Messages in this thread Patch in this message | | | Date | Fri, 29 May 2020 15:34:26 -0700 | From | Jaegeuk Kim <> | Subject | Re: [PATCH] Revert "f2fs: fix quota_sync failure due to f2fs_lock_op" |
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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.
--- fs/f2fs/segment.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index ebbadde6cbced..f67cffc38975e 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -3095,6 +3095,14 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, struct curseg_info *curseg = CURSEG_I(sbi, type); bool put_pin_sem = false; + /* + * 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); + if (type == CURSEG_COLD_DATA) { /* GC during CURSEG_COLD_DATA_PINNED allocation */ if (down_read_trylock(&sbi->pin_sem)) { @@ -3174,6 +3182,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, 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) -- 2.27.0.rc0.183.gde8f92d652-goog
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