Re: Regression v6.11 booting cannot mount harddisks (xfs)

Linus Torvalds
2024-09-10T18:30:22Z

On Tue, 10 Sept 2024 at 10:53, Jesper Dangaard Brouer <hawk@kernel.org> wrote:
>
> af2814149883e2c1851866ea2afcd8eadc040f79 is the first bad commit

Just for fun - can you test moving the queue freezing *inside* the
mutex, ie something like

--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -670,11 +670,11 @@ queue_attr_store(struct kobject *kobj, struct
attribute *attr,
if (!entry->store)
return -EIO;

- blk_mq_freeze_queue(q);
mutex_lock(&q->sysfs_lock);
+ blk_mq_freeze_queue(q);
res = entry->store(disk, page, length);
- mutex_unlock(&q->sysfs_lock);
blk_mq_unfreeze_queue(q);
+ mutex_unlock(&q->sysfs_lock);
return res;
}

(Just do it by hand, my patch is whitespace-damaged on purpose -
untested and not well thought through).

Because I'm wondering whether maybe some IO is done under the
sysfs_lock, and then you might have a deadlock?

Linus