From: Dan Carpenter <dan.carpenter@oracle.com>
To: daehojeong@google.com
Cc: linux-f2fs-devel@lists.sourceforge.net
Subject: [f2fs-dev] [bug report] f2fs: introduce periodic iostat io latency traces
Date: Mon, 16 Aug 2021 10:35:59 +0300 [thread overview]
Message-ID: <20210816073559.GA12039@kili> (raw)
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
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next reply other threads:[~2021-08-16 7:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 7:35 Dan Carpenter [this message]
2021-08-17 4:09 ` [f2fs-dev] [bug report] f2fs: introduce periodic iostat io latency traces Daeho Jeong
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