On Wed, Nov 07, 2012 at 01:45:27PM +0800, Wanlong Gao wrote:
On 11/07/2012 11:54 AM, Gao feng wrote:
于 2012年11月06日 20:55, Richard W.M. Jones 写道:
On Tue, Nov 06, 2012 at 07:50:33PM +0800, Gao feng wrote:
于 2012年11月06日 17:11, Richard W.M. Jones 写道:
On Tue, Nov 06, 2012 at 04:54:59PM +0800, Gao feng wrote:
Because libvirt_lxc create a thread to mount fuse filesystem. and then libvirt_lxc will try to access the fuse filesystem.
Without waiting,libvirt_lxc may access fuse before it is mounted.
And I can't find a better way to make accessing fuse after the fuse being mounted,because fuse_main will return until fuse being unmounted,so I don't know how to pass message to tell libvirt_lxc whether the fuse is mounted success.
Oh I see. This is solvable, but I believe that you cannot use fuse_main. You have to look at the fuse sources (quite complex!) and do the individual fuse operations.
Have a look at how libguestfs does it ...
https://github.com/libguestfs/libguestfs/blob/master/src/fuse.c#L911 http://libguestfs.org/guestfs.3.html#mount-local
Thanks for the information.
Can fuse_mount & fuse_new & fuse_loop avoid the waiting?
It seems has the same problem.
It waits, but it doesn't busy wait in a loop. The first access to the filesystem hangs until the thread which is handling the filesystem is listening for requests.
It makes me confuse.
There are two threads(A and B). thread A mounts fuse filesystem on mountpoint /mnt/fuse. thread B try to access file /mnt/fuse/meminfo. and we don't know which thread will execute first.
The information I got from your comment is that because thread A doesn't mount fuse to /mnt/fuse, when thread B access to the /mnt/fuse/meminfo,it will hang. I am right?
If I'm not wrong, I think Rich means that you should create the mountpoint and the operations using fuse_mount and fuse_new before you create the thread B, then make another thread A using fuse_loop to loop behind. Then if thread B try to access the mountpoint before thread A runs, B will hang until thread A runs into the loop.
This is right. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones New in Fedora 11: Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 70 libraries supprt'd http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw