From 22ad0b6ab46683975c6da032f1c2593066c7b3bd Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Thu, 9 Feb 2017 10:38:09 -0800 Subject: f2fs: add bitmaps for empty or full NAT blocks This patches adds bitmaps to represent empty or full NAT blocks containing free nid entries. If we can find valid crc|cp_ver in the last block of checkpoint pack, we'll use these bitmaps when building free nids. In order to avoid checkpointing burden, up-to-date bitmaps will be flushed only during umount time. So, normally we can get this gain, but when power-cut happens, we rely on fsck.f2fs which recovers this bitmap again. After this patch, we build free nids from nid #0 at mount time to make more full NAT blocks, but in runtime, we check empty NAT blocks to load free nids without loading any NAT pages from disk. Signed-off-by: Jaegeuk Kim --- include/linux/f2fs_fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/f2fs_fs.h') diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h index f0748524ca8c..1c92ace2e8f8 100644 --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -114,6 +114,7 @@ struct f2fs_super_block { /* * For checkpoint */ +#define CP_NAT_BITS_FLAG 0x00000080 #define CP_CRC_RECOVERY_FLAG 0x00000040 #define CP_FASTBOOT_FLAG 0x00000020 #define CP_FSCK_FLAG 0x00000010 -- cgit v1.2.3