mainlining shenanigans
7dd76d1fee
The current DM code (ab)uses late assignment of dm_io->orig_bio (after __map_bio() returns and any bio splitting is complete) to indicate the FS bio has been processed and can be accounted. This results in awkward waiting until ->orig_bio is set in dm_submit_bio_remap(). Also the bio splitting was implemented using bio_split()+bio_chain() -- a well-worn pattern but it requires bio cloning purely for the benefit of more natural IO accounting. The bio_split() result was stored in ->orig_bio to represent the mapped part of the original FS bio. DM has switched to the bdev based IO accounting interface. DM's IO accounting can be implemented in terms of the original FS bio (now stored early in ->orig_bio) via access to its sectors/bio_op. And if/when splitting is needed, set a new DM_IO_WAS_SPLIT flag and use new dm_io fields of .sector_offset & .sectors to allow IO accounting for split bios _without_ needing to clone a new bio to store in ->orig_bio. Signed-off-by: Ming Lei <ming.lei@redhat.com> Co-developed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Mike Snitzer <snitzer@kernel.org> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.