tree 891c5ad3db41ed640b077abd2167e2d274c2aa0c
parent 2484be0f88dc6c9670362d51f6a04f2da0626b50
author Vitaly Wool <vitaly.wool@konsulko.com> 1608001950 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1608063225 -0800

z3fold: simplify freeing slots

Patch series "z3fold: stability / rt fixes".

Address z3fold stability issues under stress load, primarily in the
reclaim and free aspects.  Besides, it fixes the locking problems that
were only seen in real-time kernel configuration.

This patch (of 3):

There used to be two places in the code where slots could be freed, namely
when freeing the last allocated handle from the slots and when releasing
the z3fold header these slots aree linked to.  The logic to decide on
whether to free certain slots was complicated and error prone in both
functions and it led to failures in RT case.

To fix that, make free_handle() the single point of freeing slots.

Link: https://lkml.kernel.org/r/20201209145151.18994-1-vitaly.wool@konsulko.com
Link: https://lkml.kernel.org/r/20201209145151.18994-2-vitaly.wool@konsulko.com
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Tested-by: Mike Galbraith <efault@gmx.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>