cvs commit: src/sys/kern vfs_cache.c

[Jeff Roberson]

jeff        2005-06-17 01:05:13 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             vfs_cache.c 
  Log:
   - Fix a leaked reference to a vnode via v_dd.  We rely on cache_purge() and
     cache_zap() to clear the v_dd pointers when a directory vnode is forcibly
     discarded.  For this to work, all vnodes with v_dd pointers to a directory
     must also have name cache entries linked via v_cache_dst to that dvp
     otherwise we could not find them at cache_purge() time.  The following
     code snipit could break this guarantee by unlinking a directory before
     fetching it's dotdot.  The dotdot lookup would initialize the v_dd field
     of the unlinked directory which could never be cleared.  To fix this
     we don't initialize v_dd for orphaned vnodes.
          printf("rmdir: %d\n", rmdir("../foo")); /* foo is cwd */
          printf("chdir: %d\n", chdir(".."));
          printf("%s\n", getwd(NULL));
  
  Sponsored by:   Isilon Systems, Inc.
  Discovered by:  kkenn
  Approved by:    re (blanket vfs)
  
  Revision  Changes    Path
  1.103     +11 -1     src/sys/kern/vfs_cache.c