On Wed, Aug 07, 2002 at 05:32:51PM +0200, Jan Hudec wrote:
> Hello,
>
> I have a (possibly stupid) question. Is it OK, that dentries created by
> binding unix-domain sockets remain in filesystem?
That is the classical behaviour, possibly because of tradition
where they relate to named pipes created with mknod(1) command.
http://www.ecst.csuchico.edu/~beej/guide/ipc/usock.html
> What I do is create a unix socket in /tmp and wait for clients to
> connect in. The program removes the socket dentry when it shuts down,
> but it sometimes crashes and the socket remains there.
>
> Is there some reason the socket should remain unless explicitely
> removed?
Traditional is also to unlink() the socket name just prior
to bind(3):ing it just in case there is a left-over entity
with that name.
The object name (it is NAMED entity, after all) space is
filesystem name space. I don't see any reason why not:
- There could pre-exist the named socket (at a R/O
filesystem), and no new name needs to be allocated
in the filesystem for it.
- The entire named entity would not be allowed to
exist purely in VFS space, that is: creation wise
the permission verification could ignore location
directory being on a read/only file system, and
just use directory permissions. (Questions about
memory expenditure, etc. all kinds of trade-offs.)
What the new POSIX writes about the issue, that I haven't
yet looked into.
> Jan 'Bulb' Hudec <bulb@ucw.cz>
/Matti Aarnio
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This archive was generated by hypermail 2b29 : Wed Aug 07 2002 - 22:00:36 EST