Hi Paulo,
On 06/09, Paulo Alcantara wrote:
Hi Enzo,
Enzo Matsumiya <ematsumiya@xxxxxxx> writes:
These 2 patches are a simple way to fix the DNS issue that
currently exists in cifs, where the upcall to key.dns_resolver will
always return 0 for the record TTL, hence, making the resolve worker
always use the default value SMB_DNS_RESOLVE_INTERVAL_DEFAULT
(currently 600 seconds).
This also makes the new setting `dns_interval' user-configurable via
procfs (/proc/fs/cifs/dns_interval).
How is the user supposed to know which TTL value will be used? If the
expire time is set by either key.dns_resolver or any other program used
for dns_resolver key, the above setting would no longer work and users
might get confused.
The initial value is the same as before (SMB_DNS_RESOLVE_INTERVAL_DEFAULT, 600s).
The user don't need to know a value to be used, unless they know the
value the server uses (either manually set by themselves or by some
external script) and then they can use that same value for this new
dns_interval setting.
A very simple example on how one could do it, if there's no desire to
use the default 600s:
# TTL=$(dig +noall +answer my.server.domain | awk '{ print $2 }')
# echo $TTL > /proc/fs/cifs/dns_interval
Cheers,
Enzo
