linux-kernel - Re: [PATCH] fanotify: Make wait for permission events interruptible

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Message-ID: <77d23991-48c0-7b87-ad49-41e505909dd7@nwra.com>
Date:   Mon, 29 Apr 2019 10:05:58 -0600
From:   Orion Poplawski <orion@...a.com>
To:     Jan Kara <jack@...e.cz>, linux-fsdevel@...r.kernel.org
Cc:     Vivek Trivedi <t.vivek@...sung.com>,
        Amir Goldstein <amir73il@...il.com>, linux-api@...r.kernel.org,
        LKML <linux-kernel@...r.kernel.org>,
        "Eric W. Biederman" <ebiederm@...ssion.com>
Subject: Re: [PATCH] fanotify: Make wait for permission events interruptible

On 4/15/19 3:59 AM, Jan Kara wrote:
> On Thu 21-03-19 16:11:42, Jan Kara wrote:
>> Switch waiting for response to fanotify permission events interruptible.
>> This allows e.g. the system to be suspended while there are some
>> fanotify permission events pending (which is reportedly pretty common
>> when for example AV solution is in use). However just making the wait
>> interruptible can result in e.g. open(2) returning -EINTR where
>> previously such error code never happened in practice. To avoid
>> confusion of userspace due to this error code, return -ERESTARTNOINTR
>> instead.
>>
>> Signed-off-by: Jan Kara <jack@...e.cz>
>> ---
>>  fs/notify/fanotify/fanotify.c | 11 +++++++++--
>>  1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> Orion, can you give this patch some testing with your usecase? Also if anybody
>> sees any issue with returning -ERESTARTNOINTR I have missed, please speak up.
> 
> Ping Orion? Did you have any chance to give this patch a try? Does it fix
> hibernation issues you observe without causing issues with bash and other
> programs? I'd like to queue this patch for the coming merge window but
> I'd like to see some testing results showing that it actually helps
> anything... Thanks!
> 
> 								Honza


I've been running it for a while with mostly promising results but one
concern.  Notably, when running in conjuction with BitDefender Anti-Virus I
have noticed issues when cloning large git projects (seems to be a good stress
test on open()).  I believe the problems go away when BD is stopped.  At this
point I'm not sure if the issue lies more with BD or with the kernel patch.


-- 
Orion Poplawski
Manager of NWRA Technical Systems          720-772-5637
NWRA, Boulder/CoRA Office             FAX: 303-415-9702
3380 Mitchell Lane                       orion@...a.com
Boulder, CO 80301                 https://www.nwra.com/


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