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To: Miklos Szeredi <miklos@szeredi.hu>
CC: <fuse-devel@lists.sourceforge.net>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Kinsbursky Stanislav <skinsbursky@virtuozzo.com>
From: Maxim Patlasov <mpatlasov@virtuozzo.com>
Subject: fuse does not show lock info in /proc/.../fdinfo/...
Message-ID: <5751D130.5010202@virtuozzo.com>
Date: Fri, 3 Jun 2016 11:49:20 -0700
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Hi Miklos,

fuse_file_lock() since its inception in 2006 implements F_SETLK command 
like this:

>         if (fc->no_lock)
>             err = posix_lock_file(file, fl, NULL);
>         else
>             err = fuse_setlk(file, fl, 0);

where fc->no_lock is a per-mount-point tunable. It would be more natural 
to posix-lock in both cases, like this:

>         err = posix_lock_file(file, fl, NULL);
>         if (!err && !fc->no_lock)
>             err = fuse_setlk(file, fl, 0);

Otherwise, by default, when fc->no_lock=0, posix_lock_file() is never 
called, and from end-user perspective it is weird that the file was 
locked successfully, but "fdinfo" does not show the lock.

Do you think there were some reasons to implement it that way -- not 
calling posix_lock_file unconditionally?

Thanks,
Maxim