2bebc6dcd3
[ Upstream commit 3afae09ffea5e08f523823be99a784675995d6bb ]
generic/269 reports a hangtask issue, the root cause is ABBA deadlock
described as below:
Thread A Thread B
- down_write(&sbi->gc_lock) -- A
- f2fs_write_data_pages
- lock all pages in cluster -- B
- f2fs_write_multi_pages
- f2fs_write_raw_pages
- f2fs_write_single_data_page
- f2fs_balance_fs
- down_write(&sbi->gc_lock) -- A
- f2fs_gc
- do_garbage_collect
- ra_data_block
- pagecache_get_page -- B
To fix this, it needs to avoid calling f2fs_balance_fs() if there is
still cluster pages been locked in context of cluster writeback, so
instead, let's call f2fs_balance_fs() in the end of
f2fs_write_raw_pages() when all cluster pages were unlocked.
Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.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 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.