Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
drivers/md/dm-snap.c | 175 +++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 165 insertions(+), 10 deletions(-)
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index bea98b4..ae8bb34 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -575,8 +575,8 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
cow_path = argv[1];
persistent = toupper(*argv[2]);
- if (persistent != 'P' && persistent != 'N') {
- ti->error = "Persistent flag is not P or N";
+ if (persistent != 'P' && persistent != 'N' && persistent != 'S') {
+ ti->error = "Persistent flag is not P, N, or S";
r = -EINVAL;
goto bad1;
}
@@ -625,7 +625,9 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
s->store.snap = s;
- if (persistent == 'P')
+ if (persistent == 'S')
+ r = dm_create_shared(&s->store);
+ else if (persistent == 'P')
r = dm_create_persistent(&s->store);
else
r = dm_create_transient(&s->store);
@@ -1393,6 +1395,136 @@ static int origin_status(struct dm_target *ti, status_type_t type, char *result,
return 0;
}
+/*
+ * shared exception origin code
+ */
+
+struct dm_shared_origin {
+ struct dm_dev *origin;
+
+ struct dm_snapshot *origin_snap;
+};
+
+/*
+ * Construct a shared origin mapping: <origin_dev> <COW-dev> <p/n> <chunk-size>
+ */
+static int shared_origin_ctr(struct dm_target *ti, unsigned int argc,
+ char **argv)
+{
+ int r;
+ struct dm_shared_origin *dso;
+ struct dm_snapshot *s;
+
+ if (argc != 4) {
+ ti->error = "origin: incorrect number of arguments";
+ return -EINVAL;
+ }
+
+ dso = kzalloc(sizeof(*dso), GFP_KERNEL);
+ if (!dso)
+ return -ENOMEM;
+
+ r = snapshot_ctr(ti, argc, argv);
+ if (r)
+ goto out;
+
+ s = ti->private;
+
+ if (s->chunk_size != 16) {
+ r = -EINVAL;
+ ti->error = "invalid chunk size";
+ snapshot_dtr(ti);
+ goto out;
+ }
+
+ s->active = 1;
+
+ dso->origin = s->origin;
+ dso->origin_snap = s;
+ ti->private = dso;
+
+ return 0;
+out:
+ kfree(dso);
+ return r;
+}
+
+static void shared_origin_dtr(struct dm_target *ti)
+{
+ struct dm_shared_origin *dso = ti->private;
+
+ ti->private = dso->origin_snap;
+ snapshot_dtr(ti);
+ kfree(dso);
+}
+
+static int shared_origin_map(struct dm_target *ti, struct bio *bio,
+ union map_info *map_context)
+{
+ struct dm_shared_origin *dso = ti->private;
+ struct dm_dev *dev = dso->origin;
+
+ bio->bi_bdev = dev->bdev;
+
+ /* Only tell snapshots if this is a write */
+ return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : DM_MAPIO_REMAPPED;
+}
+
+static int shared_origin_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
+{
+ struct dm_shared_origin *dso = ti->private;
+ struct dm_snapshot *snap = dso->origin_snap;
+ struct exception_store *store = &snap->store;
+ unsigned long map[DIV_ROUND_UP(MAX_SNAPSHOTS, BITS_PER_LONG)];
+ int r, nr, i;
+
+ switch (type) {
+ case STATUSTYPE_INFO:
+
+ memset(map, 0, sizeof(map));
+
+ down_write(&store->snap->lock);
+ nr = store->get_snapshot_info(store, map, sizeof(map));
+ up_write(&store->snap->lock);
+
+ if (nr) {
+ r = snprintf(result, maxlen, "%d ", nr);
+ result += r;
+ maxlen -= min_t(int, r, maxlen);
+
+ for (i = 0; maxlen && i < MAX_SNAPSHOTS; i++) {
+ if (test_bit(i, map)) {
+ r = snprintf(result, maxlen, "%d ", i);
+ result += r;
+ maxlen -= min_t(int, r, maxlen);
+ }
+ }
+ } else
+ snprintf(result, maxlen, ": no snapshot");
+
+ break;
+
+ case STATUSTYPE_TABLE:
+ r = snprintf(result, maxlen, "%s", snap->origin->name);
+ if (r > 0 && r < maxlen)
+ snprintf(result + r, maxlen - r, "%s %s %llu",
+ snap->origin->name, snap->cow->name,
+ (unsigned long long)snap->chunk_size);
+ break;
+ }
+
+ return 0;
+}
+
+static int shared_origin_message(struct dm_target *ti, unsigned argc,
+ char **argv)
+{
+ struct dm_shared_origin *dso = ti->private;
+ struct dm_snapshot *snap = dso->origin_snap;
+ return snap->store.message(&snap->store, argc, argv);
+}
+
static struct target_type origin_target = {
.name = "snapshot-origin",
.version = {1, 6, 0},
@@ -1416,6 +1548,17 @@ static struct target_type snapshot_target = {
.status = snapshot_status,
};
+static struct target_type shared_origin_target = {
+ .name = "s-snap-origin",
+ .version = {1, 0, 0},
+ .module = THIS_MODULE,
+ .ctr = shared_origin_ctr,
+ .dtr = shared_origin_dtr,
+ .map = shared_origin_map,
+ .status = shared_origin_status,
+ .message = shared_origin_message,
+};
+
static int __init dm_snapshot_init(void)
{
int r;
@@ -1432,31 +1575,37 @@ static int __init dm_snapshot_init(void)
goto bad1;
}
+ r = dm_register_target(&shared_origin_target);
+ if (r) {
+ DMERR("shared origin target register failed %d", r);
+ goto bad2;
+ }
+
r = init_origin_hash();
if (r) {
DMERR("init_origin_hash failed.");
- goto bad2;
+ goto bad3;
}
exception_cache = KMEM_CACHE(dm_snap_exception, 0);
if (!exception_cache) {
DMERR("Couldn't create exception cache.");
r = -ENOMEM;
- goto bad3;
+ goto bad4;
}
pending_cache = KMEM_CACHE(dm_snap_pending_exception, 0);
if (!pending_cache) {
DMERR("Couldn't create pending cache.");
r = -ENOMEM;
- goto bad4;
+ goto bad5;
}
tracked_chunk_cache = KMEM_CACHE(dm_snap_tracked_chunk, 0);
if (!tracked_chunk_cache) {
DMERR("Couldn't create cache to track chunks in use.");
r = -ENOMEM;
- goto bad5;
+ goto bad6;
}
ksnapd = create_singlethread_workqueue("ksnapd");
@@ -1470,12 +1619,14 @@ static int __init dm_snapshot_init(void)
bad_pending_pool:
kmem_cache_destroy(tracked_chunk_cache);
- bad5:
+ bad6:
kmem_cache_destroy(pending_cache);
- bad4:
+ bad5:
kmem_cache_destroy(exception_cache);
- bad3:
+ bad4:
exit_origin_hash();
+ bad3:
+ dm_unregister_target(&shared_origin_target);
bad2:
dm_unregister_target(&origin_target);
bad1:
@@ -1497,6 +1648,10 @@ static void __exit dm_snapshot_exit(void)
if (r)
DMERR("origin unregister failed %d", r);
+ r = dm_unregister_target(&shared_origin_target);
+ if (r)
+ DMERR("shared origin unregister failed %d", r);
+
exit_origin_hash();
kmem_cache_destroy(pending_cache);
kmem_cache_destroy(exception_cache);
--
1.5.5.GIT
--
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