Take out a lock when reading as well as writing the third-party dynamic FS module list while still allowing the known Subversion modules to continue to be accessible without locking.
Take out a lock when reading as well as writing the third-party
dynamic FS module list while still allowing the known Subversion
modules to continue to be accessible without locking.

* subversion/libsvn_fs/fs-loader.c
  (get_or_allocate_third): Start loop at point determined by caller,
   return early if the module is found.
  (get_library_vtable): Check the known Subversion modules outside
   the lock, move the rest of the loop inside the lock.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion