From: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
To: Zhao Heming <heming.zhao@suse.com>, linux-raid@vger.kernel.org
Cc: neilb@suse.com, song@kernel.org
Subject: Re: [PATCH v5 1/2] md-cluster: fix safemode_delay value when converting to clustered bitmap
Date: Tue, 21 Jul 2020 10:35:11 +0200 [thread overview]
Message-ID: <8f122dea-2a4a-4523-653f-fe6fc2842653@cloud.ionos.com> (raw)
In-Reply-To: <1595268533-7040-2-git-send-email-heming.zhao@suse.com>
On 7/20/20 8:08 PM, Zhao Heming wrote:
> When array convert to clustered bitmap, the safe_mode_delay doesn't
> clean and vice versa. the /sys/block/mdX/md/safe_mode_delay keep original
> value after changing bitmap type. In safe_delay_store(), the code forbids
> setting mddev->safemode_delay when array is clustered. So in cluster-md
> env, the expected safemode_delay value should be 0.
>
> Reproducible steps:
> ```
> node1 # mdadm --zero-superblock /dev/sd{b,c,d}
> node1 # mdadm -C /dev/md0 -b internal -e 1.2 -n 2 -l mirror /dev/sdb /dev/sdc
> node1 # cat /sys/block/md0/md/safe_mode_delay
> 0.204
> node1 # mdadm -G /dev/md0 -b none
> node1 # mdadm --grow /dev/md0 --bitmap=clustered
> node1 # cat /sys/block/md0/md/safe_mode_delay
> 0.204 <== doesn't change, should ZERO for cluster-md
>
> node1 # mdadm --zero-superblock /dev/sd{b,c,d}
> node1 # mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sdb /dev/sdc
> node1 # cat /sys/block/md0/md/safe_mode_delay
> 0.000
> node1 # mdadm -G /dev/md0 -b none
> node1 # cat /sys/block/md0/md/safe_mode_delay
> 0.000 <== doesn't change, should default value
> ```
>
> Signed-off-by: Zhao Heming <heming.zhao@suse.com>
> ---
> drivers/md/md.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index f567f536b529..1bde3df3fa18 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -101,6 +101,8 @@ static void mddev_detach(struct mddev *mddev);
> * count by 2 for every hour elapsed between read errors.
> */
> #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
> +/* Default safemode delay: 200 msec */
> +#define DEFAULT_SAFEMODE_DELAY ((200 * HZ)/1000 +1)
> /*
> * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
> * is 1000 KB/sec, so the extra system load does not show up that much.
> @@ -5982,7 +5984,7 @@ int md_run(struct mddev *mddev)
> if (mddev_is_clustered(mddev))
> mddev->safemode_delay = 0;
> else
> - mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
> + mddev->safemode_delay = DEFAULT_SAFEMODE_DELAY;
> mddev->in_sync = 1;
> smp_wmb();
> spin_lock(&mddev->lock);
> @@ -7361,6 +7363,7 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
>
> mddev->bitmap_info.nodes = 0;
> md_cluster_ops->leave(mddev);
> + mddev->safemode_delay = DEFAULT_SAFEMODE_DELAY;
> }
Not about the patch itself, just confuse about the meaning of
safemode_delay.
As safemode_delay represents 200 ms delay, but md_write_end has this.
/* The roundup() ensures this only performs locking once
* every ->safemode_delay *jiffies*
*/
mod_timer(&mddev->safemode_timer,
roundup(jiffies, mddev->safemode_delay) +
mddev->safemode_delay);
And the second argument in mod_timer() means "new timeout in jiffies",
does the above need to convert from ms to jiffies? Am I miss something?
Thanks,
Guoqing
next prev parent reply other threads:[~2020-07-21 8:35 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-20 18:08 [PATCH v5 0/2] md_cluster: bugs fix Zhao Heming
2020-07-20 18:08 ` [PATCH v5 1/2] md-cluster: fix safemode_delay value when converting to clustered bitmap Zhao Heming
2020-07-20 23:02 ` NeilBrown
2020-07-21 8:35 ` Guoqing Jiang [this message]
2020-07-21 8:58 ` heming.zhao
2020-07-20 18:08 ` [PATCH v5 2/2] md-cluster: fix rmmod issue when md_cluster convert bitmap to none Zhao Heming
2020-07-22 5:01 ` [PATCH v5 0/2] md_cluster: bugs fix Song Liu
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