linux-kernel - Re: [f2fs-dev] [PATCH v3] f2fs: avoid inifinite loop to wait for flushing node pages at cp

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Message-ID: <20200526015650.GA207949@google.com>
Date:   Mon, 25 May 2020 18:56:50 -0700
From:   Jaegeuk Kim <jaegeuk@...nel.org>
To:     Chao Yu <yuchao0@...wei.com>
Cc:     kernel-team@...roid.com, linux-kernel@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net
Subject: Re: [f2fs-dev] [PATCH v3] f2fs: avoid inifinite loop to wait for
 flushing node pages at cp_error

On 05/26, Chao Yu wrote:
> On 2020/5/26 9:11, Chao Yu wrote:
> > On 2020/5/25 23:06, Jaegeuk Kim wrote:
> >> On 05/25, Chao Yu wrote:
> >>> On 2020/5/25 11:56, Jaegeuk Kim wrote:
> >>>> Shutdown test is somtimes hung, since it keeps trying to flush dirty node pages
> >>>
> >>> IMO, for umount case, we should drop dirty reference and dirty pages on meta/data
> >>> pages like we change for node pages to avoid potential dead loop...
> >>
> >> I believe we're doing for them. :P
> > 
> > Actually, I mean do we need to drop dirty meta/data pages explicitly as below:
> > 
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index 3dc3ac6fe143..4c08fd0a680a 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -299,8 +299,15 @@ static int __f2fs_write_meta_page(struct page *page,
> > 
> >  	trace_f2fs_writepage(page, META);
> > 
> > -	if (unlikely(f2fs_cp_error(sbi)))
> > +	if (unlikely(f2fs_cp_error(sbi))) {
> > +		if (is_sbi_flag_set(sbi, SBI_IS_CLOSE)) {
> > +			ClearPageUptodate(page);
> > +			dec_page_count(sbi, F2FS_DIRTY_META);
> > +			unlock_page(page);
> > +			return 0;
> > +		}
> >  		goto redirty_out;
> > +	}
> >  	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
> >  		goto redirty_out;
> >  	if (wbc->for_reclaim && page->index < GET_SUM_BLOCK(sbi, 0))
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index 48a622b95b76..94b342802513 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -2682,6 +2682,12 @@ int f2fs_write_single_data_page(struct page *page, int *submitted,
> > 
> >  	/* we should bypass data pages to proceed the kworkder jobs */
> >  	if (unlikely(f2fs_cp_error(sbi))) {
> > +		if (is_sbi_flag_set(sbi, SBI_IS_CLOSE)) {
> > +			ClearPageUptodate(page);
> > +			inode_dec_dirty_pages(inode);
> > +			unlock_page(page);
> > +			return 0;
> > +		}
> 
> Oh, I notice previously, we will drop non-directory inode's dirty pages directly,
> however, during umount, we'd better drop directory inode's dirty pages as well, right?

Hmm, I remember I dropped them before. Need to double check.

> 
> >  		mapping_set_error(page->mapping, -EIO);
> >  		/*
> >  		 * don't drop any dirty dentry pages for keeping lastest
> > 
> >>
> >>>
> >>> Thanks,
> >>>
> >>>> in an inifinite loop. Let's drop dirty pages at umount in that case.
> >>>>
> >>>> Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
> >>>> ---
> >>>> v3:
> >>>>  - fix wrong unlock
> >>>>
> >>>> v2:
> >>>>  - fix typos
> >>>>
> >>>>  fs/f2fs/node.c | 9 ++++++++-
> >>>>  1 file changed, 8 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> >>>> index e632de10aedab..e0bb0f7e0506e 100644
> >>>> --- a/fs/f2fs/node.c
> >>>> +++ b/fs/f2fs/node.c
> >>>> @@ -1520,8 +1520,15 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
> >>>>  
> >>>>  	trace_f2fs_writepage(page, NODE);
> >>>>  
> >>>> -	if (unlikely(f2fs_cp_error(sbi)))
> >>>> +	if (unlikely(f2fs_cp_error(sbi))) {
> >>>> +		if (is_sbi_flag_set(sbi, SBI_IS_CLOSE)) {
> >>>> +			ClearPageUptodate(page);
> >>>> +			dec_page_count(sbi, F2FS_DIRTY_NODES);
> >>>> +			unlock_page(page);
> >>>> +			return 0;
> >>>> +		}
> >>>>  		goto redirty_out;
> >>>> +	}
> >>>>  
> >>>>  	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
> >>>>  		goto redirty_out;
> >>>>
> >> .
> >>
> > 
> > 
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@...ts.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > .
> >