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From:   "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
To:     Ignat Korchagin <ignat@cloudflare.com>
Cc:     agk@redhat.com, snitzer@redhat.com, dm-devel@redhat.com,
        dm-crypt@saout.de, linux-kernel@vger.kernel.org,
        ebiggers@kernel.org, Damien.LeMoal@wdc.com, mpatocka@redhat.com,
        herbert@gondor.apana.org.au, kernel-team@cloudflare.com,
        nobuto.murata@canonical.com, Chris Mason <clm@fb.com>,
        Josef Bacik <josef@toxicpanda.com>,
        David Sterba <dsterba@suse.com>, linux-btrfs@vger.kernel.org,
        linux-crypto <linux-crypto@vger.kernel.org>
References: <16ffadab-42ba-f9c7-8203-87fda3dc9b44@maciej.szmigiero.name>
Subject: Re: dm-crypt with no_read_workqueue and no_write_workqueue + btrfs
 scrub = BUG()
Message-ID: <74c7129b-a437-ebc4-1466-7fb9f034e006@maciej.szmigiero.name>
Date:   Wed, 23 Dec 2020 16:37:34 +0100
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On 14.12.2020 19:11, Maciej S. Szmigiero wrote:
> Hi,
> 
> I hit a reproducible BUG() when scrubbing a btrfs fs on top of
> a dm-crypt device with no_read_workqueue and no_write_workqueue
> flags enabled.

Still happens on the current torvalds/master.

Due to this bug it is not possible to use btrfs on top of
a dm-crypt device with no_read_workqueue and no_write_workqueue
flags enabled.

@Ignat:
Can you have a look at this as the person who added these flags?

It looks like to me that the skcipher API might not be safe to
call from a softirq context, after all.

Maciej