0ecfe3974b
commit b40a2b00370931b0c50148681dd7364573e52e6b upstream.
The page cache of the atomic file keeps new data pages which will be
stored in the COW file. It can also keep old data pages when GCing the
atomic file. In this case, new data can be overwritten by old data if a
GC thread sets the old data page as dirty after new data page was
evicted.
Also, since all writes to the atomic file are redirected to COW inodes,
GC for the atomic file is not working well as below.
f2fs_gc(gc_type=FG_GC)
- select A as a victim segment
do_garbage_collect
- iget atomic file's inode for block B
move_data_page
f2fs_do_write_data_page
- use dn of cow inode
- set fio->old_blkaddr from cow inode
- seg_freed is 0 since block B is still valid
- goto gc_more and A is selected as victim again
To solve the problem, let's separate GC writes and updates in the atomic
file by using the meta inode for GC writes.
Fixes: 3db1de0e582c ("f2fs: change the current atomic write way")
Cc: stable@vger.kernel.org #v5.19+
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Yeongjin Gil <youngjin.gil@samsung.com>
Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.