On 2019-8-29 14:35, Shin'ichiro Kawasaki wrote:
> On sudden f2fs shutdown, zoned block device status and f2fs current
> segment positions in meta data can be inconsistent. When f2fs shutdown
> happens before write operations completes, write pointers of zoned block
> devices can go further but f2fs meta data keeps current segments at
> positions before the write operations. After remounting the f2fs, the
> inconsistency causes write operations not at write pointers and
> "Unaligned write command" error is reported. This error was observed when
> xfstests test case generic/388 was run with f2fs on a zoned block device.
> 
> To avoid the error, have f2fs.fsck check consistency between each current
> segment's position and the write pointer of the zone the current segment
> points to. If the write pointer goes advance from the current segment,
> fix the current segment position setting at same as the write pointer
> position. In case the write pointer is behind the current segment, write
> zero data at the write pointer position to make write pointer position at
> same as the current segment.
> 
> When inconsistencies are found, turn on c.bug_on flag in fsck_verify() to
> ask users to fix them or not. When inconsistencies get fixed, turn on
> 'force' flag in fsck_verify() to enforce fixes in following checks. This
> position fix is done at the beginning of do_fsck() function so that other
> checks reflect the current segment modification.
> 
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawas...@wdc.com>
> Reviewed-by: Chao Yu <yuch...@huawei.com>
> ---
>  fsck/fsck.c | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  fsck/fsck.h |   3 ++
>  fsck/main.c |   2 +
>  3 files changed, 136 insertions(+)
> 
> diff --git a/fsck/fsck.c b/fsck/fsck.c
> index 8953ca1..f45ca39 100644
> --- a/fsck/fsck.c
> +++ b/fsck/fsck.c
> @@ -2574,6 +2574,123 @@ out:
>       return cnt;
>  }
>  
> +struct write_pointer_check_data {
> +     struct f2fs_sb_info *sbi;
> +     struct device_info *dev;
> +};
> +
> +static int fsck_chk_write_pointer(int i, struct blk_zone *blkz, void *opaque)
> +{
> +     struct write_pointer_check_data *wpd = opaque;
> +     struct f2fs_sb_info *sbi = wpd->sbi;
> +     struct device_info *dev = wpd->dev;
> +     struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
> +     block_t zone_block, wp_block, wp_blkoff, cs_block, b;
> +     unsigned int zone_segno, wp_segno;
> +     struct seg_entry *se;
> +     struct curseg_info *cs;
> +     int cs_index, ret;
> +     int log_sectors_per_block = sbi->log_blocksize - SECTOR_SHIFT;
> +     unsigned int segs_per_zone = sbi->segs_per_sec * sbi->secs_per_zone;
> +     void *zero_blk;
> +
> +     if (blk_zone_conv(blkz))
> +             return 0;
> +
> +     zone_block = dev->start_blkaddr
> +             + (blk_zone_sector(blkz) >> log_sectors_per_block);
> +     zone_segno = GET_SEGNO(sbi, zone_block);
> +     wp_block = dev->start_blkaddr
> +             + (blk_zone_wp_sector(blkz) >> log_sectors_per_block);
> +     wp_segno = GET_SEGNO(sbi, wp_block);
> +     wp_blkoff = wp_block - START_BLOCK(sbi, wp_segno);
> +
> +     /* find the curseg which points to the zone */
> +     for (cs_index = 0; cs_index < NO_CHECK_TYPE; cs_index++) {
> +             cs = &SM_I(sbi)->curseg_array[cs_index];
> +             if (zone_segno <= cs->segno &&
> +                 cs->segno < zone_segno + segs_per_zone)
> +                     break;
> +     }
> +
> +     if (cs_index >= NR_CURSEG_TYPE)
> +             return 0;
> +
> +     /* check write pointer consistency with the curseg in the zone */
> +     cs_block = START_BLOCK(sbi, cs->segno) + cs->next_blkoff;
> +     if (wp_block == cs_block)
> +             return 0;
> +
> +     if (!c.fix_on) {
> +             MSG(0, "Inconsistent write pointer: "
> +                 "curseg %d[0x%x,0x%x] wp[0x%x,0x%x]\n",
> +                 cs_index, cs->segno, cs->next_blkoff, wp_segno, wp_blkoff);
> +             fsck->chk.wp_inconsistent_zones++;
> +             return 0;
> +     }
> +
> +     /*
> +      * If the curseg is in advance from the write pointer, write zero to
> +      * move the write pointer forward to the same position as the curseg.
> +      */
> +     if (wp_block < cs_block) {
> +             ret = 0;
> +             zero_blk = calloc(BLOCK_SZ, 1);
> +             if (!zero_blk)
> +                     return -EINVAL;
> +
> +             FIX_MSG("Advance write pointer to match with curseg %d: "
> +                     "[0x%x,0x%x]->[0x%x,0x%x]",
> +                     cs_index, wp_segno, wp_blkoff,
> +                     cs->segno, cs->next_blkoff);
> +             for (b = wp_block; b < cs_block && !ret; b++)
> +                     ret = dev_write_block(zero_blk, b);
> +
> +             fsck->chk.wp_fixed_zones++;
> +             free(zero_blk);
> +             return ret;
> +     }
> +
> +     /*
> +      * If the write pointer is in advance from the curseg, modify the
> +      * curseg position to be same as the write pointer.
> +      */
> +     FIX_MSG("Advance curseg %d: [0x%x,0x%x]->[0x%x,0x%x]",
> +             cs_index, cs->segno, cs->next_blkoff, wp_segno, wp_blkoff);
> +     se = get_seg_entry(sbi, wp_segno);
> +     se->type = cs_index;
> +     cs->segno = wp_segno;
> +     cs->next_blkoff = wp_blkoff;

I have one more question, if current zone is closed, will wp_blkoff equal to
segment size (wp_block equal to zone size)?

As you know, .next_blkoff should never equal to segment size.

Thanks,

> +     fsck->chk.wp_fixed_zones++;
> +
> +     return 0;
> +}
> +
> +void fsck_chk_write_pointers(struct f2fs_sb_info *sbi)
> +{
> +     unsigned int i;
> +     struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
> +     struct write_pointer_check_data wpd = { sbi, NULL };
> +
> +     if (c.zoned_model != F2FS_ZONED_HM)
> +             return;
> +
> +     for (i = 0; i < MAX_DEVICES; i++) {
> +             if (!c.devices[i].path)
> +                     break;
> +
> +             wpd.dev = c.devices + i;
> +             if (f2fs_report_zones(i, fsck_chk_write_pointer, &wpd)) {
> +                     printf("[FSCK] Write pointer check failed: %s\n",
> +                            c.devices[i].path);
> +                     return;
> +             }
> +     }
> +
> +     if (fsck->chk.wp_fixed_zones && c.fix_on)
> +             write_curseg_info(sbi);
> +}
> +
>  int fsck_chk_curseg_info(struct f2fs_sb_info *sbi)
>  {
>       struct curseg_info *curseg;
> @@ -2624,6 +2741,20 @@ int fsck_verify(struct f2fs_sb_info *sbi)
>  
>       printf("\n");
>  
> +     if (c.zoned_model == F2FS_ZONED_HM) {
> +             printf("[FSCK] Write pointers consistency                    ");
> +             if (fsck->chk.wp_inconsistent_zones == 0x0) {
> +                     printf(" [Ok..]\n");
> +             } else {
> +                     printf(" [Fail] [0x%x]\n",
> +                            fsck->chk.wp_inconsistent_zones);
> +                     c.bug_on = 1;
> +             }
> +
> +             if (fsck->chk.wp_fixed_zones && c.fix_on)
> +                     force = 1;
> +     }
> +
>       if (c.feature & cpu_to_le32(F2FS_FEATURE_LOST_FOUND)) {
>               for (i = 0; i < fsck->nr_nat_entries; i++)
>                       if (f2fs_test_bit(i, fsck->nat_area_bitmap) != 0)
> diff --git a/fsck/fsck.h b/fsck/fsck.h
> index d38e8de..aa3dbe7 100644
> --- a/fsck/fsck.h
> +++ b/fsck/fsck.h
> @@ -80,6 +80,8 @@ struct f2fs_fsck {
>               u32 multi_hard_link_files;
>               u64 sit_valid_blocks;
>               u32 sit_free_segs;
> +             u32 wp_fixed_zones;
> +             u32 wp_inconsistent_zones;
>       } chk;
>  
>       struct hard_link_node *hard_link_list_head;
> @@ -156,6 +158,7 @@ int fsck_chk_inline_dentries(struct f2fs_sb_info *, 
> struct f2fs_node *,
>               struct child_info *);
>  void fsck_chk_checkpoint(struct f2fs_sb_info *sbi);
>  int fsck_chk_meta(struct f2fs_sb_info *sbi);
> +void fsck_chk_write_pointers(struct f2fs_sb_info *);
>  int fsck_chk_curseg_info(struct f2fs_sb_info *);
>  void pretty_print_filename(const u8 *raw_name, u32 len,
>                          char out[F2FS_PRINT_NAMELEN], int enc_name);
> diff --git a/fsck/main.c b/fsck/main.c
> index 9aca024..4b4a789 100644
> --- a/fsck/main.c
> +++ b/fsck/main.c
> @@ -584,6 +584,8 @@ static void do_fsck(struct f2fs_sb_info *sbi)
>  
>       print_cp_state(flag);
>  
> +     fsck_chk_write_pointers(sbi);
> +
>       fsck_chk_curseg_info(sbi);
>  
>       if (!c.fix_on && !c.bug_on) {
> 


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