Re: [f2fs-dev] [PATCH v2] fsck.f2fs: support to fix inconsistent sit->type of segments in large section

[Chao Yu via Linux-f2fs-devel <linux-f2fs-devel@lists.sourceforge.net>]

On 6/17/26 08:39, Jaegeuk Kim wrote:
> On 05/21, Chao Yu via Linux-f2fs-devel wrote:
>> fsck.f2fs -d1 <device>
>>
>> [fix_section_type:3036] wrong sit->type (4) in DATA secno:1 segno:2
>> [fix_section_type:3036] wrong sit->type (4) in DATA secno:5 segno:11
>>
>> fsck.f2fs -f <device>
>>
>> [FIX] (fix_section_type:3040)  --> Fix wrong sit->type (4 -> 2) in DATA secno (1), segno (2)
>> [FIX] (fix_section_type:3050)  --> Fix wrong sit->type in DATA secno (1), totally 1 empty segment(s)
>> [FIX] (fix_section_type:3040)  --> Fix wrong sit->type (4 -> 2) in DATA secno (5), segno (11)
>> [FIX] (fix_section_type:3050)  --> Fix wrong sit->type in DATA secno (5), totally 1 empty segment(s)
>>
>> Now it can only fix wrong sit->type of segment from NODE to DATA in a DATA
>> section, such inconsistent image can be generated by recovery.
>>
>> For fuzzed image which contains below inconsistent sit->type, we can support
>> to detect and repair later:
>> 1) empty NODE segment in DATA section (FIXED w/ current patch)
>> 2) empty DATA segment in NODE section
>> 3) valid segments w/ different temperature in DATA section
>> 4) valid segments w/ different temperature in NODE section
>> 5) valid segments w/ different sit->type in section
>>
>> Cc: Daeho Jeong <daehojeong@google.com>
>> Signed-off-by: Chao Yu <chao@kernel.org>
>> ---
>> v2:
>> - fix printed log
>>  fsck/f2fs.h | 13 ++++++++
>>  fsck/fsck.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 107 insertions(+)
>>
>> diff --git a/fsck/f2fs.h b/fsck/f2fs.h
>> index 5e7eb63..e4e5d0c 100644
>> --- a/fsck/f2fs.h
>> +++ b/fsck/f2fs.h
>> @@ -572,6 +572,19 @@ static inline int IS_CUR_SEGNO(struct f2fs_sb_info *sbi, u32 segno)
>>  	return 0;
>>  }
>>  
>> +static inline int IS_CUR_SECNO(struct f2fs_sb_info *sbi, u32 secno)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < NO_CHECK_TYPE; i++) {
>> +		struct curseg_info *curseg = CURSEG_I(sbi, i);
>> +
>> +		if (secno == GET_SEC_FROM_SEG(sbi, curseg->segno))
>> +			return 1;
>> +	}
>> +	return 0;
>> +}
>> +
>>  static inline u64 BLKOFF_FROM_MAIN(struct f2fs_sb_info *sbi, u64 blk_addr)
>>  {
>>  	ASSERT(blk_addr >= SM_I(sbi)->main_blkaddr);
>> diff --git a/fsck/fsck.c b/fsck/fsck.c
>> index 1230d7b..4fca4dd 100644
>> --- a/fsck/fsck.c
>> +++ b/fsck/fsck.c
>> @@ -3012,6 +3012,97 @@ int check_sit_types(struct f2fs_sb_info *sbi)
>>  	}
>>  	return err;
>>  }
>> +enum type_fix   {
>> +	TYPE_DATA,		/* fix sit->type of empty node segment to data */
>> +	TYPE_NODE,		/* fix sit->type of empty data segment to node */
>> +	TYPE_DATA_TEMP,		/* fix inconsistent sit->type temperature of data segment */
>> +	TYPE_NODE_TEMP,		/* fix inconsistent sit->type temperature of node segment */
>> +	TYPE_MIGRATE,		/* migrate node segments in mixed section */
>> +};
>> +static bool fix_section_type(struct f2fs_sb_info *sbi, unsigned int secno,
>> +				unsigned char type, enum type_fix type_fix)
>> +{
>> +	unsigned int segno = secno * sbi->segs_per_sec;
>> +	unsigned int end_segno = segno + sbi->segs_per_sec;
>> +	unsigned int empty = 0;
>> +	bool fixed = false;
>> +
>> +	for (; segno < end_segno; segno++) {
>> +		struct seg_entry *se = get_seg_entry(sbi, segno);
>> +
>> +		if (type_fix == TYPE_DATA) {
>> +			if (se->valid_blocks)
>> +				continue;
>> +			DBG(1, "wrong sit->type (%d) in DATA secno:%d segno:%d\n",
>> +				se->type, secno, segno);
>> +			if (!c.fix_on)
>> +				continue;
>> +			FIX_MSG("Fix wrong sit->type (%d -> %d) in DATA secno (%u), segno (%d)",
>> +				se->type, type, secno, segno);
>> +			se->type = type;
>> +			empty++;
>> +			fixed = true;
>> +			continue;
>> +		}
>> +	}
>> +
>> +	if (fixed && type_fix == TYPE_DATA)
>> +		FIX_MSG("Fix wrong sit->type in DATA secno (%u), totally %d empty segment(s)",
>> +			secno, empty);
>> +
>> +	return fixed;
>> +}
>> +
>> +static bool check_large_section_types(struct f2fs_sb_info *sbi)
>> +{
>> +	unsigned int secno;
>> +	bool fixed = false;
>> +
>> +	if (sbi->segs_per_sec <= 1)
>> +		return 0;
>> +
>> +	for (secno = 0; secno < sbi->total_sections; secno++) {
>> +		struct seg_entry *se;
>> +		unsigned int segno = secno * sbi->segs_per_sec;
>> +		unsigned int end_segno = segno + sbi->segs_per_sec;
>> +		unsigned short data_seg = 0;
>> +		unsigned short node_seg = 0;
>> +		unsigned short empty_data_seg = 0;
>> +		unsigned short empty_node_seg = 0;
>> +		unsigned char data_type = NO_CHECK_TYPE;
>> +
>> +		if (IS_CUR_SECNO(sbi, secno))
>> +			continue;
>> +
>> +		for (; segno < end_segno; segno++) {
>> +			se = get_seg_entry(sbi, segno);
>> +			if (IS_DATASEG(se->type)) {
>> +				if (se->valid_blocks) {
>> +					data_seg++;
>> +					data_type = se->type;
>> +				} else {
>> +					empty_data_seg++;
> 
> Don't we need to check empty_data_seg below?

I guess we need to check empty_data_seg when we start to sanity check & fix
inconsistent case 2) below, now we don't need.

1) empty NODE segment in DATA section (FIXED w/ current patch)
2) empty DATA segment in NODE section
3) valid segments w/ different temperature in DATA section
4) valid segments w/ different temperature in NODE section
5) valid segments w/ different sit->type in section

Let me remove this variable if it causes confusing or compile warning.

Thanks,

> 
>> +				}
>> +			} else {
>> +				if (se->valid_blocks)
>> +					node_seg++;
>> +				else
>> +					empty_node_seg++;
>> +			}
>> +		}
>> +
>> +		/* skip free section */
>> +		if (!data_seg && !node_seg)
>> +			continue;
>> +
>> +		/* data section, fix sit->type of empty node segment to data */
>> +		if (data_seg && !node_seg && empty_node_seg) {
>> +			if (fix_section_type(sbi, secno, data_type, TYPE_DATA))
>> +				fixed = true;
>> +		}
>> +	}
>> +	return fixed;
>> +}
>>  
>>  static struct f2fs_node *fsck_get_lpf(struct f2fs_sb_info *sbi)
>>  {
>> @@ -3834,6 +3925,9 @@ int fsck_verify(struct f2fs_sb_info *sbi)
>>  	if (check_sit_types(sbi) != 0)
>>  		force = 1;
>>  
>> +	if (check_large_section_types(sbi))
>> +		force = 1;
>> +
>>  	printf("[FSCK] other corrupted bugs                          ");
>>  	if (c.bug_on == 0) {
>>  		printf(" [Ok..]\n");
>> -- 
>> 2.49.0
>>
>>
>>
>> _______________________________________________
>> Linux-f2fs-devel mailing list
>> Linux-f2fs-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel



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