[PATCH] md/raid5: release/flush io in raid5_do_work()

[PATCH] md/raid5: release/flush io in raid5_do_work()

[Song Liu]

In raid5, there are scenarios where some ios are deferred to a later
time, and some IO need a flush to complete. To make sure we make
progress with these IOs, we need to call the following functions:

    flush_deferred_bios(conf);
    r5l_flush_stripe_to_raid(conf->log);

Both of these functions are called in raid5d(), but missing in
raid5_do_work(). As a result, these functions are not called
when multi-threading (group_thread_cnt > 0) is enabled. This patch
adds calls to these function to raid5_do_work().

Note for stable branches:

  r5l_flush_stripe_to_raid(conf->log) is need for 4.4+
  flush_deferred_bios(conf) is only needed for 4.11+

Cc: stable@vger.kernel.org (4.4+)
Signed-off-by: Song Liu <songliubraving@fb.com>
---
 drivers/md/raid5.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index f64ff32..6af57c6 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6226,6 +6226,10 @@ static void raid5_do_work(struct work_struct *work)
 
 	spin_unlock_irq(&conf->device_lock);
 
+	flush_deferred_bios(conf);
+
+	r5l_flush_stripe_to_raid(conf->log);
+
 	async_tx_issue_pending_all();
 	blk_finish_plug(&plug);
 
-- 
2.9.5

Re: [PATCH] md/raid5: release/flush io in raid5_do_work()

[Shaohua Li]

On Thu, Aug 24, 2017 at 09:53:59AM -0700, Song Liu wrote:
> In raid5, there are scenarios where some ios are deferred to a later
> time, and some IO need a flush to complete. To make sure we make
> progress with these IOs, we need to call the following functions:
> 
>     flush_deferred_bios(conf);
>     r5l_flush_stripe_to_raid(conf->log);
> 
> Both of these functions are called in raid5d(), but missing in
> raid5_do_work(). As a result, these functions are not called
> when multi-threading (group_thread_cnt > 0) is enabled. This patch
> adds calls to these function to raid5_do_work().
> 
> Note for stable branches:
> 
>   r5l_flush_stripe_to_raid(conf->log) is need for 4.4+
>   flush_deferred_bios(conf) is only needed for 4.11+
> 
> Cc: stable@vger.kernel.org (4.4+)
> Signed-off-by: Song Liu <songliubraving@fb.com>

Applied, thanks!
> ---
>  drivers/md/raid5.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index f64ff32..6af57c6 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -6226,6 +6226,10 @@ static void raid5_do_work(struct work_struct *work)
>  
>  	spin_unlock_irq(&conf->device_lock);
>  
> +	flush_deferred_bios(conf);
> +
> +	r5l_flush_stripe_to_raid(conf->log);
> +
>  	async_tx_issue_pending_all();
>  	blk_finish_plug(&plug);
>  
> -- 
> 2.9.5
> 
> --
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