[PATCH v2] f2fs: sysfs: support gc_io_aware

[liujinbao1]

From: liujinbao1 <liujinbao1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>

Currently, IO can only be ignored when GC_URGENT_HIGH is set,
and the default algorithm used for GC_URGENT_HIGH is greedy.
It gives a way to enable/disable IO aware feature for background
gc, so that we can tune background gc more precisely. e.g.
force to disable IO aware and choose more suitable algorithm
if there are large number of dirty segments.

Signed-off-by: liujinbao1 <liujinbao1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>

changes of v2: Improve the patch according to Chao's suggestions

---
 Documentation/ABI/testing/sysfs-fs-f2fs | 6 ++++++
 fs/f2fs/gc.c                            | 3 ++-
 fs/f2fs/gc.h                            | 1 +
 fs/f2fs/sysfs.c                         | 9 +++++++++
 4 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 36c3cb547901..47f02fa471fe 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -16,6 +16,12 @@ Contact:	"Namjae Jeon" <namjae.jeon@xxxxxxxxxxx>
 Description:	Controls the default sleep time for gc_thread. Time
 		is in milliseconds.
 
+What:		/sys/fs/f2fs/<disk>/gc_io_aware
+Date:		January 2024
+Contact:	"Jinbao Liu" <liujinbao1@xxxxxxxxxx>
+Description:	It controls to enable/disable IO aware feature for background gc.
++		By default, the value is 1 which indicates IO aware is on.
+
 What:		/sys/fs/f2fs/<disk>/gc_idle
 Date:		July 2013
 Contact:	"Namjae Jeon" <namjae.jeon@xxxxxxxxxxx>
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 309da3d0faff..0b75d37acc63 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -109,7 +109,7 @@ static int gc_thread_func(void *data)
 			goto next;
 		}
 
-		if (!is_idle(sbi, GC_TIME)) {
+		if (gc_th->io_aware && !is_idle(sbi, GC_TIME)) {
 			increase_sleep_time(gc_th, &wait_ms);
 			f2fs_up_write(&sbi->gc_lock);
 			stat_io_skip_bggc_count(sbi);
@@ -182,6 +182,7 @@ int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
+	gc_th->io_aware = true;
 
 	gc_th->gc_wake = false;
 
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 28a00942802c..51d6ad26b76a 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -41,6 +41,7 @@ struct f2fs_gc_kthread {
 	unsigned int min_sleep_time;
 	unsigned int max_sleep_time;
 	unsigned int no_gc_sleep_time;
+	bool io_aware;
 
 	/* for changing gc mode */
 	bool gc_wake;
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 417fae96890f..e8d5667cfddd 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -516,6 +516,13 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 		return count;
 	}
 
+	if (!strcmp(a->attr.name, "gc_io_aware")) {
+		if (t > 1)
+			return -EINVAL;
+		*ui = t ? true : false;
+		return count;
+	}
+
 	if (!strcmp(a->attr.name, "migration_granularity")) {
 		if (t == 0 || t > sbi->segs_per_sec)
 			return -EINVAL;
@@ -906,6 +913,7 @@ GC_THREAD_RW_ATTR(gc_urgent_sleep_time, urgent_sleep_time);
 GC_THREAD_RW_ATTR(gc_min_sleep_time, min_sleep_time);
 GC_THREAD_RW_ATTR(gc_max_sleep_time, max_sleep_time);
 GC_THREAD_RW_ATTR(gc_no_gc_sleep_time, no_gc_sleep_time);
+GC_THREAD_RW_ATTR(gc_io_aware, io_aware);
 
 /* SM_INFO ATTR */
 SM_INFO_RW_ATTR(reclaim_segments, rec_prefree_segments);
@@ -1061,6 +1069,7 @@ static struct attribute *f2fs_attrs[] = {
 	ATTR_LIST(gc_min_sleep_time),
 	ATTR_LIST(gc_max_sleep_time),
 	ATTR_LIST(gc_no_gc_sleep_time),
+	ATTR_LIST(gc_io_aware),
 	ATTR_LIST(gc_idle),
 	ATTR_LIST(gc_urgent),
 	ATTR_LIST(reclaim_segments),
-- 
2.43.0