block: zram: replace scnprintf() with sysfs_emit() in *_show() functions

Replace scnprintf() with sysfs_emit() or sysfs_emit_at() in sysfs
*_show() functions in zram_drv.c to follow the kernel's guidelines
from Documentation/filesystems/sysfs.rst.

This improves consistency, safety, and makes the code easier to
maintain and update in the future.

Signed-off-by: Rahul Kumar <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: rahul19kumar8

drivers/block/zram/zram_drv.c

@@ -373,15 +373,15 @@ static ssize_t initstate_show(struct device *dev,
 	val = init_done(zram);
 	up_read(&zram->init_lock);
 
-	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
+	return sysfs_emit(buf, "%u\n", val);
 }
 
 static ssize_t disksize_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct zram *zram = dev_to_zram(dev);
 
-	return scnprintf(buf, PAGE_SIZE, "%llu\n", zram->disksize);
+	return sysfs_emit(buf, "%llu\n", zram->disksize);
 }
 
 static ssize_t mem_limit_store(struct device *dev,
@@ -532,7 +532,7 @@ static ssize_t writeback_limit_enable_show(struct device *dev,
 	spin_unlock(&zram->wb_limit_lock);
 	up_read(&zram->init_lock);
 
-	return scnprintf(buf, PAGE_SIZE, "%d\n", val);
+	return sysfs_emit(buf, "%d\n", val);
 }
 
 static ssize_t writeback_limit_store(struct device *dev,
@@ -567,7 +567,7 @@ static ssize_t writeback_limit_show(struct device *dev,
 	spin_unlock(&zram->wb_limit_lock);
 	up_read(&zram->init_lock);
 
-	return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
+	return sysfs_emit(buf, "%llu\n", val);
 }
 
 static void reset_bdev(struct zram *zram)
@@ -1415,7 +1415,7 @@ static ssize_t recomp_algorithm_show(struct device *dev,
 		if (!zram->comp_algs[prio])
 			continue;
 
-		sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2, "#%d: ", prio);
+		sz += sysfs_emit_at(buf, sz, "#%d: ", prio);
 		sz += __comp_algorithm_show(zram, prio, buf + sz);
 	}
 
@@ -1488,7 +1488,7 @@ static ssize_t io_stat_show(struct device *dev,
 	ssize_t ret;
 
 	down_read(&zram->init_lock);
-	ret = scnprintf(buf, PAGE_SIZE,
+	ret = sysfs_emit(buf,
 			"%8llu %8llu 0 %8llu\n",
 			(u64)atomic64_read(&zram->stats.failed_reads),
 			(u64)atomic64_read(&zram->stats.failed_writes),
@@ -1518,7 +1518,7 @@ 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,
+	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),
@@ -1543,8 +1543,8 @@ 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)));
@@ -1562,7 +1562,7 @@ static ssize_t debug_stat_show(struct device *dev,
 	ssize_t ret;
 
 	down_read(&zram->init_lock);
-	ret = scnprintf(buf, PAGE_SIZE,
+	ret = sysfs_emit(buf,
 			"version: %d\n0 %8llu\n",
 			version,
 			(u64)atomic64_read(&zram->stats.miss_free));
@@ -2810,7 +2810,7 @@ static ssize_t hot_add_show(const struct class *class,
 
 	if (ret < 0)
 		return ret;
-	return scnprintf(buf, PAGE_SIZE, "%d\n", ret);
+	return sysfs_emit(buf, "%d\n", ret);
 }
 /* This attribute must be set to 0400, so CLASS_ATTR_RO() can not be used */
 static struct class_attribute class_attr_hot_add =