From: Xiao Ni <xni@redhat.com>
To: Yu Kuai <yukuai1@huaweicloud.com>,
guoqing.jiang@linux.dev, agk@redhat.com, snitzer@kernel.org,
dm-devel@redhat.com, song@kernel.org
Cc: yi.zhang@huawei.com, yangerkun@huawei.com,
linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
yukuai3@huawei.com
Subject: Re: [dm-devel] [PATCH -next v2 2/6] md: refactor action_store() for 'idle' and 'frozen'
Date: Tue, 13 Jun 2023 16:02:51 +0800 [thread overview]
Message-ID: <b780ccfd-66b1-fdd1-b33e-aa680fbd86f1@redhat.com> (raw)
In-Reply-To: <20230529132037.2124527-3-yukuai1@huaweicloud.com>
在 2023/5/29 下午9:20, Yu Kuai 写道:
> From: Yu Kuai <yukuai3@huawei.com>
>
> Prepare to handle 'idle' and 'frozen' differently to fix a deadlock, there
> are no functional changes except that MD_RECOVERY_RUNNING is checked
> again after 'reconfig_mutex' is held.
Can you explain more about why it needs to check MD_RECOVERY_RUNNING
again here?
>
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
> drivers/md/md.c | 61 ++++++++++++++++++++++++++++++++++++-------------
> 1 file changed, 45 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 9b97731e1fe4..23e8e7eae062 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -4755,6 +4755,46 @@ action_show(struct mddev *mddev, char *page)
> return sprintf(page, "%s\n", type);
> }
>
> +static void stop_sync_thread(struct mddev *mddev)
> +{
> + if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
> + return;
> +
> + if (mddev_lock(mddev))
> + return;
> +
> + /*
> + * Check again in case MD_RECOVERY_RUNNING is cleared before lock is
> + * held.
> + */
> + if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
> + mddev_unlock(mddev);
> + return;
> + }
> +
> + if (work_pending(&mddev->del_work))
> + flush_workqueue(md_misc_wq);
> +
> + if (mddev->sync_thread) {
> + set_bit(MD_RECOVERY_INTR, &mddev->recovery);
> + md_reap_sync_thread(mddev);
> + }
> +
> + mddev_unlock(mddev);
> +}
> +
> +static void idle_sync_thread(struct mddev *mddev)
> +{
> + clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
> + stop_sync_thread(mddev);
> +}
> +
> +static void frozen_sync_thread(struct mddev *mddev)
> +{
> + set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
> + stop_sync_thread(mddev);
> +}
> +
> static ssize_t
> action_store(struct mddev *mddev, const char *page, size_t len)
> {
> @@ -4762,22 +4802,11 @@ action_store(struct mddev *mddev, const char *page, size_t len)
> return -EINVAL;
>
>
> - if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
> - if (cmd_match(page, "frozen"))
> - set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
> - else
> - clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
> - if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
> - mddev_lock(mddev) == 0) {
> - if (work_pending(&mddev->del_work))
> - flush_workqueue(md_misc_wq);
> - if (mddev->sync_thread) {
> - set_bit(MD_RECOVERY_INTR, &mddev->recovery);
> - md_reap_sync_thread(mddev);
> - }
> - mddev_unlock(mddev);
> - }
> - } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
> + if (cmd_match(page, "idle"))
> + idle_sync_thread(mddev);
> + else if (cmd_match(page, "frozen"))
> + frozen_sync_thread(mddev);
> + else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
> return -EBUSY;
> else if (cmd_match(page, "resync"))
> clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
next prev parent reply other threads:[~2023-06-13 8:04 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-29 13:20 [PATCH -next v2 0/6] md: fix that MD_RECOVERY_RUNNING can be cleared while sync_thread is still running Yu Kuai
2023-05-29 13:20 ` [PATCH -next v2 1/6] Revert "md: unlock mddev before reap sync_thread in action_store" Yu Kuai
2023-06-13 6:25 ` Xiao Ni
2023-06-13 11:58 ` Yu Kuai
2023-05-29 13:20 ` [PATCH -next v2 2/6] md: refactor action_store() for 'idle' and 'frozen' Yu Kuai
2023-06-13 8:02 ` Xiao Ni [this message]
2023-06-13 12:00 ` [dm-devel] " Yu Kuai
2023-06-13 12:25 ` Xiao Ni
2023-06-13 12:44 ` Yu Kuai
2023-06-13 14:14 ` Xiao Ni
2023-05-29 13:20 ` [PATCH -next v2 3/6] md: add a mutex to synchronize idle and frozen in action_store() Yu Kuai
2023-06-13 14:43 ` [dm-devel] " Xiao Ni
2023-06-14 1:15 ` Yu Kuai
2023-06-16 6:41 ` Song Liu
2023-05-29 13:20 ` [PATCH -next v2 4/6] md: refactor idle/frozen_sync_thread() to fix deadlock Yu Kuai
2023-06-13 14:50 ` [dm-devel] " Xiao Ni
2023-06-14 1:48 ` Yu Kuai
2023-06-14 2:04 ` Yu Kuai
2023-06-14 7:12 ` Xiao Ni
2023-06-14 7:38 ` Yu Kuai
2023-06-14 7:57 ` Xiao Ni
2023-06-14 8:28 ` Yu Kuai
2023-06-14 9:08 ` Xiao Ni
2023-06-15 1:28 ` Yu Kuai
2023-06-15 8:01 ` Xiao Ni
2023-06-15 8:17 ` Xiao Ni
2023-06-15 9:05 ` Yu Kuai
2023-06-15 9:14 ` Xiao Ni
2023-06-14 3:47 ` Xiao Ni
2023-06-14 6:04 ` Yu Kuai
2023-06-14 6:37 ` Xiao Ni
2023-05-29 13:20 ` [PATCH -next v2 5/6] md: wake up 'resync_wait' at last in md_reap_sync_thread() Yu Kuai
2023-06-14 7:20 ` Xiao Ni
2023-05-29 13:20 ` [PATCH -next v2 6/6] md: enhance checking in md_check_recovery() Yu Kuai
2023-06-14 7:24 ` [dm-devel] " Xiao Ni
2023-06-08 2:41 ` [PATCH -next v2 0/6] md: fix that MD_RECOVERY_RUNNING can be cleared while sync_thread is still running Yu Kuai
2023-06-09 4:44 ` Song Liu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b780ccfd-66b1-fdd1-b33e-aa680fbd86f1@redhat.com \
--to=xni@redhat.com \
--cc=agk@redhat.com \
--cc=dm-devel@redhat.com \
--cc=guoqing.jiang@linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=snitzer@kernel.org \
--cc=song@kernel.org \
--cc=yangerkun@huawei.com \
--cc=yi.zhang@huawei.com \
--cc=yukuai1@huaweicloud.com \
--cc=yukuai3@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).