Re: [f2fs-dev] [PATCH] f2fs: fix iostat related lock protection

[Jaegeuk Kim]

On 06/16, Chao Yu wrote:
> On 2022/6/16 0:54, Jaegeuk Kim wrote:
> > On 06/15, Chao Yu wrote:
> > > On 2022/6/11 2:32, Daeho Jeong wrote:
> > > > From: Daeho Jeong <daehojeong@xxxxxxxxxx>
> > > > 
> > > > Made iostat related locks safe to be called from irq context again.
> > > > 
> > > 
> > > Will be better to add a 'Fixes' line?
> > 
> > Added some tags. Thanks,
> > 
> > https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev&id=f8ed39ad779fbc5d37d08e83643384fc06e4bae4
> 
> It looks there are several patches not in mailing list?
> 

Which one doe you mean?

> Thanks,
> 
> > 
> > 
> > > 
> > > Thanks,
> > > 
> > > > Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
> > > > ---
> > > >    fs/f2fs/iostat.c | 31 ++++++++++++++++++-------------
> > > >    1 file changed, 18 insertions(+), 13 deletions(-)
> > > > 
> > > > diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
> > > > index be599f31d3c4..d84c5f6cc09d 100644
> > > > --- a/fs/f2fs/iostat.c
> > > > +++ b/fs/f2fs/iostat.c
> > > > @@ -91,8 +91,9 @@ static inline void __record_iostat_latency(struct f2fs_sb_info *sbi)
> > > >    	unsigned int cnt;
> > > >    	struct f2fs_iostat_latency iostat_lat[MAX_IO_TYPE][NR_PAGE_TYPE];
> > > >    	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
> > > > +	unsigned long flags;
> > > > -	spin_lock_bh(&sbi->iostat_lat_lock);
> > > > +	spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
> > > >    	for (idx = 0; idx < MAX_IO_TYPE; idx++) {
> > > >    		for (io = 0; io < NR_PAGE_TYPE; io++) {
> > > >    			cnt = io_lat->bio_cnt[idx][io];
> > > > @@ -106,7 +107,7 @@ static inline void __record_iostat_latency(struct f2fs_sb_info *sbi)
> > > >    			io_lat->bio_cnt[idx][io] = 0;
> > > >    		}
> > > >    	}
> > > > -	spin_unlock_bh(&sbi->iostat_lat_lock);
> > > > +	spin_unlock_irqrestore(&sbi->iostat_lat_lock, flags);
> > > >    	trace_f2fs_iostat_latency(sbi, iostat_lat);
> > > >    }
> > > > @@ -115,14 +116,15 @@ static inline void f2fs_record_iostat(struct f2fs_sb_info *sbi)
> > > >    {
> > > >    	unsigned long long iostat_diff[NR_IO_TYPE];
> > > >    	int i;
> > > > +	unsigned long flags;
> > > >    	if (time_is_after_jiffies(sbi->iostat_next_period))
> > > >    		return;
> > > >    	/* Need double check under the lock */
> > > > -	spin_lock_bh(&sbi->iostat_lock);
> > > > +	spin_lock_irqsave(&sbi->iostat_lock, flags);
> > > >    	if (time_is_after_jiffies(sbi->iostat_next_period)) {
> > > > -		spin_unlock_bh(&sbi->iostat_lock);
> > > > +		spin_unlock_irqrestore(&sbi->iostat_lock, flags);
> > > >    		return;
> > > >    	}
> > > >    	sbi->iostat_next_period = jiffies +
> > > > @@ -133,7 +135,7 @@ static inline void f2fs_record_iostat(struct f2fs_sb_info *sbi)
> > > >    				sbi->prev_rw_iostat[i];
> > > >    		sbi->prev_rw_iostat[i] = sbi->rw_iostat[i];
> > > >    	}
> > > > -	spin_unlock_bh(&sbi->iostat_lock);
> > > > +	spin_unlock_irqrestore(&sbi->iostat_lock, flags);
> > > >    	trace_f2fs_iostat(sbi, iostat_diff);
> > > > @@ -145,25 +147,27 @@ void f2fs_reset_iostat(struct f2fs_sb_info *sbi)
> > > >    	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
> > > >    	int i;
> > > > -	spin_lock_bh(&sbi->iostat_lock);
> > > > +	spin_lock_irq(&sbi->iostat_lock);
> > > >    	for (i = 0; i < NR_IO_TYPE; i++) {
> > > >    		sbi->rw_iostat[i] = 0;
> > > >    		sbi->prev_rw_iostat[i] = 0;
> > > >    	}
> > > > -	spin_unlock_bh(&sbi->iostat_lock);
> > > > +	spin_unlock_irq(&sbi->iostat_lock);
> > > > -	spin_lock_bh(&sbi->iostat_lat_lock);
> > > > +	spin_lock_irq(&sbi->iostat_lat_lock);
> > > >    	memset(io_lat, 0, sizeof(struct iostat_lat_info));
> > > > -	spin_unlock_bh(&sbi->iostat_lat_lock);
> > > > +	spin_unlock_irq(&sbi->iostat_lat_lock);
> > > >    }
> > > >    void f2fs_update_iostat(struct f2fs_sb_info *sbi,
> > > >    			enum iostat_type type, unsigned long long io_bytes)
> > > >    {
> > > > +	unsigned long flags;
> > > > +
> > > >    	if (!sbi->iostat_enable)
> > > >    		return;
> > > > -	spin_lock_bh(&sbi->iostat_lock);
> > > > +	spin_lock_irqsave(&sbi->iostat_lock, flags);
> > > >    	sbi->rw_iostat[type] += io_bytes;
> > > >    	if (type == APP_BUFFERED_IO || type == APP_DIRECT_IO)
> > > > @@ -172,7 +176,7 @@ void f2fs_update_iostat(struct f2fs_sb_info *sbi,
> > > >    	if (type == APP_BUFFERED_READ_IO || type == APP_DIRECT_READ_IO)
> > > >    		sbi->rw_iostat[APP_READ_IO] += io_bytes;
> > > > -	spin_unlock_bh(&sbi->iostat_lock);
> > > > +	spin_unlock_irqrestore(&sbi->iostat_lock, flags);
> > > >    	f2fs_record_iostat(sbi);
> > > >    }
> > > > @@ -185,6 +189,7 @@ static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
> > > >    	struct f2fs_sb_info *sbi = iostat_ctx->sbi;
> > > >    	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
> > > >    	int idx;
> > > > +	unsigned long flags;
> > > >    	if (!sbi->iostat_enable)
> > > >    		return;
> > > > @@ -202,12 +207,12 @@ static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
> > > >    			idx = WRITE_ASYNC_IO;
> > > >    	}
> > > > -	spin_lock_bh(&sbi->iostat_lat_lock);
> > > > +	spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
> > > >    	io_lat->sum_lat[idx][iotype] += ts_diff;
> > > >    	io_lat->bio_cnt[idx][iotype]++;
> > > >    	if (ts_diff > io_lat->peak_lat[idx][iotype])
> > > >    		io_lat->peak_lat[idx][iotype] = ts_diff;
> > > > -	spin_unlock_bh(&sbi->iostat_lat_lock);
> > > > +	spin_unlock_irqrestore(&sbi->iostat_lat_lock, flags);
> > > >    }
> > > >    void iostat_update_and_unbind_ctx(struct bio *bio, int rw)
> > > 
> > > 
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