zvol: implement platform-independent part of block cloning #16901
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Motivation and Context
In Linux, block devices currently lack support for
copy_file_range
API because the kernel does not provide thenecessary functionality. However, there is an ongoing upstream effort to address this limitation: https://patchwork.kernel.org/project/dm-devel/cover/[email protected]/.
We have adopted this upstream kernel patch into the TrueNAS kernel and made some additional modifications to enable block cloning specifically for the zvol block device. This patch implements the platform- independent portions of these changes for inclusion in OpenZFS. This patch does not introduce any new functionality directly into OpenZFS.
The
TX_CLONE_RANGE
replay capability is only relevant when zvols are migrated to non-TrueNAS systems that support Clone Range replay in the ZIL. Complete support in ZFS, Linux kernel, and SCST can be found in the respective links for curious readers.Description
How Has This Been Tested?
Types of changes
Checklist:
Signed-off-by
.