[PATCH 2/2 v4] f2fs: add sysfs nodes to set last_age_weight

[qixiaoyu1]

Signed-off-by: qixiaoyu1 <qixiaoyu1@xxxxxxxxxx>
Signed-off-by: xiongping1 <xiongping1@xxxxxxxxxx>
---
change log v3 -> v4:
  - allow 0 and 100 to a valid value

 Documentation/ABI/testing/sysfs-fs-f2fs |  5 +++++
 fs/f2fs/extent_cache.c                  | 15 +++++++++------
 fs/f2fs/f2fs.h                          |  1 +
 fs/f2fs/sysfs.c                         | 11 +++++++++++
 4 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 9e3756625a81..11af7dbb6bc9 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -669,3 +669,8 @@ Contact:	"Ping Xiong" <xiongping1@xxxxxxxxxx>
 Description:	When DATA SEPARATION is on, it controls the age threshold to indicate
 		the data blocks as warm. By default it was initialized as 2621440 blocks
 		(equals to 10GB).
+
+What:           /sys/fs/f2fs/<disk>/last_age_weight
+Date:           January 2023
+Contact:        "Ping Xiong" <xiongping1@xxxxxxxxxx>
+Description:    When DATA SEPARATION is on, it controls the weight of last data block age.
diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index d9f12f404beb..ce99882ba81c 100644
--- a/fs/f2fs/extent_cache.c
+++ b/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;
@@ -1233,6 +1235,7 @@ 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)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e8953c3dc81a..c3609cbc28c7 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1679,6 +1679,7 @@ 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 */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 83a366f3ee80..cd2fb52d1f3c 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -686,6 +686,15 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 		return count;
 	}
 
+	if (!strcmp(a->attr.name, "last_age_weight")) {
+		if (t < 0 || t > 100)
+			return -EINVAL;
+		if (t == *ui)
+			return count;
+		*ui = (unsigned int)t;
+		return count;
+	}
+
 	*ui = (unsigned int)t;
 
 	return count;
@@ -944,6 +953,7 @@ 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[] = {
@@ -1042,6 +1052,7 @@ 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);
-- 
2.39.0