f2fs: add sysfs nodes to set last_age_weight

Signed-off-by: qixiaoyu1 <qixiaoyu1@xiaomi.com>
Signed-off-by: xiongping1 <xiongping1@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Documentation/ABI/testing/sysfs-fs-f2fs

@@ -717,3 +717,8 @@ Description:	Controls background discard granularity of inner discard thread
 		is smaller than granularity. The unit size is one block(4KB), now only
 		support configuring in range of [0, 512].
 		Default: 512
+
+What:		/sys/fs/f2fs/<disk>/last_age_weight
+Date:		January 2023
+Contact:	"Ping Xiong" <xiongping1@xiaomi.com>
+Description:	When DATA SEPARATION is on, it controls the weight of last data block age.

fs/f2fs/extent_cache.c

@@ -871,19 +871,21 @@ void f2fs_update_read_extent_tree_range_compressed(struct inode *inode,
 }
 #endif
 
-static unsigned long long __calculate_block_age(unsigned long long new,
+static unsigned long long __calculate_block_age(struct f2fs_sb_info *sbi,
+						unsigned long long new,
 						unsigned long long old)
 {
 	unsigned int rem_old, rem_new;
 	unsigned long long res;
+	unsigned int weight = sbi->last_age_weight;
 
-	res = div_u64_rem(new, 100, &rem_new) * (100 - LAST_AGE_WEIGHT)
-		+ div_u64_rem(old, 100, &rem_old) * LAST_AGE_WEIGHT;
+	res = div_u64_rem(new, 100, &rem_new) * (100 - weight)
+		+ div_u64_rem(old, 100, &rem_old) * weight;
 
 	if (rem_new)
-		res += rem_new * (100 - LAST_AGE_WEIGHT) / 100;
+		res += rem_new * (100 - weight) / 100;
 	if (rem_old)
-		res += rem_old * LAST_AGE_WEIGHT / 100;
+		res += rem_old * weight / 100;
 
 	return res;
 }
@@ -917,7 +919,7 @@ static int __get_new_block_age(struct inode *inode, struct extent_info *ei,
 			cur_age = ULLONG_MAX - tei.last_blocks + cur_blocks;
 
 		if (tei.age)
-			ei->age = __calculate_block_age(cur_age, tei.age);
+			ei->age = __calculate_block_age(sbi, cur_age, tei.age);
 		else
 			ei->age = cur_age;
 		ei->last_blocks = cur_blocks;
@@ -1244,6 +1246,7 @@ void f2fs_init_extent_cache_info(struct f2fs_sb_info *sbi)
 	atomic64_set(&sbi->allocated_data_blocks, 0);
 	sbi->hot_data_age_threshold = DEF_HOT_DATA_AGE_THRESHOLD;
 	sbi->warm_data_age_threshold = DEF_WARM_DATA_AGE_THRESHOLD;
+	sbi->last_age_weight = LAST_AGE_WEIGHT;
 }
 
 int __init f2fs_create_extent_cache(void)

fs/f2fs/f2fs.h

@@ -1671,6 +1671,7 @@ struct f2fs_sb_info {
 	/* The threshold used for hot and warm data seperation*/
 	unsigned int hot_data_age_threshold;
 	unsigned int warm_data_age_threshold;
+	unsigned int last_age_weight;
 
 	/* basic filesystem units */
 	unsigned int log_sectors_per_block;	/* log2 sectors per block */

fs/f2fs/sysfs.c

@@ -697,6 +697,15 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 		return count;
 	}
 
+	if (!strcmp(a->attr.name, "last_age_weight")) {
+		if (t > 100)
+			return -EINVAL;
+		if (t == *ui)
+			return count;
+		*ui = (unsigned int)t;
+		return count;
+	}
+
 	*ui = (unsigned int)t;
 
 	return count;
@@ -956,6 +965,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, revoked_atomic_block, revoked_atomic_block)
 /* For block age extent cache */
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, hot_data_age_threshold, hot_data_age_threshold);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, warm_data_age_threshold, warm_data_age_threshold);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, last_age_weight, last_age_weight);
 
 #define ATTR_LIST(name) (&f2fs_attr_##name.attr)
 static struct attribute *f2fs_attrs[] = {
@@ -1055,6 +1065,7 @@ static struct attribute *f2fs_attrs[] = {
 	ATTR_LIST(revoked_atomic_block),
 	ATTR_LIST(hot_data_age_threshold),
 	ATTR_LIST(warm_data_age_threshold),
+	ATTR_LIST(last_age_weight),
 	NULL,
 };
 ATTRIBUTE_GROUPS(f2fs);