[PATCH 3/7] f2fs: add reserved_segments sysfs node

[Daeho Jeong <daeho43@gmail.com>]

From: Daeho Jeong <daehojeong@google.com>

For the fine tuning of GC behavior, add reserved_segments sysfs node.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
---
 Documentation/ABI/testing/sysfs-fs-f2fs | 6 ++++++
 fs/f2fs/sysfs.c                         | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index cad6c3dc1f9c..4fcd0f824bde 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -763,3 +763,9 @@ Date:		November 2023
 Contact:	"Chao Yu" <chao@kernel.org>
 Description:	It controls to enable/disable IO aware feature for background discard.
 		By default, the value is 1 which indicates IO aware is on.
+
+What:		/sys/fs/f2fs/<disk>/reserved_segments
+Date:		August 2024
+Contact:	"Daeho Jeong" <daehojeong@google.com>
+Description:	In order to fine tune GC behavior, we can control the number of
+		reserved segments.
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index fee7ee45ceaa..2ed773132f40 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -969,6 +969,7 @@ SM_INFO_GENERAL_RW_ATTR(min_fsync_blocks);
 SM_INFO_GENERAL_RW_ATTR(min_seq_blocks);
 SM_INFO_GENERAL_RW_ATTR(min_hot_blocks);
 SM_INFO_GENERAL_RW_ATTR(min_ssr_sections);
+SM_INFO_GENERAL_RW_ATTR(reserved_segments);
 
 /* DCC_INFO ATTR */
 DCC_INFO_RW_ATTR(max_small_discards, max_discards);
@@ -1138,6 +1139,7 @@ static struct attribute *f2fs_attrs[] = {
 	ATTR_LIST(min_seq_blocks),
 	ATTR_LIST(min_hot_blocks),
 	ATTR_LIST(min_ssr_sections),
+	ATTR_LIST(reserved_segments),
 	ATTR_LIST(max_victim_search),
 	ATTR_LIST(migration_granularity),
 	ATTR_LIST(dir_level),
-- 
2.46.0.469.g59c65b2a67-goog