On 2019/11/8 12:27, Shinichiro Kawasaki wrote: > 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
If so, any place to check recovery is done? You know, user can choose to skip recovery by using disable_roll_forward/norecovery mount option. > 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. Also f2fs_stop_checkpoint() will stop any data/node/meta writeback, so it'd be safe here. Thanks, > > 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