Messages in this thread | | | Subject | Re: [PATCH] Revert "f2fs: fix quota_sync failure due to f2fs_lock_op" | From | Chao Yu <> | Date | Sat, 30 May 2020 10:02:57 +0800 |
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On 2020/5/30 9:49, Jaegeuk Kim wrote: > On 05/30, Chao Yu wrote: >> On 2020/5/30 6:34, Jaegeuk Kim wrote: >>> On 05/29, Chao Yu wrote: >>>> Under heavy fsstress, we may triggle panic while issuing discard, >>>> because __check_sit_bitmap() detects that discard command may earse >>>> valid data blocks, the root cause is as below race stack described, >>>> since we removed lock when flushing quota data, quota data writeback >>>> may race with write_checkpoint(), so that it causes inconsistency in >>>> between cached discard entry and segment bitmap. >>>> >>>> - f2fs_write_checkpoint >>>> - block_operations >>>> - set_sbi_flag(sbi, SBI_QUOTA_SKIP_FLUSH) >>>> - f2fs_flush_sit_entries >>>> - add_discard_addrs >>>> - __set_bit_le(i, (void *)de->discard_map); >>>> - f2fs_write_data_pages >>>> - f2fs_write_single_data_page >>>> : inode is quota one, cp_rwsem won't be locked >>>> - f2fs_do_write_data_page >>>> - f2fs_allocate_data_block >>>> - f2fs_wait_discard_bio >>>> : discard entry has not been added yet. >>>> - update_sit_entry >>>> - f2fs_clear_prefree_segments >>>> - f2fs_issue_discard >>>> : add discard entry >>>> >>>> This patch fixes this issue by reverting 435cbab95e39 ("f2fs: fix quota_sync >>>> failure due to f2fs_lock_op"). >>>> >>>> Fixes: 435cbab95e39 ("f2fs: fix quota_sync failure due to f2fs_lock_op") >>> >>> The previous patch fixes quota_sync gets EAGAIN all the time. >>> How about this? It seems this works for fsstress test. >>> > > Then this? > > --- > fs/f2fs/segment.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index ebbadde6cbced..ed11dcf2d69ed 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -3107,6 +3107,14 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, > type = CURSEG_COLD_DATA; > } > > + /* > + * We need to wait for node_write to avoid block allocation during > + * checkpoint. This can only happen to quota writes which can cause > + * the below discard race condition. > + */ > + if (IS_DATASEG(type)) > + down_write(&sbi->node_write); > + > down_read(&SM_I(sbi)->curseg_lock); > > mutex_lock(&curseg->curseg_mutex); > @@ -3174,6 +3182,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
Minor thing: unlock order.
if (IS_DATASEG(type)) up_write(&sbi->node_write);
Could you merge the diff into this patch?
> > if (put_pin_sem) > up_read(&sbi->pin_sem); > + > + if (IS_DATASEG(type)) > + up_write(&sbi->node_write); > } > > static void update_device_state(struct f2fs_io_info *fio) >
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