Something like this, maybe: https://review.gerrithub.io/371713
On Fri, Jul 28, 2017 at 10:30 AM, Daniel Gryniewicz <d...@redhat.com> wrote: > It's definitely not okay to drop the content lock around the > refresh_attrs, since the order of getting the content locks is > important. However, maybe we can re-arrange the code to drop both > locks before doing the refresh. I'll look into it. > > On Fri, Jul 28, 2017 at 10:06 AM, Pradeep <pradeep.tho...@gmail.com> wrote: >> Hello, >> >> I seem to be hitting a deadlock in Ganesha mdcache. I have debugged it >> and here is what I see on the hung process: >> >> Thread1 is doing a rename operation. Lets say file1 being moved from >> 'dir0' to 'dir1'. This calls mdcache_rename() >> - Holds content_lock for both parents - dir0 and dir1 >> - In mdcache_refresh_attrs_no_invalidate() on 'dir1' >> o Tries to hold attr_lock in write mode [ attr_lock is needed when >> calling mdcache_refresh_attrs() ] >> >> Thread2 is doing a getattr on 'dir1' [ the destination diretory of the >> rename]. This calls mdcache_getattrs(). >> - Holds attr_lock in write mode. >> - Calls mdcache_refresh_attrs( invalidate=true) >> o Tries to hold content_lock in write mode if ‘invalidate’ is needed. >> >> These two threads ends up in a deadlock and all other threads waiting >> for attr_lock in READ mode also are hung. >> >> To fix this, is it ok to drop content_lock before calling >> mdcache_refresh_attrs() in mdcache_rename(). From the locking >> guidelines, it appears that mdcache_refresh_attrs() doesn't require >> content_lock. >> >> ------------------------------------------------------------------------------ >> Check out the vibrant tech community on one of the world's most >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot >> _______________________________________________ >> Nfs-ganesha-devel mailing list >> Nfs-ganesha-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Nfs-ganesha-devel mailing list Nfs-ganesha-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
