f2fs: add mount option for segment allocation policy
This patch adds an mount option, "alloc_mode=%s" having two options, "default"
and "reuse".
In "alloc_mode=reuse" case, f2fs starts to allocate segments from 0'th segment
all the time to reassign segments. It'd be useful for small-sized eMMC parts.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 1c38e9c..c588159 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2170,6 +2170,11 @@
if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
return SIT_I(sbi)->last_victim[ALLOC_NEXT];
+
+ /* find segments from 0 to reuse freed segments */
+ if (sbi->alloc_mode == ALLOC_MODE_REUSE)
+ return 0;
+
return CURSEG_I(sbi, type)->segno;
}