On Mon, Mar 29, 2010 at 7:54 PM, Kevin Wolf <kw...@redhat.com> wrote:
> Am 28.03.2010 19:07, schrieb Ryota Ozaki:
>> This patch allows to operate on nbd device file
>> without write permission for the file if read-only
>> option is specified.
>>
>> Signed-off-by: Ryota Ozaki <ozaki.ry...@gmail.com>
>
> The help for -r should be changed, too. Currently it says:
>
> -r, --read-only export read-only
Indeed.
>
>> ---
>> qemu-nbd.c | 10 +++++-----
>> 1 files changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/qemu-nbd.c b/qemu-nbd.c
>> index 00b8896..7ef409f 100644
>> --- a/qemu-nbd.c
>> +++ b/qemu-nbd.c
>> @@ -162,7 +162,7 @@ static int find_partition(BlockDriverState *bs, int
>> partition,
>> return -1;
>> }
>>
>> -static void show_parts(const char *device)
>> +static void show_parts(const char *device, bool readonly)
>> {
>> if (fork() == 0) {
>> int nbd;
>> @@ -172,7 +172,7 @@ static void show_parts(const char *device)
>> * but remember to load the module with max_part != 0 :
>> * modprobe nbd max_part=63
>> */
>> - nbd = open(device, O_RDWR);
>> + nbd = open(device, readonly ? O_RDONLY : O_RDWR);
>> if (nbd != -1) {
>> close(nbd);
>> }
>
> Can't we always use O_RDONLY here? Assuming that this is enough to
> trigger a partition table update, I haven't tested it. But if it's not
> enough, wouldn't be enough for readonly either.
You're right. It works always with O_RDONLY. So we can remove the
condition expression.
However, I will drop this patch because I found I misunderstood about
nbd. The patch intended to be for non-root users, but it does not make
sense because nbd requires CAP_SYS_ADMIN.
So I hold it until I understand well and focus on the last patch at first.
I'm sorry for messing up.
Thanks,
ozaki-r
>
> Kevin
>
