From: Daeho Jeong <daeho43@gmail.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Daeho Jeong <daehojeong@google.com>,
linux-f2fs-devel@lists.sourceforge.net
Subject: Re: [f2fs-dev] [bug report] f2fs: introduce periodic iostat io latency traces
Date: Mon, 16 Aug 2021 21:09:45 -0700 [thread overview]
Message-ID: <CACOAw_w3TC8ZM9AKE7frPHnMRcXTE8n1aQChEJR7L3tsJ-K0_w@mail.gmail.com> (raw)
In-Reply-To: <20210816073559.GA12039@kili>
Hi Dan,
We don't use NR_PAGE_TYPE for the index.
Thank you,
On Mon, Aug 16, 2021 at 12:37 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> Hello Daeho Jeong,
>
> The patch f4b05791dda9: "f2fs: introduce periodic iostat io latency
> traces" from Aug 3, 2021, leads to the following
> Smatch static checker warnings:
>
> fs/f2fs/f2fs.h:3365 __update_iostat_latency() error: buffer overflow 'sbi->rd_sum_lat' 3 <= 3
> fs/f2fs/f2fs.h:3366 __update_iostat_latency() error: buffer overflow 'sbi->rd_bio_cnt' 3 <= 3
> fs/f2fs/f2fs.h:3367 __update_iostat_latency() error: buffer overflow 'sbi->rd_peak_lat' 3 <= 3
> fs/f2fs/f2fs.h:3368 __update_iostat_latency() error: buffer overflow 'sbi->rd_peak_lat' 3 <= 3
> fs/f2fs/f2fs.h:3370 __update_iostat_latency() error: buffer overflow 'sbi->wr_sum_lat[sync]' 3 <= 3
> fs/f2fs/f2fs.h:3371 __update_iostat_latency() error: buffer overflow 'sbi->wr_bio_cnt[sync]' 3 <= 3
> fs/f2fs/f2fs.h:3372 __update_iostat_latency() error: buffer overflow 'sbi->wr_peak_lat[sync]' 3 <= 3
> fs/f2fs/f2fs.h:3373 __update_iostat_latency() error: buffer overflow 'sbi->wr_peak_lat[sync]' 3 <= 3
>
> fs/f2fs/f2fs.h
> 3348 static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
> 3349 int rw, int sync)
> 3350 {
> 3351 unsigned long ts_diff;
> 3352 unsigned int iotype = iostat_ctx->type;
> 3353 unsigned long flags;
> 3354 struct f2fs_sb_info *sbi = iostat_ctx->sbi;
> 3355
> 3356 if (!sbi->iostat_enable)
> 3357 return;
> 3358
> 3359 ts_diff = jiffies - iostat_ctx->submit_ts;
> 3360 if (iotype >= META_FLUSH)
> ^^^^^^^^^^^^^^^^^^^^
> This means the highest value of "iotype" is NR_PAGE_TYPE.
>
> 3361 iotype = META;
> 3362
> 3363 spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
> 3364 if (rw == 0) {
> --> 3365 sbi->rd_sum_lat[iotype] += ts_diff;
> ^^^^^^^^^^^^^^^^^^^^^^^
> 3366 sbi->rd_bio_cnt[iotype]++;
> ^^^^^^^^^^^^^^^^^^^^^^
> These arrays have NR_PAGE_TYPE elements so it's off by one.
>
> 3367 if (ts_diff > sbi->rd_peak_lat[iotype])
> 3368 sbi->rd_peak_lat[iotype] = ts_diff;
> 3369 } else {
> 3370 sbi->wr_sum_lat[sync][iotype] += ts_diff;
> 3371 sbi->wr_bio_cnt[sync][iotype]++;
> 3372 if (ts_diff > sbi->wr_peak_lat[sync][iotype])
> 3373 sbi->wr_peak_lat[sync][iotype] = ts_diff;
> 3374 }
> 3375 spin_unlock_irqrestore(&sbi->iostat_lat_lock, flags);
> 3376 }
>
> regards,
> dan carpenter
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
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prev parent reply other threads:[~2021-08-17 4:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 7:35 [f2fs-dev] [bug report] f2fs: introduce periodic iostat io latency traces Dan Carpenter
2021-08-17 4:09 ` Daeho Jeong [this message]
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