f2fs: checkpoint disabling
Note that, it requires "f2fs: return correct errno in f2fs_gc".
This adds a lightweight non-persistent snapshotting scheme to f2fs.
To use, mount with the option checkpoint=disable, and to return to
normal operation, remount with checkpoint=enable. If the filesystem
is shut down before remounting with checkpoint=enable, it will revert
back to its apparent state when it was first mounted with
checkpoint=disable. This is useful for situations where you wish to be
able to roll back the state of the disk in case of some critical
failure.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
[Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 0861500..ab3465f 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -339,6 +339,12 @@ static inline unsigned int get_valid_blocks(struct f2fs_sb_info *sbi,
return get_seg_entry(sbi, segno)->valid_blocks;
}
+static inline unsigned int get_ckpt_valid_blocks(struct f2fs_sb_info *sbi,
+ unsigned int segno)
+{
+ return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
+}
+
static inline void seg_info_from_raw_sit(struct seg_entry *se,
struct f2fs_sit_entry *rs)
{
@@ -576,6 +582,15 @@ static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi,
reserved_sections(sbi) + needed);
}
+static inline int f2fs_is_checkpoint_ready(struct f2fs_sb_info *sbi)
+{
+ if (likely(!is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
+ return 0;
+ if (likely(!has_not_enough_free_secs(sbi, 0, 0)))
+ return 0;
+ return -ENOSPC;
+}
+
static inline bool excess_prefree_segs(struct f2fs_sb_info *sbi)
{
return prefree_segments(sbi) > SM_I(sbi)->rec_prefree_segments;