On 03/10/2011 12:54 PM, Laine Stump wrote:
Okay, I've figured out what happened - the permission on a parent of my target directory on the NFS server had been changed during unrelated testing from (root,root) 755 to 700, so even though the target directory had the proper user (qemu,qemu), qemu was denied access to the directory due to its parent's permissions/ownership. When I set the parent directory back to 755, save and restore both work.
However, the current code still has a problem - if you try to save to/from a directory that the qemu user doesn't have permission for (and presumably if there's any other error in the child that causes it to skip the sendmsg), rather than returning an error virFileOpenAs just hangs on recvmsg waiting for the fd info to come over the pipe, while the child process sits around as a zombie because nobody has reaped its exit status.
Yep, makes sense. I'm double checking whether I reliably closed the write end of the socket in all paths, and it may boil down to changing the child to _always_ sendmsg even if there is no fd to send. I'm still thinking about it. -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org