During the "check flushtree clears adb correctly" check, expecting
"ns.flushtest.example" to always be the first name in the ADB dump is
fragile, because in a certain corner case "a.root-servers.nil" will be
the first name instead.
As the purpose of the relevant check is to ensure "ns.flushtest.example"
is removed from ADB by "rndc flushtree flushtest.example", search the
entire list of names present in ADB instead of just the first entry when
looking for "ns.flushtest.example".
(cherry picked from commit ca1049b2f3)
Dumping the cache is an asynchronous operation, so sleeping for a fixed
amount of time after running "rndc dumpdb" is imperfect as dumping cache
contents may take longer than expected on slower machines. Instead of
always sleeping for 1 second, wait until the "; Dump complete" line
appears in the dump or 10 seconds pass, whichever comes first.
(cherry picked from commit 2bbff06d36)
Unless configured otherwise in named.conf, "rndc dumpdb" causes a cache
dump to be written to a file called "named_dump.db" in the working
directory of the given named instance. Repeatedly using this command
throughout different checks in the cacheclean system test causes cache
dumps for older checks to be overwritten, which hinders failure
diagnosis. Prevent this by moving each cache dump to a check-specific
location after running "rndc dumpdb".
Furthermore, during the "check flushtree clears adb correctly" check,
dump_cache() is called twice without renaming the resulting files.
Prevent the first cache dump from being overwritten by moving it to a
different file before calling "rndc dumpdb" for the second time.
(cherry picked from commit aeea1faf01)
4892. [bug] named could leak memory when "rndc reload" was invoked
before all zone loading actions triggered by a previous
"rndc reload" command were completed. [RT #47076]
Remove a block of code which dates back to commit 8a2ab2b920, when
dns_zone_asyncload() did not yet check DNS_ZONEFLG_LOADPENDING.
Currently, no race in accessing DNS_ZONEFLG_LOADPENDING is possible any
more, because:
- dns_zone_asyncload() is still the only function which may queue
zone_asyncload(),
- dns_zone_asyncload() accesses DNS_ZONEFLG_LOADPENDING under a lock
(and potentially queues an event under the same lock),
- DNS_ZONEFLG_LOADPENDING is not cleared until the load actually
completes.
Thus, the rechecking code can be safely removed from zone_asyncload().
Note that this also brings zone_asyncload() to a state in which the
completion callback is always invoked. This is required to prevent
leaking memory in case something goes wrong in zone_asyncload() and a
zone table the zone belongs to is indefinitely left with a positive
reference count.
Code handling cancellation of asynchronous zone load events was likely
copied over from other functions when asynchronous zone loading was
first implemented in commit 8a2ab2b920. However, unlike those other
functions, asynchronous zone loading events currently have no way of
getting canceled once they get posted, which means the aforementioned
code is effectively dead. Remove it to prevent confusion.
zone_load() is not always synchronous, it may only initiate an
asynchronous load and return DNS_R_CONTINUE, which means zone loading
has not yet been completed. In such a case, zone_asyncload() must not
clear DNS_ZONEFLG_LOADPENDING immediately and leave that up to
zone_postload().
While this is not an issue in named, which only calls
dns_zone_asyncload() from task-exclusive mode, this function is exported
by libdns and thus may in theory be concurrently called for the same
zone by multiple threads. It also does not hurt to be consistent
locking-wise with other DNS_ZONEFLG_LOADPENDING accesses.
