[PATCH 00/12] Block storage copy offloading

Bart Van Assche
2026-04-24T22:42:18Z

Hi Jens,

This patch series implements a new approach for copy offloading. Compared to
Nitesh' approach, the differences are as follows:
- Two new limits have been introduced representing the maximum number of source
and destination ranges. Support for multiple source ranges for the NVMe Copy
command has been added.
- The blkdev_copy_offload() function can now submit multiple copy offload
commands instead of only one.
- The implementation no longer depends on block layer plugging.

This patch series includes copy offloading support for the Linux kernel block
layer core, the device mapper core, the null_blk and the NVMe and nvmet drivers.
Support for the scsi_debug and SCSI core will follow later.

Test scripts are available here:
https://github.com/bvanassche/blktests/tree/copy-offloading

See also Bart Van Assche, [LSF/MM/BPF TOPIC] Block storage copy offloading,
January 2026
(https://lore.kernel.org/all/0cfe6fe2-3865-4dc2-92a7-74b1240f7b63@acm.org/).

See also Nitesh Shetty, Implement copy offload support, May 2024
(https://lore.kernel.org/linux-block/20240520102033.9361-1-nj.shetty@samsung.com/).

Anuj Gupta (1):
fs/read_write: Generalize generic_copy_file_checks()

Bart Van Assche (4):
block: Introduce blkdev_copy_offload()
block: Introduce accessor functions for copy offload bios
dm: Add support for copy offloading
dm-linear: Enable copy offloading

Nitesh Shetty (7):
block: Introduce queue limits for copy offloading
block: Add the REQ_OP_COPY_{SRC,DST} operations
block: Add an onloaded copy implementation
fs, block: Add copy_file_range() support for block devices
nvme: Add copy offloading support
nvmet: Support the Copy command
null_blk: Add support for REQ_OP_COPY_*

Documentation/ABI/stable/sysfs-block | 24 +
Documentation/block/null_blk.rst | 4 +
block/Makefile | 2 +-
block/bio.c | 1 +
block/blk-copy.c | 631 +++++++++++++++++++++++++++
block/blk-core.c | 38 ++
block/blk-merge.c | 13 +
block/blk-settings.c | 36 ++
block/blk-sysfs.c | 35 ++
block/blk.h | 5 +
block/fops.c | 54 +++
drivers/block/null_blk/main.c | 113 +++++
drivers/block/null_blk/null_blk.h | 1 +
drivers/md/dm-linear.c | 6 +
drivers/md/dm-table.c | 8 +
drivers/nvme/host/constants.c | 1 +
drivers/nvme/host/core.c | 106 +++++
drivers/nvme/host/trace.c | 21 +-
drivers/nvme/target/admin-cmd.c | 26 +-
drivers/nvme/target/io-cmd-bdev.c | 80 ++++
drivers/nvme/target/io-cmd-file.c | 59 ++-
drivers/nvme/target/trace.c | 19 +
fs/read_write.c | 8 +-
include/linux/blk-copy.h | 50 +++
include/linux/blk_types.h | 57 +++
include/linux/blkdev.h | 20 +-
include/linux/nvme.h | 47 +-
27 files changed, 1449 insertions(+), 16 deletions(-)
create mode 100644 block/blk-copy.c
create mode 100644 include/linux/blk-copy.h