Re: [dm-devel] [PATCH 0/2] block: blk_interposer v3

On 2021/01/29 2:23, Sergei Shtepa wrote:

Hi all,

I`m ready to suggest the blk_interposer again.
blk_interposer allows to intercept bio requests, remap bio to
another devices or add new bios.

This version has support from device mapper.

For the dm-linear device creation command, the `noexcl` parameter
has been added, which allows to open block devices without
FMODE_EXCL mode. It allows to create dm-linear device on a block
device with an already mounted file system.
The new ioctl DM_DEV_REMAP allows to enable and disable bio
interception.

Thus, it is possible to add the dm-device to the block layer stack
without reconfiguring and rebooting.

Please add the changelog here instead of adding it in each patch. And keep the
changelog for previous versions too (i.e. v1->v2 in this case) so that the
changes overall can be tracked.

The proper formatting for the title should be [PATCH v3 X/Y] instead of adding
v3 in the title itself. With git format-patch, you can use "-v 3" option to
format this for you, or --subject-prefix="PATCH v3" option.

Sergei Shtepa (2):
  block: blk_interposer
  [dm] blk_interposer for dm-linear

 block/bio.c                   |   2 +
 block/blk-core.c              |  29 +++
 block/blk-mq.c                |  13 ++
 block/genhd.c                 |  82 ++++++++
 drivers/md/dm-core.h          |  46 +++-
 drivers/md/dm-ioctl.c         |  39 ++++
 drivers/md/dm-linear.c        |  17 +-
 drivers/md/dm-table.c         |  12 +-
 drivers/md/dm.c               | 383 ++++++++++++++++++++++++++++++++--
 drivers/md/dm.h               |   2 +-
 include/linux/blk-mq.h        |   1 +
 include/linux/blk_types.h     |   6 +-
 include/linux/device-mapper.h |   7 +
 include/linux/genhd.h         |  19 ++
 include/uapi/linux/dm-ioctl.h |  15 +-
 15 files changed, 643 insertions(+), 30 deletions(-)

-- 
Damien Le Moal
Western Digital Research