8deca17920
[ Upstream commit c5d3f9b7649abb20aa5ab3ebff9421a171eaeb22 ]
With below mount option and testcase, it hangs kernel.
1. mount -t f2fs -o compress_log_size=5 /dev/vdb /mnt/f2fs
2. touch /mnt/f2fs/file
3. chattr +c /mnt/f2fs/file
4. dd if=/dev/zero of=/mnt/f2fs/file bs=1MB count=1
5. sync
6. dd if=/dev/zero of=/mnt/f2fs/file bs=111 count=11 conv=notrunc
7. sync
INFO: task sync:4788 blocked for more than 120 seconds.
Not tainted 6.5.0-rc1+ #322
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:sync state:D stack:0 pid:4788 ppid:509 flags:0x00000002
Call Trace:
<TASK>
__schedule+0x335/0xf80
schedule+0x6f/0xf0
wb_wait_for_completion+0x5e/0x90
sync_inodes_sb+0xd8/0x2a0
sync_inodes_one_sb+0x1d/0x30
iterate_supers+0x99/0xf0
ksys_sync+0x46/0xb0
__do_sys_sync+0x12/0x20
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
The reason is f2fs_all_cluster_page_ready() assumes that pages array should
cover at least one cluster, otherwise, it will always return false, result
in deadloop.
By default, pages array size is 16, and it can cover the case cluster_size
is equal or less than 16, for the case cluster_size is larger than 16, let's
allocate memory of pages array dynamically.
Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <chao@kernel.org>
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.