Merge branch 'for-linus' of ../linux-2.6-block into block-for-2.6.39/core
This merge creates two set of conflicts. One is simple context
conflicts caused by removal of throtl_scheduled_delayed_work() in
for-linus and removal of throtl_shutdown_timer_wq() in
for-2.6.39/core.
The other is caused by commit 255bb490c8 (block: blk-flush shouldn't
call directly into q->request_fn() __blk_run_queue()) in for-linus
crashing with FLUSH reimplementation in for-2.6.39/core. The conflict
isn't trivial but the resolution is straight-forward.
* __blk_run_queue() calls in flush_end_io() and flush_data_end_io()
should be called with @force_kblockd set to %true.
* elv_insert() in blk_kick_flush() should use
%ELEVATOR_INSERT_REQUEUE.
Both changes are to avoid invoking ->request_fn() directly from
request completion path and closely match the changes in the commit
255bb490c8.
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/block/blk-flush.c b/block/blk-flush.c
index a867e3f..0bd8c9c 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -212,9 +212,14 @@
queued |= blk_flush_complete_seq(rq, seq, error);
}
- /* after populating an empty queue, kick it to avoid stall */
+ /*
+ * Moving a request silently to empty queue_head may stall the
+ * queue. Kick the queue in those cases. This function is called
+ * from request completion path and calling directly into
+ * request_fn may confuse the driver. Always use kblockd.
+ */
if (queued && was_empty)
- __blk_run_queue(q);
+ __blk_run_queue(q, true);
}
/**
@@ -257,7 +262,7 @@
q->flush_rq.end_io = flush_end_io;
q->flush_pending_idx ^= 1;
- elv_insert(q, &q->flush_rq, ELEVATOR_INSERT_FRONT);
+ elv_insert(q, &q->flush_rq, ELEVATOR_INSERT_REQUEUE);
return true;
}
@@ -266,9 +271,12 @@
struct request_queue *q = rq->q;
bool was_empty = elv_queue_empty(q);
- /* after populating an empty queue, kick it to avoid stall */
+ /*
+ * After populating an empty queue, kick it to avoid stall. Read
+ * the comment in flush_end_io().
+ */
if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error) && was_empty)
- __blk_run_queue(q);
+ __blk_run_queue(q, true);
}
/**
