Re: [PATCH] blk-sysfs: Rework documention of __blk_release_queue
From: Marcos Paulo de Souza
Date: Sat Feb 09 2019 - 13:33:02 EST
On 1/30/19 11:11 PM, Marcos Paulo de Souza wrote:
> 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 <marcos.souza.org@xxxxxxxxx>
> 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
> + * process of releasing a request queue starts with blk_cleanup_queue, which
> + * set the appropriate flags and the calls blk_put_queue, that decrements
> + * 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)