Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog

[linux-2.6-omap-h63xx.git] / drivers / md / dm-snap.h

diff --git a/drivers/md/dm-snap.h b/drivers/md/dm-snap.h
index 650e0f1f51d8a6c312a001c8443cf3bc8064d481..24f9fb73b982d0cd148ef15d56428ba6c7ce6877 100644 (file)
--- a/drivers/md/dm-snap.h
+++ b/drivers/md/dm-snap.h
@@ -16,19 +16,22 @@
 
 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 dm_snap_exception {
        struct list_head hash_list;
@@ -37,6 +40,49 @@ struct dm_snap_exception {
        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).
@@ -86,7 +132,7 @@ struct exception_store {
 
 struct dm_snapshot {
        struct rw_semaphore lock;
-       struct dm_table *table;
+       struct dm_target *ti;
 
        struct dm_dev *origin;
        struct dm_dev *cow;
@@ -123,7 +169,7 @@ struct dm_snapshot {
        /* The on disk metadata handler */
        struct exception_store store;
 
-       struct kcopyd_client *kcopyd_client;
+       struct dm_kcopyd_client *kcopyd_client;
 
        /* Queue of snapshot writes for ksnapd to flush */
        struct bio_list queued_bios;