This is a note to let you know that I've just added the patch titled
dm crypt: add cond_resched() to dmcrypt_write()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-crypt-add-cond_resched-to-dmcrypt_write.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fb294b1c0ba982144ca467a75e7d01ff26304e2b Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Date: Mon, 6 Mar 2023 11:17:58 -0500
Subject: dm crypt: add cond_resched() to dmcrypt_write()
From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
commit fb294b1c0ba982144ca467a75e7d01ff26304e2b upstream.
The loop in dmcrypt_write may be running for unbounded amount of time,
thus we need cond_resched() in it.
This commit fixes the following warning:
[ 3391.153255][ C12] watchdog: BUG: soft lockup - CPU#12 stuck for 23s! [dmcrypt_write/2:2897]
...
[ 3391.387210][ C12] Call trace:
[ 3391.390338][ C12] blk_attempt_bio_merge.part.6+0x38/0x158
[ 3391.395970][ C12] blk_attempt_plug_merge+0xc0/0x1b0
[ 3391.401085][ C12] blk_mq_submit_bio+0x398/0x550
[ 3391.405856][ C12] submit_bio_noacct+0x308/0x380
[ 3391.410630][ C12] dmcrypt_write+0x1e4/0x208 [dm_crypt]
[ 3391.416005][ C12] kthread+0x130/0x138
[ 3391.419911][ C12] ret_from_fork+0x10/0x18
Reported-by: yangerkun <yangerkun@xxxxxxxxxx>
Fixes: dc2676210c42 ("dm crypt: offload writes to thread")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-crypt.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1554,6 +1554,7 @@ pop_from_list:
io = crypt_io_from_node(rb_first(&write_tree));
rb_erase(&io->rb_node, &write_tree);
kcryptd_io_write(io);
+ cond_resched();
} while (!RB_EMPTY_ROOT(&write_tree));
blk_finish_plug(&plug);
}
Patches currently in stable-queue which might be from mpatocka@xxxxxxxxxx are
queue-5.4/dm-crypt-add-cond_resched-to-dmcrypt_write.patch
queue-5.4/dm-thin-fix-deadlock-when-swapping-to-thin-device.patch
