On Thu, Nov 24, 2011 at 3:38 AM, Chunyan Liu <cy...@suse.com> wrote: > > > 2011/11/23 Stefan Hajnoczi <stefa...@gmail.com> >> >> On Wed, Nov 23, 2011 at 10:14 AM, Chunyan Liu <cy...@suse.com> wrote: >> > V3: >> > Remove file lock in main(). >> > Try to find new free nbd device and connect to it if connecting to the >> > first >> > first found free nbd device failed. >> > >> > Signed-off-by: Chunyan Liu <cy...@suse.com> >> > --- >> > qemu-nbd.c | 80 >> > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- >> > 1 files changed, 79 insertions(+), 1 deletions(-) >> >> I not seeing the part where you adjusted the ioctl order. >> >> The /proc/partitions scanning is unnecessary since we can just loop >> over /dev/ndb%d and try to initialize. If a device is in use then >> init will fail and we need to try the next one. If a device is free >> we can continue with normal operation. I guess I'm saying that once >> you fix the ioctl order then there's no need for another mechanism to >> test whether or not a device is in use. > > The way of scanning /proc/partitions to find an unused nbd device first can > borrow the code for "qemu-nbd -c" to do the left things. . > The way of loop over /dev/nbd%d and try to initialize, from the first > thought, needs do all things in the loop, including handling -v, nbd_init, > nbd_client, etc. That part of code is quite similar to "qemu-nbd -c". I > don't know if that is better?
This might be a chance to refactor the code slightly, that would also avoid you having to introduce a goto retry. Stefan
