ext4: replace snprintf in show functions with sysfs_emit

coccicheck complains about the use of snprintf() in sysfs show functions.

Fix the coccicheck warning:
WARNING: use scnprintf or sprintf.

Use sysfs_emit instead of scnprintf or sprintf makes more sense.
Signed-off-by: NQing Wang <wangqing@vivo.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1634095731-4528-1-git-send-email-wangqing@vivo.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

fs/ext4/sysfs.c

@@ -63,7 +63,7 @@ static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
 {
 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
 
-	return snprintf(buf, PAGE_SIZE, "%lu\n",
+	return sysfs_emit(buf, "%lu\n",
 			(part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
 			 sbi->s_sectors_written_start) >> 1);
 }
@@ -72,7 +72,7 @@ static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
 {
 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
 
-	return snprintf(buf, PAGE_SIZE, "%llu\n",
+	return sysfs_emit(buf, "%llu\n",
 			(unsigned long long)(sbi->s_kbytes_written +
 			((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
@@ -130,8 +130,8 @@ static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
 static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
 {
 	if (!sbi->s_journal)
-		return snprintf(buf, PAGE_SIZE, "<none>\n");
-	return snprintf(buf, PAGE_SIZE, "%d\n",
+		return sysfs_emit(buf, "<none>\n");
+	return sysfs_emit(buf, "%d\n",
 			task_pid_vnr(sbi->s_journal->j_task));
 }
 
@@ -357,7 +357,7 @@ static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
 
 static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
 {
-	return snprintf(buf, PAGE_SIZE, "%lld\n",
+	return sysfs_emit(buf, "%lld\n",
 			((time64_t)hi << 32) + le32_to_cpu(lo));
 }
 
@@ -374,7 +374,7 @@ static ssize_t ext4_attr_show(struct kobject *kobj,
 
 	switch (a->attr_id) {
 	case attr_delayed_allocation_blocks:
-		return snprintf(buf, PAGE_SIZE, "%llu\n",
+		return sysfs_emit(buf, "%llu\n",
 				(s64) EXT4_C2B(sbi,
 		       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
 	case attr_session_write_kbytes:
@@ -382,11 +382,11 @@ static ssize_t ext4_attr_show(struct kobject *kobj,
 	case attr_lifetime_write_kbytes:
 		return lifetime_write_kbytes_show(sbi, buf);
 	case attr_reserved_clusters:
-		return snprintf(buf, PAGE_SIZE, "%llu\n",
+		return sysfs_emit(buf, "%llu\n",
 				(unsigned long long)
 				atomic64_read(&sbi->s_resv_clusters));
 	case attr_sra_exceeded_retry_limit:
-		return snprintf(buf, PAGE_SIZE, "%llu\n",
+		return sysfs_emit(buf, "%llu\n",
 				(unsigned long long)
 			percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));
 	case attr_inode_readahead:
@@ -394,42 +394,42 @@ static ssize_t ext4_attr_show(struct kobject *kobj,
 		if (!ptr)
 			return 0;
 		if (a->attr_ptr == ptr_ext4_super_block_offset)
-			return snprintf(buf, PAGE_SIZE, "%u\n",
+			return sysfs_emit(buf, "%u\n",
 					le32_to_cpup(ptr));
 		else
-			return snprintf(buf, PAGE_SIZE, "%u\n",
+			return sysfs_emit(buf, "%u\n",
 					*((unsigned int *) ptr));
 	case attr_pointer_ul:
 		if (!ptr)
 			return 0;
-		return snprintf(buf, PAGE_SIZE, "%lu\n",
+		return sysfs_emit(buf, "%lu\n",
 				*((unsigned long *) ptr));
 	case attr_pointer_u8:
 		if (!ptr)
 			return 0;
-		return snprintf(buf, PAGE_SIZE, "%u\n",
+		return sysfs_emit(buf, "%u\n",
 				*((unsigned char *) ptr));
 	case attr_pointer_u64:
 		if (!ptr)
 			return 0;
 		if (a->attr_ptr == ptr_ext4_super_block_offset)
-			return snprintf(buf, PAGE_SIZE, "%llu\n",
+			return sysfs_emit(buf, "%llu\n",
 					le64_to_cpup(ptr));
 		else
-			return snprintf(buf, PAGE_SIZE, "%llu\n",
+			return sysfs_emit(buf, "%llu\n",
 					*((unsigned long long *) ptr));
 	case attr_pointer_string:
 		if (!ptr)
 			return 0;
-		return snprintf(buf, PAGE_SIZE, "%.*s\n", a->attr_size,
+		return sysfs_emit(buf, "%.*s\n", a->attr_size,
 				(char *) ptr);
 	case attr_pointer_atomic:
 		if (!ptr)
 			return 0;
-		return snprintf(buf, PAGE_SIZE, "%d\n",
+		return sysfs_emit(buf, "%d\n",
 				atomic_read((atomic_t *) ptr));
 	case attr_feature:
-		return snprintf(buf, PAGE_SIZE, "supported\n");
+		return sysfs_emit(buf, "supported\n");
 	case attr_first_error_time:
 		return print_tstamp(buf, sbi->s_es, s_first_error_time);
 	case attr_last_error_time: