> 2023年11月29日 07:47，Bagas Sanjaya <bagasdotme@xxxxxxxxx> 写道： > > Hi, > > I notice a regression report that is rather well-handled on Bugzilla [1]. > Quoting from it: > >> >> when booting from 6.7-rc2, compiled with clang, I get this warning on one of my 3 bcachefs volumes: >> WARNING: CPU: 3 PID: 712 at block/badblocks.c:1284 badblocks_check (block/badblocks.c:1284) >> The reason why isn't clear, but the stack trace points to an error in md error handling. >> This bug didn't happen in 6.6 >> there are 3 commits in 6.7-rc2 which may cause them, >> in attachment: >> - decoded stacktrace of dmesg >> - kernel .config > > The culprit author then replied: > >> The warning is from this line of code in _badblocks_check(), >> 1284 WARN_ON(bb->shift < 0 || sectors == 0); >> >> It means the caller sent an invalid range to check. From the oops information, >> "RDX: 0000000000000000" means parameter 'sectors' is 0. >> >> So the question is, why does md raid code send a 0-length range for badblocks check? Is this behavior on purpose, or improper? >> ... >> IMHO, it doesn't make sense for caller to check a zero-length LBA range. The warning works as expect to detect improper call to badblocks_check(). > > See Bugzilla for the full thread and attached decoded dmesg and kernel config. > > Anyway, I'm adding this regression to regzbot: > > #regzbot introduced: 3ea3354cb9f03e https://bugzilla.kernel.org/show_bug.cgi?id=218184 > #regzbot title: badblocks_check regression (md error handling) on bcachefs volume > > Thanks. > > [1]: https://bugzilla.kernel.org/show_bug.cgi?id=218184 It seems the improved bad blocks code caught a zero-size bio request from upper layer, this improper behavior was silently neglected before. It might be too early or simple to decide this is a regression, especially Janpieter closes the report for now. Thanks. Coly Li
