bytes)
+{
+ return blk_end_io(rq, error, nr_bytes, bidi_bytes, NULL);
+}
+EXPORT_SYMBOL_GPL(blk_end_bidi_request);
+
+/**
* blk_end_request_callback - Special helper function for tricky drivers
* @rq: the request being processed
* @error: 0 for success, < 0 for error
@@ -3957,7 +3987,7 @@ EXPORT_SYMBOL_GPL(__blk_end_request);
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);
+ return blk_end_io(rq, error, nr_bytes, 0, drv_callback);
}
EXPORT_SYMBOL_GPL(blk_end_request_callback);