Hello everyone! Requesting for your comments and suggestions.
We propose a new kernel module - blk-snap.
This module implements snapshot and changed block tracking functionality.
It is intended to create backup copies of any block devices without usage
of device-mapper.
Snapshots are temporary and are destroyed after the backup process has
finished. Changed block tracking allows for incremental and differential
backup copies.
blk-snap uses block layer filter API.
Block layer filter API provides a callback to intercept bio-requests.
If a block device disappears for whatever reason, send a synchronous
request to remove the device from filtering.
Previously, we have already offered a patch with the implementation of the
block layer filter api (https://patchwork.kernel.org/patch/11741447/).
Link to that discussion:
https://www.mail-archive.com/[email protected]/msg2290127.html.
Now we also offer the in-tree module.
blk-snap kernel module is a product of a deep refactoring of the
out-of-tree kernel veeamsnap (https://github.com/veeam/veeamsnap/) module:
* all conditional compilation branches that served for the purpose of
compatibility with older kernels have been removed;
* linux kernel code style has been applied;
* blk-snap mostly takes advantage of the existing kernel code instead of
reinventing the wheel;
* all redundant code (such as persistent cbt and snapstore collector) has
been removed.
We would appreciate your feedback!
Several important things are still have to be done:
* refactoring the module interface for interaction with a user-space code,
it is already clear that the implementation of some calls can be improved;
* haven't yet tested the build on architectures other than x86_64;
* the user-space library is not ready yet and tool to control the module
is to be created;
* autotests need to be created;
* regression testing has been conducted in a cursory manner, so there is
a chance for mistakes.
Sergei Shtepa (1):
blk-snap - Block snapshot module This module implements snapshot and
changed block tracking functionality. It is intended to create
backup copies of any block devices without usage of device-mapper.
MAINTAINERS | 14 +
block/Kconfig | 11 +
block/Makefile | 1 +
block/blk-core.c | 11 +-
block/blk-filter-internal.h | 34 +
block/blk-filter.c | 288 ++++++
block/genhd.c | 24 +
drivers/block/Kconfig | 6 +-
drivers/block/Makefile | 3 +-
drivers/block/blk-snap/Kconfig | 24 +
drivers/block/blk-snap/Makefile | 29 +
drivers/block/blk-snap/big_buffer.c | 193 ++++
drivers/block/blk-snap/big_buffer.h | 24 +
drivers/block/blk-snap/blk-snap-ctl.h | 190 ++++
drivers/block/blk-snap/blk_deferred.c | 566 +++++++++++
drivers/block/blk-snap/blk_deferred.h | 67 ++
drivers/block/blk-snap/blk_descr_file.c | 82 ++
drivers/block/blk-snap/blk_descr_file.h | 26 +
drivers/block/blk-snap/blk_descr_mem.c | 66 ++
drivers/block/blk-snap/blk_descr_mem.h | 14 +
drivers/block/blk-snap/blk_descr_multidev.c | 86 ++
drivers/block/blk-snap/blk_descr_multidev.h | 25 +
drivers/block/blk-snap/blk_descr_pool.c | 190 ++++
drivers/block/blk-snap/blk_descr_pool.h | 38 +
drivers/block/blk-snap/blk_redirect.c | 507 ++++++++++
drivers/block/blk-snap/blk_redirect.h | 73 ++
drivers/block/blk-snap/blk_util.c | 33 +
drivers/block/blk-snap/blk_util.h | 10 +
drivers/block/blk-snap/cbt_map.c | 210 +++++
drivers/block/blk-snap/cbt_map.h | 62 ++
drivers/block/blk-snap/common.h | 29 +
drivers/block/blk-snap/ctrl_fops.c | 693 ++++++++++++++
drivers/block/blk-snap/ctrl_fops.h | 19 +
drivers/block/blk-snap/ctrl_pipe.c | 562 +++++++++++
drivers/block/blk-snap/ctrl_pipe.h | 34 +
drivers/block/blk-snap/ctrl_sysfs.c | 73 ++
drivers/block/blk-snap/ctrl_sysfs.h | 5 +
drivers/block/blk-snap/defer_io.c | 393 ++++++++
drivers/block/blk-snap/defer_io.h | 39 +
drivers/block/blk-snap/filter.c | 72 ++
drivers/block/blk-snap/filter.h | 7 +
drivers/block/blk-snap/main.c | 83 ++
drivers/block/blk-snap/params.c | 57 ++
drivers/block/blk-snap/params.h | 29 +
drivers/block/blk-snap/rangevector.c | 85 ++
drivers/block/blk-snap/rangevector.h | 31 +
drivers/block/blk-snap/snapimage.c | 982 ++++++++++++++++++++
drivers/block/blk-snap/snapimage.h | 16 +
drivers/block/blk-snap/snapshot.c | 228 +++++
drivers/block/blk-snap/snapshot.h | 17 +
drivers/block/blk-snap/snapstore.c | 929 ++++++++++++++++++
drivers/block/blk-snap/snapstore.h | 68 ++
drivers/block/blk-snap/snapstore_device.c | 532 +++++++++++
drivers/block/blk-snap/snapstore_device.h | 63 ++
drivers/block/blk-snap/snapstore_file.c | 52 ++
drivers/block/blk-snap/snapstore_file.h | 15 +
drivers/block/blk-snap/snapstore_mem.c | 89 ++
drivers/block/blk-snap/snapstore_mem.h | 20 +
drivers/block/blk-snap/snapstore_multidev.c | 118 +++
drivers/block/blk-snap/snapstore_multidev.h | 22 +
drivers/block/blk-snap/tracker.c | 521 +++++++++++
drivers/block/blk-snap/tracker.h | 50 +
drivers/block/blk-snap/tracking.c | 260 ++++++
drivers/block/blk-snap/tracking.h | 12 +
drivers/block/blk-snap/version.h | 7 +
include/linux/blk-filter.h | 41 +
include/linux/genhd.h | 3 +-
67 files changed, 9157 insertions(+), 6 deletions(-)
create mode 100644 block/blk-filter-internal.h
create mode 100644 block/blk-filter.c
create mode 100644 drivers/block/blk-snap/Kconfig
create mode 100644 drivers/block/blk-snap/Makefile
create mode 100644 drivers/block/blk-snap/big_buffer.c
create mode 100644 drivers/block/blk-snap/big_buffer.h
create mode 100644 drivers/block/blk-snap/blk-snap-ctl.h
create mode 100644 drivers/block/blk-snap/blk_deferred.c
create mode 100644 drivers/block/blk-snap/blk_deferred.h
create mode 100644 drivers/block/blk-snap/blk_descr_file.c
create mode 100644 drivers/block/blk-snap/blk_descr_file.h
create mode 100644 drivers/block/blk-snap/blk_descr_mem.c
create mode 100644 drivers/block/blk-snap/blk_descr_mem.h
create mode 100644 drivers/block/blk-snap/blk_descr_multidev.c
create mode 100644 drivers/block/blk-snap/blk_descr_multidev.h
create mode 100644 drivers/block/blk-snap/blk_descr_pool.c
create mode 100644 drivers/block/blk-snap/blk_descr_pool.h
create mode 100644 drivers/block/blk-snap/blk_redirect.c
create mode 100644 drivers/block/blk-snap/blk_redirect.h
create mode 100644 drivers/block/blk-snap/blk_util.c
create mode 100644 drivers/block/blk-snap/blk_util.h
create mode 100644 drivers/block/blk-snap/cbt_map.c
create mode 100644 drivers/block/blk-snap/cbt_map.h
create mode 100644 drivers/block/blk-snap/common.h
create mode 100644 drivers/block/blk-snap/ctrl_fops.c
create mode 100644 drivers/block/blk-snap/ctrl_fops.h
create mode 100644 drivers/block/blk-snap/ctrl_pipe.c
create mode 100644 drivers/block/blk-snap/ctrl_pipe.h
create mode 100644 drivers/block/blk-snap/ctrl_sysfs.c
create mode 100644 drivers/block/blk-snap/ctrl_sysfs.h
create mode 100644 drivers/block/blk-snap/defer_io.c
create mode 100644 drivers/block/blk-snap/defer_io.h
create mode 100644 drivers/block/blk-snap/filter.c
create mode 100644 drivers/block/blk-snap/filter.h
create mode 100644 drivers/block/blk-snap/main.c
create mode 100644 drivers/block/blk-snap/params.c
create mode 100644 drivers/block/blk-snap/params.h
create mode 100644 drivers/block/blk-snap/rangevector.c
create mode 100644 drivers/block/blk-snap/rangevector.h
create mode 100644 drivers/block/blk-snap/snapimage.c
create mode 100644 drivers/block/blk-snap/snapimage.h
create mode 100644 drivers/block/blk-snap/snapshot.c
create mode 100644 drivers/block/blk-snap/snapshot.h
create mode 100644 drivers/block/blk-snap/snapstore.c
create mode 100644 drivers/block/blk-snap/snapstore.h
create mode 100644 drivers/block/blk-snap/snapstore_device.c
create mode 100644 drivers/block/blk-snap/snapstore_device.h
create mode 100644 drivers/block/blk-snap/snapstore_file.c
create mode 100644 drivers/block/blk-snap/snapstore_file.h
create mode 100644 drivers/block/blk-snap/snapstore_mem.c
create mode 100644 drivers/block/blk-snap/snapstore_mem.h
create mode 100644 drivers/block/blk-snap/snapstore_multidev.c
create mode 100644 drivers/block/blk-snap/snapstore_multidev.h
create mode 100644 drivers/block/blk-snap/tracker.c
create mode 100644 drivers/block/blk-snap/tracker.h
create mode 100644 drivers/block/blk-snap/tracking.c
create mode 100644 drivers/block/blk-snap/tracking.h
create mode 100644 drivers/block/blk-snap/version.h
create mode 100644 include/linux/blk-filter.h
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2.28.0