Messages in this thread | | | Subject | Re: [kbuild-all] Re: drivers/md/dm-mpath.c:524 multipath_clone_and_map() error: double unlocked 'm->lock' (orig line 516) | From | Rong Chen <> | Date | Mon, 10 Aug 2020 13:13:52 +0800 |
| |
On 8/8/20 10:35 PM, Mike Snitzer wrote: > On Sat, Aug 08 2020 at 8:10am -0400, > kernel test robot <lkp@intel.com> wrote: > >> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master >> head: 449dc8c97089a6e09fb2dac4d92b1b7ac0eb7c1e >> commit: 374117ad4736c5a4f8012cfe59fc07d9d58191d5 dm mpath: use double checked locking in fast path >> date: 4 weeks ago >> config: arm-randconfig-m031-20200808 (attached as .config) >> compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 >> >> If you fix the issue, kindly add following tag as appropriate >> Reported-by: kernel test robot <lkp@intel.com> > All 3 recent reports about smatch showing "double unlocked 'm->lock'" > appear to be bogus. Think smatch is generating false positives (and > given "Old smatch warnings" it seems it has been doing so for some > time). > > In addition, does lkp@intel.com no longer test linux-next? The dm-mpath > locking changes that were just merged into mainline have been in > linux-next since July 13. Why were these tests only done against > mainline? Hi Mike,
kernel test robot still test linux-next, but the bisection worked on linus/master and didn't check the fix in linux-next, we'll optimize the bisection to avoid reporting this kind of problem.
Best Regards, Rong Chen
> > Mike > > > >> New smatch warnings: >> drivers/md/dm-mpath.c:524 multipath_clone_and_map() error: double unlocked 'm->lock' (orig line 516) >> >> Old smatch warnings: >> drivers/md/dm-mpath.c:446 choose_pgpath() error: double unlocked 'm->lock' (orig line 416) >> drivers/md/dm-mpath.c:457 choose_pgpath() error: double unlocked 'm->lock' (orig line 403) >> drivers/md/dm-mpath.c:525 multipath_clone_and_map() error: double unlocked 'm->lock' (orig line 516) >> drivers/md/dm-mpath.c:526 multipath_clone_and_map() error: double unlocked 'm->lock' (orig line 524) >> drivers/md/dm-mpath.c:626 __map_bio() error: double unlocked 'm->lock' (orig line 615) >> drivers/md/dm-mpath.c:627 __map_bio() error: double unlocked 'm->lock' (orig line 615) >> drivers/md/dm-mpath.c:628 __map_bio() error: double unlocked 'm->lock' (orig line 626) >> drivers/md/dm-mpath.c:629 __map_bio() error: double unlocked 'm->lock' (orig line 628) >> drivers/md/dm-mpath.c:1607 pg_init_done() error: double unlocked 'm->lock' (orig line 1560) >> drivers/md/dm-mpath.c:1707 multipath_end_io_bio() error: double unlocked 'm->lock' (orig line 1704) >> drivers/md/dm-mpath.c:1988 multipath_prepare_ioctl() error: double unlocked 'm->lock' (orig line 1984) >> drivers/md/dm-mpath.c:2012 multipath_prepare_ioctl() error: double unlocked 'm->lock' (orig line 2001) >> >> vim +524 drivers/md/dm-mpath.c >> >> 498 >> 499 /* >> 500 * Map cloned requests (request-based multipath) >> 501 */ >> 502 static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, >> 503 union map_info *map_context, >> 504 struct request **__clone) >> 505 { >> 506 struct multipath *m = ti->private; >> 507 size_t nr_bytes = blk_rq_bytes(rq); >> 508 struct pgpath *pgpath; >> 509 struct block_device *bdev; >> 510 struct dm_mpath_io *mpio = get_mpio(map_context); >> 511 struct request_queue *q; >> 512 struct request *clone; >> 513 >> 514 /* Do we need to select a new pgpath? */ >> 515 pgpath = READ_ONCE(m->current_pgpath); >> > 516 if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) >> 517 pgpath = choose_pgpath(m, nr_bytes); >> 518 >> 519 if (!pgpath) { >> 520 if (must_push_back_rq(m)) >> 521 return DM_MAPIO_DELAY_REQUEUE; >> 522 dm_report_EIO(m); /* Failed */ >> 523 return DM_MAPIO_KILL; >> > 524 } else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) || >> 525 mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) { >> 526 pg_init_all_paths(m); >> 527 return DM_MAPIO_DELAY_REQUEUE; >> 528 } >> 529 >> 530 mpio->pgpath = pgpath; >> 531 mpio->nr_bytes = nr_bytes; >> 532 >> 533 bdev = pgpath->path.dev->bdev; >> 534 q = bdev_get_queue(bdev); >> 535 clone = blk_get_request(q, rq->cmd_flags | REQ_NOMERGE, >> 536 BLK_MQ_REQ_NOWAIT); >> 537 if (IS_ERR(clone)) { >> 538 /* EBUSY, ENODEV or EWOULDBLOCK: requeue */ >> 539 if (blk_queue_dying(q)) { >> 540 atomic_inc(&m->pg_init_in_progress); >> 541 activate_or_offline_path(pgpath); >> 542 return DM_MAPIO_DELAY_REQUEUE; >> 543 } >> 544 >> 545 /* >> 546 * blk-mq's SCHED_RESTART can cover this requeue, so we >> 547 * needn't deal with it by DELAY_REQUEUE. More importantly, >> 548 * we have to return DM_MAPIO_REQUEUE so that blk-mq can >> 549 * get the queue busy feedback (via BLK_STS_RESOURCE), >> 550 * otherwise I/O merging can suffer. >> 551 */ >> 552 return DM_MAPIO_REQUEUE; >> 553 } >> 554 clone->bio = clone->biotail = NULL; >> 555 clone->rq_disk = bdev->bd_disk; >> 556 clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; >> 557 *__clone = clone; >> 558 >> 559 if (pgpath->pg->ps.type->start_io) >> 560 pgpath->pg->ps.type->start_io(&pgpath->pg->ps, >> 561 &pgpath->path, >> 562 nr_bytes); >> 563 return DM_MAPIO_REMAPPED; >> 564 } >> 565 >> >> --- >> 0-DAY CI Kernel Test Service, Intel Corporation >> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org > _______________________________________________ > kbuild-all mailing list -- kbuild-all@lists.01.org > To unsubscribe send an email to kbuild-all-leave@lists.01.org
| |