AZL-54978

In the Linux kernel, the following vulnerability has been resolved:

aoe: avoid potential deadlock at set_capacity

Move set_capacity() outside of the section procected by (&d->lock). To avoid possible interrupt unsafe locking scenario:

    CPU0                    CPU1
    ----                    ----

[1] lock(&bdev->bdsizelock); localirqdisable(); [2] lock(&d->lock); [3] lock(&bdev->bdsizelock); <Interrupt> [4] lock(&d->lock);

*** DEADLOCK ***

Where 1 hold by zramadd()->setcapacity(). [2]lock(&d->lock) hold by aoeblkgdalloc(). And aoeblkgdalloc() is trying to acquire 3 at setcapacity() call. In this situation an attempt to acquire [4]lock(&d->lock) from aoecmdcfg_rsp() will lead to deadlock.

So the simplest solution is breaking lock dependency 2 -> 3 by moving set_capacity() outside.