Re: [PATCH 04/22] target: Make use of the new sg_map function at 16 call sites (fwd)

From: Julia Lawall
Date: Fri Apr 14 2017 - 11:19:55 EST

It looks like &udev->cmdr_lock should be released at line 512 if it has
not been released otherwise. The lock was taken at line 438.

julia

---------- Forwarded message ----------
Date: Fri, 14 Apr 2017 22:21:44 +0800
From: kbuild test robot <fengguang.wu@xxxxxxxxx>
To: kbuild@xxxxxx
Cc: Julia Lawall <julia.lawall@xxxxxxx>
Subject: Re: [PATCH 04/22] target: Make use of the new sg_map function at 16
call sites

Hi Logan,

[auto build test WARNING on scsi/for-next]
[also build test WARNING on v4.11-rc6]
[cannot apply to next-20170413]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Logan-Gunthorpe/Introduce-common-scatterlist-map-function/20170414-142518
base: https://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git for-next
:::::: branch date: 8 hours ago
:::::: commit date: 8 hours ago

>> drivers/target/target_core_user.c:512:2-8: preceding lock on line 438
drivers/target/target_core_user.c:512:2-8: preceding lock on line 471

git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 78082134e7afdc59d744eb8d2def5c588e89c378
vim +512 drivers/target/target_core_user.c

7c9e7a6f Andy Grover 2014-10-01 432 sizeof(struct tcmu_cmd_entry));
7c9e7a6f Andy Grover 2014-10-01 433 command_size = base_command_size
7c9e7a6f Andy Grover 2014-10-01 434 + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE);
7c9e7a6f Andy Grover 2014-10-01 435
7c9e7a6f Andy Grover 2014-10-01 436 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
7c9e7a6f Andy Grover 2014-10-01 437
7c9e7a6f Andy Grover 2014-10-01 @438 spin_lock_irq(&udev->cmdr_lock);
7c9e7a6f Andy Grover 2014-10-01 439
7c9e7a6f Andy Grover 2014-10-01 440 mb = udev->mb_addr;
7c9e7a6f Andy Grover 2014-10-01 441 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
26418649 Sheng Yang 2016-02-26 442 data_length = se_cmd->data_length;
26418649 Sheng Yang 2016-02-26 443 if (se_cmd->se_cmd_flags & SCF_BIDI) {
26418649 Sheng Yang 2016-02-26 444 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
26418649 Sheng Yang 2016-02-26 445 data_length += se_cmd->t_bidi_data_sg->length;
26418649 Sheng Yang 2016-02-26 446 }
554617b2 Andy Grover 2016-08-25 447 if ((command_size > (udev->cmdr_size / 2)) ||
554617b2 Andy Grover 2016-08-25 448 data_length > udev->data_size) {
554617b2 Andy Grover 2016-08-25 449 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
3d9b9555 Andy Grover 2016-08-25 450 "cmd ring/data area\n", command_size, data_length,
7c9e7a6f Andy Grover 2014-10-01 451 udev->cmdr_size, udev->data_size);
554617b2 Andy Grover 2016-08-25 452 spin_unlock_irq(&udev->cmdr_lock);
554617b2 Andy Grover 2016-08-25 453 return TCM_INVALID_CDB_FIELD;
554617b2 Andy Grover 2016-08-25 454 }
7c9e7a6f Andy Grover 2014-10-01 455
26418649 Sheng Yang 2016-02-26 456 while (!is_ring_space_avail(udev, command_size, data_length)) {
7c9e7a6f Andy Grover 2014-10-01 457 int ret;
7c9e7a6f Andy Grover 2014-10-01 458 DEFINE_WAIT(__wait);
7c9e7a6f Andy Grover 2014-10-01 459
7c9e7a6f Andy Grover 2014-10-01 460 prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE);
7c9e7a6f Andy Grover 2014-10-01 461
7c9e7a6f Andy Grover 2014-10-01 462 pr_debug("sleeping for ring space\n");
7c9e7a6f Andy Grover 2014-10-01 463 spin_unlock_irq(&udev->cmdr_lock);
7c9e7a6f Andy Grover 2014-10-01 464 ret = schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT));
7c9e7a6f Andy Grover 2014-10-01 465 finish_wait(&udev->wait_cmdr, &__wait);
7c9e7a6f Andy Grover 2014-10-01 466 if (!ret) {
7c9e7a6f Andy Grover 2014-10-01 467 pr_warn("tcmu: command timed out\n");
02eb924f Andy Grover 2016-10-06 468 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
7c9e7a6f Andy Grover 2014-10-01 469 }
7c9e7a6f Andy Grover 2014-10-01 470
7c9e7a6f Andy Grover 2014-10-01 471 spin_lock_irq(&udev->cmdr_lock);
7c9e7a6f Andy Grover 2014-10-01 472
7c9e7a6f Andy Grover 2014-10-01 473 /* We dropped cmdr_lock, cmd_head is stale */
7c9e7a6f Andy Grover 2014-10-01 474 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
7c9e7a6f Andy Grover 2014-10-01 475 }
7c9e7a6f Andy Grover 2014-10-01 476
f56574a2 Andy Grover 2014-10-02 477 /* Insert a PAD if end-of-ring space is too small */
f56574a2 Andy Grover 2014-10-02 478 if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
f56574a2 Andy Grover 2014-10-02 479 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
f56574a2 Andy Grover 2014-10-02 480
7c9e7a6f Andy Grover 2014-10-01 481 entry = (void *) mb + CMDR_OFF + cmd_head;
7c9e7a6f Andy Grover 2014-10-01 482 tcmu_flush_dcache_range(entry, sizeof(*entry));
0ad46af8 Andy Grover 2015-04-14 483 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
0ad46af8 Andy Grover 2015-04-14 484 tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
0ad46af8 Andy Grover 2015-04-14 485 entry->hdr.cmd_id = 0; /* not used for PAD */
0ad46af8 Andy Grover 2015-04-14 486 entry->hdr.kflags = 0;
0ad46af8 Andy Grover 2015-04-14 487 entry->hdr.uflags = 0;
7c9e7a6f Andy Grover 2014-10-01 488
7c9e7a6f Andy Grover 2014-10-01 489 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
7c9e7a6f Andy Grover 2014-10-01 490
7c9e7a6f Andy Grover 2014-10-01 491 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
7c9e7a6f Andy Grover 2014-10-01 492 WARN_ON(cmd_head != 0);
7c9e7a6f Andy Grover 2014-10-01 493 }
7c9e7a6f Andy Grover 2014-10-01 494
7c9e7a6f Andy Grover 2014-10-01 495 entry = (void *) mb + CMDR_OFF + cmd_head;
7c9e7a6f Andy Grover 2014-10-01 496 tcmu_flush_dcache_range(entry, sizeof(*entry));
0ad46af8 Andy Grover 2015-04-14 497 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
0ad46af8 Andy Grover 2015-04-14 498 tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
0ad46af8 Andy Grover 2015-04-14 499 entry->hdr.cmd_id = tcmu_cmd->cmd_id;
0ad46af8 Andy Grover 2015-04-14 500 entry->hdr.kflags = 0;
0ad46af8 Andy Grover 2015-04-14 501 entry->hdr.uflags = 0;
7c9e7a6f Andy Grover 2014-10-01 502
26418649 Sheng Yang 2016-02-26 503 bitmap_copy(old_bitmap, udev->data_bitmap, DATA_BLOCK_BITS);
26418649 Sheng Yang 2016-02-26 504
3d9b9555 Andy Grover 2016-08-25 505 /* Handle allocating space from the data area */
7c9e7a6f Andy Grover 2014-10-01 506 iov = &entry->req.iov[0];
f97ec7db Ilias Tsitsimpis 2015-04-23 507 iov_cnt = 0;
e4648b01 Ilias Tsitsimpis 2015-04-23 508 copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE
e4648b01 Ilias Tsitsimpis 2015-04-23 509 || se_cmd->se_cmd_flags & SCF_BIDI);
78082134 Logan Gunthorpe 2017-04-13 510 if (alloc_and_scatter_data_area(udev, se_cmd->t_data_sg,
78082134 Logan Gunthorpe 2017-04-13 511 se_cmd->t_data_nents, &iov, &iov_cnt, copy_to_data_area))
78082134 Logan Gunthorpe 2017-04-13 @512 return TCM_OUT_OF_RESOURCES;
78082134 Logan Gunthorpe 2017-04-13 513
7c9e7a6f Andy Grover 2014-10-01 514 entry->req.iov_cnt = iov_cnt;
0ad46af8 Andy Grover 2015-04-14 515 entry->req.iov_dif_cnt = 0;

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