[SSSD] [PATCH 0/3] Improve robustness of mmap cache handling

Jakub Hrozek jhrozek at redhat.com
Thu Dec 20 13:24:01 UTC 2012


On Thu, Dec 20, 2012 at 12:30:17PM +0100, Pavel Březina wrote:
> On 12/20/2012 06:10 AM, Simo Sorce wrote:
> >The function that reclaims free slots of memory was not very robust and
> >I think is the root cause of a segfault Jakub can easily reproduce as of
> >late. It is augmented by the fact the new functions I introduced that
> >invalidate records did not actually free the space they used in the
> >free slots table.
> >
> >I split the fixes in 3 small patches that should make it easier to review.
> >I did some quick testing on my machine and it seem ok.
> >
> >Simo.
> >
> >
> >Simo Sorce (3):
> >   Update free table when records are invalidated.
> >   Carefully check records when forcibly invalidating
> >   mmap cache: invalidate cache on fatal error
> >
> >  src/responder/nss/nsssrv_cmd.c        |    4 +-
> >  src/responder/nss/nsssrv_mmap_cache.c |  177 +++++++++++++++++++++++++++------
> >  src/responder/nss/nsssrv_mmap_cache.h |    4 +-
> >  src/util/mmap_cache.h                 |    6 +-
> >  4 files changed, 153 insertions(+), 38 deletions(-)
> >
> >_______________________________________________
> >sssd-devel mailing list
> >sssd-devel at lists.fedorahosted.org
> >https://lists.fedorahosted.org/mailman/listinfo/sssd-devel
> >
> 
> Hi,
> how should I test those patches?

For me it was enough to run:

for i in `getent group someverylargegroup | tr ',' ' '`; do id $i; done

The patches fixed the crash for me, but I had to remove the fastcache files
that I had on the system from the previous run. I guess it's expected that
the memcache files got corrupt. I think we should do the same on upgrades
in the specfile, then.



More information about the sssd-devel mailing list