On Nov 05, 2019 / 19:06, Chao Yu wrote:
> On 2019/10/28 14:55, Shin'ichiro Kawasaki wrote:
> > On sudden f2fs shutdown, 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, this inconsistency causes
> > write operations not at write pointers and "Unaligned write command"
> > error is reported.
> >
> > To avoid the error, have f2fs.fsck check consistency of write pointers
> > of open zones that current segments point to. Compare each current
> > segment's position and the write pointer position of the open zone. If
> > inconsistency is found and 'fix_on' flag is set, assign a new zone to the
> > current segment and check the newly assigned zone has write pointer at
> > the zone start. Leave the original zone as is to keep data recorded in
> > it.
> >
> > To care about fsync data, refer each seg_entry's ckpt_valid_map to get
> > the last valid block in the zone. If the last valid block is beyond the
> > current segments position, fsync data exits in the zone. In case fsync
> > data exists, do not assign a new zone to the current segment not to lose
> > the fsync data. It is expected that the kernel replay the fsync data and
> > fix the write pointer inconsistency at mount time.
> >
> > Also check consistency between write pointer of the zone the current
> > segment points to with valid block maps of the zone. If the last valid
> > block is beyond the write pointer position, report to indicate f2fs bug.
> > If 'fix_on' flag is set, assign a new zone to the current segment.
> >
> > When inconsistencies are found, turn on '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 check and fix is done twice. The first is done at the beginning of
> > do_fsck() function so that other fixes can reflect the current segment
> > modification. The second is done in fsck_verify() to reflect updated meta
> > data by other fixes.
> >
> > Signed-off-by: Shin'ichiro Kawasaki <[email protected]>
> > ---
> > fsck/f2fs.h | 5 ++
> > fsck/fsck.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++++++
> > fsck/fsck.h | 3 +
> > fsck/main.c | 2 +
> > fsck/mount.c | 49 +++++++++++++++-
> > 5 files changed, 212 insertions(+), 1 deletion(-)
> >
> > diff --git a/fsck/f2fs.h b/fsck/f2fs.h
> > index 399c74d..07513cb 100644
> > --- a/fsck/f2fs.h
> > +++ b/fsck/f2fs.h
> > @@ -429,6 +429,11 @@ static inline block_t __end_block_addr(struct
> > f2fs_sb_info *sbi)
> > #define GET_BLKOFF_FROM_SEG0(sbi, blk_addr)
> > \
> > (GET_SEGOFF_FROM_SEG0(sbi, blk_addr) & (sbi->blocks_per_seg - 1))
> >
> > +#define GET_SEC_FROM_SEG(sbi, segno)
> > \
> > + ((segno) / (sbi)->segs_per_sec)
> > +#define GET_SEG_FROM_SEC(sbi, secno)
> > \
> > + ((secno) * (sbi)->segs_per_sec)
> > +
> > #define FREE_I_START_SEGNO(sbi)
> > \
> > GET_SEGNO_FROM_SEG0(sbi, SM_I(sbi)->main_blkaddr)
> > #define GET_R2L_SEGNO(sbi, segno) (segno + FREE_I_START_SEGNO(sbi))
> > diff --git a/fsck/fsck.c b/fsck/fsck.c
> > index 2ae3bd5..e0eda4e 100644
> > --- a/fsck/fsck.c
> > +++ b/fsck/fsck.c
> > @@ -2181,6 +2181,125 @@ static void fix_checkpoints(struct f2fs_sb_info
> > *sbi)
> > fix_checkpoint(sbi);
> > }
> >
> > +#ifdef HAVE_LINUX_BLKZONED_H
> > +
> > +/*
> > + * Refer valid block map and return offset of the last valid block in the
> > zone.
> > + * Obtain valid block map from SIT and fsync data.
> > + * If there is no valid block in the zone, return -1.
> > + */
> > +static int last_vblk_off_in_zone(struct f2fs_sb_info *sbi,
> > + unsigned int zone_segno)
> > +{
> > + unsigned int s;
> > + unsigned int segs_per_zone = sbi->segs_per_sec * sbi->secs_per_zone;
> > + struct seg_entry *se;
> > + block_t b;
> > + int ret = -1;
> > +
> > + for (s = 0; s < segs_per_zone; s++) {
> > + se = get_seg_entry(sbi, zone_segno + s);
> > +
> > + /*
> > + * Refer not cur_valid_map but ckpt_valid_map which reflects
> > + * fsync data.
> > + */
> > + ASSERT(se->ckpt_valid_map);
> > + for (b = 0; b < sbi->blocks_per_seg; b++)
> > + if (f2fs_test_bit(b, (const char*)se->ckpt_valid_map))
> > + ret = b + (s << sbi->log_blocks_per_seg);
>
> Minor thing, I guess we only need to find last valid block in target zone?
>
> int s, b;
>
> for (s = segs_per_zone - 1; s >= 0; s--) {
> for (b = sbi->blocks_per_seg - 1; b >= 0; b--)
> if (f2fs_test_bit(b, (const char*)se->ckpt_valid_map)) {
> ret = b + (s << sbi->log_blocks_per_seg);
> break;
> }
> }
Yes, reveresed search is the better. Will modify the code as suggested.
>
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int check_curseg_write_pointer(struct f2fs_sb_info *sbi, int type)
> > +{
> > + struct curseg_info *curseg = CURSEG_I(sbi, type);
> > + struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
> > + struct blk_zone blkz;
> > + block_t cs_block, wp_block, zone_last_vblock;
> > + u_int64_t cs_sector, wp_sector;
> > + int i, ret;
> > + unsigned int zone_segno;
> > + int log_sectors_per_block = sbi->log_blocksize - SECTOR_SHIFT;
> > +
> > + /* get the device the curseg points to */
> > + cs_block = START_BLOCK(sbi, curseg->segno) + curseg->next_blkoff;
> > + for (i = 0; i < MAX_DEVICES; i++) {
> > + if (!c.devices[i].path)
> > + break;
> > + if (c.devices[i].start_blkaddr <= cs_block &&
> > + cs_block <= c.devices[i].end_blkaddr)
> > + break;
> > + }
> > +
> > + if (i >= MAX_DEVICES)
> > + return -EINVAL;
> > +
> > + /* get write pointer position of the zone the curseg points to */
> > + cs_sector = (cs_block - c.devices[i].start_blkaddr)
> > + << log_sectors_per_block;
> > + ret = f2fs_report_zone(i, cs_sector, &blkz);
> > + if (ret)
> > + return ret;
> > +
> > + if (blk_zone_type(&blkz) != BLK_ZONE_TYPE_SEQWRITE_REQ)
> > + return 0;
> > +
> > + /* check consistency between the curseg and the write pointer */
> > + wp_block = c.devices[i].start_blkaddr +
> > + (blk_zone_wp_sector(&blkz) >> log_sectors_per_block);
> > + wp_sector = blk_zone_wp_sector(&blkz);
> > +
> > + if (cs_sector == wp_sector)
> > + return 0;
> > +
> > + if (cs_sector > wp_sector) {
> > + MSG(0, "Inconsistent write pointer with curseg %d: "
> > + "curseg %d[0x%x,0x%x] > wp[0x%x,0x%x]\n",
> > + type, type, curseg->segno, curseg->next_blkoff,
> > + GET_SEGNO(sbi, wp_block), OFFSET_IN_SEG(sbi, wp_block));
> > + fsck->chk.wp_inconsistent_zones++;
> > + return -EINVAL;
> > + }
> > +
> > + MSG(0, "Write pointer goes advance from curseg %d: "
> > + "curseg %d[0x%x,0x%x] wp[0x%x,0x%x]\n",
> > + type, type, curseg->segno, curseg->next_blkoff,
> > + GET_SEGNO(sbi, wp_block), OFFSET_IN_SEG(sbi, wp_block));
> > +
> > + zone_segno = GET_SEG_FROM_SEC(sbi,
> > + GET_SEC_FROM_SEG(sbi, curseg->segno));
> > + zone_last_vblock = START_BLOCK(sbi, zone_segno) +
> > + last_vblk_off_in_zone(sbi, zone_segno);
> > +
> > + /*
> > + * If fsync data exists between the curseg and the last valid block,
> > + * it is not an error to fix. Leave it for kernel to recover later.
> > + */
> > + if (cs_block <= zone_last_vblock) {
>
> According to above comments, should condition be?
>
> if (cs_block < zone_last_vblock && zone_last_vblock <= wp_block)
>
To be precise, cs_block points to curseg->next_blkoff, which is the block
curseg will write in the next write request. Then, if cs_block equals to
zone_last_vblock, it means that the block curseg->next_blkoff points to
already have valid block and fsync data. Then, comparator between cs_block
and zone_last_vblock should be "<=".
I agree that it is the better to check zone_last_vblock with wp_block.
wp_block corresponds to the write pointer position that next write will be
made. It wp_block equals to zone_last_vblock, it means that unexpected data
is written beyond the write pointer. Then, comparator should be "<" between
zone_last_vblock and wp_block.
In short, I suggest the condition check below as the good one.
if (cs_block <= zone_last_vblock && zone_last_vblock < wp_block)
> > + MSG(0, "Curseg has fsync data: curseg %d[0x%x,0x%x] "
> > + "last valid block in zone[0x%x,0x%x]\n",
> > + type, curseg->segno, curseg->next_blkoff,
> > + GET_SEGNO(sbi, zone_last_vblock),
> > + OFFSET_IN_SEG(sbi, zone_last_vblock));
> > + return 0;
> > + }
> > +
> > + fsck->chk.wp_inconsistent_zones++;
> > + return -EINVAL;
> > +}
> > +
> > +#else
> > +
> > +static int check_curseg_write_pointer(struct f2fs_sb_info *sbi, int type)
> > +{
> > + return 0;
> > +}
> > +
> > +#endif
> > +
> > int check_curseg_offset(struct f2fs_sb_info *sbi, int type)
> > {
> > struct curseg_info *curseg = CURSEG_I(sbi, type);
> > @@ -2209,6 +2328,10 @@ int check_curseg_offset(struct f2fs_sb_info *sbi,
> > int type)
> > return -EINVAL;
> > }
> > }
> > +
> > + if (c.zoned_model == F2FS_ZONED_HM)
> > + return check_curseg_write_pointer(sbi, type);
> > +
> > return 0;
> > }
> >
> > @@ -2628,6 +2751,23 @@ out:
> > return cnt;
> > }
> >
> > +/*
> > + * Check and fix consistency with write pointers at the beginning of
> > + * fsck so that following writes by fsck do not fail.
> > + */
> > +void fsck_chk_and_fix_write_pointers(struct f2fs_sb_info *sbi)
> > +{
> > + struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
> > +
> > + if (c.zoned_model != F2FS_ZONED_HM)
> > + return;
> > +
> > + if (check_curseg_offsets(sbi) && c.fix_on) {
> > + fix_curseg_info(sbi);
> > + fsck->chk.wp_fixed = 1;
> > + }
> > +}
> > +
> > int fsck_chk_curseg_info(struct f2fs_sb_info *sbi)
> > {
> > struct curseg_info *curseg;
> > @@ -2678,6 +2818,20 @@ 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 && 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 75052d8..c4432e8 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;
> > + u32 wp_inconsistent_zones;
> > } chk;
> >
> > struct hard_link_node *hard_link_list_head;
> > @@ -162,6 +164,7 @@ 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_and_fix_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 8c62a14..9a7d499 100644
> > --- a/fsck/main.c
> > +++ b/fsck/main.c
> > @@ -602,6 +602,8 @@ static void do_fsck(struct f2fs_sb_info *sbi)
> >
> > print_cp_state(flag);
> >
> > + fsck_chk_and_fix_write_pointers(sbi);
> > +
> > fsck_chk_curseg_info(sbi);
> >
> > if (!c.fix_on && !c.bug_on) {
> > diff --git a/fsck/mount.c b/fsck/mount.c
> > index 2979865..5085e6c 100644
> > --- a/fsck/mount.c
> > +++ b/fsck/mount.c
> > @@ -2465,6 +2465,52 @@ void set_section_type(struct f2fs_sb_info *sbi,
> > unsigned int segno, int type)
> > }
> > }
> >
> > +#ifdef HAVE_LINUX_BLKZONED_H
> > +
> > +static bool write_pointer_at_zone_start(struct f2fs_sb_info *sbi,
> > + unsigned int zone_segno)
> > +{
> > + u_int64_t sector;
> > + struct blk_zone blkz;
> > + block_t block = START_BLOCK(sbi, zone_segno);
> > + int log_sectors_per_block = sbi->log_blocksize - SECTOR_SHIFT;
> > + int ret, j;
> > +
> > + if (c.zoned_model != F2FS_ZONED_HM)
> > + return true;
> > +
> > + for (j = 0; j < MAX_DEVICES; j++) {
> > + if (!c.devices[j].path)
> > + break;
> > + if (c.devices[j].start_blkaddr <= block &&
> > + block <= c.devices[j].end_blkaddr)
> > + break;
> > + }
> > +
> > + if (j >= MAX_DEVICES)
> > + return false;
> > +
> > + sector = (block - c.devices[j].start_blkaddr) << log_sectors_per_block;
> > + ret = f2fs_report_zone(j, sector, &blkz);
> > + if (ret)
> > + return false;
> > +
> > + if (blk_zone_type(&blkz) != BLK_ZONE_TYPE_SEQWRITE_REQ)
> > + return true;
> > +
> > + return blk_zone_sector(&blkz) == blk_zone_wp_sector(&blkz);
> > +}
> > +
> > +#else
> > +
> > +static bool write_pointer_at_zone_start(struct f2fs_sb_info *sbi,
> > + unsigned int zone_segno)
> > +{
> > + return true;
> > +}
> > +
> > +#endif
> > +
> > int find_next_free_block(struct f2fs_sb_info *sbi, u64 *to, int left, int
> > want_type, bool new_sec)
> > {
> > struct f2fs_super_block *sb = F2FS_RAW_SUPER(sbi);
> > @@ -2517,7 +2563,8 @@ int find_next_free_block(struct f2fs_sb_info *sbi,
> > u64 *to, int left, int want_t
> > break;
> > }
> >
> > - if (i == sbi->segs_per_sec) {
> > + if (i == sbi->segs_per_sec &&
> > + write_pointer_at_zone_start(sbi, segno)) {
> > set_section_type(sbi, segno, want_type);
> > return 0;
> > }
> >
--
Best Regards,
Shin'ichiro Kawasaki
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