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From: David Sterba <dsterba@suse.cz>
To: Anand Jain <anand.jain@oracle.com>
Cc: Josef Bacik <josef@toxicpanda.com>,
	linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH 2/4] btrfs: init sysfs for devices outside of the chunk_mutex
Date: Wed, 2 Sep 2020 19:45:49 +0200	[thread overview]
Message-ID: <20200902174549.GL28318@twin.jikos.cz> (raw)
In-Reply-To: <79ace2bf-6f01-39ee-0566-727182c5ff85@oracle.com>

On Wed, Sep 02, 2020 at 02:21:31PM +0800, Anand Jain wrote:
> > @@ -2609,6 +2606,10 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
> >   	btrfs_clear_space_info_full(fs_info);
> >   
> >   	mutex_unlock(&fs_info->chunk_mutex);
> > +
> > +	/* add sysfs device entry */
> > +	btrfs_sysfs_add_devices_dir(fs_devices, device);
> > +
> >   	mutex_unlock(&fs_devices->device_list_mutex);
> >   
> >   	if (seeding_dev) {
> > 
> 
> Strange we should get this splat when btrfs_sysfs_add_devices_dir()
> already has implicit GFP_NOFS allocation scope right? What did I
> miss?

The problem is the sysfs' kernfs_mutex, all sysfs allocations are
GFP_KERNEL thus it can grab fs_reclaim at some point.

  reply	other threads:[~2020-09-02 17:47 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-01 21:40 [PATCH 0/4][v2] Lockdep fixes Josef Bacik
2020-09-01 21:40 ` [PATCH 1/4] btrfs: fix lockdep splat in add_missing_dev Josef Bacik
2020-09-02  6:23   ` Anand Jain
2020-09-03 11:17   ` David Sterba
2020-09-01 21:40 ` [PATCH 2/4] btrfs: init sysfs for devices outside of the chunk_mutex Josef Bacik
2020-09-02  6:21   ` Anand Jain
2020-09-02 17:45     ` David Sterba [this message]
2020-09-03 11:41       ` Anand Jain
2020-09-03 11:42       ` Anand Jain
2020-09-03 11:18   ` David Sterba
2020-09-01 21:40 ` [PATCH 3/4] btrfs: kill the rcu protection for fs_info->space_info Josef Bacik
2020-09-02  8:04   ` Nikolay Borisov
2020-09-02 10:32   ` David Sterba
2020-09-01 21:40 ` [PATCH 4/4] btrfs: do not create raid sysfs entries under any locks Josef Bacik
2020-09-08 12:40   ` David Sterba
2020-09-08 12:52     ` Josef Bacik
2020-09-04 14:20 ` [PATCH 0/4][v2] Lockdep fixes David Sterba
2020-09-07 13:05   ` David Sterba

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