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Date:   Tue, 8 Sep 2020 14:40:03 +0200
From:   David Sterba <dsterba@suse.cz>
To:     Josef Bacik <josef@toxicpanda.com>
Cc:     linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH 4/4] btrfs: do not create raid sysfs entries under any
 locks
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On Tue, Sep 01, 2020 at 05:40:38PM -0400, Josef Bacik wrote:
>  	}
>  
>  	list_for_each_entry(space_info, &info->space_info, list) {
> +		int i;
> +
> +		for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
> +			if (list_empty(&space_info->block_groups[i]))
> +				continue;
> +			cache = list_first_entry(&space_info->block_groups[i],
> +						 struct btrfs_block_group,
> +						 list);
> +			btrfs_sysfs_add_block_group_type(cache);
> +		}
> +

I had the previous version of the patch pass fstests, with no lockdep
warnings and then realized it's not the v2 that depends on the 3rd patch
removing RCU from this list traversal.

btrfs_sysfs_add_block_group_type does not seem to be conflicting RCU in
this loop so now I'm undecided if v1 is ok or if we really need v2, sice
the patch 3 removing RCU seems suspicious.