[PATCH 18/20] block, blksnap: Kconfig

Sergei Shtepa
2022-06-13T18:57:35Z

The module configuration file allows you to set default values for
module parameters.

Signed-off-by: Sergei Shtepa <sergei.shtepa@veeam.com>
---
drivers/block/blksnap/Kconfig | 101 ++++++++++++++++++++++++++++++++++
1 file changed, 101 insertions(+)
create mode 100644 drivers/block/blksnap/Kconfig

diff --git a/drivers/block/blksnap/Kconfig b/drivers/block/blksnap/Kconfig
new file mode 100644
index 000000000000..8588a89e30ad
--- /dev/null
+++ b/drivers/block/blksnap/Kconfig
@@ -0,0 +1,101 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# block io layer filter module configuration
+#
+#
+
+config BLK_SNAP
+ tristate "Block device snapshot and change tracker module"
+ depends on BLK_FILTER
+ help
+ Allow to create snapshots and track block changes for a block
+ devices. Designed for creating backups for any block devices
+ (without device mapper). Snapshots are temporary and are released
+ then backup is completed. Change block tracking allows you to
+ create incremental or differential backups.
+
+config BLK_SNAP_TRACKING_BLOCK_MINIMUM_SHIFT
+ depends on BLK_SNAP
+ int "The power of 2 for minimum trackings block size"
+ default 16
+ help
+ The minimum tracking block size by default is 64 KB (shift 16)
+ It's looks good for block device 128 GB or lower.
+ In this case, the block device is divided into 2097152 blocks.
+
+config BLK_SNAP_TRACKING_BLOCK_MAXIMUM_COUNT
+ depends on BLK_SNAP
+ int "The limit of the maximum number of trackings blocks"
+ default 2097152
+ help
+ As the size of the block device grows, the size of the tracking block
+ size should also grow. For this purpose, the limit of the maximum
+ number of block size is set.
+
+config BLK_SNAP_CHUNK_MINIMUM_SHIFT
+ depends on BLK_SNAP
+ int "The power of 2 for minimum snapshots chunk size"
+ default 18
+ help
+ The minimum chunk size by default is 256 KB (shift 18)
+ It's looks good for block device 128 GB or lower.
+ In this case, the block device is divided into 524288 chunks.
+
+config BLK_SNAP_CHUNK_MAXIMUM_COUNT
+ depends on BLK_SNAP
+ int "The limit of the maximum number of snapshots chunks"
+ default 2097152
+ help
+ As the size of the block device grows, the size of the chunk
+ should also grow. For this purpose, the limit of the maximum number
+ of chunks is set.
+
+config BLK_SNAP_CHUNK_MAXIMUM_IN_CACHE
+ depends on BLK_SNAP
+ int "The limit of the maximum chunks in memory cache"
+ default 64
+ help
+ Since reading and writing to snapshots is performed in large chunks,
+ a cache is implemented to optimize reading small portions of data
+ from the snapshot image. As the number of chunks in the cache
+ increases, memory consumption also increases.
+ The minimum recommended value is four.
+
+config BLK_SNAP_FREE_DIFF_BUFFER_POOL_SIZE
+ depends on BLK_SNAP
+ int "The maximum size of the free buffers pool"
+ default 128
+ help
+ A buffer can be allocated for each chunk. After use, this buffer is
+ not released immediately, but is sent to the pool of free buffers.
+ However, if there are too many free buffers in the pool, they are
+ released immediately. The maximum size of the pool is regulated by
+ this define.
+
+config BLK_SNAP_DIFF_STORAGE_MINIMUM
+ depends on BLK_SNAP
+ int "The minimum allowable size of the difference storage in sectors"
+ default 2097152
+ help
+ When reached, an event is generated about the lack of free space.
+
+config BLK_SNAP_DEBUG_MEMORY_LEAK
+ depends on BLK_SNAP
+ bool "Enable memory leak detector"
+ default n
+ help
+ Enables debugging code to monitor memory consumption by the module.
+
+ If unsure, say N.
+
+config BLK_SNAP_ALLOW_DIFF_STORAGE_IN_MEMORY
+ depends on BLK_SNAP
+ bool "Allow difference storage in memory"
+ default n
+ help
+ Enables the ability to create a repository of changes in memory.
+ This feature can be useful for debugging. Or it can be used for
+ mobile phones or other devices if there are guaranteed not to be
+ a large number of writings during the snapshot hold.
+
+ If unsure, say N.
--
2.20.1