f2fs: add reserved_segments sysfs node

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

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index e6fa55037daf53344ecc41c35e00b6ac054a35f8..6527a14082d2fe5269c08e2131f52cc0e04acfa6 100644 (file)
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -791,3 +791,9 @@ Description:        Controls migration window granularity of garbage collection on larg
                section. it can control the scanning window granularity for GC migration
                in a unit of segment, while migration_granularity controls the number
                of segments which can be migrated at the same turn.
+
+What:          /sys/fs/f2fs/<disk>/reserved_segments
+Date:          September 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 02b35edc9e1d7a1640c9c884aaba6fb8370c43e9..8eedba8ae71016cc005230885818a3bc060134db 100644 (file)
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -986,6 +986,7 @@ 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);
@@ -1158,6 +1159,7 @@ 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(migration_window_granularity),