Re: [f2fs-dev] [PATCH 1/2] f2fs: zone: fix to calculate first_zoned_segno correctly

[Chao Yu]

On 3/25/25 04:49, Daeho Jeong wrote:
> On Mon, Mar 24, 2025 at 4:54 AM Chao Yu via Linux-f2fs-devel
> <linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> A zoned device can has both conventional zones and sequential zones,
>> so we should not treat first segment of zoned device as first_zoned_segno,
>> instead, we need to check zone type for each zone during traversing zoned
>> device to find first_zoned_segno.
>>
>> Otherwise, for below case, first_zoned_segno will be 0, which could be
>> wrong.
>>
>> create_null_blk 512 2 1024 1024
>> mkfs.f2fs -m /dev/nullb0
>>
>> Fixes: 9703d69d9d15 ("f2fs: support file pinning for zoned devices")
>> Cc: Daeho Jeong <daehojeong@xxxxxxxxxx>
>> Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
>> ---
>>  fs/f2fs/f2fs.h    | 18 +++++++++++++-----
>>  fs/f2fs/segment.c |  2 +-
>>  fs/f2fs/super.c   | 32 +++++++++++++++++++++++++++-----
>>  3 files changed, 41 insertions(+), 11 deletions(-)
>>
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index ca884e39a5ff..3dea037faa55 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -4630,12 +4630,16 @@ F2FS_FEATURE_FUNCS(readonly, RO);
>>  F2FS_FEATURE_FUNCS(device_alias, DEVICE_ALIAS);
>>
>>  #ifdef CONFIG_BLK_DEV_ZONED
>> -static inline bool f2fs_blkz_is_seq(struct f2fs_sb_info *sbi, int devi,
>> -                                   block_t blkaddr)
>> +static inline bool f2fs_zone_is_seq(struct f2fs_sb_info *sbi, int devi,
>> +                                                       unsigned int zone)
>>  {
>> -       unsigned int zno = blkaddr / sbi->blocks_per_blkz;
>> +       return test_bit(zone, FDEV(devi).blkz_seq);
>> +}
>>
>> -       return test_bit(zno, FDEV(devi).blkz_seq);
>> +static inline bool f2fs_blkz_is_seq(struct f2fs_sb_info *sbi, int devi,
>> +                                                               block_t blkaddr)
>> +{
>> +       return f2fs_zone_is_seq(sbi, devi, blkaddr / sbi->blocks_per_blkz);
>>  }
>>  #endif
>>
>> @@ -4711,9 +4715,13 @@ static inline bool f2fs_valid_pinned_area(struct f2fs_sb_info *sbi,
>>                                           block_t blkaddr)
>>  {
>>         if (f2fs_sb_has_blkzoned(sbi)) {
>> +#ifdef CONFIG_BLK_DEV_ZONED
>>                 int devi = f2fs_target_device_index(sbi, blkaddr);
>>
>> -               return !bdev_is_zoned(FDEV(devi).bdev);
>> +               return !f2fs_blkz_is_seq(sbi, devi, blkaddr);
>> +#else
>> +               return true;
>> +#endif
>>         }
>>         return true;
>>  }
>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>> index 396ef71f41e3..dc360b4b0569 100644
>> --- a/fs/f2fs/segment.c
>> +++ b/fs/f2fs/segment.c
>> @@ -3311,7 +3311,7 @@ int f2fs_allocate_pinning_section(struct f2fs_sb_info *sbi)
>>
>>         if (f2fs_sb_has_blkzoned(sbi) && err == -EAGAIN && gc_required) {
>>                 f2fs_down_write(&sbi->gc_lock);
>> -               err = f2fs_gc_range(sbi, 0, GET_SEGNO(sbi, FDEV(0).end_blk),
>> +               err = f2fs_gc_range(sbi, 0, sbi->first_zoned_segno - 1,
>>                                 true, ZONED_PIN_SEC_REQUIRED_COUNT);
>>                 f2fs_up_write(&sbi->gc_lock);
>>
>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>> index 011925ee54f8..b2342366020a 100644
>> --- a/fs/f2fs/super.c
>> +++ b/fs/f2fs/super.c
>> @@ -4307,12 +4307,26 @@ static void f2fs_record_error_work(struct work_struct *work)
>>
>>  static inline unsigned int get_first_zoned_segno(struct f2fs_sb_info *sbi)
>>  {
>> -       int devi;
>> +#ifdef CONFIG_BLK_DEV_ZONED
>> +       unsigned int segno;
>> +       int devi, i;
>>
>> -       for (devi = 0; devi < sbi->s_ndevs; devi++)
>> -               if (bdev_is_zoned(FDEV(devi).bdev))
>> -                       return GET_SEGNO(sbi, FDEV(devi).start_blk);
>> -       return 0;
>> +       if (!f2fs_sb_has_blkzoned(sbi))
>> +               return NULL_SEGNO;
>> +
>> +       for (devi = 0; devi < sbi->s_ndevs; devi++) {
>> +               if (!bdev_is_zoned(FDEV(devi).bdev))
>> +                       continue;
>> +
>> +               segno = GET_SEGNO(sbi, FDEV(devi).start_blk);
>> +               for (i = 0; i < FDEV(devi).total_segments; i++) {
>> +                       if (f2fs_zone_is_seq(sbi, devi,
>> +                               GET_ZONE_FROM_SEG(sbi, segno + i)))
> 
> Maybe we can check it with a zone unit?

Yeah, better, let me update it in v2.

Thanks,

> 
>> +                               return segno + i;
>> +               }
>> +       }
>> +#endif
>> +       return NULL_SEGNO;
>>  }
>>
>>  static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
>> @@ -4349,6 +4363,14 @@ static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
>>  #endif
>>
>>         for (i = 0; i < max_devices; i++) {
>> +               if (max_devices == 1) {
>> +                       FDEV(i).total_segments =
>> +                               le32_to_cpu(raw_super->segment_count_main);
>> +                       FDEV(i).start_blk = 0;
>> +                       FDEV(i).end_blk = FDEV(i).total_segments *
>> +                                               BLKS_PER_SEG(sbi);
>> +               }
>> +
>>                 if (i == 0)
>>                         FDEV(0).bdev_file = sbi->sb->s_bdev_file;
>>                 else if (!RDEV(i).path[0])
>> --
>> 2.48.1
>>
>>
>>
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