Re: dm-crypt with no_read_workqueue and no_write_workqueue + btrfs scrub = BUG()

From: Maciej S. Szmigiero
Date: Wed Dec 23 2020 - 10:38:32 EST


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