Re: [PATCH v5 1/2] f2fs: fix to avoid broken of dnode block list
From: Jaegeuk Kim
Date: Sat Jul 28 2018 - 22:50:36 EST
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.
>
> 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