mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-09-22 04:31:58 +08:00
7609afac67
Currently btrfs handles checksum validation and repair in the end I/O handler for the btrfs_bio. This leads to a lot of duplicate code plus issues with varying semantics or bugs, e.g. - the until recently broken repair for compressed extents - the fact that encoded reads validate the checksums but do not kick of read repair - the inconsistent checking of the BTRFS_FS_STATE_NO_CSUMS flag This commit revamps the checksum validation and repair code to instead work below the btrfs_submit_bio interfaces. In case of a checksum failure (or a plain old I/O error), the repair is now kicked off before the upper level ->end_io handler is invoked. Progress of an in-progress repair is tracked by a small structure that is allocated using a mempool for each original bio with failed sectors, which holds a reference to the original bio. This new structure is allocated using a mempool to guarantee forward progress even under memory pressure. The mempool will be replenished when the repair completes, just as the mempools backing the bios. There is one significant behavior change here: If repair fails or is impossible to start with, the whole bio will be failed to the upper layer. This is the behavior that all I/O submitters except for buffered I/O already emulated in their end_io handler. For buffered I/O this now means that a large readahead request can fail due to a single bad sector, but as readahead errors are ignored the following readpage if the sector is actually accessed will still be able to read. This also matches the I/O failure handling in other file systems. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 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 | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .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 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.