kernel-vfs_races-2.6.20-vanilla.patch

   1 Index: linux-2.6.20.3/fs/dcache.c
   2 ===================================================================
   3 --- linux-2.6.20.3.orig/fs/dcache.c     2007-08-14 18:10:44.000000000 +0200
   4 +++ linux-2.6.20.3/fs/dcache.c  2007-08-14 18:17:16.000000000 +0200
   5 @@ -235,6 +235,13 @@
   6                 spin_unlock(&dcache_lock);
   7                 return 0;
   8         }
   9 +
  10 +       /* network invalidation by Lustre */
  11 +       if (dentry->d_flags & DCACHE_LUSTRE_INVALID) {
  12 +               spin_unlock(&dcache_lock);
  13 +               return 0;
  14 +       }
  15 +
  16         /*
  17          * Check whether to do a partial shrink_dcache
  18          * to get rid of unused child entries.
  19 @@ -1412,13 +1419,22 @@
  20   * Adds a dentry to the hash according to its name.
  21   */
  22
  23 -void d_rehash(struct dentry * entry)
  24 +void d_rehash_cond(struct dentry * entry, int lock)
  25  {
  26 -       spin_lock(&dcache_lock);
  27 +       if (lock)
  28 +               spin_lock(&dcache_lock);
  29         spin_lock(&entry->d_lock);
  30         _d_rehash(entry);
  31         spin_unlock(&entry->d_lock);
  32 -       spin_unlock(&dcache_lock);
  33 +       if (lock)
  34 +               spin_unlock(&dcache_lock);
  35 +}
  36 +
  37 +EXPORT_SYMBOL(d_rehash_cond);
  38 +
  39 +void d_rehash(struct dentry * entry)
  40 +{
  41 +       d_rehash_cond(entry, 1);
  42  }
  43
  44  #define do_switch(x,y) do { \
  45 Index: linux-2.6.20.3/include/linux/dcache.h
  46 ===================================================================
  47 --- linux-2.6.20.3.orig/include/linux/dcache.h  2007-08-14 18:10:44.000000000 +0200
  48 +++ linux-2.6.20.3/include/linux/dcache.h       2007-08-14 18:17:16.000000000 +0200
  49 @@ -173,6 +173,8 @@
  50
  51  #define DCACHE_REFERENCED      0x0008  /* Recently used, don't discard. */
  52  #define DCACHE_UNHASHED                0x0010
  53 +#define DCACHE_LUSTRE_INVALID     0x0040  /* Lustre invalidated */
  54 +
  55
  56  #define DCACHE_INOTIFY_PARENT_WATCHED  0x0020 /* Parent inode is watched */
  57