src/patches/suse-2.6.27.25/patches.suse/ocfs2-Calculate-EA-hash-only-by-its-suffix.patch

   1 From: Tao Ma <tao.ma@oracle.com>
   2 Subject: ocfs2: Calculate EA hash only by its suffix.
   3 Patch-mainline: 2.6.28
   4
   5 According to Christoph Hellwig's advice, the hash value of EA
   6 is only calculated by its suffix.
   7
   8 Signed-off-by: Tao Ma <tao.ma@oracle.com>
   9 Signed-off-by: Mark Fasheh <mfasheh@suse.com>
  10 ---
  11  fs/ocfs2/xattr.c |   35 +++++------------------------------
  12  1 files changed, 5 insertions(+), 30 deletions(-)
  13
  14 Index: linux-2.6.27/fs/ocfs2/xattr.c
  15 ===================================================================
  16 --- linux-2.6.27.orig/fs/ocfs2/xattr.c
  17 +++ linux-2.6.27/fs/ocfs2/xattr.c
  18 @@ -164,21 +164,13 @@ static inline struct xattr_handler *ocfs
  19  }
  20
  21  static u32 ocfs2_xattr_name_hash(struct inode *inode,
  22 -                                char *prefix,
  23 -                                int prefix_len,
  24 -                                char *name,
  25 +                                const char *name,
  26                                  int name_len)
  27  {
  28         /* Get hash value of uuid from super block */
  29         u32 hash = OCFS2_SB(inode->i_sb)->uuid_hash;
  30         int i;
  31
  32 -       /* hash extended attribute prefix */
  33 -       for (i = 0; i < prefix_len; i++) {
  34 -               hash = (hash << OCFS2_HASH_SHIFT) ^
  35 -                      (hash >> (8*sizeof(hash) - OCFS2_HASH_SHIFT)) ^
  36 -                      *prefix++;
  37 -       }
  38         /* hash extended attribute name */
  39         for (i = 0; i < name_len; i++) {
  40                 hash = (hash << OCFS2_HASH_SHIFT) ^
  41 @@ -199,14 +191,9 @@ static void ocfs2_xattr_hash_entry(struc
  42                                    struct ocfs2_xattr_entry *entry)
  43  {
  44         u32 hash = 0;
  45 -       struct xattr_handler *handler =
  46 -                       ocfs2_xattr_handler(ocfs2_xattr_get_type(entry));
  47 -       char *prefix = handler->prefix;
  48         char *name = (char *)header + le16_to_cpu(entry->xe_name_offset);
  49 -       int prefix_len = strlen(handler->prefix);
  50
  51 -       hash = ocfs2_xattr_name_hash(inode, prefix, prefix_len, name,
  52 -                                    entry->xe_name_len);
  53 +       hash = ocfs2_xattr_name_hash(inode, name, entry->xe_name_len);
  54         entry->xe_name_hash = cpu_to_le32(hash);
  55
  56         return;
  57 @@ -2109,18 +2096,6 @@ cleanup:
  58         return ret;
  59  }
  60
  61 -static inline u32 ocfs2_xattr_hash_by_name(struct inode *inode,
  62 -                                          int name_index,
  63 -                                          const char *suffix_name)
  64 -{
  65 -       struct xattr_handler *handler = ocfs2_xattr_handler(name_index);
  66 -       char *prefix = handler->prefix;
  67 -       int prefix_len = strlen(handler->prefix);
  68 -
  69 -       return ocfs2_xattr_name_hash(inode, prefix, prefix_len,
  70 -                                    (char *)suffix_name, strlen(suffix_name));
  71 -}
  72 -
  73  /*
  74   * Find the xattr extent rec which may contains name_hash.
  75   * e_cpos will be the first name hash of the xattr rec.
  76 @@ -2411,7 +2386,7 @@ static int ocfs2_xattr_index_block_find(
  77         struct ocfs2_extent_list *el = &xb_root->xt_list;
  78         u64 p_blkno = 0;
  79         u32 first_hash, num_clusters = 0;
  80 -       u32 name_hash = ocfs2_xattr_hash_by_name(inode, name_index, name);
  81 +       u32 name_hash = ocfs2_xattr_name_hash(inode, name, strlen(name));
  82
  83         if (le16_to_cpu(el->l_next_free_rec) == 0)
  84                 return -ENODATA;
  85 @@ -4451,8 +4426,8 @@ static int ocfs2_xattr_set_in_bucket(str
  86         size_t value_len;
  87         char *val = (char *)xi->value;
  88         struct ocfs2_xattr_entry *xe = xs->here;
  89 -       u32 name_hash = ocfs2_xattr_hash_by_name(inode,
  90 -                                                xi->name_index, xi->name);
  91 +       u32 name_hash = ocfs2_xattr_name_hash(inode, xi->name,
  92 +                                             strlen(xi->name));
  93
  94         if (!xs->not_found && !ocfs2_xattr_is_local(xe)) {
  95                 /*