[PATCH 4.4 018/104] f2fs: detect wrong layout

From: Greg Kroah-Hartman
Date: Thu Jan 24 2019 - 14:24:34 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

commit 2040fce83fe17763b07c97c1f691da2bb85e4135 upstream.

Previous mkfs.f2fs allows small partition inappropriately, so f2fs should detect
that as well.

Refer this in f2fs-tools.

mkfs.f2fs: detect small partition by overprovision ratio and # of segments

Reported-and-Tested-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/f2fs/segment.h | 2 ++
fs/f2fs/super.c | 11 +++++++++++
2 files changed, 13 insertions(+)

--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -17,6 +17,8 @@

#define DEF_RECLAIM_PREFREE_SEGMENTS 5 /* 5% over total segments */

+#define F2FS_MIN_SEGMENTS 9 /* SB + 2 (CP + SIT + NAT) + SSA + MAIN */
+
/* L: Logical segment # in volume, R: Relative segment # in main area */
#define GET_L2R_SEGNO(free_i, segno) (segno - free_i->start_segno)
#define GET_R2L_SEGNO(free_i, segno) (segno + free_i->start_segno)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1078,6 +1078,7 @@ int sanity_check_ckpt(struct f2fs_sb_inf
unsigned int total, fsmeta;
struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+ unsigned int ovp_segments, reserved_segments;
unsigned int main_segs, blocks_per_seg;
unsigned int sit_segs, nat_segs;
unsigned int sit_bitmap_size, nat_bitmap_size;
@@ -1096,6 +1097,16 @@ int sanity_check_ckpt(struct f2fs_sb_inf
if (unlikely(fsmeta >= total))
return 1;

+ ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
+ reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
+
+ if (unlikely(fsmeta < F2FS_MIN_SEGMENTS ||
+ ovp_segments == 0 || reserved_segments == 0)) {
+ f2fs_msg(sbi->sb, KERN_ERR,
+ "Wrong layout: check mkfs.f2fs version");
+ return 1;
+ }
+
main_segs = le32_to_cpu(raw_super->segment_count_main);
blocks_per_seg = sbi->blocks_per_seg;