From: Nikolay Borisov <nborisov@suse.com>
To: Anand Jain <anand.jain@oracle.com>,
linux-btrfs@vger.kernel.org, dsterba@suse.com
Cc: l@damenly.su
Subject: Re: [PATCH RFC V5 2/2] btrfs: consolidate device_list_mutex in prepare_sprout to its parent
Date: Tue, 31 Aug 2021 16:03:57 +0300 [thread overview]
Message-ID: <ca0f8867-74ff-9130-f69f-0f7972540be0@suse.com> (raw)
In-Reply-To: <f00bad4ba0e8fd7f0c46c21118537fd49fd3c359.1630370459.git.anand.jain@oracle.com>
On 31.08.21 г. 4:21, Anand Jain wrote:
> btrfs_prepare_sprout() moves seed devices into its own struct fs_devices,
> so that its parent function btrfs_init_new_device() can add the new sprout
> device to fs_info->fs_devices.
>
> Both btrfs_prepare_sprout() and btrfs_init_new_device() needs
> device_list_mutex. But they are holding it sequentially, thus creates a
> small window to an opportunity to race. Close this opportunity and hold
> device_list_mutex common to both btrfs_init_new_device() and
> btrfs_prepare_sprout().
>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
That's a moot point, what's important is that btrfs_prepare_sprout
leaves the fs_devices in a consistent state and btrfs_init_new_device
also takes the lock when it's about to modify the devices list, so
that's fine as well. While the patch itself won't do any harm I think
it's irrelevant.
<snip>
next prev parent reply other threads:[~2021-08-31 13:04 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-31 1:21 [PATCH V5 0/2] btrfs: device_list_mutex fix lockdep warn and cleanup Anand Jain
2021-08-31 1:21 ` [PATCH V5 1/2] btrfs: fix lockdep warning while mounting sprout fs Anand Jain
2021-08-31 8:18 ` Nikolay Borisov
2021-09-02 23:51 ` Anand Jain
2021-08-31 12:37 ` Nikolay Borisov
2021-09-01 0:49 ` Su Yue
2021-09-02 15:28 ` David Sterba
2021-08-31 1:21 ` [PATCH RFC V5 2/2] btrfs: consolidate device_list_mutex in prepare_sprout to its parent Anand Jain
2021-08-31 13:03 ` Nikolay Borisov [this message]
2021-09-03 3:08 ` Anand Jain
2021-09-17 15:37 ` David Sterba
2021-09-18 0:10 ` Anand Jain
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