[PATCH 04/20] block, blksnap: init() and exit() functions

[Sergei Shtepa <sergei.shtepa@veeam.com>]

Contains callback functions for loading and unloading the module. The
module parameters and other mandatory declarations for the kernel module
are also defined.

Signed-off-by: Sergei Shtepa <sergei.shtepa@veeam.com>
---
 drivers/block/blksnap/main.c    | 109 ++++++++++++++++++++++++++++++++
 drivers/block/blksnap/params.h  |  10 +++
 drivers/block/blksnap/version.h |   8 +++
 3 files changed, 127 insertions(+)
 create mode 100644 drivers/block/blksnap/main.c
 create mode 100644 drivers/block/blksnap/params.h
 create mode 100644 drivers/block/blksnap/version.h

diff --git a/drivers/block/blksnap/main.c b/drivers/block/blksnap/main.c
new file mode 100644
index 000000000000..9737df4e6461
--- /dev/null
+++ b/drivers/block/blksnap/main.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/blk_snap.h>
+#ifdef CONFIG_BLK_SNAP_DEBUG_MEMORY_LEAK
+#include "memory_checker.h"
+#endif
+#include "version.h"
+#include "params.h"
+#include "ctrl.h"
+#include "sysfs.h"
+#include "snapimage.h"
+#include "snapshot.h"
+#include "tracker.h"
+#include "diff_io.h"
+
+static int __init blk_snap_init(void)
+{
+	int result;
+
+	pr_info("Loading\n");
+	pr_debug("Version: %s\n", VERSION_STR);
+	pr_debug("tracking_block_minimum_shift: %d\n",
+		 tracking_block_minimum_shift);
+	pr_debug("tracking_block_maximum_count: %d\n",
+		 tracking_block_maximum_count);
+	pr_debug("chunk_minimum_shift: %d\n", chunk_minimum_shift);
+	pr_debug("chunk_maximum_count: %d\n", chunk_maximum_count);
+	pr_debug("chunk_maximum_in_cache: %d\n", chunk_maximum_in_cache);
+	pr_debug("free_diff_buffer_pool_size: %d\n",
+		 free_diff_buffer_pool_size);
+	pr_debug("diff_storage_minimum: %d\n", diff_storage_minimum);
+
+	result = diff_io_init();
+	if (result)
+		return result;
+
+	result = snapimage_init();
+	if (result)
+		return result;
+
+	result = tracker_init();
+	if (result)
+		return result;
+
+	result = ctrl_init();
+	if (result)
+		return result;
+
+	result = sysfs_init();
+	return result;
+}
+
+static void __exit blk_snap_exit(void)
+{
+	pr_info("Unloading module\n");
+
+	sysfs_done();
+	ctrl_done();
+
+	diff_io_done();
+	snapshot_done();
+	snapimage_done();
+	tracker_done();
+
+	pr_info("Module was unloaded\n");
+}
+
+module_init(blk_snap_init);
+module_exit(blk_snap_exit);
+
+int tracking_block_minimum_shift = CONFIG_BLK_SNAP_TRACKING_BLOCK_MINIMUM_SHIFT;
+int tracking_block_maximum_count = CONFIG_BLK_SNAP_TRACKING_BLOCK_MAXIMUM_COUNT;
+int chunk_minimum_shift = CONFIG_BLK_SNAP_CHUNK_MINIMUM_SHIFT;
+int chunk_maximum_count = CONFIG_BLK_SNAP_CHUNK_MAXIMUM_COUNT;
+int chunk_maximum_in_cache = CONFIG_BLK_SNAP_CHUNK_MAXIMUM_IN_CACHE;
+int free_diff_buffer_pool_size = CONFIG_BLK_SNAP_FREE_DIFF_BUFFER_POOL_SIZE;
+int diff_storage_minimum = CONFIG_BLK_SNAP_DIFF_STORAGE_MINIMUM;
+
+module_param_named(tracking_block_minimum_shift, tracking_block_minimum_shift,
+		   int, 0644);
+MODULE_PARM_DESC(tracking_block_minimum_shift,
+		 "The power of 2 for minimum trackings block size");
+module_param_named(tracking_block_maximum_count, tracking_block_maximum_count,
+		   int, 0644);
+MODULE_PARM_DESC(tracking_block_maximum_count,
+		 "The limit of the maximum number of trackings blocks");
+module_param_named(chunk_minimum_shift, chunk_minimum_shift, int, 0644);
+MODULE_PARM_DESC(chunk_minimum_shift,
+		 "The power of 2 for minimum snapshots chunk size");
+module_param_named(chunk_maximum_count, chunk_maximum_count, int, 0644);
+MODULE_PARM_DESC(chunk_maximum_count,
+		 "The limit of the maximum number of snapshots chunks");
+module_param_named(chunk_maximum_in_cache, chunk_maximum_in_cache, int, 0644);
+MODULE_PARM_DESC(chunk_maximum_in_cache,
+		 "The limit of the maximum chunks in memory cache");
+module_param_named(free_diff_buffer_pool_size, free_diff_buffer_pool_size, int,
+		   0644);
+MODULE_PARM_DESC(free_diff_buffer_pool_size,
+		 "The maximum size of the free buffers pool");
+module_param_named(diff_storage_minimum, diff_storage_minimum, int, 0644);
+MODULE_PARM_DESC(
+	diff_storage_minimum,
+	"The minimum allowable size of the difference storage in sectors");
+
+MODULE_DESCRIPTION("Block Layer Snapshot Kernel Module");
+MODULE_VERSION(VERSION_STR);
+MODULE_AUTHOR("Veeam Software Group GmbH");
+MODULE_LICENSE("GPL");
diff --git a/drivers/block/blksnap/params.h b/drivers/block/blksnap/params.h
new file mode 100644
index 000000000000..1f8f0bd23e9f
--- /dev/null
+++ b/drivers/block/blksnap/params.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#pragma once
+
+extern int tracking_block_minimum_shift;
+extern int tracking_block_maximum_count;
+extern int chunk_minimum_shift;
+extern int chunk_maximum_count;
+extern int chunk_maximum_in_cache;
+extern int free_diff_buffer_pool_size;
+extern int diff_storage_minimum;
diff --git a/drivers/block/blksnap/version.h b/drivers/block/blksnap/version.h
new file mode 100644
index 000000000000..0d02a68f44a8
--- /dev/null
+++ b/drivers/block/blksnap/version.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#pragma once
+
+#define VERSION_MAJOR 1
+#define VERSION_MINOR 0
+#define VERSION_REVISION 0
+#define VERSION_BUILD 0
+#define VERSION_STR "1.0.0.0"
-- 
2.20.1