dm snapshot: remove dm_snap header

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

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 467c586e24391337081bca1beaadc7aa8bb05ba5..bb28f9782bddbe958004d066957500fbfae4a3ee 100644 (file)
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -20,9 +20,9 @@
 #include <linux/vmalloc.h>
 #include <linux/log2.h>
 #include <linux/dm-kcopyd.h>
+#include <linux/workqueue.h>
 
 #include "dm-exception-store.h"
-#include "dm-snap.h"
 #include "dm-bio-list.h"
 
 #define DM_MSG_PREFIX "snapshots"
@@ -47,9 +47,79 @@
  */
 #define MIN_IOS 256
 
+#define DM_TRACKED_CHUNK_HASH_SIZE     16
+#define DM_TRACKED_CHUNK_HASH(x)       ((unsigned long)(x) & \
+                                        (DM_TRACKED_CHUNK_HASH_SIZE - 1))
+
+struct exception_table {
+       uint32_t hash_mask;
+       unsigned hash_shift;
+       struct list_head *table;
+};
+
+struct dm_snapshot {
+       struct rw_semaphore lock;
+
+       struct dm_dev *origin;
+
+       /* List of snapshots per Origin */
+       struct list_head list;
+
+       /* You can't use a snapshot if this is 0 (e.g. if full) */
+       int valid;
+
+       /* Origin writes don't trigger exceptions until this is set */
+       int active;
+
+       /* Used for display of table */
+       char type;
+
+       mempool_t *pending_pool;
+
+       atomic_t pending_exceptions_count;
+
+       struct exception_table pending;
+       struct exception_table complete;
+
+       /*
+        * pe_lock protects all pending_exception operations and access
+        * as well as the snapshot_bios list.
+        */
+       spinlock_t pe_lock;
+
+       /* The on disk metadata handler */
+       struct dm_exception_store *store;
+
+       struct dm_kcopyd_client *kcopyd_client;
+
+       /* Queue of snapshot writes for ksnapd to flush */
+       struct bio_list queued_bios;
+       struct work_struct queued_bios_work;
+
+       /* Chunks with outstanding reads */
+       mempool_t *tracked_chunk_pool;
+       spinlock_t tracked_chunk_lock;
+       struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
+};
+
 static struct workqueue_struct *ksnapd;
 static void flush_queued_bios(struct work_struct *work);
 
+static sector_t chunk_to_sector(struct dm_exception_store *store,
+                               chunk_t chunk)
+{
+       return chunk << store->chunk_shift;
+}
+
+static int bdev_equal(struct block_device *lhs, struct block_device *rhs)
+{
+       /*
+        * There is only ever one instance of a particular block
+        * device so we can compare pointers safely.
+        */
+       return lhs == rhs;
+}
+
 struct dm_snap_pending_exception {
        struct dm_snap_exception e;