md: remove the 'super' sysfs attribute from devices in an 'md' array

[linux-2.6] / drivers / md / dm-snap.h

diff --git a/drivers/md/dm-snap.h b/drivers/md/dm-snap.h
index 15fa2ae6cdc2971f590a814578d06536b75b8484..93bce5d49742e3441fd24b5cd511483b8027c846 100644 (file)
--- a/drivers/md/dm-snap.h
+++ b/drivers/md/dm-snap.h
@@ -16,27 +16,73 @@
 
 struct exception_table {
        uint32_t hash_mask;
+       unsigned hash_shift;
        struct list_head *table;
 };
 
 /*
  * The snapshot code deals with largish chunks of the disk at a
- * time. Typically 64k - 256k.
+ * time. Typically 32k - 512k.
  */
-/* FIXME: can we get away with limiting these to a uint32_t ? */
 typedef sector_t chunk_t;
 
 /*
  * An exception is used where an old chunk of data has been
  * replaced by a new one.
+ * If chunk_t is 64 bits in size, the top 8 bits of new_chunk hold the number
+ * of chunks that follow contiguously.  Remaining bits hold the number of the
+ * chunk within the device.
  */
-struct exception {
+struct dm_snap_exception {
        struct list_head hash_list;
 
        chunk_t old_chunk;
        chunk_t new_chunk;
 };
 
+/*
+ * Funtions to manipulate consecutive chunks
+ */
+#  if defined(CONFIG_LBD) || (BITS_PER_LONG == 64)
+#    define DM_CHUNK_CONSECUTIVE_BITS 8
+#    define DM_CHUNK_NUMBER_BITS 56
+
+static inline chunk_t dm_chunk_number(chunk_t chunk)
+{
+       return chunk & (chunk_t)((1ULL << DM_CHUNK_NUMBER_BITS) - 1ULL);
+}
+
+static inline unsigned dm_consecutive_chunk_count(struct dm_snap_exception *e)
+{
+       return e->new_chunk >> DM_CHUNK_NUMBER_BITS;
+}
+
+static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
+{
+       e->new_chunk += (1ULL << DM_CHUNK_NUMBER_BITS);
+
+       BUG_ON(!dm_consecutive_chunk_count(e));
+}
+
+#  else
+#    define DM_CHUNK_CONSECUTIVE_BITS 0
+
+static inline chunk_t dm_chunk_number(chunk_t chunk)
+{
+       return chunk;
+}
+
+static inline unsigned dm_consecutive_chunk_count(struct dm_snap_exception *e)
+{
+       return 0;
+}
+
+static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
+{
+}
+
+#  endif
+
 /*
  * Abstraction to handle the meta/layout of exception stores (the
  * COW device).
@@ -58,13 +104,13 @@ struct exception_store {
         * Find somewhere to store the next exception.
         */
        int (*prepare_exception) (struct exception_store *store,
-                                 struct exception *e);
+                                 struct dm_snap_exception *e);
 
        /*
         * Update the metadata with this exception.
         */
        void (*commit_exception) (struct exception_store *store,
-                                 struct exception *e,
+                                 struct dm_snap_exception *e,
                                  void (*callback) (void *, int success),
                                  void *callback_context);