On 12/15, heyunlei wrote:
> 
> 
> >-----Original Message-----
> >From: Jaegeuk Kim [mailto:[email protected]]
> >Sent: Friday, December 15, 2017 12:21 PM
> >To: heyunlei
> >Cc: Yuchao (T); [email protected]; Wangbintian; Jianing 
> >(Euler)
> >Subject: Re: [f2fs-dev][PATCH RFC] f2fs: fix an error case of missing update 
> >inode page
> >
> >On 12/15, heyunlei wrote:
> >>
> >>
> >> >-----Original Message-----
> >> >From: Jaegeuk Kim [mailto:[email protected]]
> >> >Sent: Friday, December 15, 2017 3:46 AM
> >> >To: heyunlei
> >> >Cc: Yuchao (T); [email protected]; Wangbintian; 
> >> >Jianing (Euler)
> >> >Subject: Re: [f2fs-dev][PATCH RFC] f2fs: fix an error case of missing 
> >> >update inode page
> >> >
> >> >On 12/05, Yunlei He wrote:
> >> >> -Thread A                                       Thread B
> >> >>
> >> >> -write_checkpoint
> >> >>         -block_operations
> >> >>                 -f2fs_unlock_all                -f2fs_sync_file
> >> >>                                                         
> >> >> -f2fs_write_inode
> >> >>                                                                 
> >> >> -f2fs_inode_synced
> >> >>
> >> >>                         -f2fs_sync_inode_meta
> >> >>                                 -sync_node_pages
> >> >>                                                                         
> >> >> -set_page_drity
> >> >>
> >> >> In this case, if sudden power off without next new checkpoint,
> >> >> the last inode page update will lost. wb_writeback is same with
> >> >> fsync.
> >> >
> >> >Does this patch fix the problem?
> >> >
> >> I modify code as below:
> >> @@ -366,7 +366,7 @@ int update_inode(struct inode *inode, struct page 
> >> *node_page)
> >>         struct extent_tree *et = F2FS_I(inode)->extent_tree;
> >>
> >>         f2fs_inode_synced(inode);
> >> -
> >> +       msleep(10000);
> >>         f2fs_wait_on_page_writeback(node_page, NODE, true);
> >>
> >> shell 1:                                       shell2:
> >> dd if=/dev/zero of=./test bs=1M count=10
> >> sync
> >> echo "hello" >> ./test
> >> fsync test  // sleep 10s
> >>                                                     sync  //return quickly
> >>                                                                            
> >>          echo c > /proc/sysrq-trigger  //before fsync return
> >> fsck will find iblocks mismatch, and with this patch it 's ok.
> >
> >So, do you mean it was fixed by adding msleep() on top of this patch as well?
> >Like:
> >     - f2fs_write_inode()
> >             - set_page_drity
> >             - f2fs_inode_synced
> >             - msleep(10000);
> >
> Yes,  write_checkpoint will be blocked in sync dirty node pages, until fsync 
> update inode
> page and unlock node page.

Got it. I've concerned about inversion of PageDirty() and f2fs_inode_synced(),
but for now, I can't find any corner case simply. Let me do stress test with
this.

Thanks,

> 
> Thanks.
> >>
> >> Besides,I came across another error like this:
> >>
> >> f2fs_inode-> i_xattr_nid is non-zero, but node blkaddr in raw nat entry is 
> >> NULL.
> >>
> >> This case makes sense to this problem also.
> >>
> >> > -write_checkpoint
> >> >  -block_operations
> >> >          -f2fs_unlock_all                -f2fs_sync_file
> >> >                                                  -f2fs_write_inode
> >> >                                                          -set_page_drity
> >> >                                                          
> >> > -f2fs_inode_synced
> >> >                  -f2fs_sync_inode_meta
> >> >                          -sync_node_pages
> >> >
> >> >I think, we need to cover f2fs_lock_op() for f2fs_write_inode() again.
> >>
> >> It can also work well with f2fs_lock_op(), I am afraid other cases will 
> >> update inode
> >> like f2fs_write_inode without f2fs_lock_op
> >>
> >> Thanks
> >> >
> >> >Thanks,
> >> >
> >> >>
> >> >> Signed-off-by: Yunlei He <[email protected]>
> >> >> ---
> >> >>  fs/f2fs/f2fs.h  |  4 ++--
> >> >>  fs/f2fs/inode.c | 15 +++++++--------
> >> >>  2 files changed, 9 insertions(+), 10 deletions(-)
> >> >>
> >> >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> >> >> index 82f1dc3..38f9324 100644
> >> >> --- a/fs/f2fs/f2fs.h
> >> >> +++ b/fs/f2fs/f2fs.h
> >> >> @@ -2513,8 +2513,8 @@ int f2fs_getattr(const struct path *path, struct 
> >> >> kstat *stat,
> >> >>  struct inode *f2fs_iget(struct super_block *sb, unsigned long ino);
> >> >>  struct inode *f2fs_iget_retry(struct super_block *sb, unsigned long 
> >> >> ino);
> >> >>  int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink);
> >> >> -int update_inode(struct inode *inode, struct page *node_page);
> >> >> -int update_inode_page(struct inode *inode);
> >> >> +void update_inode(struct inode *inode, struct page *node_page);
> >> >> +void update_inode_page(struct inode *inode);
> >> >>  int f2fs_write_inode(struct inode *inode, struct writeback_control 
> >> >> *wbc);
> >> >>  void f2fs_evict_inode(struct inode *inode);
> >> >>  void handle_failed_inode(struct inode *inode);
> >> >> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> >> >> index b4c4f2b..10d3c7c 100644
> >> >> --- a/fs/f2fs/inode.c
> >> >> +++ b/fs/f2fs/inode.c
> >> >> @@ -360,14 +360,15 @@ struct inode *f2fs_iget_retry(struct super_block 
> >> >> *sb, unsigned long ino)
> >> >>         return inode;
> >> >>  }
> >> >>
> >> >> -int update_inode(struct inode *inode, struct page *node_page)
> >> >> +void update_inode(struct inode *inode, struct page *node_page)
> >> >>  {
> >> >>         struct f2fs_inode *ri;
> >> >>         struct extent_tree *et = F2FS_I(inode)->extent_tree;
> >> >>
> >> >> -       f2fs_inode_synced(inode);
> >> >> -
> >> >>         f2fs_wait_on_page_writeback(node_page, NODE, true);
> >> >> +       set_page_dirty(node_page);
> >> >> +
> >> >> +       f2fs_inode_synced(inode);
> >> >>
> >> >>         ri = F2FS_INODE(node_page);
> >> >>
> >> >> @@ -426,10 +427,9 @@ int update_inode(struct inode *inode, struct page 
> >> >> *node_page)
> >> >>         if (inode->i_nlink == 0)
> >> >>                 clear_inline_node(node_page);
> >> >>
> >> >> -       return set_page_dirty(node_page);
> >> >>  }
> >> >>
> >> >> -int update_inode_page(struct inode *inode)
> >> >> +void update_inode_page(struct inode *inode)
> >> >>  {
> >> >>         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> >> >>         struct page *node_page;
> >> >> @@ -444,11 +444,10 @@ int update_inode_page(struct inode *inode)
> >> >>                 } else if (err != -ENOENT) {
> >> >>                         f2fs_stop_checkpoint(sbi, false);
> >> >>                 }
> >> >> -               return 0;
> >> >> +               return;
> >> >>         }
> >> >> -       ret = update_inode(inode, node_page);
> >> >> +       update_inode(inode, node_page);
> >> >>         f2fs_put_page(node_page, 1);
> >> >> -       return ret;
> >> >>  }
> >> >>
> >> >>  int f2fs_write_inode(struct inode *inode, struct writeback_control 
> >> >> *wbc)
> >> >> --
> >> >> 1.9.1

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