From: ebiederm@xmission.com (Eric W. Biederman)
To: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: tglx@linutronix.de, mingo@redhat.com, davem@davemloft.net,
hpa@zytor.com, thierry.reding@avionic-design.de,
bfields@redhat.com, eric.dumazet@gmail.com, xemul@parallels.com,
neilb@suse.de, netdev@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, paul.gortmaker@windriver.com,
viro@zeniv.linux.org.uk, gorcunov@openvz.org,
akpm@linux-foundation.org, tim.c.chen@linux.intel.com,
devel@openvz.org
Subject: Re: [RFC PATCH 0/5] net: socket bind to file descriptor introduced
Date: Wed, 15 Aug 2012 20:03:24 -0700 [thread overview]
Message-ID: <87y5lf7d37.fsf@xmission.com> (raw)
In-Reply-To: <20120815161141.7598.16682.stgit@localhost.localdomain> (Stanislav Kinsbursky's message of "Wed, 15 Aug 2012 20:21:56 +0400")
Stanislav Kinsbursky <skinsbursky@parallels.com> writes:
> This patch set introduces new socket operation and new system call:
> sys_fbind(), which allows to bind socket to opened file.
> File to bind to can be created by sys_mknod(S_IFSOCK) and opened by
> open(O_PATH).
>
> This system call is especially required for UNIX sockets, which has name
> lenght limitation.
>
> The following series implements...
Hmm. I just realized this patchset is even sillier than I thought.
Stanislav is the problem you are ultimately trying to solve nfs clients
in a container connecting to the wrong user space rpciod?
Aka net/sunrpc/xprtsock.c:xs_setup_local only taking an absolute path
and then creating a delayed work item to actually open the unix domain
socket?
The straight correct and straight forward thing to do appears to be:
- Capture the root from current->fs in xs_setup_local.
- In xs_local_finish_connect change current->fs.root to the captured
version of root before kernel_connect, and restore current->fs.root
after kernel_connect.
It might not be a bad idea to implement open on unix domain sockets in
a filesystem as create(AF_LOCAL)+connect() which would allow you to
replace __sock_create + kernel_connect with a simple file_open_root.
But I think the simple scheme of:
struct path old_root;
old_root = current->fs.root;
kernel_connect(...);
current->fs.root = old_root;
Is more than sufficient and will remove the need for anything
except a purely local change to get nfs clients to connect from
containers.
Eric
next prev parent reply other threads:[~2012-08-16 3:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-15 16:21 [RFC PATCH 0/5] net: socket bind to file descriptor introduced Stanislav Kinsbursky
2012-08-15 16:22 ` [RFC PATCH 1/5] net: cleanup unix_bind() a little Stanislav Kinsbursky
2012-08-15 16:22 ` [RFC PATCH 2/5] net: split unix_bind() Stanislav Kinsbursky
2012-08-15 16:22 ` [RFC PATCH 3/5] net: new protocol operation fbind() introduced Stanislav Kinsbursky
2012-08-15 16:22 ` [RFC PATCH 4/5] net: fbind() for unix sockets protocol operations introduced Stanislav Kinsbursky
2012-08-15 16:22 ` [RFC PATCH 5/5] syscall: sys_fbind() introduced Stanislav Kinsbursky
2012-08-15 16:30 ` H. Peter Anvin
2012-08-15 16:43 ` Stanislav Kinsbursky
2012-08-15 16:52 ` [RFC PATCH 0/5] net: socket bind to file descriptor introduced Ben Pfaff
2012-08-15 17:54 ` H. Peter Anvin
2012-08-15 19:49 ` Eric W. Biederman
2012-08-15 20:58 ` H. Peter Anvin
2012-08-15 21:25 ` Eric W. Biederman
2012-08-16 3:03 ` Eric W. Biederman [this message]
2012-08-16 13:54 ` J. Bruce Fields
2012-08-20 10:18 ` Stanislav Kinsbursky
2012-09-04 19:00 ` J. Bruce Fields
2012-10-05 20:00 ` J. Bruce Fields
2012-10-08 8:37 ` Stanislav Kinsbursky
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