On 5/28/21 7:00 PM, Sagi Grimberg wrote:
Hi
I would like to report one regression issue we found recently, after
blktests nvme/011 finished, the device node still exists and seems
there is a lock issue from the log, let me know if you need any
testing for it, thanks.
Hannes, this is a result of your patch most likely.
# ./check nvme/011
nvme/011 (run data verification fio job on NVMeOF file-backed ns)
[passed]
runtime 71.350s ... 77.131s
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 465.8G 0 disk
├─sda1 8:1 0 1G 0 part /boot
├─sda2 8:2 0 31.5G 0 part [SWAP]
├─sda3 8:3 0 15G 0 part
├─sda4 8:4 0 1K 0 part
├─sda5 8:5 0 15G 0 part
├─sda6 8:6 0 5G 0 part
└─sda7 8:7 0 398.3G 0 part /
zram0 253:0 0 4G 0 disk [SWAP]
nvme0n1 259:1 0 1G 0 disk
#dmesg
[ 793.719149] run blktests nvme/011 at 2021-05-28 05:45:49
[ 793.899062] nvmet: adding nsid 1 to subsystem blktests-subsystem-1
[ 793.950783] nvmet: creating controller 1 for subsystem
blktests-subsystem-1 for NQN
nqn.2014-08.org.nvmexpress:uuid:d39240f497c64fc8bf7ca767d256a394.
[ 793.964271] nvme nvme0: creating 48 I/O queues.
[ 793.973187] nvme nvme0: new ctrl: "blktests-subsystem-1"
[ 863.401172] nvme nvme0: Removing ctrl: NQN "blktests-subsystem-1"
[ 863.656534] block nvme0n1: no available path - failing I/O
[ 863.662039] block nvme0n1: no available path - failing I/O
[ 863.667546] block nvme0n1: no available path - failing I/O
[ 863.673029] block nvme0n1: no available path - failing I/O
[ 863.678530] block nvme0n1: no available path - failing I/O
[ 863.684032] block nvme0n1: no available path - failing I/O
[ 863.689523] block nvme0n1: no available path - failing I/O
[ 863.695014] block nvme0n1: no available path - failing I/O
[ 863.700502] block nvme0n1: no available path - failing I/O
[ 863.705994] Buffer I/O error on dev nvme0n1, logical block 262016,
async page read
[ 1108.488647] INFO: task systemd-udevd:2400 blocked for more than 122
seconds.
[ 1108.495699] Not tainted 5.13.0-rc3+ #8
[ 1108.499972] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 1108.507797] task:systemd-udevd state:D stack: 0 pid: 2400
ppid: 1134 flags:0x00004004
[ 1108.516140] Call Trace:
[ 1108.518589] __schedule+0x247/0x6f0
[ 1108.522088] schedule+0x46/0xb0
[ 1108.525233] schedule_preempt_disabled+0xa/0x10
[ 1108.529767] __mutex_lock.constprop.0+0x2a4/0x470
[ 1108.534472] ? __kernfs_remove.part.0+0x174/0x1f0
[ 1108.539178] ? kernfs_remove_by_name_ns+0x5c/0x90
[ 1108.543885] del_gendisk+0x99/0x230
[ 1108.547378] nvme_mpath_remove_disk+0x97/0xb0 [nvme_core]
[ 1108.552787] nvme_put_ns_head+0x2a/0xb0 [nvme_core]
[ 1108.557664] __blkdev_put+0x115/0x160
[ 1108.561339] blkdev_put+0x4c/0x130
[ 1108.564745] blkdev_close+0x22/0x30
[ 1108.568238] __fput+0x94/0x240
[ 1108.571307] task_work_run+0x5f/0x90
[ 1108.574885] exit_to_user_mode_loop+0x119/0x120
[ 1108.579428] exit_to_user_mode_prepare+0x97/0xa0
[ 1108.584047] syscall_exit_to_user_mode+0x12/0x40
[ 1108.588664] do_syscall_64+0x4d/0x80
[ 1108.592254] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 1108.597314] RIP: 0033:0x7f222e799627
[ 1108.600903] RSP: 002b:00007ffd07c2b518 EFLAGS: 00000246 ORIG_RAX:
0000000000000003
[ 1108.608477] RAX: 0000000000000000 RBX: 00007f222d801240 RCX:
00007f222e799627
[ 1108.615620] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
0000000000000006
[ 1108.622762] RBP: 0000000000000006 R08: 000055badf77ba70 R09:
0000000000000000
[ 1108.629901] R10: 0000000000000000 R11: 0000000000000246 R12:
00007ffd07c2b5c0
[ 1108.637026] R13: 0000000000000000 R14: 000055bae0be5820 R15:
000055bae0b8bec0
[ 1231.370531] INFO: task systemd-udevd:2400 blocked for more than 245
seconds.
[ 1231.377579] Not tainted 5.13.0-rc3+ #8
[ 1231.381853] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 1231.389679] task:systemd-udevd state:D stack: 0 pid: 2400
ppid: 1134 flags:0x00004004
[ 1231.398024] Call Trace:
[ 1231.400478] __schedule+0x247/0x6f0
[ 1231.403970] schedule+0x46/0xb0
[ 1231.407112] schedule_preempt_disabled+0xa/0x10
[ 1231.411638] __mutex_lock.constprop.0+0x2a4/0x470
[ 1231.416345] ? __kernfs_remove.part.0+0x174/0x1f0
[ 1231.421051] ? kernfs_remove_by_name_ns+0x5c/0x90
[ 1231.425765] del_gendisk+0x99/0x230
[ 1231.429268] nvme_mpath_remove_disk+0x97/0xb0 [nvme_core]
[ 1231.434692] nvme_put_ns_head+0x2a/0xb0 [nvme_core]
[ 1231.439581] __blkdev_put+0x115/0x160
[ 1231.443255] blkdev_put+0x4c/0x130
[ 1231.446668] blkdev_close+0x22/0x30
[ 1231.450171] __fput+0x94/0x240
[ 1231.453232] task_work_run+0x5f/0x90
[ 1231.456809] exit_to_user_mode_loop+0x119/0x120
[ 1231.461351] exit_to_user_mode_prepare+0x97/0xa0
[ 1231.465980] syscall_exit_to_user_mode+0x12/0x40
[ 1231.470608] do_syscall_64+0x4d/0x80
[ 1231.474187] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 1231.479247] RIP: 0033:0x7f222e799627
[ 1231.482835] RSP: 002b:00007ffd07c2b518 EFLAGS: 00000246 ORIG_RAX:
0000000000000003
[ 1231.490392] RAX: 0000000000000000 RBX: 00007f222d801240 RCX:
00007f222e799627
[ 1231.497537] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
0000000000000006
[ 1231.504670] RBP: 0000000000000006 R08: 000055badf77ba70 R09:
0000000000000000
[ 1231.511800] R10: 0000000000000000 R11: 0000000000000246 R12:
00007ffd07c2b5c0
[ 1231.518925] R13: 0000000000000000 R14: 000055bae0be5820 R15:
000055bae0b8bec0
[ 1354.252532] INFO: task systemd-udevd:2400 blocked for more than 368
seconds.
[ 1354.259581] Not tainted 5.13.0-rc3+ #8
[ 1354.263853] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 1354.271678] task:systemd-udevd state:D stack: 0 pid: 2400
ppid: 1134 flags:0x00004004
[ 1354.280025] Call Trace:
[ 1354.282469] __schedule+0x247/0x6f0
[ 1354.285962] schedule+0x46/0xb0
[ 1354.289105] schedule_preempt_disabled+0xa/0x10
[ 1354.293630] __mutex_lock.constprop.0+0x2a4/0x470
[ 1354.298327] ? __kernfs_remove.part.0+0x174/0x1f0
[ 1354.303027] ? kernfs_remove_by_name_ns+0x5c/0x90
[ 1354.307732] del_gendisk+0x99/0x230
[ 1354.311226] nvme_mpath_remove_disk+0x97/0xb0 [nvme_core]
[ 1354.316628] nvme_put_ns_head+0x2a/0xb0 [nvme_core]
[ 1354.321506] __blkdev_put+0x115/0x160
[ 1354.325171] blkdev_put+0x4c/0x130
[ 1354.328576] blkdev_close+0x22/0x30
[ 1354.332070] __fput+0x94/0x240
[ 1354.335127] task_work_run+0x5f/0x90
[ 1354.338717] exit_to_user_mode_loop+0x119/0x120
[ 1354.343249] exit_to_user_mode_prepare+0x97/0xa0
[ 1354.347860] syscall_exit_to_user_mode+0x12/0x40
[ 1354.352480] do_syscall_64+0x4d/0x80
[ 1354.356059] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 1354.361111] RIP: 0033:0x7f222e799627
[ 1354.364684] RSP: 002b:00007ffd07c2b518 EFLAGS: 00000246 ORIG_RAX:
0000000000000003
[ 1354.372247] RAX: 0000000000000000 RBX: 00007f222d801240 RCX:
00007f222e799627
[ 1354.379371] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
0000000000000006
[ 1354.386501] RBP: 0000000000000006 R08: 000055badf77ba70 R09:
0000000000000000
[ 1354.393629] R10: 0000000000000000 R11: 0000000000000246 R12:
00007ffd07c2b5c0
[ 1354.400754] R13: 0000000000000000 R14: 000055bae0be5820 R15:
000055bae0b8bec0
Ah. Deadlock on bd_mutex.
Can you check if the attached patch fixes this issue?
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
>From 433ef6dea38de57289ce6ae26147cabe03c9b114 Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@xxxxxxx>
Date: Sat, 29 May 2021 13:54:22 +0200
Subject: [PATCH] nvme-multipath: call del_gendisk() in
nvme_mpath_check_last_path()
We cannot call del_gendisk() during the final nvme_put_ns_head(), as
this might be called from blkdev_put(), as we then will deadlock on
bd_mutex:
[ 1108.529767] __mutex_lock.constprop.0+0x2a4/0x470
[ 1108.534472] ? __kernfs_remove.part.0+0x174/0x1f0
[ 1108.539178] ? kernfs_remove_by_name_ns+0x5c/0x90
[ 1108.543885] del_gendisk+0x99/0x230
[ 1108.547378] nvme_mpath_remove_disk+0x97/0xb0 [nvme_core]
[ 1108.552787] nvme_put_ns_head+0x2a/0xb0 [nvme_core]
[ 1108.557664] __blkdev_put+0x115/0x160
[ 1108.561339] blkdev_put+0x4c/0x130
[ 1108.564745] blkdev_close+0x22/0x30
[ 1108.568238] __fput+0x94/0x240
So call 'del_gendisk()' when checking if the last path has been removed
to avoid this deadlock.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/nvme/host/multipath.c | 13 +++++++++++--
drivers/nvme/host/nvme.h | 9 +--------
2 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 127a17b4c13d..22e2febf86bc 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -776,14 +776,23 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
#endif
}
-void nvme_mpath_remove_disk(struct nvme_ns_head *head)
+void nvme_mpath_check_last_path(struct nvme_ns *ns)
{
+ struct nvme_ns_head *head = ns->head;
+
if (!head->disk)
return;
- if (head->disk->flags & GENHD_FL_UP) {
+
+ if (list_empty(&head->list) && head->disk->flags & GENHD_FL_UP) {
nvme_cdev_del(&head->cdev, &head->cdev_device);
del_gendisk(head->disk);
}
+}
+
+void nvme_mpath_remove_disk(struct nvme_ns_head *head)
+{
+ if (!head->disk)
+ return;
blk_set_queue_dying(head->disk->queue);
/* make sure all pending bios are cleaned up */
kblockd_schedule_work(&head->requeue_work);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 1f397ecba16c..8a497a420ea2 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -716,14 +716,7 @@ void nvme_mpath_uninit(struct nvme_ctrl *ctrl);
void nvme_mpath_stop(struct nvme_ctrl *ctrl);
bool nvme_mpath_clear_current_path(struct nvme_ns *ns);
void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl);
-
-static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
-{
- struct nvme_ns_head *head = ns->head;
-
- if (head->disk && list_empty(&head->list))
- kblockd_schedule_work(&head->requeue_work);
-}
+void nvme_mpath_check_last_path(struct nvme_ns *ns);
static inline void nvme_trace_bio_complete(struct request *req)
{
--
2.26.2
