Re: How to use mandatory file locking on afpfs volumes
Re: How to use mandatory file locking on afpfs volumes
- Subject: Re: How to use mandatory file locking on afpfs volumes
- From: Vivek Verma <email@hidden>
- Date: Wed, 28 Mar 2018 20:49:45 -0700
> On Feb 26, 2018, at 12:11 PM, James Bucanek <email@hidden> wrote:
>
> More annoying questions...
>
> How does one use "AFP-style mandatory file locking" in macOS (10.9...current)?
>
> I'm trying to implement file locking/coordination across various filesystems
> and servers.
>
> The man page for getattrlist() includes the following filesystem capability
> test:
>
> VOL_CAP_INT_MANLOCK If this bit is set, the volume format implementation
> supports AFP-style mandatory byte range locks
> via ioctl(2).
>
> AFPFS (a.k.a. AppleShare) volumes, particularly those on AirPort Extreme /
> Time Capsule devices, return 1 for this capability. These volumes do not
> support flock() or fcntl(F_SETLK) style advisory locking.
>
> I looked at the man page for ioctl(2) and it contains no real information. It
> says the commands for ioctl(2) are documented in <sys/ioctl.h>.
>
> So I had a look at <sys/ioctl.h> and found very little there; it's basically
> an umbrella header for several other headers. So I went through them one at a
> time: <sys/ttycom.h>, <sys/ioccom.h>, <sys/filio.h> (the one I would have
> assumed it would be in), and <sys/sockio.h>. I could found no mention of any
> kind of file or byte range locking commands defined.
>
> So, is it possible to lock files/ranges on an AFPFS volume using ioctl(2),
> and if so where are these commands defined?
>
You're going to be in deprecated & unsupported territory but you're going to
find your answers in
http://www.sqlite.org/src/raw/src/os_unix.c?name=10e0c4dcdbec8d4189890fdf3e71b32efae194e3
>
>
> _______________________________________________
> Do not post admin requests to the list. They will be ignored.
> Filesystem-dev mailing list (email@hidden)
> Help/Unsubscribe/Update your Subscription:
>
> This email sent to email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Filesystem-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden