[bug report] BUG libfc_em (Not tainted): Objects remaining in libfc_em on __kmem_cache_shutdown()

[Guangwu Zhang]

Hi,
I found kernel panic issue with latest linux-block/for-next.
repo : https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
Merge branch 'for-6.4/block' into for-next

Reproducer:
1. found qedf HBA host
2. create npiv port
3. remove some modules
modprobe -r qedf
modprobe -r libfcoe
modprobe -r libfc
4. remove npiv port

=============================================================================
[  218.400452] BUG libfc_em (Not tainted): Objects remaining in
libfc_em on __kmem_cache_shutdown()
[  218.410255] -----------------------------------------------------------------------------
[  218.410255]
[  218.421028] Slab 0xffffda6cc4444f00 objects=36 used=4
fp=0xffff92381113ea40
flags=0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
[  218.435392] CPU: 22 PID: 3794 Comm: modprobe Kdump: loaded Not
tainted 6.3.0+ #1
[  218.443645] Hardware name: Dell Inc. PowerEdge R730/0H21J3, BIOS
2.16.0 07/20/2022
[  218.452091] Call Trace:
[  218.454817]  <TASK>
[  218.457154]  dump_stack_lvl+0x33/0x50
[  218.461240]  slab_err+0xc3/0x130
[  218.464842]  ? pick_next_task+0x57/0x9b0
[  218.469219]  ? check_preempt_curr+0x5d/0x70
[  218.473883]  ? ttwu_do_activate+0x6b/0x220
[  218.478453]  ? __switch_to_asm+0x3a/0x80
[  218.482831]  __kmem_cache_shutdown+0x159/0x310
[  218.487789]  kmem_cache_destroy+0x51/0x160
[  218.492361]  libfc_exit+0xa/0x280 [libfc]
[  218.496848]  __do_sys_delete_module.constprop.0+0x17a/0x2f0
[  218.503067]  ? syscall_trace_enter.constprop.0+0x126/0x1a0
[  218.509188]  do_syscall_64+0x5c/0x90
[  218.513177]  ? exit_to_user_mode_prepare+0xc4/0xd0
[  218.518522]  ? syscall_exit_to_user_mode+0x12/0x30
[  218.523866]  ? do_syscall_64+0x69/0x90
[  218.528046]  ? exc_page_fault+0x65/0x150
[  218.532420]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
[  218.538058] RIP: 0033:0x7f9fafa3f5ab
[  218.542046] Code: 73 01 c3 48 8b 0d 75 a8 1b 00 f7 d8 64 89 01 48
83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 45 a8 1b 00 f7 d8 64 89
01 48
[  218.563001] RSP: 002b:00007fff16e560c8 EFLAGS: 00000206 ORIG_RAX:
00000000000000b0
[  218.571448] RAX: ffffffffffffffda RBX: 000055631b3dc510 RCX: 00007f9fafa3f5ab
[  218.579407] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055631b3dc578
[  218.587367] RBP: 000055631b3dc510 R08: 0000000000000000 R09: 0000000000000000
[  218.595328] R10: 00007f9fafb9eac0 R11: 0000000000000206 R12: 000055631b3dc578
[  218.603287] R13: 0000000000000000 R14: 000055631b3dbda8 R15: 00007fff16e58458
[  218.611248]  </TASK>
[  218.613683] Disabling lock debugging due to kernel taint
[  218.619610] Object 0xffff92381113c740 @offset=1856
[  218.624953] Allocated in mempool_init_node+0x92/0xd0 age=205368 cpu=0 pid=391
[  218.632917]  mempool_init_node+0x92/0xd0
[  218.637291]  mempool_create+0x56/0x80
[  218.641374]  fc_exch_mgr_alloc+0xd4/0x220 [libfc]
[  218.646631]  0xffffffffc0a10cbf
[  218.650133]  0xffffffffc0a12ce1
[  218.653633]  local_pci_probe+0x46/0xa0
[  218.657813]  work_for_cpu_fn+0x16/0x20
[  218.661994]  process_one_work+0x1e5/0x3f0
[  218.666467]  worker_thread+0x1c4/0x3a0
[  218.670647]  kthread+0xe2/0x110
[  218.674150]  ret_from_fork+0x2c/0x50
[  218.678138] Object 0xffff92381113d8c0 @offset=6336
[  218.683481] Allocated in mempool_init_node+0x92/0xd0 age=205133 cpu=0 pid=391
[  218.691442]  mempool_init_node+0x92/0xd0
[  218.695816]  mempool_create+0x56/0x80
[  218.699898]  fc_exch_mgr_alloc+0xd4/0x220 [libfc]
[  218.705155]  0xffffffffc0a10cbf
[  218.708655]  0xffffffffc0a12ce1
[  218.712156]  local_pci_probe+0x46/0xa0
[  218.716334]  work_for_cpu_fn+0x16/0x20
[  218.720515]  process_one_work+0x1e5/0x3f0
[  218.724986]  worker_thread+0x1c4/0x3a0
[  218.729167]  kthread+0xe2/0x110
[  218.732668]  ret_from_fork+0x2c/0x50
[  218.736656] Object 0xffff92381113da80 @offset=6784
[  218.741998] Allocated in mempool_init_node+0x92/0xd0 age=205192 cpu=0 pid=391
[  218.749959]  mempool_init_node+0x92/0xd0
[  218.754333]  mempool_create+0x56/0x80
[  218.758416]  fc_exch_mgr_alloc+0xd4/0x220 [libfc]
[  218.763673]  0xffffffffc0a10cbf
[  218.767173]  0xffffffffc0a12ce1
[  218.770674]  local_pci_probe+0x46/0xa0
[  218.774852]  work_for_cpu_fn+0x16/0x20
[  218.779031]  process_one_work+0x1e5/0x3f0
[  218.783504]  worker_thread+0x1c4/0x3a0
[  218.787683]  kthread+0xe2/0x110
[  218.791184]  ret_from_fork+0x2c/0x50
[  218.795172] Object 0xffff92381113dfc0 @offset=8128
[  218.800514] Allocated in mempool_init_node+0x92/0xd0 age=205544 cpu=0 pid=391
[  218.808477]  mempool_init_node+0x92/0xd0
[  218.812851]  mempool_create+0x56/0x80
[  218.816933]  fc_exch_mgr_alloc+0xd4/0x220 [libfc]
[  218.822187]  0xffffffffc0a10cbf
[  218.825688]  0xffffffffc0a12ce1
[  218.829188]  local_pci_probe+0x46/0xa0
[  218.833367]  work_for_cpu_fn+0x16/0x20
[  218.837547]  process_one_work+0x1e5/0x3f0
[  218.842018]  worker_thread+0x1c4/0x3a0
[  218.846197]  kthread+0xe2/0x110
[  218.849698]  ret_from_fork+0x2c/0x50