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A mirror of the official Linux kernel repository just in case
1a0bd289a5
Case #1:
SQLite App GC Thread Kworker Shrinker
- f2fs_ioc_start_atomic_write
- f2fs_ioc_commit_atomic_write
- f2fs_commit_atomic_write
- filemap_write_and_wait_range
: write atomic_file's data to cow_inode
echo 3 > drop_caches
to drop atomic_file's
cache.
- f2fs_gc
- gc_data_segment
- move_data_page
- set_page_dirty
- writepages
- f2fs_do_write_data_page
: overwrite atomic_file's data
to cow_inode
- f2fs_down_write(&fi->i_gc_rwsem[WRITE])
- __f2fs_commit_atomic_write
- f2fs_up_write(&fi->i_gc_rwsem[WRITE])
Case #2:
SQLite App GC Thread Kworker
- f2fs_ioc_start_atomic_write
- __writeback_single_inode
- do_writepages
- f2fs_write_cache_pages
- f2fs_write_single_data_page
- f2fs_do_write_data_page
: write atomic_file's data to cow_inode
- f2fs_gc
- gc_data_segment
- move_data_page
- set_page_dirty
- writepages
- f2fs_do_write_data_page
: overwrite atomic_file's data to cow_inode
- f2fs_ioc_commit_atomic_write
In above cases racing in between atomic_write and GC, previous
data in atomic_file may be overwrited to cow_file, result in
data corruption.
This patch introduces PAGE_PRIVATE_ATOMIC_WRITE bit flag in page.private,
and use it to indicate that there is last dirty data in atomic file,
and the data should be writebacked into cow_file, if the flag is not
tagged in page, we should never write data across files.
Fixes:
|
||
|---|---|---|
| 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 | ||
| .editorconfig | ||
| .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 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.