Am 25.06.2015 um 23:08 schrieb Paolo Bonzini: > > On 16/06/2015 13:45, Peter Lieven wrote: >> libiscsi starting with 1.15 will properly support timeout of iscsi >> commands. The default will remain no timeout, but this can >> be changed via cmdline parameters, e.g.: >> >> qemu -iscsi timeout=30 -drive file=iscsi://... >> >> If a timeout occurs a reconnect is scheduled and the timed out command >> will be requeued for processing after a successful reconnect. >> >> The required API call iscsi_set_timeout is present since libiscsi >> 1.10 which was released in October 2013. However, due to some bugs >> in the libiscsi code the use is not recommended before version 1.15. > If so, QEMU should not allow it if libiscsi is older than 1.15.
Not accept a timeout parameter or ignore it and print a warning? > >> Please note that this patch bumps the libiscsi requirement to 1.10 >> to have all function and macros defined. > This is not acceptable, unfortunately. I explained this two months ago > (https://lists.gnu.org/archive/html/qemu-devel/2015-04/msg01847.html) > and it is still true. Sorry, i missed that. Can you verify if 1.15.0 has a soname that makes it possible to jump to 1.15.0 at some point in the future? > > libiscsi keeps breaking ABI compatibility and for a while did not even > bump the soname when they do. This makes it completely impossible for > distros to upgrade to a newer libiscsi, and RHEL7 is thus stuck with 1.9. > > Yes, it is 2 years old. It doesn't matter. If libiscsi upstream only > _tried_ to preserve ABI compatibility, they wouldn't be in this > situation. And I know that it is not even trying, because it broke > again sometime between 1.11 and 1.14 for a totally trivial reason: > > --- a/iscsi/iscsi.h > +++ b/iscsi/iscsi.h > @@ -91,6 +136,8 @@ struct iscsi_url { > char target[MAX_STRING_SIZE + 1]; > char user[MAX_STRING_SIZE + 1]; > char passwd[MAX_STRING_SIZE + 1]; > + char target_user[MAX_STRING_SIZE + 1]; > + char target_passwd[MAX_STRING_SIZE + 1]; > int lun; > struct iscsi_context *iscsi; > }; > > > This is the only change between these releases that breaks the ABI, but > it is already one too much. :( > > (Also, the parsing of URLs into iscsi_url doesn't even try to obey the > RFCs...). > >> The patch fixes also a >> off-by-one error in the NOP timeout calculation which was fixed >> while touching these code parts. > Can you please separate this part anyway? Sure. I will send a v2 that is compatible with 1.9.0 and enables the timeout stuff only for libiscsi >= 1.15.0 Peter
