On 07/16, Chao Yu wrote: > On 2020/7/16 3:10, Jaegeuk Kim wrote: > > 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. :( > > Still quota data was left? what about dentry?
Huh, at this time, only node and meta pages were left as dirty. > > Thanks, > > > > >> > >> 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)) > >>>>>>>>>>> > >>>>>>>>> . > >>>>>>>>> > >>>>>>> . > >>>>>>> > >>>>> . > >>>>> > >>> . > >>> > > . > >
