On Nov 05, 2019 / 20:22, Chao Yu wrote: > On 2019/10/28 14:58, 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. 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 the 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 <shinichiro.kawas...@wdc.com> > > --- > > fs/f2fs/f2fs.h | 3 + > > fs/f2fs/segment.c | 147 ++++++++++++++++++++++++++++++++++++++++++++++ > > fs/f2fs/super.c | 11 ++-- > > 3 files changed, 157 insertions(+), 4 deletions(-) > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > index 0216282c5b80..e8524be17852 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, bool > > check_only); > > +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 2b6e637dd6d3..20ef5b3705e1 100644 > > --- a/fs/f2fs/segment.c > > +++ b/fs/f2fs/segment.c > > @@ -4333,6 +4333,131 @@ 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 s, wp_segno, wp_blkoff, zone_secno, zone_segno, segno; > > + block_t zone_block, wp_block, last_valid_block, b; > > + unsigned int log_sectors_per_block = sbi->log_blocksize - SECTOR_SHIFT; > > + int i; > > + 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; > > + > > + /* > > + * If a curseg points to the zone, skip check because the zone > > + * may have fsync data that valid block map does not mark. > > None-curseg zone may also contain fsynced data as well? Maybe we can only > verify > on clean image or recovered image?
Right. This function for none-curseg zones should be called after fsync data recovery. I think my comment above is confusing. The point is that this function is for none-curseg zones, and other function covers check for curseg zones. Let me revise the comment as follows: 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 = 0; s < sbi->segs_per_sec; s++) { > > + segno = zone_segno + s; > > + se = get_seg_entry(sbi, segno); > > + for (b = 0; b < sbi->blocks_per_seg; b++) > > + if (f2fs_test_bit(b, se->cur_valid_map)) > > + last_valid_block = START_BLOCK(sbi, segno) + b; > > + } > > We search bitmap table reversedly. Yes, will reverse the loops in the next post. > > > + > > + /* > > + * 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 and mark the > > + * zone as used. > > + */ > > + 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); > > + __set_inuse(sbi, zone_segno); > > Why do we need to set it inused? if this is necessary, we need to call this > under free_i->segmap_lock. I once thought that I need to set inconsistent zones in use, because I observed that write operation happened after zone consistency check failure (in fill_super() after free_meta label). It caused unaligned writer error. To avoid it, I added __set_inuse() to keep inconsistent zones not selected for the write target. But that write operation happened because the write pointer fix curseg was done out of the SBI_POR_DOING protection. Now I learned SBI_POR_DOING can protect write operation, and I don't think set in use for the inconsistent zones is required. Will remove __set_inuse() calls from this patch and the first patch. Thanks! -- Best Regards, Shin'ichiro Kawasaki _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel