[PATCH 1/2] f2fs: detect wrong layout

[PATCH 1/2] f2fs: detect wrong layout

[Jaegeuk Kim]

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-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/segment.h |  2 ++
 fs/f2fs/super.c   | 11 +++++++++++
 2 files changed, 13 insertions(+)

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 89ab4301ef02..9d44ce83acb2 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -18,6 +18,8 @@
 #define DEF_RECLAIM_PREFREE_SEGMENTS	5	/* 5% over total segments */
 #define DEF_MAX_RECLAIM_PREFREE_SEGMENTS	4096	/* 8GB in maximum */
 
+#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)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 7591d2d7b612..1a526474b332 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1452,6 +1452,7 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 	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;
 
 	total = le32_to_cpu(raw_super->segment_count);
 	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
@@ -1463,6 +1464,16 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 	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;
+	}
+
 	if (unlikely(f2fs_cp_error(sbi))) {
 		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
 		return 1;
-- 
2.11.0

[PATCH 2/2] f2fs: free meta pages if sanity check for ckpt is failed

[Jaegeuk Kim]

This fixes missing freeing meta pages in the error case.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/checkpoint.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 35601b0d077f..698b13ae261c 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -770,7 +770,7 @@ int get_valid_checkpoint(struct f2fs_sb_info *sbi)
 
 	/* Sanity checking of checkpoint */
 	if (sanity_check_ckpt(sbi))
-		goto fail_no_cp;
+		goto free_fail_no_cp;
 
 	if (cur_page == cp1)
 		sbi->cur_cp_pack = 1;
@@ -798,6 +798,9 @@ int get_valid_checkpoint(struct f2fs_sb_info *sbi)
 	f2fs_put_page(cp2, 1);
 	return 0;
 
+free_fail_no_cp:
+	f2fs_put_page(cp1, 1);
+	f2fs_put_page(cp2, 1);
 fail_no_cp:
 	kfree(sbi->ckpt);
 	return -EINVAL;
-- 
2.11.0

Re: [PATCH 1/2] f2fs: detect wrong layout

[Eric Biggers]

On Tue, Dec 06, 2016 at 05:16:24PM -0800, Jaegeuk Kim wrote:
> 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-by: Eric Biggers <ebiggers@google.com>
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---

Hi Jaegeuk, I tested these two patches and they seem to work correctly --- the
kernel now doesn't allow mounting a 32 MB f2fs filesystem.

Thanks!

Eric

Re: [PATCH 1/2] f2fs: detect wrong layout

[Jaegeuk Kim]

On Wed, Dec 07, 2016 at 12:16:50PM -0800, Eric Biggers wrote:
> On Tue, Dec 06, 2016 at 05:16:24PM -0800, Jaegeuk Kim wrote:
> > 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-by: Eric Biggers <ebiggers@google.com>
> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> > ---
> 
> Hi Jaegeuk, I tested these two patches and they seem to work correctly --- the
> kernel now doesn't allow mounting a 32 MB f2fs filesystem.

Okay, thank you for verifying this.
Let me put Tested-by you. ;)

Thanks,

> 
> Thanks!
> 
> Eric