On Aug 27, 2019 / 10:13, Chao Yu wrote: > On 2019/8/27 10:01, Chao Yu wrote: > > On 2019/8/21 12:48, 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> > >> --- > >> fsck/fsck.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > >> fsck/fsck.h | 3 ++ > >> fsck/main.c | 2 + > >> 3 files changed, 138 insertions(+) > >> > >> diff --git a/fsck/fsck.c b/fsck/fsck.c > >> index 8953ca1..21a06ac 100644 > >> --- a/fsck/fsck.c > >> +++ b/fsck/fsck.c > >> @@ -2574,6 +2574,125 @@ out: > >> return cnt; > >> } > >> > >> +struct write_pointer_check_data { > >> + struct f2fs_sb_info *sbi; > >> + struct device_info *dev; > >> +}; > >> + > >> +#define SECTOR_SHIFT 9 > >> + > >> +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; > >> + } > > > > Will this happen? > > > > - write checkpoint > > - curseg points zone A > > - write large number of data > > - curseg points zone B, write pointer > 0 > > - sudden power cut, curseg will be reset to zone A > > > > zone B's write pointer won't be verified due to curseg points to zone A? > > IIUC, we are trying fix such condition in a separated PATCH 4/4. > > Reviewed-by: Chao Yu <yuch...@huawei.com>
Yes, that's the failure scenario that PATCH 4/4 tried to address. As I responded separately, I would like to drop PATCH 4/4 at this moment. Will add your reviewed-by tag to this PATCH 3/4 in the next version. 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