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-rw-r--r--block/blk-core.c8
-rw-r--r--block/blk-flush.c20
-rw-r--r--block/blk.h2
-rw-r--r--include/linux/blkdev.h1
4 files changed, 25 insertions, 6 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index b850bedad229..7c59b0f5eae8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1700,6 +1700,7 @@ EXPORT_SYMBOL_GPL(blk_rq_check_limits);
int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
{
unsigned long flags;
+ int where = ELEVATOR_INSERT_BACK;
if (blk_rq_check_limits(q, rq))
return -EIO;
@@ -1716,7 +1717,10 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
*/
BUG_ON(blk_queued_rq(rq));
- add_acct_request(q, rq, ELEVATOR_INSERT_BACK);
+ if (rq->cmd_flags & (REQ_FLUSH|REQ_FUA))
+ where = ELEVATOR_INSERT_FLUSH;
+
+ add_acct_request(q, rq, where);
spin_unlock_irqrestore(q->queue_lock, flags);
return 0;
@@ -2273,7 +2277,7 @@ static bool blk_end_bidi_request(struct request *rq, int error,
* %false - we are done with this request
* %true - still buffers pending for this request
**/
-static bool __blk_end_bidi_request(struct request *rq, int error,
+bool __blk_end_bidi_request(struct request *rq, int error,
unsigned int nr_bytes, unsigned int bidi_bytes)
{
if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 2d162bd840d3..491eb30a242d 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -123,7 +123,7 @@ static void blk_flush_restore_request(struct request *rq)
/* make @rq a normal request */
rq->cmd_flags &= ~REQ_FLUSH_SEQ;
- rq->end_io = NULL;
+ rq->end_io = rq->flush.saved_end_io;
}
/**
@@ -301,9 +301,6 @@ void blk_insert_flush(struct request *rq)
unsigned int fflags = q->flush_flags; /* may change, cache */
unsigned int policy = blk_flush_policy(fflags, rq);
- BUG_ON(rq->end_io);
- BUG_ON(!rq->bio || rq->bio != rq->biotail);
-
/*
* @policy now records what operations need to be done. Adjust
* REQ_FLUSH and FUA for the driver.
@@ -313,6 +310,19 @@ void blk_insert_flush(struct request *rq)
rq->cmd_flags &= ~REQ_FUA;
/*
+ * An empty flush handed down from a stacking driver may
+ * translate into nothing if the underlying device does not
+ * advertise a write-back cache. In this case, simply
+ * complete the request.
+ */
+ if (!policy) {
+ __blk_end_bidi_request(rq, 0, 0, 0);
+ return;
+ }
+
+ BUG_ON(!rq->bio || rq->bio != rq->biotail);
+
+ /*
* If there's data but flush is not necessary, the request can be
* processed directly without going through flush machinery. Queue
* for normal execution.
@@ -320,6 +330,7 @@ void blk_insert_flush(struct request *rq)
if ((policy & REQ_FSEQ_DATA) &&
!(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) {
list_add_tail(&rq->queuelist, &q->queue_head);
+ blk_run_queue_async(q);
return;
}
@@ -330,6 +341,7 @@ void blk_insert_flush(struct request *rq)
memset(&rq->flush, 0, sizeof(rq->flush));
INIT_LIST_HEAD(&rq->flush.list);
rq->cmd_flags |= REQ_FLUSH_SEQ;
+ rq->flush.saved_end_io = rq->end_io; /* Usually NULL */
rq->end_io = flush_data_end_io;
blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0);
diff --git a/block/blk.h b/block/blk.h
index d6586287adc9..20b900a377c9 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -17,6 +17,8 @@ int blk_rq_append_bio(struct request_queue *q, struct request *rq,
struct bio *bio);
void blk_dequeue_request(struct request *rq);
void __blk_queue_free_tags(struct request_queue *q);
+bool __blk_end_bidi_request(struct request *rq, int error,
+ unsigned int nr_bytes, unsigned int bidi_bytes);
void blk_rq_timed_out_timer(unsigned long data);
void blk_delete_timer(struct request *);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 847928546076..84b15d54f8c2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -118,6 +118,7 @@ struct request {
struct {
unsigned int seq;
struct list_head list;
+ rq_end_io_fn *saved_end_io;
} flush;
};