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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/md/dm-snap-transient.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/md/dm-snap-transient.c')
-rw-r--r--kernel/drivers/md/dm-snap-transient.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/kernel/drivers/md/dm-snap-transient.c b/kernel/drivers/md/dm-snap-transient.c
new file mode 100644
index 000000000..1ce9a2586
--- /dev/null
+++ b/kernel/drivers/md/dm-snap-transient.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
+ * Copyright (C) 2006-2008 Red Hat GmbH
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm-exception-store.h"
+
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/vmalloc.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/dm-io.h>
+
+#define DM_MSG_PREFIX "transient snapshot"
+
+/*-----------------------------------------------------------------
+ * Implementation of the store for non-persistent snapshots.
+ *---------------------------------------------------------------*/
+struct transient_c {
+ sector_t next_free;
+};
+
+static void transient_dtr(struct dm_exception_store *store)
+{
+ kfree(store->context);
+}
+
+static int transient_read_metadata(struct dm_exception_store *store,
+ int (*callback)(void *callback_context,
+ chunk_t old, chunk_t new),
+ void *callback_context)
+{
+ return 0;
+}
+
+static int transient_prepare_exception(struct dm_exception_store *store,
+ struct dm_exception *e)
+{
+ struct transient_c *tc = store->context;
+ sector_t size = get_dev_size(dm_snap_cow(store->snap)->bdev);
+
+ if (size < (tc->next_free + store->chunk_size))
+ return -1;
+
+ e->new_chunk = sector_to_chunk(store, tc->next_free);
+ tc->next_free += store->chunk_size;
+
+ return 0;
+}
+
+static void transient_commit_exception(struct dm_exception_store *store,
+ struct dm_exception *e,
+ void (*callback) (void *, int success),
+ void *callback_context)
+{
+ /* Just succeed */
+ callback(callback_context, 1);
+}
+
+static void transient_usage(struct dm_exception_store *store,
+ sector_t *total_sectors,
+ sector_t *sectors_allocated,
+ sector_t *metadata_sectors)
+{
+ *sectors_allocated = ((struct transient_c *) store->context)->next_free;
+ *total_sectors = get_dev_size(dm_snap_cow(store->snap)->bdev);
+ *metadata_sectors = 0;
+}
+
+static int transient_ctr(struct dm_exception_store *store,
+ unsigned argc, char **argv)
+{
+ struct transient_c *tc;
+
+ tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL);
+ if (!tc)
+ return -ENOMEM;
+
+ tc->next_free = 0;
+ store->context = tc;
+
+ return 0;
+}
+
+static unsigned transient_status(struct dm_exception_store *store,
+ status_type_t status, char *result,
+ unsigned maxlen)
+{
+ unsigned sz = 0;
+
+ switch (status) {
+ case STATUSTYPE_INFO:
+ break;
+ case STATUSTYPE_TABLE:
+ DMEMIT(" N %llu", (unsigned long long)store->chunk_size);
+ }
+
+ return sz;
+}
+
+static struct dm_exception_store_type _transient_type = {
+ .name = "transient",
+ .module = THIS_MODULE,
+ .ctr = transient_ctr,
+ .dtr = transient_dtr,
+ .read_metadata = transient_read_metadata,
+ .prepare_exception = transient_prepare_exception,
+ .commit_exception = transient_commit_exception,
+ .usage = transient_usage,
+ .status = transient_status,
+};
+
+static struct dm_exception_store_type _transient_compat_type = {
+ .name = "N",
+ .module = THIS_MODULE,
+ .ctr = transient_ctr,
+ .dtr = transient_dtr,
+ .read_metadata = transient_read_metadata,
+ .prepare_exception = transient_prepare_exception,
+ .commit_exception = transient_commit_exception,
+ .usage = transient_usage,
+ .status = transient_status,
+};
+
+int dm_transient_snapshot_init(void)
+{
+ int r;
+
+ r = dm_exception_store_type_register(&_transient_type);
+ if (r) {
+ DMWARN("Unable to register transient exception store type");
+ return r;
+ }
+
+ r = dm_exception_store_type_register(&_transient_compat_type);
+ if (r) {
+ DMWARN("Unable to register old-style transient "
+ "exception store type");
+ dm_exception_store_type_unregister(&_transient_type);
+ return r;
+ }
+
+ return r;
+}
+
+void dm_transient_snapshot_exit(void)
+{
+ dm_exception_store_type_unregister(&_transient_type);
+ dm_exception_store_type_unregister(&_transient_compat_type);
+}