On 07/14, Chao Yu wrote: > On 2020/7/14 1:59, Jaegeuk Kim wrote: > > On 07/10, Chao Yu wrote: > >> On 2020/7/10 11:50, Jaegeuk Kim wrote: > >>> On 07/10, Chao Yu wrote: > >>>> On 2020/7/10 11:26, Jaegeuk Kim wrote: > >>>>> On 07/10, Chao Yu wrote: > >>>>>> On 2020/7/10 3:05, Jaegeuk Kim wrote: > >>>>>>> On 07/09, Chao Yu wrote: > >>>>>>>> On 2020/7/9 13:30, Jaegeuk Kim wrote: > >>>>>>>>> It doesn't need to bypass flushing quota data in background. > >>>>>>>> > >>>>>>>> The condition is used to flush quota data in batch to avoid random > >>>>>>>> small-sized udpate, did you hit any problem here? > >>>>>>> > >>>>>>> I suspect this causes fault injection test being stuck by waiting for > >>>>>>> inode > >>>>>>> writeback completion. With this patch, it has been running w/o any > >>>>>>> issue so far. > >>>>>>> I keep an eye on this. > >>>>>> > >>>>>> Hmmm.. so that this patch may not fix the root cause, and it may > >>>>>> hiding the > >>>>>> issue deeper. > >>>>>> > >>>>>> How about just keeping this patch in our private branch to let fault > >>>>>> injection > >>>>>> test not be stuck? until we find the root cause in upstream codes. > >>>>> > >>>>> Well, I don't think this hides something. When the issue happens, I saw > >>>>> inodes > >>>>> being stuck due to writeback while only quota has some dirty data. At > >>>>> that time, > >>>>> there was no dirty data page from other inodes. > >>>> > >>>> Okay, > >>>> > >>>>> > >>>>> More specifically, I suspect __writeback_inodes_sb_nr() gives > >>>>> WB_SYNC_NONE and > >>>>> waits for wb_wait_for_completion(). > >>>> > >>>> Did you record any callstack after the issue happened? > >>> > >>> I found this. > >>> > >>> [213389.297642] __schedule+0x2dd/0x780^M > >>> [213389.299224] schedule+0x55/0xc0^M > >>> [213389.300745] wb_wait_for_completion+0x56/0x90^M > >>> [213389.302469] ? wait_woken+0x80/0x80^M > >>> [213389.303997] __writeback_inodes_sb_nr+0xa8/0xd0^M > >>> [213389.305760] writeback_inodes_sb+0x4b/0x60^M > >>> [213389.307439] sync_filesystem+0x2e/0xa0^M > >>> [213389.308999] generic_shutdown_super+0x27/0x110^M > >>> [213389.310738] kill_block_super+0x27/0x50^M > >>> [213389.312327] kill_f2fs_super+0x76/0xe0 [f2fs]^M > >>> [213389.314014] deactivate_locked_super+0x3b/0x80^M > >>> [213389.315692] deactivate_super+0x3e/0x50^M > >>> [213389.317226] cleanup_mnt+0x109/0x160^M > >>> [213389.318718] __cleanup_mnt+0x12/0x20^M > >>> [213389.320177] task_work_run+0x70/0xb0^M > >>> [213389.321609] exit_to_usermode_loop+0x131/0x160^M > >>> [213389.323306] do_syscall_64+0x170/0x1b0^M > >>> [213389.324762] entry_SYSCALL_64_after_hwframe+0x44/0xa9^M > >>> [213389.326477] RIP: 0033:0x7fc4b5e6a35b^M > >> > >> Does this only happen during umount? If so, will below change help? > >> > >> if ((S_ISDIR(inode->i_mode) || IS_NOQUOTA(inode)) && > >> + !is_sbi_flag_set(sbi, SBI_IS_CLOSE) && > >> wbc->sync_mode == WB_SYNC_NONE && > >> get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) && > >> f2fs_available_free_memory(sbi, DIRTY_DENTS)) > >> goto skip_write; > > > > Hmm, this doesn't work. The writeback was called before put_super? > > Oops, still be confused about this issue. :(
Huam, I hit the problem with the patch. I need to return back and think in other way. :( > > Thanks, > > > I'll try the original patch one more time. > > > >> > >>> > >>>> > >>>> Still I'm confused that why directory's data written could be skipped, > >>>> but > >>>> quota's data couldn't, what's the difference? > >>> > >>> I suspect different blocking timing from cp_error between quota and > >>> dentry. > >>> e.g., we block dir operations right after cp_error, while quota can make > >> > >> No guarantee that there is no dirty dentry being created after > >> cp_error, right? > >> > >> e.g. > >> > >> Thread A Thread B > >> - f2fs_create > >> - bypass f2fs_cp_error > >> - set cp_error > >> - create dirty dentry > >> > >> BTW, do you know what __writeback_inodes_sb_nr is waiting for? > >> > >>> dirty pages in more fine granularity. > >>> > >>>> > >>>>> > >>>>>> > >>>>>> Thanks, > >>>>>> > >>>>>>> > >>>>>>> Thanks, > >>>>>>> > >>>>>>>> > >>>>>>>> Thanks, > >>>>>>>> > >>>>>>>>> > >>>>>>>>> Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org> > >>>>>>>>> --- > >>>>>>>>> fs/f2fs/data.c | 2 +- > >>>>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>>>>>>>> > >>>>>>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > >>>>>>>>> index 44645f4f914b6..72e8b50e588c1 100644 > >>>>>>>>> --- a/fs/f2fs/data.c > >>>>>>>>> +++ b/fs/f2fs/data.c > >>>>>>>>> @@ -3148,7 +3148,7 @@ static int __f2fs_write_data_pages(struct > >>>>>>>>> address_space *mapping, > >>>>>>>>> if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING))) > >>>>>>>>> goto skip_write; > >>>>>>>>> > >>>>>>>>> - if ((S_ISDIR(inode->i_mode) || IS_NOQUOTA(inode)) && > >>>>>>>>> + if (S_ISDIR(inode->i_mode) && > >>>>>>>>> wbc->sync_mode == WB_SYNC_NONE && > >>>>>>>>> get_dirty_pages(inode) < nr_pages_to_skip(sbi, > >>>>>>>>> DATA) && > >>>>>>>>> f2fs_available_free_memory(sbi, DIRTY_DENTS)) > >>>>>>>>> > >>>>>>> . > >>>>>>> > >>>>> . > >>>>> > >>> . > >>> > > . > >
