On Nov 30, 2019 / 15:49, Chao Yu wrote:
> On 2019/11/29 13:21, Shinichiro Kawasaki wrote:
> > On Nov 28, 2019 / 20:39, Chao Yu wrote:
> >> On 2019/11/28 13:31, Shinichiro Kawasaki wrote:
> >>> On Nov 25, 2019 / 15:37, Chao Yu wrote:
> >>>> On 2019/11/14 16:19, Shin'ichiro Kawasaki wrote:
> >>>>> To catch f2fs bugs in write pointer handling code for zoned block
> >>>>> devices, check write pointers of non-open zones that current segments do
> >>>>> not point to. Do this check at mount time, after the fsync data recovery
> >>>>> and current segments' write pointer consistency fix. Or when fsync data
> >>>>> recovery is disabled by mount option, do the check when there is no
> >>>>> fsync
> >>>>> data.
> >>>>>
> >>>>> Check two items comparing write pointers with valid block maps in SIT.
> >>>>> The first item is check for zones with no valid blocks. When there is no
> >>>>> valid blocks in a zone, the write pointer should be at the start of the
> >>>>> zone. If not, next write operation to the zone will cause unaligned
> >>>>> write
> >>>>> error. If write pointer is not at the zone start, make mount fail and
> >>>>> ask
> >>>>> users to run fsck.
> >>>>>
> >>>>> The second item is check between the write pointer position and the last
> >>>>> valid block in the zone. It is unexpected that the last valid block
> >>>>> position is beyond the write pointer. In such a case, report as a bug.
> >>>>> Fix is not required for such zone, because the zone is not selected for
> >>>>> next write operation until the zone get discarded.
> >>>>>
> >>>>> Also move a constant F2FS_REPORT_ZONE from super.c to f2fs.h to use it
> >>>>> in segment.c also.
> >>>>>
> >>>>> Signed-off-by: Shin'ichiro Kawasaki <[email protected]>
> >>>>> ---
> >>>>> fs/f2fs/f2fs.h | 3 +
> >>>>> fs/f2fs/segment.c | 149 ++++++++++++++++++++++++++++++++++++++++++++++
> >>>>> fs/f2fs/super.c | 16 ++++-
> >>>>> 3 files changed, 165 insertions(+), 3 deletions(-)
> >>>>>
> >>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> >>>>> index a2e24718c13b..1bb64950d793 100644
> >>>>> --- a/fs/f2fs/f2fs.h
> >>>>> +++ b/fs/f2fs/f2fs.h
> >>>>> @@ -3137,6 +3137,7 @@ int f2fs_lookup_journal_in_cursum(struct
> >>>>> f2fs_journal *journal, int type,
> >>>>> unsigned int val, int alloc);
> >>>>> void f2fs_flush_sit_entries(struct f2fs_sb_info *sbi, struct
> >>>>> cp_control *cpc);
> >>>>> int f2fs_fix_curseg_write_pointer(struct f2fs_sb_info *sbi);
> >>>>> +int f2fs_check_write_pointer(struct f2fs_sb_info *sbi);
> >>>>> int f2fs_build_segment_manager(struct f2fs_sb_info *sbi);
> >>>>> void f2fs_destroy_segment_manager(struct f2fs_sb_info *sbi);
> >>>>> int __init f2fs_create_segment_manager_caches(void);
> >>>>> @@ -3610,6 +3611,8 @@ static inline bool f2fs_blkz_is_seq(struct
> >>>>> f2fs_sb_info *sbi, int devi,
> >>>>>
> >>>>> return test_bit(zno, FDEV(devi).blkz_seq);
> >>>>> }
> >>>>> +
> >>>>> +#define F2FS_REPORT_NR_ZONES 4096
> >>>>> #endif
> >>>>>
> >>>>> static inline bool f2fs_hw_should_discard(struct f2fs_sb_info *sbi)
> >>>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> >>>>> index 6ece146dab34..29e3b6f62f8c 100644
> >>>>> --- a/fs/f2fs/segment.c
> >>>>> +++ b/fs/f2fs/segment.c
> >>>>> @@ -4333,6 +4333,133 @@ static int sanity_check_curseg(struct
> >>>>> f2fs_sb_info *sbi)
> >>>>>
> >>>>> #ifdef CONFIG_BLK_DEV_ZONED
> >>>>>
> >>>>> +static int check_zone_write_pointer(struct f2fs_sb_info *sbi,
> >>>>> + struct f2fs_dev_info *fdev,
> >>>>> + struct blk_zone *zone)
> >>>>> +{
> >>>>> + unsigned int wp_segno, wp_blkoff, zone_secno, zone_segno, segno;
> >>>>> + block_t zone_block, wp_block, last_valid_block;
> >>>>> + unsigned int log_sectors_per_block = sbi->log_blocksize -
> >>>>> SECTOR_SHIFT;
> >>>>> + int i, s, b;
> >>>>> + struct seg_entry *se;
> >>>>> +
> >>>>> + wp_block = fdev->start_blk + (zone->wp >>
> >>>>> log_sectors_per_block);
> >>>>> + wp_segno = GET_SEGNO(sbi, wp_block);
> >>>>> + wp_blkoff = wp_block - START_BLOCK(sbi, wp_segno);
> >>>>> + zone_block = fdev->start_blk + (zone->start >>
> >>>>> log_sectors_per_block);
> >>>>> + zone_segno = GET_SEGNO(sbi, zone_block);
> >>>>> + zone_secno = GET_SEC_FROM_SEG(sbi, zone_segno);
> >>>>> +
> >>>>> + if (zone_segno >= MAIN_SEGS(sbi))
> >>>>> + return 0;
> >>>>> +
> >>>>> + /*
> >>>>> + * Skip check of zones cursegs point to, since
> >>>>> + * fix_curseg_write_pointer() checks them.
> >>>>> + */
> >>>>> + for (i = 0; i < NO_CHECK_TYPE; i++)
> >>>>> + if (zone_secno == GET_SEC_FROM_SEG(sbi,
> >>>>> + CURSEG_I(sbi,
> >>>>> i)->segno))
> >>>>> + return 0;
> >>>>> +
> >>>>> + /*
> >>>>> + * Get last valid block of the zone.
> >>>>> + */
> >>>>> + last_valid_block = zone_block - 1;
> >>>>> + for (s = sbi->segs_per_sec - 1; s >= 0; s--) {
> >>>>> + segno = zone_segno + s;
> >>>>> + se = get_seg_entry(sbi, segno);
> >>>>> + for (b = sbi->blocks_per_seg - 1; b >= 0; b--)
> >>>>> + if (f2fs_test_bit(b, se->cur_valid_map)) {
> >>>>> + last_valid_block = START_BLOCK(sbi,
> >>>>> segno) + b;
> >>>>> + break;
> >>>>> + }
> >>>>> + if (last_valid_block >= zone_block)
> >>>>> + break;
> >>>>> + }
> >>>>> +
> >>>>> + /*
> >>>>> + * If last valid block is beyond the write pointer, report the
> >>>>> + * inconsistency. This inconsistency does not cause write error
> >>>>> + * because the zone will not be selected for write operation
> >>>>> until
> >>>>> + * it get discarded. Just report it.
> >>>>> + */
> >>>>> + if (last_valid_block >= wp_block) {
> >>>>> + f2fs_notice(sbi, "Valid block beyond write pointer: "
> >>>>> + "valid block[0x%x,0x%x] wp[0x%x,0x%x]",
> >>>>> + GET_SEGNO(sbi, last_valid_block),
> >>>>> + GET_BLKOFF_FROM_SEG0(sbi, last_valid_block),
> >>>>> + wp_segno, wp_blkoff);
> >>>>> + return 0;
> >>>>> + }
> >>>>> +
> >>>>> + /*
> >>>>> + * If there is no valid block in the zone and if write pointer
> >>>>> is
> >>>>> + * not at zone start, report the error to run fsck.
> >>>>
> >>>> So we only need to report this as inconsistent status in the condition of
> >>>> discard has been triggered, right? otherwise, f2fs will trigger discard
> >>>> later
> >>>> to reset zone->wp before opening this zone?
> >>>
> >>> Hmm, my intent was to catch the inconsistency at mount time, assuming the
> >>> inconsistency is not expected at mount time. In other words, I assume that
> >>> discard is triggered for zones without valid blocks before that last clean
> >>
> >> IIUC, if there is too many pending discards, put_super() may drop discard
> >> entries
> >> to avoid delaying umount, so we can not assume all discards are always
> >> being
> >> triggered.
> >
> > I see. In this case, current code in the patch will miss-detect the zone
> > with
> > the dropped discard entries. This is not good. Thank you for catching this
> > :)
> >
> >>
> >> So what I mean is for the condition of a) there is valid (including
> >> fsycned) block,
> >> b) zone->wp is not at correct position, f2fs can handle it by issuing
> >> discard. Let
> >> me know if I misread this comment.
> >
> > For the condition a), do you mean "there is _no_ valid (include fsynced)
> > block"?
>
> Oops, yes, I meant that. :)
OK, will add the discard by reset zone and will post next version. Thanks.
Also, I noticed that this patch series have conflicts with the latest linux
kernel master branch because of the commit d41003513e61 "block: rework zone
reporting", which changed interface of blkdev_report_zones() function.
Will rebase to the master branch and resolve the conflicts.
--
best Regards,
Shin'ichiro Kawasaki
>
> Thanks,
>
> > If so, yes, I agree that f2fs can issue discard and both a) and b) are
> > true. I
> > can add a simple function call of "reset zone" to discard the zone.
> >
> >>
> >>> umount. If the last sudden f2fs shutdown without clean umount caused the
> >>> inconsistency, it should be reported and fixed, I think.
> >>>
> >>> SIT valid blocks are referred to check if there is no valid blocks in the
> >>> zone.
> >>> SIT may be broken due to software bug or hardware flaw, then I think it
> >>> is the
> >>> better to run fsck rather than discard by f2fs.
> >>>
> >>> If I miss anything, please let me know.
> >>>
> >>> --
> >>> Best Regards,
> >>> Shin'ichiro Kawasaki
> >>>
> >>>>
> >>>> Thanks,
> >>>>
> >>>>> + */
> >>>>> + if (last_valid_block + 1 == zone_block && zone->wp !=
> >>>>> zone->start) {
> >>>>> + f2fs_notice(sbi,
> >>>>> + "Zone without valid block has non-zero
> >>>>> write "
> >>>>> + "pointer, run fsck to fix: wp[0x%x,0x%x]",
> >>>>> + wp_segno, wp_blkoff);
> >>>>> + f2fs_stop_checkpoint(sbi, true);
> >>>>> + set_sbi_flag(sbi, SBI_NEED_FSCK);
> >>>>> + return -EINVAL;
> >>>>> + }
> >>>>> +
> >>>>> + return 0;
> >>>>> +}
> >>>>> +
> >>>>> +static int check_dev_write_pointer(struct f2fs_sb_info *sbi,
> >>>>> + struct f2fs_dev_info *fdev) {
> >>>>> + sector_t nr_sectors = fdev->bdev->bd_part->nr_sects;
> >>>>> + sector_t sector = 0;
> >>>>> + struct blk_zone *zones;
> >>>>> + unsigned int i, nr_zones;
> >>>>> + unsigned int n = 0;
> >>>>> + int err = -EIO;
> >>>>> +
> >>>>> + if (!bdev_is_zoned(fdev->bdev))
> >>>>> + return 0;
> >>>>> +
> >>>>> + zones = f2fs_kzalloc(sbi,
> >>>>> + array_size(F2FS_REPORT_NR_ZONES,
> >>>>> + sizeof(struct blk_zone)),
> >>>>> + GFP_KERNEL);
> >>>>> + if (!zones)
> >>>>> + return -ENOMEM;
> >>>>> +
> >>>>> + /* Get block zones type */
> >>>>> + while (zones && sector < nr_sectors) {
> >>>>> +
> >>>>> + nr_zones = F2FS_REPORT_NR_ZONES;
> >>>>> + err = blkdev_report_zones(fdev->bdev, sector, zones,
> >>>>> &nr_zones);
> >>>>> + if (err)
> >>>>> + break;
> >>>>> + if (!nr_zones) {
> >>>>> + err = -EIO;
> >>>>> + break;
> >>>>> + }
> >>>>> +
> >>>>> + for (i = 0; i < nr_zones; i++) {
> >>>>> + if (zones[i].type ==
> >>>>> BLK_ZONE_TYPE_SEQWRITE_REQ) {
> >>>>> + err = check_zone_write_pointer(sbi,
> >>>>> fdev,
> >>>>> +
> >>>>> &zones[i]);
> >>>>> + if (err)
> >>>>> + break;
> >>>>> + }
> >>>>> + sector += zones[i].len;
> >>>>> + n++;
> >>>>> + }
> >>>>> + if (err)
> >>>>> + break;
> >>>>> + }
> >>>>> +
> >>>>> + kvfree(zones);
> >>>>> +
> >>>>> + return err;
> >>>>> +}
> >>>>> +
> >>>>> static struct f2fs_dev_info *get_target_zoned_dev(struct f2fs_sb_info
> >>>>> *sbi,
> >>>>> block_t zone_blkaddr)
> >>>>> {
> >>>>> @@ -4399,6 +4526,10 @@ static int fix_curseg_write_pointer(struct
> >>>>> f2fs_sb_info *sbi, int type)
> >>>>> "curseg[0x%x,0x%x]", type, cs->segno,
> >>>>> cs->next_blkoff);
> >>>>> allocate_segment_by_default(sbi, type, true);
> >>>>>
> >>>>> + /* check consistency of the zone curseg pointed to */
> >>>>> + if (check_zone_write_pointer(sbi, zbd, &zone))
> >>>>> + return -EIO;
> >>>>> +
> >>>>> /* check newly assigned zone */
> >>>>> cs_section = GET_SEC_FROM_SEG(sbi, cs->segno);
> >>>>> cs_zone_block = START_BLOCK(sbi, GET_SEG_FROM_SEC(sbi,
> >>>>> cs_section));
> >>>>> @@ -4444,11 +4575,29 @@ int f2fs_fix_curseg_write_pointer(struct
> >>>>> f2fs_sb_info *sbi)
> >>>>>
> >>>>> return 0;
> >>>>> }
> >>>>> +
> >>>>> +int f2fs_check_write_pointer(struct f2fs_sb_info *sbi)
> >>>>> +{
> >>>>> + int i, ret;
> >>>>> +
> >>>>> + for (i = 0; i < sbi->s_ndevs; i++) {
> >>>>> + ret = check_dev_write_pointer(sbi, &FDEV(i));
> >>>>> + if (ret)
> >>>>> + return ret;
> >>>>> + }
> >>>>> +
> >>>>> + return 0;
> >>>>> +}
> >>>>> #else
> >>>>> int f2fs_fix_curseg_write_pointer(struct f2fs_sb_info *sbi)
> >>>>> {
> >>>>> return 0;
> >>>>> }
> >>>>> +
> >>>>> +int f2fs_check_write_pointer(struct f2fs_sb_info *sbi)
> >>>>> +{
> >>>>> + return 0;
> >>>>> +}
> >>>>> #endif
> >>>>>
> >>>>> /*
> >>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> >>>>> index 1443cee15863..8ca772670c67 100644
> >>>>> --- a/fs/f2fs/super.c
> >>>>> +++ b/fs/f2fs/super.c
> >>>>> @@ -2890,8 +2890,6 @@ static int init_blkz_info(struct f2fs_sb_info
> >>>>> *sbi, int devi)
> >>>>> if (!FDEV(devi).blkz_seq)
> >>>>> return -ENOMEM;
> >>>>>
> >>>>> -#define F2FS_REPORT_NR_ZONES 4096
> >>>>> -
> >>>>> zones = f2fs_kzalloc(sbi,
> >>>>> array_size(F2FS_REPORT_NR_ZONES,
> >>>>> sizeof(struct blk_zone)),
> >>>>> @@ -3509,7 +3507,8 @@ static int f2fs_fill_super(struct super_block
> >>>>> *sb, void *data, int silent)
> >>>>>
> >>>>> err = f2fs_recover_fsync_data(sbi, false);
> >>>>> if (err < 0) {
> >>>>> - if (err != -ENOMEM)
> >>>>> + if (err != -ENOMEM &&
> >>>>> + !is_sbi_flag_set(sbi, SBI_NEED_FSCK))
> >>>>> skip_recovery = true;
> >>>>> need_fsck = true;
> >>>>> f2fs_err(sbi, "Cannot recover all fsync data
> >>>>> errno=%d",
> >>>>> @@ -3525,6 +3524,17 @@ static int f2fs_fill_super(struct super_block
> >>>>> *sb, void *data, int silent)
> >>>>> goto free_meta;
> >>>>> }
> >>>>> }
> >>>>> +
> >>>>> + /*
> >>>>> + * If the f2fs is not readonly and fsync data recovery succeeds,
> >>>>> + * check zoned block devices' write pointer consistency.
> >>>>> + */
> >>>>> + if (!err && !f2fs_readonly(sb) && f2fs_sb_has_blkzoned(sbi)) {
> >>>>> + err = f2fs_check_write_pointer(sbi);
> >>>>> + if (err)
> >>>>> + goto free_meta;
> >>>>> + }
> >>>>> +
> >>>>> reset_checkpoint:
> >>>>> /* f2fs_recover_fsync_data() cleared this already */
> >>>>> clear_sbi_flag(sbi, SBI_POR_DOING);
> >>>>> .
> >>>
> >
> > --
> > Best Regards,
> > Shin'ichiro Kawasaki
> > .
> >
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