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[PATCH] Issue 2732 -- Apache shutdown crash

From: D.J. Heap <djheap_at_gmail.com>
Date: 2007-04-06 02:33:26 CEST

Could someone review and test this patch on Linux? I think this is
the simplest way to solve the problem, but I'm not positive.


Fix the undefined behavior invoked when the fs module is dynamically
unloaded and the bdb cache tries to clean itself up.

This occurred because the bdb cache was allocated in the global pool
which gets cleaned up *after* the fs module has been unloaded from
memory (meaning the cleanup hook code may or may not still
actually be there depending on what the OS does with the newly freed

The fix is to pass the fs module's common_pool down to the fs_base
and fs_fs module's init routines so that they can allocate fs global
stuff and know that they can clean it up before they are unloaded.

* subversion/libsvn_fs_base/bdb/env.h
  (svn_fs_bdb__init): Add a pool parameter that we can use to store
  the bdb cache in since it is fs module scoped.

* subversion/libsvn_fs_base/bdb/env.c
  (svn_fs_bdb__init, bdb_init_cb): Add and use the new fs module
  scoped pool for the bdb cache.

* subversion/libsvn_fs_base/fs.c
  (svn_fs_base__init): Renamed to...
  (svn_fs_base__init2): in order to add a pool parameter and prevent
  old modules from getting called with unexpected parameters. Also
  pass the pool on to the underlying init functions.

* subversion/include/svn_fs.h:
  (svn_fs_initialize): Update docs to note that undefined behavior can
  result if the fs module is dynamically loaded and the bdb fs is used.

* subversion/include/private/svn_atomic.h
  (svn_atomic__init_once): Add pool parameter.

* subversion/libsvn_fs/fs-loader.h
  (fs_init_func_t): Add pool parameter.
  (svn_fs_base__init, svn_fs_fs__init): Renamed to...
  (svn_fs_base__init2, svn_fs_fs__init2): in order to add a pool
  parameter and prevent old modules from getting called with
  unexpected parameters.

* subversion/libsvn_fs/fs-loader.c
  (fs_type_defn): Refer to the new svn_fs_*__init2 functions.
  (serialized_init): Move the best-effort common_pool init to...
  (get_library_vtable_direct): here in order to init it earlier when
  svn_fs_initialize is not called. Also pass the common_pool on
  to the init function for the underlying fs module.

* subversion/libsvn_subr/atomic.c
  (svn_atomic__init_once): Add pool parameter and pass it to
  the init_func.

* subversion/libsvn_fs_fs/fs_fs.c
  (svn_fs_fs__init): Renamed to...
  (svn_fs_fs__init2): in order to add a pool parameter and prevent old
  modules from getting called with unexpected parameters.

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Received on Fri Apr 6 02:33:43 2007

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