| Message ID | 1655135593-1900-19-git-send-email-sergei.shtepa@veeam.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blksnap - creating non-persistent snapshots for backup | expand |
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 <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 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.
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?
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.
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