mirror of
https://github.com/torvalds/linux.git
synced 2026-07-29 10:41:49 +02:00
Linux kernel source tree
98077f7f21
With all the preparation patches, we're able to finally enable btrfs block size (sector size) larger than page size support and give it a full fstests run. And obviously this new feature is hidden behind experimental flags, and should not be considered as a core feature yet as btrfs' default block size is still 4K. But this is still a feature that will shine in the future where 16K block sized device are widely adopted. For now there are some features explicitly disabled: - Direct IO This is the most complex part to support, the root reason is we can not control the pages of iov iter passed in. User space programs can only ensure the virtual addresses are contiguous, but have no control on their physical addresses. Our bs > ps support heavily relies on large folios, and direct IO memory can easily break it. So direct IO is disabled and will always fall back to buffered IO. - RAID56 In theory we can convert RAID56 to use large folios, but it will need to be converted back to page based if we want to support direct IO in the future. So just reject it for now. - Encoded send - Encoded read Both are utilizing btrfs_encoded_read_regular_fill_pages(), and send is utilizing vmallocated memory. Unfortunately for vmallocated memory we can not guarantee the minimal folio order. For send, it will just always fallback to regular writes, which reads from page cache and will follow the existing folio order requirement. - Encoded write Encoded write itself is allocating pages by themselves, and we can easily change it to follow the minimal order. But since encoded read is already disabled, there is no need to only enable encoded write. Finally just like what we did for bs < ps support in the past, add a warning message for bs > ps mounts. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .rustfmt.toml | ||
| 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 reStructuredText 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.