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authorTejun Heo <tj@kernel.org>2012-03-05 13:14:58 -0800
committerJens Axboe <axboe@kernel.dk>2012-03-06 21:27:21 +0100
commitd732580b4eb31553c63744a47d590f770cafb8f0 (patch)
treeea4e8e21df1b639603693e6f5fdfc5a620cd8737 /block/elevator.c
parentb2fab5acd28ead6f0dd6c3996ba23f0ef1772f15 (diff)
downloadlwn-d732580b4eb31553c63744a47d590f770cafb8f0.tar.gz
lwn-d732580b4eb31553c63744a47d590f770cafb8f0.zip
block: implement blk_queue_bypass_start/end()
Rename and extend elv_queisce_start/end() to blk_queue_bypass_start/end() which are exported and supports nesting via @q->bypass_depth. Also add blk_queue_bypass() to test bypass state. This will be further extended and used for blkio_group management. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/elevator.c')
-rw-r--r--block/elevator.c25
1 files changed, 3 insertions, 22 deletions
diff --git a/block/elevator.c b/block/elevator.c
index f81c061dad15..0bdea0ed03a3 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -553,25 +553,6 @@ void elv_drain_elevator(struct request_queue *q)
}
}
-void elv_quiesce_start(struct request_queue *q)
-{
- if (!q->elevator)
- return;
-
- spin_lock_irq(q->queue_lock);
- queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
- spin_unlock_irq(q->queue_lock);
-
- blk_drain_queue(q, false);
-}
-
-void elv_quiesce_end(struct request_queue *q)
-{
- spin_lock_irq(q->queue_lock);
- queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
- spin_unlock_irq(q->queue_lock);
-}
-
void __elv_add_request(struct request_queue *q, struct request *rq, int where)
{
trace_block_rq_insert(q, rq);
@@ -903,7 +884,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
* using INSERT_BACK. All requests have SOFTBARRIER set and no
* merge happens either.
*/
- elv_quiesce_start(q);
+ blk_queue_bypass_start(q);
/* unregister and clear all auxiliary data of the old elevator */
if (registered)
@@ -933,7 +914,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
/* done, kill the old one and finish */
elevator_exit(old);
- elv_quiesce_end(q);
+ blk_queue_bypass_end(q);
blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
@@ -945,7 +926,7 @@ fail_init:
/* switch failed, restore and re-register old elevator */
q->elevator = old;
elv_register_queue(q);
- elv_quiesce_end(q);
+ blk_queue_bypass_end(q);
return err;
}