From: Sergei Shtepa <[email protected]>
Allows to build a module and add the blksnap to the kernel tree.
Co-developed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Sergei Shtepa <[email protected]>
---
drivers/block/Kconfig | 2 ++
drivers/block/Makefile | 2 ++
drivers/block/blksnap/Kconfig | 31 +++++++++++++++++++++++++++++++
drivers/block/blksnap/Makefile | 15 +++++++++++++++
4 files changed, 50 insertions(+)
create mode 100644 drivers/block/blksnap/Kconfig
create mode 100644 drivers/block/blksnap/Makefile
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 5b9d4aaebb81..74d2d55526a3 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -404,4 +404,6 @@ config BLKDEV_UBLK_LEGACY_OPCODES
source "drivers/block/rnbd/Kconfig"
+source "drivers/block/blksnap/Kconfig"
+
endif # BLK_DEV
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 101612cba303..9a2a9a56a247 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -40,3 +40,5 @@ obj-$(CONFIG_BLK_DEV_NULL_BLK) += null_blk/
obj-$(CONFIG_BLK_DEV_UBLK) += ublk_drv.o
swim_mod-y := swim.o swim_asm.o
+
+obj-$(CONFIG_BLKSNAP) += blksnap/
diff --git a/drivers/block/blksnap/Kconfig b/drivers/block/blksnap/Kconfig
new file mode 100644
index 000000000000..f52272c12e1b
--- /dev/null
+++ b/drivers/block/blksnap/Kconfig
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Block device snapshot module configuration
+#
+
+config BLKSNAP
+ tristate "Block Devices Snapshots Module (blksnap)"
+ help
+ Allow to create snapshots and track block changes for block devices.
+ Designed for creating backups for block devices. Snapshots are
+ temporary and are released when backup is completed. Change block
+ tracking allows to create incremental or differential backups.
+
+config BLKSNAP_DIFF_BLKDEV
+ bool "Use an optimized algorithm to store difference on a block device"
+ depends on BLKSNAP
+ default y
+ help
+ The difference storage for a snapshot can be a regular file or a
+ block device. We can work with a block device through the interface
+ of a regular file. However, direct management of I/O units should
+ allow for higher performance.
+
+config BLKSNAP_CHUNK_DIFF_BIO_SYNC
+ bool "Use a synchronous I/O unit processing algorithm for the snapshot image"
+ depends on BLKSNAP
+ default n
+ help
+ Theoretical asynchronous algorithm for processing I/O units should
+ have higher performance. However, an attempt to confirm this on test
+ runs did not bring any results.
diff --git a/drivers/block/blksnap/Makefile b/drivers/block/blksnap/Makefile
new file mode 100644
index 000000000000..8d528b95579a
--- /dev/null
+++ b/drivers/block/blksnap/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+
+blksnap-y := \
+ cbt_map.o \
+ chunk.o \
+ diff_area.o \
+ diff_buffer.o \
+ diff_storage.o \
+ event_queue.o \
+ main.o \
+ snapimage.o \
+ snapshot.o \
+ tracker.o
+
+obj-$(CONFIG_BLKSNAP) += blksnap.o
--
2.20.1
> +config BLKSNAP_DIFF_BLKDEV
> + bool "Use an optimized algorithm to store difference on a block device"
> + depends on BLKSNAP
> + default y
> + help
> + The difference storage for a snapshot can be a regular file or a
> + block device. We can work with a block device through the interface
> + of a regular file. However, direct management of I/O units should
> + allow for higher performance.
Is there much of a point in making this option?
Btw, Linus hates defaul y, so we should not have one in there.
> +config BLKSNAP_CHUNK_DIFF_BIO_SYNC
> + bool "Use a synchronous I/O unit processing algorithm for the snapshot image"
> + depends on BLKSNAP
> + default n
n the default default, so no need to add it. But unless there is a
really good reason to have two different bio submission mechanisms
upstream I'd strongly suggest dropping one of them and this option.