The module configuration file allows you to set default values for
module parameters.
Signed-off-by: Sergei Shtepa <[email protected]>
---
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
Hi--
On 6/13/22 08:53, Sergei Shtepa wrote:
> The module configuration file allows you to set default values for
> module parameters.
>
> Signed-off-by: Sergei Shtepa <[email protected]>
> ---
> 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
I prefer IO or I/O
but that's up to Jens.
> +#
> +#
> +
> +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
for 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"
tracking (I think.)
> + default 16
> + help
> + The minimum tracking block size by default is 64 KB (shift 16)
End above with a period ('.'): (shift 16).
> + It's looks good for block device 128 GB or lower.
It looks good
except saying something about performance would be better than "looks good".
> + 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"
tracking (IMO)
> + 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)
(shift 18).
> + It's looks good for block device 128 GB or lower.
It looks good
except that something more technical would be better here.
> + 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.
Is the "limit of the maximum number" the same as "the maximum number" of chunks?
Using "limit ... maximum" seems redundant to me.
> +
> +config BLK_SNAP_CHUNK_MAXIMUM_IN_CACHE
> + depends on BLK_SNAP
> + int "The limit of the maximum chunks in memory cache"
or just "Maximum number of 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
Here, does "they"
mean the extra buffers (> BLK_SNAP_DIFF_BUFFER_POOL_SIZE) or all of the
pool of free buffers?
> + released immediately. The maximum size of the pool is regulated by
> + this define.
I would s/define/configuration/.
> +
> +config BLK_SNAP_DIFF_STORAGE_MINIMUM
> + depends on BLK_SNAP
> + int "The minimum allowable size of the difference storage in sectors"
What is "difference storage"?
> + 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"
Is "difference storage" described somewhere?
> + 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.
thanks.
--
~Randy
On Mon, Jun 13, 2022 at 06:53:11PM +0300, Sergei Shtepa wrote:
> +config BLK_SNAP_TRACKING_BLOCK_MINIMUM_SHIFT
> + depends on BLK_SNAP
> + int "The power of 2 for minimum trackings block size"
> +config BLK_SNAP_TRACKING_BLOCK_MAXIMUM_COUNT
> + depends on BLK_SNAP
> +config BLK_SNAP_CHUNK_MINIMUM_SHIFT
> + depends on BLK_SNAP
> +config BLK_SNAP_CHUNK_MAXIMUM_COUNT
> + depends on BLK_SNAP
> + int "The limit of the maximum number of snapshots chunks"
...
Is there any good reason for these to be compile options vs runtime
settings?
> +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.
Is there any advantage in this over kmemleak and friends?