Merge branch 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-block

[karo-tx-linux.git] / drivers / md / dm-snap.c

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 54853773510c41216c263c5096164559df7782b8..f30f6e8d594e1cc90b52d6d73a4b110367ae2d6f 100644 (file)
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -148,6 +148,12 @@ struct dm_snapshot {
 #define RUNNING_MERGE          0
 #define SHUTDOWN_MERGE         1
 
+struct dm_dev *dm_snap_origin(struct dm_snapshot *s)
+{
+       return s->origin;
+}
+EXPORT_SYMBOL(dm_snap_origin);
+
 struct dm_dev *dm_snap_cow(struct dm_snapshot *s)
 {
        return s->cow;
@@ -700,8 +706,6 @@ static int dm_add_exception(void *context, chunk_t old, chunk_t new)
        return 0;
 }
 
-#define min_not_zero(l, r) (((l) == 0) ? (r) : (((r) == 0) ? (l) : min(l, r)))
-
 /*
  * Return a minimum chunk size of all snapshots that have the specified origin.
  * Return zero if the origin has no snapshots.
@@ -1065,10 +1069,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                origin_mode = FMODE_WRITE;
        }
 
-       origin_path = argv[0];
-       argv++;
-       argc--;
-
        s = kmalloc(sizeof(*s), GFP_KERNEL);
        if (!s) {
                ti->error = "Cannot allocate snapshot context private "
@@ -1077,6 +1077,16 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                goto bad;
        }
 
+       origin_path = argv[0];
+       argv++;
+       argc--;
+
+       r = dm_get_device(ti, origin_path, origin_mode, &s->origin);
+       if (r) {
+               ti->error = "Cannot get origin device";
+               goto bad_origin;
+       }
+
        cow_path = argv[0];
        argv++;
        argc--;
@@ -1097,12 +1107,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
        argv += args_used;
        argc -= args_used;
 
-       r = dm_get_device(ti, origin_path, origin_mode, &s->origin);
-       if (r) {
-               ti->error = "Cannot get origin device";
-               goto bad_origin;
-       }
-
        s->ti = ti;
        s->valid = 1;
        s->active = 0;
@@ -1212,15 +1216,15 @@ bad_kcopyd:
        dm_exception_table_exit(&s->complete, exception_cache);
 
 bad_hash_tables:
-       dm_put_device(ti, s->origin);
-
-bad_origin:
        dm_exception_store_destroy(s->store);
 
 bad_store:
        dm_put_device(ti, s->cow);
 
 bad_cow:
+       dm_put_device(ti, s->origin);
+
+bad_origin:
        kfree(s);
 
 bad:
@@ -1314,12 +1318,12 @@ static void snapshot_dtr(struct dm_target *ti)
 
        mempool_destroy(s->pending_pool);
 
-       dm_put_device(ti, s->origin);
-
        dm_exception_store_destroy(s->store);
 
        dm_put_device(ti, s->cow);
 
+       dm_put_device(ti, s->origin);
+
        kfree(s);
 }
 
@@ -1686,7 +1690,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio,
        chunk_t chunk;
 
        if (unlikely(bio_empty_barrier(bio))) {
-               if (!map_context->flush_request)
+               if (!map_context->target_request_nr)
                        bio->bi_bdev = s->origin->bdev;
                else
                        bio->bi_bdev = s->cow->bdev;
@@ -1899,8 +1903,14 @@ static int snapshot_iterate_devices(struct dm_target *ti,
                                    iterate_devices_callout_fn fn, void *data)
 {
        struct dm_snapshot *snap = ti->private;
+       int r;
+
+       r = fn(ti, snap->origin, 0, ti->len, data);
+
+       if (!r)
+               r = fn(ti, snap->cow, 0, get_dev_size(snap->cow->bdev), data);
 
-       return fn(ti, snap->origin, 0, ti->len, data);
+       return r;
 }
 
 
@@ -2159,6 +2169,21 @@ static int origin_status(struct dm_target *ti, status_type_t type, char *result,
        return 0;
 }
 
+static int origin_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
+                       struct bio_vec *biovec, int max_size)
+{
+       struct dm_dev *dev = ti->private;
+       struct request_queue *q = bdev_get_queue(dev->bdev);
+
+       if (!q->merge_bvec_fn)
+               return max_size;
+
+       bvm->bi_bdev = dev->bdev;
+       bvm->bi_sector = bvm->bi_sector;
+
+       return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
+}
+
 static int origin_iterate_devices(struct dm_target *ti,
                                  iterate_devices_callout_fn fn, void *data)
 {
@@ -2176,6 +2201,7 @@ static struct target_type origin_target = {
        .map     = origin_map,
        .resume  = origin_resume,
        .status  = origin_status,
+       .merge   = origin_merge,
        .iterate_devices = origin_iterate_devices,
 };