f2ba11ba93
commit 5079e1c0c879311668b77075de3e701869804adf upstream.
generic/082 reports a bug as below:
__schedule+0x332/0xf60
schedule+0x6f/0xf0
schedule_timeout+0x23b/0x2a0
wait_for_completion+0x8f/0x140
f2fs_issue_checkpoint+0xfe/0x1b0
f2fs_sync_fs+0x9d/0xb0
sync_filesystem+0x87/0xb0
dquot_load_quota_sb+0x41b/0x460
dquot_load_quota_inode+0xa5/0x130
dquot_quota_on+0x4b/0x60
f2fs_quota_on+0xe3/0x1b0
do_quotactl+0x483/0x700
__x64_sys_quotactl+0x15c/0x310
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
The root casue is race case as below:
Thread A Kworker IRQ
- write()
: write data to quota.user file
- writepages
- f2fs_submit_page_write
- __is_cp_guaranteed return false
- inc_page_count(F2FS_WB_DATA)
- submit_bio
- quotactl(Q_QUOTAON)
- f2fs_quota_on
- dquot_quota_on
- dquot_load_quota_inode
- vfs_setup_quota_inode
: inode->i_flags |= S_NOQUOTA
- f2fs_write_end_io
- __is_cp_guaranteed return true
- dec_page_count(F2FS_WB_CP_DATA)
- dquot_load_quota_sb
- f2fs_sync_fs
- f2fs_issue_checkpoint
- do_checkpoint
- f2fs_wait_on_all_pages(F2FS_WB_CP_DATA)
: loop due to F2FS_WB_CP_DATA count is negative
Calling filemap_fdatawrite() and filemap_fdatawait() to keep all data
clean before quota file setup.
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sergio González Collado <sergio.collado@gmail.com>
Reported-by: syzbot+d0ab8746c920a592aeab@syzkaller.appspotmail.com
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 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.