Thread (3 messages) 3 messages, 2 authors, 2019-02-10

Re: [PATCH] blk-sysfs: Rework documention of __blk_release_queue

From: Jens Axboe <axboe@kernel.dk>
Date: 2019-02-10 15:23:31
Also in: lkml

On 2/9/19 11:34 AM, Marcos Paulo de Souza wrote:
Ping :)

On 1/30/19 11:11 PM, Marcos Paulo de Souza wrote:
quoted
The Notes section of the comment was removed, because now
blk_release_queue can only be executed from blk_cleanup_queue (being
called when the q->kobj reaches zero), and also blk_init_queue was removed
in a1ce35fa4985.

Signed-off-by: Marcos Paulo de Souza <redacted>
---
 This is basically a v2 of https://lkml.org/lkml/2019/1/14/1098

 But, I tried to describe when this function is called, removing redundancies.
 Maybe it would be better placed in blk-core.c, where the q->kobj is initialized
 with blk_queue_ktype (which .release pointer points to blk_release_queue)?

 block/blk-sysfs.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 590d1ef2f961..d4dea9179fa6 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -817,21 +817,16 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head)
 }
 
 /**
- * __blk_release_queue - release a request queue when it is no longer needed
+ * __blk_release_queue - release a request queue
  * @work: pointer to the release_work member of the request queue to be released
  *
  * Description:
- *     blk_release_queue is the counterpart of blk_init_queue(). It should be
- *     called when a request queue is being released; typically when a block
- *     device is being de-registered. Its primary task it to free the queue
- *     itself.
- *
- * Notes:
- *     The low level driver must have finished any outstanding requests first
- *     via blk_cleanup_queue().
- *
- *     Although blk_release_queue() may be called with preemption disabled,
- *     __blk_release_queue() may sleep.
+ *     This function is called when a block device is being de-registered. The
unregistered
quoted
+ *     process of releasing a request queue starts with blk_cleanup_queue, which
+ *     set the appropriate flags and the calls blk_put_queue, that decrements
s/the/then
quoted
+ *     the reference counter of the request queue. Once the reference counter
+ *     of the request queue reaches zero, blk_release_queue is called to release
+ *     all allocated resources of the request queue.
  */
 static void __blk_release_queue(struct work_struct *work)
 {

-- 
Jens Axboe
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help