[Devel] [PATCH hci-8.1 2/4] dm-ploop: fix a lost wakeup of the ploop_allocator() thread

[no-reply at sashiko.virtuozzo.com]

> From: Denis V. Lunev <den at openvz.org>
> 
> ploop_allocator() tests prealloc_size and only then sets itself
> TASK_INTERRUPTIBLE before schedule(). A request that lands between the
> two finds the thread still running, so wake_up_process() does nothing,
> and the thread goes to sleep with the request pending. A pio whose
> cluster is past the end of the top delta then waits in
> ploop_allocate_cluster() until some later request wakes the thread. The
> dispatcher waits for every runner to go idle before it hands out more
> work, so the whole device stalls, and an idle device has no later
> request.
> 
> Set the task state before testing prealloc_size.
> 
> Fixes: cf489cf22cd5 ("dm-ploop: make filespace preallocations async")
> Reported-by: Konstantin Khorenko <khorenko at virtuozzo.com>
> https://virtuozzo.atlassian.net/browse/VSTOR-152984
> Feature: dm-ploop: ploop target driver
> Signed-off-by: Denis V. Lunev <den at openvz.org>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.vzint.dev/#/patchset/20261103083642.130885-1-den@openvz.org?part=2