From: Shaohua Li <shli@kernel.org>
To: Guoqing Jiang <gqjiang@suse.com>
Cc: neilb@suse.de, linux-raid@vger.kernel.org,
Martin Kepplinger <martink@posteo.de>,
Andrew Morton <akpm@linux-foundation.org>,
Denys Vlasenko <dvlasenk@redhat.com>,
Sasha Levin <sasha.levin@oracle.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] md: set MD_CHANGE_PENDING in a atomic region
Date: Sun, 8 May 2016 15:12:27 -0700 [thread overview]
Message-ID: <20160508221227.GA2271@kernel.org> (raw)
In-Reply-To: <1462328535-22566-1-git-send-email-gqjiang@suse.com>
On Tue, May 03, 2016 at 10:22:13PM -0400, Guoqing Jiang wrote:
> Some code waits for a metadata update by:
>
> 1. flagging that it is needed (MD_CHANGE_DEVS or MD_CHANGE_CLEAN)
> 2. setting MD_CHANGE_PENDING and waking the management thread
> 3. waiting for MD_CHANGE_PENDING to be cleared
>
> If the first two are done without locking, the code in md_update_sb()
> which checks if it needs to repeat might test if an update is needed
> before step 1, then clear MD_CHANGE_PENDING after step 2, resulting
> in the wait returning early.
>
> So make sure all places that set MD_CHANGE_PENDING are atomicial, and
> bit_clear_unless (suggested by Neil) is introduced for the purpose.
Applied the 3, thanks!
prev parent reply other threads:[~2016-05-08 22:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-04 2:22 [PATCH 1/3] md: set MD_CHANGE_PENDING in a atomic region Guoqing Jiang
2016-05-04 2:22 ` [PATCH 2/3] md-cluster: gather resync infos and enable recv_thread after bitmap is ready Guoqing Jiang
2016-05-04 5:52 ` Guoqing Jiang
2016-05-04 6:17 ` [Update PATCH] " Guoqing Jiang
2016-05-04 2:22 ` [PATCH 3/3] md-cluster: check the return value of process_recvd_msg Guoqing Jiang
2016-05-08 22:12 ` Shaohua Li [this message]
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