Hi Jaegeuk, On 2018/2/12 7:32, Jaegeuk Kim wrote: > On 02/06, Weichao Guo wrote: >> There is a potential inconsistent metadata case due to a cp block >> crc invalid in the latest checkpoint caused by hardware issues: >> 1) write nodes into segment x; >> 2) write checkpoint A; >> 3) remove nodes in segment x; >> 4) write checkpoint B; >> 5) issue discard or write datas into segment x; >> 6) sudden power-cut; >> 7) use checkpoint A after reboot as checkpoint B is invalid >> >> This inconsistency may be found after several reboots long time later >> and the kernel log about cp block crc invalid has disappeared. This >> makes the root cause of the inconsistency is hard to locate. Let us >> separate such other part issues from f2fs logical bugs in debug version. >> >> Signed-off-by: Weichao Guo <guoweic...@huawei.com> >> --- >> fs/f2fs/checkpoint.c | 8 ++++++-- >> 1 file changed, 6 insertions(+), 2 deletions(-) >> >> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c >> index 8b0945b..16ba96a 100644 >> --- a/fs/f2fs/checkpoint.c >> +++ b/fs/f2fs/checkpoint.c >> @@ -737,13 +737,17 @@ static int get_checkpoint_version(struct f2fs_sb_info >> *sbi, block_t cp_addr, >> crc_offset = le32_to_cpu((*cp_block)->checksum_offset); >> if (crc_offset > (blk_size - sizeof(__le32))) { >> f2fs_msg(sbi->sb, KERN_WARNING, >> - "invalid crc_offset: %zu", crc_offset); >> + "invalid crc_offset: %zu at blk_addr: 0x%x", >> + crc_offset, cp_addr); >> + f2fs_bug_on(sbi, 1); > > I don't think we can use bug_on here, since we're easily getting this when > power-cut happened in the middle of checkpoint pack writes, which is an > expected > behavior. Hmm, we need to consider another way to detect that. We only check CP block crc here. The two CP blocks may have different CP versions when power-cut happened, but their crc value should be valid. IMO, this patch will trigger a bug_on only when some external issues cause CP block crc invalid as one 4K page is persisted atomically.
Thanks, > > Thanks, > >> return -EINVAL; >> } >> >> crc = cur_cp_crc(*cp_block); >> if (!f2fs_crc_valid(sbi, crc, *cp_block, crc_offset)) { >> - f2fs_msg(sbi->sb, KERN_WARNING, "invalid crc value"); >> + f2fs_msg(sbi->sb, KERN_WARNING, >> + "invalid crc value at blk_addr: 0x%x", cp_addr); >> + f2fs_bug_on(sbi, 1); >> return -EINVAL; >> } >> >> -- >> 2.10.1 > > . > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel