dm snapshot: extend exception store functions

Supply dm_add_exception as a callback to the read_metadata function.
Add a status function ready for a later patch and name the functions
consistently.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 26 insertions, 16 deletions

diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index 57c946c69ee7..936b34e0959f 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -395,7 +395,11 @@ static void write_exception(struct pstore *ps,
  * 'full' is filled in to indicate if the area has been
  * filled.
  */
-static int insert_exceptions(struct pstore *ps, int *full)
+static int insert_exceptions(struct pstore *ps,
+                             int (*callback)(void *callback_context,
+                                             chunk_t old, chunk_t new),
+                             void *callback_context,
+                             int *full)
 {
         int r;
         unsigned int i;
@@ -428,7 +432,7 @@ static int insert_exceptions(struct pstore *ps, int *full)
                 /*
                  * Otherwise we add the exception to the snapshot.
                  */
-                r = dm_add_exception(ps->snap, de.old_chunk, de.new_chunk);
+                r = callback(callback_context, de.old_chunk, de.new_chunk);
                 if (r)
                         return r;
         }
@@ -436,7 +440,10 @@ static int insert_exceptions(struct pstore *ps, int *full)
         return 0;
 }
 
-static int read_exceptions(struct pstore *ps)
+static int read_exceptions(struct pstore *ps,
+                           int (*callback)(void *callback_context, chunk_t old,
+                                           chunk_t new),
+                           void *callback_context)
 {
         int r, full = 1;
 
@@ -449,7 +456,7 @@ static int read_exceptions(struct pstore *ps)
                 if (r)
                         return r;
 
-                r = insert_exceptions(ps, &full);
+                r = insert_exceptions(ps, callback, callback_context, &full);
                 if (r)
                         return r;
         }
@@ -482,7 +489,10 @@ static void persistent_destroy(struct dm_exception_store *store)
         kfree(ps);
 }
 
-static int persistent_read_metadata(struct dm_exception_store *store)
+static int persistent_read_metadata(struct dm_exception_store *store,
+                                    int (*callback)(void *callback_context,
+                                                    chunk_t old, chunk_t new),
+                                    void *callback_context)
 {
         int r, uninitialized_var(new_snapshot);
         struct pstore *ps = get_info(store);
@@ -540,7 +550,7 @@ static int persistent_read_metadata(struct dm_exception_store *store)
                 /*
                  * Read the metadata.
                  */
-                r = read_exceptions(ps);
+                r = read_exceptions(ps, callback, callback_context);
                 if (r)
                         return r;
         }
@@ -548,8 +558,8 @@ static int persistent_read_metadata(struct dm_exception_store *store)
         return 0;
 }
 
-static int persistent_prepare(struct dm_exception_store *store,
-                              struct dm_snap_exception *e)
+static int persistent_prepare_exception(struct dm_exception_store *store,
+                                        struct dm_snap_exception *e)
 {
         struct pstore *ps = get_info(store);
         uint32_t stride;
@@ -575,10 +585,10 @@ static int persistent_prepare(struct dm_exception_store *store,
         return 0;
 }
 
-static void persistent_commit(struct dm_exception_store *store,
-                              struct dm_snap_exception *e,
-                              void (*callback) (void *, int success),
-                              void *callback_context)
+static void persistent_commit_exception(struct dm_exception_store *store,
+                                        struct dm_snap_exception *e,
+                                        void (*callback) (void *, int success),
+                                        void *callback_context)
 {
         unsigned int i;
         struct pstore *ps = get_info(store);
@@ -637,7 +647,7 @@ static void persistent_commit(struct dm_exception_store *store,
         ps->callback_count = 0;
 }
 
-static void persistent_drop(struct dm_exception_store *store)
+static void persistent_drop_snapshot(struct dm_exception_store *store)
 {
         struct pstore *ps = get_info(store);
 
@@ -675,9 +685,9 @@ int dm_create_persistent(struct dm_exception_store *store)
 
         store->destroy = persistent_destroy;
         store->read_metadata = persistent_read_metadata;
-        store->prepare_exception = persistent_prepare;
-        store->commit_exception = persistent_commit;
-        store->drop_snapshot = persistent_drop;
+        store->prepare_exception = persistent_prepare_exception;
+        store->commit_exception = persistent_commit_exception;
+        store->drop_snapshot = persistent_drop_snapshot;
         store->fraction_full = persistent_fraction_full;
         store->context = ps;