Re: [PATCH v5 1/2] f2fs: fix to avoid broken of dnode block list
From: Chao Yu
Date: Sat Jul 28 2018 - 22:55:19 EST
On 2018/7/29 10:49, Jaegeuk Kim wrote:
> On 07/29, Chao Yu wrote:
>> On 2018/7/29 9:33, Jaegeuk Kim wrote:
>>> On 07/28, Chao Yu wrote:
>>>> f2fs recovery flow is relying on dnode block link list, it means fsynced
>>>> file recovery depends on previous dnode's persistence in the list, so
>>>> during fsync() we should wait on all regular inode's dnode writebacked
>>>> before issuing flush.
>>>>
>>>> By this way, we can avoid dnode block list being broken by out-of-order
>>>> IO submission due to IO scheduler or driver.
>>>>
>>>> Sheng Yong helps to do the test with this patch:
>>>>
>>>> Target:/data (f2fs, -)
>>>> 64MB / 32768KB / 4KB / 8
>>>>
>>>> 1 / PERSIST / Index
>>>>
>>>> Base:
>>>> SEQ-RD(MB/s) SEQ-WR(MB/s) RND-RD(IOPS) RND-WR(IOPS) Insert(TPS) Update(TPS) Delete(TPS)
>>>> 1 867.82 204.15 41440.03 41370.54 680.8 1025.94 1031.08
>>>> 2 871.87 205.87 41370.3 40275.2 791.14 1065.84 1101.7
>>>> 3 866.52 205.69 41795.67 40596.16 694.69 1037.16 1031.48
>>>> Avg 868.7366667 205.2366667 41535.33333 40747.3 722.21 1042.98 1054.753333
>>>>
>>>> After:
>>>> SEQ-RD(MB/s) SEQ-WR(MB/s) RND-RD(IOPS) RND-WR(IOPS) Insert(TPS) Update(TPS) Delete(TPS)
>>>> 1 798.81 202.5 41143 40613.87 602.71 838.08 913.83
>>>> 2 805.79 206.47 40297.2 41291.46 604.44 840.75 924.27
>>>> 3 814.83 206.17 41209.57 40453.62 602.85 834.66 927.91
>>>> Avg 806.4766667 205.0466667 40883.25667 40786.31667 603.3333333 837.83 922.0033333
>>>>
>>>> Patched/Original:
>>>> 0.928332713 0.999074239 0.984300676 1.000957528 0.835398753 0.803303994 0.874141189
>>>
>>> I expect Sheng will provide more test results tho, at least it seems SEQ-RD
>>> in Base shows better than two After results, even if it doesn't matter with
>>> the issue. Please confirm it first in order for anybody to say there is no
>>> regression.
>>
>> Agreed.
>
> Hmm, this patch breaks fault injection test where gives a panic in put_super
> having fsync_node_num.
Let me do the test and fix it.
Thanks,
>
>>
>> Thanks,
>>
>>>
>>>>
>>>> It looks like atomic write will suffer performance regression.
>>>>
>>>> I suspect that the criminal is that we forcing to wait all dnode being in
>>>> storage cache before we issue PREFLUSH+FUA.
>>>>
>>>> BTW, will commit ("f2fs: don't need to wait for node writes for atomic write")
>>>> cause the problem: we will lose data of last transaction after SPO, even if
>>>> atomic write return no error:
>>>>
>>>> - atomic_open();
>>>> - write() P1, P2, P3;
>>>> - atomic_commit();
>>>> - writeback data: P1, P2, P3;
>>>> - writeback node: N1, N2, N3; <--- If N1, N2 is not writebacked, N3 with fsync_mark is
>>>> writebacked, In SPOR, we won't find N3 since node chain is broken, turns out that losing
>>>> last transaction.
>>>> - preflush + fua;
>>>> - power-cut
>>>>
>>>> If we don't wait dnode writeback for atomic_write:
>>>>
>>>> SEQ-RD(MB/s) SEQ-WR(MB/s) RND-RD(IOPS) RND-WR(IOPS) Insert(TPS) Update(TPS) Delete(TPS)
>>>> 1 779.91 206.03 41621.5 40333.16 716.9 1038.21 1034.85
>>>> 2 848.51 204.35 40082.44 39486.17 791.83 1119.96 1083.77
>>>> 3 772.12 206.27 41335.25 41599.65 723.29 1055.07 971.92
>>>> Avg 800.18 205.55 41013.06333 40472.99333 744.0066667 1071.08 1030.18
>>>>
>>>> Patched/Original:
>>>> 0.92108464 1.001526693 0.987425886 0.993268102 1.030180511 1.026942031 0.976702294
>>>>
>>>> SQLite's performance recovers.
>>>>
>>>> Jaegeuk:
>>>> "Practically, I don't see db corruption becase of this. We can excuse to lose
>>>> the last transaction."
>>>>
>>>> Finally, we decide to keep original implementation of atomic write interface
>>>> sematics that we don't wait all dnode writeback before preflush+fua submission.
>>>>
>>>> Tested-by: Sheng Yong <shengyong1@xxxxxxxxxx>
>>>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>>>> ---
>>>> v5:
>>>> - add missing Tested-by.
>>>> - fix f2fs_reset_fsync_node_info() to reset sbi->fsync_seg_id correctly.
>>>> fs/f2fs/checkpoint.c | 2 +
>>>> fs/f2fs/data.c | 2 +
>>>> fs/f2fs/f2fs.h | 21 ++++++-
>>>> fs/f2fs/file.c | 5 +-
>>>> fs/f2fs/node.c | 144 +++++++++++++++++++++++++++++++++++--------
>>>> fs/f2fs/super.c | 4 ++
>>>> 6 files changed, 150 insertions(+), 28 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
>>>> index 581710760ba6..2136430f9f0d 100644
>>>> --- a/fs/f2fs/checkpoint.c
>>>> +++ b/fs/f2fs/checkpoint.c
>>>> @@ -1410,6 +1410,8 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
>>>>
>>>> f2fs_release_ino_entry(sbi, false);
>>>>
>>>> + f2fs_reset_fsync_node_info(sbi);
>>>> +
>>>> clear_sbi_flag(sbi, SBI_IS_DIRTY);
>>>> clear_sbi_flag(sbi, SBI_NEED_CP);
>>>> __set_cp_next_pack(sbi);
>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>>> index 6b8ca5011bfd..572c91e43337 100644
>>>> --- a/fs/f2fs/data.c
>>>> +++ b/fs/f2fs/data.c
>>>> @@ -177,6 +177,8 @@ static void f2fs_write_end_io(struct bio *bio)
>>>> page->index != nid_of_node(page));
>>>>
>>>> dec_page_count(sbi, type);
>>>> + if (f2fs_in_warm_node_list(sbi, page))
>>>> + f2fs_del_fsync_node_entry(sbi, page);
>>>> clear_cold_data(page);
>>>> end_page_writeback(page);
>>>> }
>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>>> index 0374f069520c..6627fef9ae38 100644
>>>> --- a/fs/f2fs/f2fs.h
>>>> +++ b/fs/f2fs/f2fs.h
>>>> @@ -228,6 +228,12 @@ struct inode_entry {
>>>> struct inode *inode; /* vfs inode pointer */
>>>> };
>>>>
>>>> +struct fsync_node_entry {
>>>> + struct list_head list; /* list head */
>>>> + struct page *page; /* warm node page pointer */
>>>> + unsigned int seq_id; /* sequence id */
>>>> +};
>>>> +
>>>> /* for the bitmap indicate blocks to be discarded */
>>>> struct discard_entry {
>>>> struct list_head list; /* list head */
>>>> @@ -1156,6 +1162,11 @@ struct f2fs_sb_info {
>>>>
>>>> struct inode_management im[MAX_INO_ENTRY]; /* manage inode cache */
>>>>
>>>> + spinlock_t fsync_node_lock; /* for node entry lock */
>>>> + struct list_head fsync_node_list; /* node list head */
>>>> + unsigned int fsync_seg_id; /* sequence id */
>>>> + unsigned int fsync_node_num; /* number of node entries */
>>>> +
>>>> /* for orphan inode, use 0'th array */
>>>> unsigned int max_orphans; /* max orphan inodes */
>>>>
>>>> @@ -2822,6 +2833,10 @@ struct node_info;
>>>>
>>>> int f2fs_check_nid_range(struct f2fs_sb_info *sbi, nid_t nid);
>>>> bool f2fs_available_free_memory(struct f2fs_sb_info *sbi, int type);
>>>> +bool f2fs_in_warm_node_list(struct f2fs_sb_info *sbi, struct page *page);
>>>> +void f2fs_init_fsync_node_info(struct f2fs_sb_info *sbi);
>>>> +void f2fs_del_fsync_node_entry(struct f2fs_sb_info *sbi, struct page *page);
>>>> +void f2fs_reset_fsync_node_info(struct f2fs_sb_info *sbi);
>>>> int f2fs_need_dentry_mark(struct f2fs_sb_info *sbi, nid_t nid);
>>>> bool f2fs_is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid);
>>>> bool f2fs_need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino);
>>>> @@ -2831,7 +2846,8 @@ pgoff_t f2fs_get_next_page_offset(struct dnode_of_data *dn, pgoff_t pgofs);
>>>> int f2fs_get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode);
>>>> int f2fs_truncate_inode_blocks(struct inode *inode, pgoff_t from);
>>>> int f2fs_truncate_xattr_node(struct inode *inode);
>>>> -int f2fs_wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino);
>>>> +int f2fs_wait_on_node_pages_writeback(struct f2fs_sb_info *sbi,
>>>> + unsigned int seq_id);
>>>> int f2fs_remove_inode_page(struct inode *inode);
>>>> struct page *f2fs_new_inode_page(struct inode *inode);
>>>> struct page *f2fs_new_node_page(struct dnode_of_data *dn, unsigned int ofs);
>>>> @@ -2840,7 +2856,8 @@ struct page *f2fs_get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid);
>>>> struct page *f2fs_get_node_page_ra(struct page *parent, int start);
>>>> void f2fs_move_node_page(struct page *node_page, int gc_type);
>>>> int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>>>> - struct writeback_control *wbc, bool atomic);
>>>> + struct writeback_control *wbc, bool atomic,
>>>> + unsigned int *seq_id);
>>>> int f2fs_sync_node_pages(struct f2fs_sb_info *sbi,
>>>> struct writeback_control *wbc,
>>>> bool do_balance, enum iostat_type io_type);
>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>>> index 8f9ab66858ca..7bd2412a8c37 100644
>>>> --- a/fs/f2fs/file.c
>>>> +++ b/fs/f2fs/file.c
>>>> @@ -213,6 +213,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
>>>> .nr_to_write = LONG_MAX,
>>>> .for_reclaim = 0,
>>>> };
>>>> + unsigned int seq_id = 0;
>>>>
>>>> if (unlikely(f2fs_readonly(inode->i_sb)))
>>>> return 0;
>>>> @@ -275,7 +276,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
>>>> }
>>>> sync_nodes:
>>>> atomic_inc(&sbi->wb_sync_req[NODE]);
>>>> - ret = f2fs_fsync_node_pages(sbi, inode, &wbc, atomic);
>>>> + ret = f2fs_fsync_node_pages(sbi, inode, &wbc, atomic, &seq_id);
>>>> atomic_dec(&sbi->wb_sync_req[NODE]);
>>>> if (ret)
>>>> goto out;
>>>> @@ -301,7 +302,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
>>>> * given fsync mark.
>>>> */
>>>> if (!atomic) {
>>>> - ret = f2fs_wait_on_node_pages_writeback(sbi, ino);
>>>> + ret = f2fs_wait_on_node_pages_writeback(sbi, seq_id);
>>>> if (ret)
>>>> goto out;
>>>> }
>>>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>>>> index 9d9f4c9750c4..e109c671cd84 100644
>>>> --- a/fs/f2fs/node.c
>>>> +++ b/fs/f2fs/node.c
>>>> @@ -28,6 +28,7 @@
>>>> static struct kmem_cache *nat_entry_slab;
>>>> static struct kmem_cache *free_nid_slab;
>>>> static struct kmem_cache *nat_entry_set_slab;
>>>> +static struct kmem_cache *fsync_node_entry_slab;
>>>>
>>>> /*
>>>> * Check whether the given nid is within node id range.
>>>> @@ -264,6 +265,72 @@ static unsigned int __gang_lookup_nat_set(struct f2fs_nm_info *nm_i,
>>>> start, nr);
>>>> }
>>>>
>>>> +bool f2fs_in_warm_node_list(struct f2fs_sb_info *sbi, struct page *page)
>>>> +{
>>>> + return NODE_MAPPING(sbi) == page->mapping &&
>>>> + IS_DNODE(page) && is_cold_node(page);
>>>> +}
>>>> +
>>>> +void f2fs_init_fsync_node_info(struct f2fs_sb_info *sbi)
>>>> +{
>>>> + spin_lock_init(&sbi->fsync_node_lock);
>>>> + INIT_LIST_HEAD(&sbi->fsync_node_list);
>>>> + sbi->fsync_seg_id = 0;
>>>> + sbi->fsync_node_num = 0;
>>>> +}
>>>> +
>>>> +static unsigned int f2fs_add_fsync_node_entry(struct f2fs_sb_info *sbi,
>>>> + struct page *page)
>>>> +{
>>>> + struct fsync_node_entry *fn;
>>>> + unsigned long flags;
>>>> + unsigned int seq_id;
>>>> +
>>>> + fn = f2fs_kmem_cache_alloc(fsync_node_entry_slab, GFP_NOFS);
>>>> +
>>>> + get_page(page);
>>>> + fn->page = page;
>>>> + INIT_LIST_HEAD(&fn->list);
>>>> +
>>>> + spin_lock_irqsave(&sbi->fsync_node_lock, flags);
>>>> + list_add_tail(&fn->list, &sbi->fsync_node_list);
>>>> + fn->seq_id = sbi->fsync_seg_id++;
>>>> + seq_id = fn->seq_id;
>>>> + sbi->fsync_node_num++;
>>>> + spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
>>>> +
>>>> + return seq_id;
>>>> +}
>>>> +
>>>> +void f2fs_del_fsync_node_entry(struct f2fs_sb_info *sbi, struct page *page)
>>>> +{
>>>> + struct fsync_node_entry *fn;
>>>> + unsigned long flags;
>>>> +
>>>> + spin_lock_irqsave(&sbi->fsync_node_lock, flags);
>>>> + list_for_each_entry(fn, &sbi->fsync_node_list, list) {
>>>> + if (fn->page == page) {
>>>> + list_del(&fn->list);
>>>> + sbi->fsync_node_num--;
>>>> + spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
>>>> + kmem_cache_free(fsync_node_entry_slab, fn);
>>>> + put_page(page);
>>>> + return;
>>>> + }
>>>> + }
>>>> + spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
>>>> + f2fs_bug_on(sbi, 1);
>>>> +}
>>>> +
>>>> +void f2fs_reset_fsync_node_info(struct f2fs_sb_info *sbi)
>>>> +{
>>>> + unsigned long flags;
>>>> +
>>>> + spin_lock_irqsave(&sbi->fsync_node_lock, flags);
>>>> + sbi->fsync_seg_id = 0;
>>>> + spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
>>>> +}
>>>> +
>>>> int f2fs_need_dentry_mark(struct f2fs_sb_info *sbi, nid_t nid)
>>>> {
>>>> struct f2fs_nm_info *nm_i = NM_I(sbi);
>>>> @@ -1384,7 +1451,7 @@ static struct page *last_fsync_dnode(struct f2fs_sb_info *sbi, nid_t ino)
>>>>
>>>> static int __write_node_page(struct page *page, bool atomic, bool *submitted,
>>>> struct writeback_control *wbc, bool do_balance,
>>>> - enum iostat_type io_type)
>>>> + enum iostat_type io_type, unsigned int *seq_id)
>>>> {
>>>> struct f2fs_sb_info *sbi = F2FS_P_SB(page);
>>>> nid_t nid;
>>>> @@ -1401,6 +1468,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
>>>> .io_type = io_type,
>>>> .io_wbc = wbc,
>>>> };
>>>> + unsigned int seq;
>>>>
>>>> trace_f2fs_writepage(page, NODE);
>>>>
>>>> @@ -1442,6 +1510,13 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
>>>>
>>>> set_page_writeback(page);
>>>> ClearPageError(page);
>>>> +
>>>> + if (f2fs_in_warm_node_list(sbi, page)) {
>>>> + seq = f2fs_add_fsync_node_entry(sbi, page);
>>>> + if (seq_id)
>>>> + *seq_id = seq;
>>>> + }
>>>> +
>>>> fio.old_blkaddr = ni.blk_addr;
>>>> f2fs_do_write_node_page(nid, &fio);
>>>> set_node_addr(sbi, &ni, fio.new_blkaddr, is_fsync_dnode(page));
>>>> @@ -1489,7 +1564,7 @@ void f2fs_move_node_page(struct page *node_page, int gc_type)
>>>> goto out_page;
>>>>
>>>> if (__write_node_page(node_page, false, NULL,
>>>> - &wbc, false, FS_GC_NODE_IO))
>>>> + &wbc, false, FS_GC_NODE_IO, NULL))
>>>> unlock_page(node_page);
>>>> goto release_page;
>>>> } else {
>>>> @@ -1506,11 +1581,13 @@ void f2fs_move_node_page(struct page *node_page, int gc_type)
>>>> static int f2fs_write_node_page(struct page *page,
>>>> struct writeback_control *wbc)
>>>> {
>>>> - return __write_node_page(page, false, NULL, wbc, false, FS_NODE_IO);
>>>> + return __write_node_page(page, false, NULL, wbc, false,
>>>> + FS_NODE_IO, NULL);
>>>> }
>>>>
>>>> int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>>>> - struct writeback_control *wbc, bool atomic)
>>>> + struct writeback_control *wbc, bool atomic,
>>>> + unsigned int *seq_id)
>>>> {
>>>> pgoff_t index;
>>>> pgoff_t last_idx = ULONG_MAX;
>>>> @@ -1591,7 +1668,7 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>>>> ret = __write_node_page(page, atomic &&
>>>> page == last_page,
>>>> &submitted, wbc, true,
>>>> - FS_NODE_IO);
>>>> + FS_NODE_IO, seq_id);
>>>> if (ret) {
>>>> unlock_page(page);
>>>> f2fs_put_page(last_page, 0);
>>>> @@ -1708,7 +1785,7 @@ int f2fs_sync_node_pages(struct f2fs_sb_info *sbi,
>>>> set_dentry_mark(page, 0);
>>>>
>>>> ret = __write_node_page(page, false, &submitted,
>>>> - wbc, do_balance, io_type);
>>>> + wbc, do_balance, io_type, NULL);
>>>> if (ret)
>>>> unlock_page(page);
>>>> else if (submitted)
>>>> @@ -1739,35 +1816,46 @@ int f2fs_sync_node_pages(struct f2fs_sb_info *sbi,
>>>> return ret;
>>>> }
>>>>
>>>> -int f2fs_wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
>>>> +int f2fs_wait_on_node_pages_writeback(struct f2fs_sb_info *sbi,
>>>> + unsigned int seq_id)
>>>> {
>>>> - pgoff_t index = 0;
>>>> - struct pagevec pvec;
>>>> + struct fsync_node_entry *fn;
>>>> + struct page *page;
>>>> + struct list_head *head = &sbi->fsync_node_list;
>>>> + unsigned long flags;
>>>> + unsigned int cur_seq_id = 0;
>>>> int ret2, ret = 0;
>>>> - int nr_pages;
>>>>
>>>> - pagevec_init(&pvec);
>>>> + while (seq_id && cur_seq_id < seq_id) {
>>>> + spin_lock_irqsave(&sbi->fsync_node_lock, flags);
>>>> + if (list_empty(head)) {
>>>> + spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
>>>> + break;
>>>> + }
>>>> + fn = list_first_entry(head, struct fsync_node_entry, list);
>>>> + if (fn->seq_id > seq_id) {
>>>> + spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
>>>> + break;
>>>> + }
>>>> + cur_seq_id = fn->seq_id;
>>>> + page = fn->page;
>>>> + get_page(page);
>>>> + spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
>>>>
>>>> - while ((nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
>>>> - PAGECACHE_TAG_WRITEBACK))) {
>>>> - int i;
>>>> + f2fs_wait_on_page_writeback(page, NODE, true);
>>>> + if (TestClearPageError(page))
>>>> + ret = -EIO;
>>>>
>>>> - for (i = 0; i < nr_pages; i++) {
>>>> - struct page *page = pvec.pages[i];
>>>> + put_page(page);
>>>>
>>>> - if (ino && ino_of_node(page) == ino) {
>>>> - f2fs_wait_on_page_writeback(page, NODE, true);
>>>> - if (TestClearPageError(page))
>>>> - ret = -EIO;
>>>> - }
>>>> - }
>>>> - pagevec_release(&pvec);
>>>> - cond_resched();
>>>> + if (ret)
>>>> + break;
>>>> }
>>>>
>>>> ret2 = filemap_check_errors(NODE_MAPPING(sbi));
>>>> if (!ret)
>>>> ret = ret2;
>>>> +
>>>> return ret;
>>>> }
>>>>
>>>> @@ -2982,8 +3070,15 @@ int __init f2fs_create_node_manager_caches(void)
>>>> sizeof(struct nat_entry_set));
>>>> if (!nat_entry_set_slab)
>>>> goto destroy_free_nid;
>>>> +
>>>> + fsync_node_entry_slab = f2fs_kmem_cache_create("fsync_node_entry",
>>>> + sizeof(struct fsync_node_entry));
>>>> + if (!fsync_node_entry_slab)
>>>> + goto destroy_nat_entry_set;
>>>> return 0;
>>>>
>>>> +destroy_nat_entry_set:
>>>> + kmem_cache_destroy(nat_entry_set_slab);
>>>> destroy_free_nid:
>>>> kmem_cache_destroy(free_nid_slab);
>>>> destroy_nat_entry:
>>>> @@ -2994,6 +3089,7 @@ int __init f2fs_create_node_manager_caches(void)
>>>>
>>>> void f2fs_destroy_node_manager_caches(void)
>>>> {
>>>> + kmem_cache_destroy(fsync_node_entry_slab);
>>>> kmem_cache_destroy(nat_entry_set_slab);
>>>> kmem_cache_destroy(free_nid_slab);
>>>> kmem_cache_destroy(nat_entry_slab);
>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>>> index 0eff4637fe55..cb1ba9f18353 100644
>>>> --- a/fs/f2fs/super.c
>>>> +++ b/fs/f2fs/super.c
>>>> @@ -1030,6 +1030,8 @@ static void f2fs_put_super(struct super_block *sb)
>>>> */
>>>> f2fs_release_ino_entry(sbi, true);
>>>>
>>>> + f2fs_bug_on(sbi, sbi->fsync_node_num);
>>>> +
>>>> f2fs_leave_shrinker(sbi);
>>>> mutex_unlock(&sbi->umount_mutex);
>>>>
>>>> @@ -2923,6 +2925,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>>>>
>>>> f2fs_init_ino_entry_info(sbi);
>>>>
>>>> + f2fs_init_fsync_node_info(sbi);
>>>> +
>>>> /* setup f2fs internal modules */
>>>> err = f2fs_build_segment_manager(sbi);
>>>> if (err) {
>>>> --
>>>> 2.18.0.rc1