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Date:   Mon, 14 Nov 2022 13:02:51 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     yang.yang29@zte.com.cn
Cc:     Andrew Morton <akpm@linux-foundation.org>, minchan@kernel.org,
        ngupta@vflare.org, senozhatsky@chromium.org, axboe@kernel.dk,
        linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        xu.panda@zte.com.cn
Subject: Re: [PATCH linux-next] zram: use sysfs_emit() to instead of
 scnprintf()
Message-ID: <Y3G9649G6j99N/F2@google.com>
References: <202211141141400847357@zte.com.cn>
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In-Reply-To: <202211141141400847357@zte.com.cn>
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On (22/11/14 11:41), yang.yang29@zte.com.cn wrote:
[..]
>  static ssize_t max_comp_streams_store(struct device *dev,
> @@ -1191,8 +1191,7 @@ static ssize_t io_stat_show(struct device *dev,
>  	ssize_t ret;
> 
>  	down_read(&zram->init_lock);
> -	ret = scnprintf(buf, PAGE_SIZE,
> -			"%8llu %8llu %8llu %8llu\n",
> +	ret = sysfs_emit(buf, "%8llu %8llu %8llu %8llu\n",
>  			(u64)atomic64_read(&zram->stats.failed_reads),
>  			(u64)atomic64_read(&zram->stats.failed_writes),
>  			(u64)atomic64_read(&zram->stats.invalid_io),

sysfs_emit() params need to be realigned to match (.

> @@ -1222,8 +1221,7 @@ static ssize_t mm_stat_show(struct device *dev,
>  	orig_size = atomic64_read(&zram->stats.pages_stored);
>  	max_used = atomic_long_read(&zram->stats.max_used_pages);
> 
> -	ret = scnprintf(buf, PAGE_SIZE,
> -			"%8llu %8llu %8llu %8lu %8ld %8llu %8lu %8llu %8llu\n",
> +	ret = sysfs_emit(buf, "%8llu %8llu %8llu %8lu %8ld %8llu %8lu %8llu %8llu\n",
>  			orig_size << PAGE_SHIFT,
>  			(u64)atomic64_read(&zram->stats.compr_data_size),
>  			mem_used << PAGE_SHIFT,

Ditto.

> @@ -1247,8 +1245,7 @@ static ssize_t bd_stat_show(struct device *dev,
>  	ssize_t ret;
> 
>  	down_read(&zram->init_lock);
> -	ret = scnprintf(buf, PAGE_SIZE,
> -		"%8llu %8llu %8llu\n",
> +	ret = sysfs_emit(buf, "%8llu %8llu %8llu\n",
>  			FOUR_K((u64)atomic64_read(&zram->stats.bd_count)),
>  			FOUR_K((u64)atomic64_read(&zram->stats.bd_reads)),
>  			FOUR_K((u64)atomic64_read(&zram->stats.bd_writes)));

Ditto.

> @@ -1266,9 +1263,7 @@ static ssize_t debug_stat_show(struct device *dev,
>  	ssize_t ret;
> 
>  	down_read(&zram->init_lock);
> -	ret = scnprintf(buf, PAGE_SIZE,
> -			"version: %d\n%8llu %8llu\n",
> -			version,
> +	ret = sysfs_emit(buf, "version: %d\n%8llu %8llu\n", version,
>  			(u64)atomic64_read(&zram->stats.writestall),
>  			(u64)atomic64_read(&zram->stats.miss_free));

Ditto.

---

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 01ab32f2897e..430933b73c1b 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1192,10 +1192,10 @@ static ssize_t io_stat_show(struct device *dev,
 
 	down_read(&zram->init_lock);
 	ret = sysfs_emit(buf, "%8llu %8llu %8llu %8llu\n",
-			(u64)atomic64_read(&zram->stats.failed_reads),
-			(u64)atomic64_read(&zram->stats.failed_writes),
-			(u64)atomic64_read(&zram->stats.invalid_io),
-			(u64)atomic64_read(&zram->stats.notify_free));
+			 (u64)atomic64_read(&zram->stats.failed_reads),
+			 (u64)atomic64_read(&zram->stats.failed_writes),
+			 (u64)atomic64_read(&zram->stats.invalid_io),
+			 (u64)atomic64_read(&zram->stats.notify_free));
 	up_read(&zram->init_lock);
 
 	return ret;
@@ -1222,15 +1222,15 @@ static ssize_t mm_stat_show(struct device *dev,
 	max_used = atomic_long_read(&zram->stats.max_used_pages);
 
 	ret = sysfs_emit(buf, "%8llu %8llu %8llu %8lu %8ld %8llu %8lu %8llu %8llu\n",
-			orig_size << PAGE_SHIFT,
-			(u64)atomic64_read(&zram->stats.compr_data_size),
-			mem_used << PAGE_SHIFT,
-			zram->limit_pages << PAGE_SHIFT,
-			max_used << PAGE_SHIFT,
-			(u64)atomic64_read(&zram->stats.same_pages),
-			atomic_long_read(&pool_stats.pages_compacted),
-			(u64)atomic64_read(&zram->stats.huge_pages),
-			(u64)atomic64_read(&zram->stats.huge_pages_since));
+			 orig_size << PAGE_SHIFT,
+			 (u64)atomic64_read(&zram->stats.compr_data_size),
+			 mem_used << PAGE_SHIFT,
+			 zram->limit_pages << PAGE_SHIFT,
+			 max_used << PAGE_SHIFT,
+			 (u64)atomic64_read(&zram->stats.same_pages),
+			 atomic_long_read(&pool_stats.pages_compacted),
+			 (u64)atomic64_read(&zram->stats.huge_pages),
+			 (u64)atomic64_read(&zram->stats.huge_pages_since));
 	up_read(&zram->init_lock);
 
 	return ret;
@@ -1246,9 +1246,9 @@ static ssize_t bd_stat_show(struct device *dev,
 
 	down_read(&zram->init_lock);
 	ret = sysfs_emit(buf, "%8llu %8llu %8llu\n",
-			FOUR_K((u64)atomic64_read(&zram->stats.bd_count)),
-			FOUR_K((u64)atomic64_read(&zram->stats.bd_reads)),
-			FOUR_K((u64)atomic64_read(&zram->stats.bd_writes)));
+			 FOUR_K((u64)atomic64_read(&zram->stats.bd_count)),
+			 FOUR_K((u64)atomic64_read(&zram->stats.bd_reads)),
+			 FOUR_K((u64)atomic64_read(&zram->stats.bd_writes)));
 	up_read(&zram->init_lock);
 
 	return ret;
@@ -1264,8 +1264,8 @@ static ssize_t debug_stat_show(struct device *dev,
 
 	down_read(&zram->init_lock);
 	ret = sysfs_emit(buf, "version: %d\n%8llu %8llu\n", version,
-			(u64)atomic64_read(&zram->stats.writestall),
-			(u64)atomic64_read(&zram->stats.miss_free));
+			 (u64)atomic64_read(&zram->stats.writestall),
+			 (u64)atomic64_read(&zram->stats.miss_free));
 	up_read(&zram->init_lock);
 
 	return ret;