f2fs: use crc and cp version to determine roll-forward recovery
Previously, we used cp_version only to detect recoverable dnodes.
In order to avoid same garbage cp_version, we needed to truncate the next
dnode during checkpoint, resulting in additional discard or data write.
If we can distinguish this by using crc in addition to cp_version, we can
remove this overhead.
There is backward compatibility concern where it changes node_footer layout.
So, this patch introduces a new checkpoint flag, CP_CRC_RECOVERY_FLAG, to
detect new layout. New layout will be activated only when this flag is set.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 29e3cf4..9649b79 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1827,6 +1827,9 @@
if (need_fsck)
set_sbi_flag(sbi, SBI_NEED_FSCK);
+ if (!retry)
+ goto skip_recovery;
+
err = recover_fsync_data(sbi, false);
if (err < 0) {
need_fsck = true;
@@ -1844,7 +1847,7 @@
goto free_kobj;
}
}
-
+skip_recovery:
/* recover_fsync_data() cleared this already */
clear_sbi_flag(sbi, SBI_POR_DOING);