On 11/23/2011 07:51 AM, Chun Yan Liu wrote:
According to above code logic, if lock in an early place is not
accepted, then removing CLEAR_SOCK in nbd_init phase can also solve
problem. In fact, if cleanup work done well, I think that ioctl is not
needed. Any comments?
I think you're right. In
I've had a look at nbd driver code and viewed the trace log, and get clear
about why the previously mentioned problem happens:
1st time: qemu-nbd -c /dev/nbd0 disk.img
nbd_init: send these ioctl(s) in order, SET_BLKSIZE, SET_SIZE, CLEAR_SOCK,
SET_SOCK
nbd_clinet: NBD_DO_IT (it will then handl
On 11/18/2011 02:25 AM, Chun Yan Liu wrote:
Yes. I have tested using same device twice as described in my previous
mail. Without lock:
If issuing "qemu-nbd -c /dev/nbd0 disk.img" and "qemu-nbd -c /dev/nbd0
disk1.img" almost at the same time, both can pass nbd_init() and get to
nbd_client(), the
Yes. I have tested using same device twice as described in my previous mail.
Without lock:
If issuing "qemu-nbd -c /dev/nbd0 disk.img" and "qemu-nbd -c /dev/nbd0
disk1.img" almost at the same time, both can pass nbd_init() and get to
nbd_client(), then the latter one will fail and exit, but t
On Thu, Nov 17, 2011 at 1:41 PM, Paolo Bonzini wrote:
> On 11/17/2011 12:36 PM, Chunyan Liu wrote:
>>
>> Adding lock to the nbd device before connecting disk image to that device
>> to
>> handling race conditions.
>
> This removes the possibility for other programs to lock. Have you checked
> wha
On 11/17/2011 12:36 PM, Chunyan Liu wrote:
Adding lock to the nbd device before connecting disk image to that device to
handling race conditions.
This removes the possibility for other programs to lock. Have you
checked what happens if you use the same device twice and whether you
can piggy
Adding -f option to qemu-nbd to support finding a free nbd device and connect
disk image to that device. Usage of this option is similar to "losetup -f".
#qemu-nbd -f
show the first free nbd device found at the very moment.
#qemu-nbd -f disk.img
find a free nbd device and connect disk.img to that d
