From: Sagi Grimberg sagi@grimberg.me
[ Upstream commit 3b4b19721ec652ad2c4fe51dfbe5124212b5f581 ]
Revert fab7772bfbcf ("nvme-multipath: revalidate nvme_ns_head gendisk in nvme_validate_ns")
When adding a new namespace to the head disk (via nvme_mpath_set_live) we will see partition scan which triggers I/O on the mpath device node. This process will usually be triggered from the scan_work which holds the scan_lock. If I/O blocks (if we got ana change currently have only available paths but none are accessible) this can deadlock on the head disk bd_mutex as both partition scan I/O takes it, and head disk revalidation takes it to check for resize (also triggered from scan_work on a different path). See trace [1].
The mpath disk revalidation was originally added to detect online disk size change, but this is no longer needed since commit cb224c3af4df ("nvme: Convert to use set_capacity_revalidate_and_notify") which already updates resize info without unnecessarily revalidating the disk (the mpath disk doesn't even implement .revalidate_disk fop).
[1]: -- kernel: INFO: task kworker/u65:9:494 blocked for more than 241 seconds. kernel: Tainted: G OE 5.3.5-050305-generic #201910071830 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: kworker/u65:9 D 0 494 2 0x80004000 kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: schedule_preempt_disabled+0xe/0x10 kernel: __mutex_lock.isra.0+0x182/0x4f0 kernel: __mutex_lock_slowpath+0x13/0x20 kernel: mutex_lock+0x2e/0x40 kernel: revalidate_disk+0x63/0xa0 kernel: __nvme_revalidate_disk+0xfe/0x110 [nvme_core] kernel: nvme_revalidate_disk+0xa4/0x160 [nvme_core] kernel: ? evict+0x14c/0x1b0 kernel: revalidate_disk+0x2b/0xa0 kernel: nvme_validate_ns+0x49/0x940 [nvme_core] kernel: ? blk_mq_free_request+0xd2/0x100 kernel: ? __nvme_submit_sync_cmd+0xbe/0x1e0 [nvme_core] kernel: nvme_scan_work+0x24f/0x380 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x249/0x400 kernel: kthread+0x104/0x140 kernel: ? process_one_work+0x380/0x380 kernel: ? kthread_park+0x80/0x80 kernel: ret_from_fork+0x1f/0x40 ... kernel: INFO: task kworker/u65:1:2630 blocked for more than 241 seconds. kernel: Tainted: G OE 5.3.5-050305-generic #201910071830 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: kworker/u65:1 D 0 2630 2 0x80004000 kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: io_schedule+0x16/0x40 kernel: do_read_cache_page+0x438/0x830 kernel: ? __switch_to_asm+0x34/0x70 kernel: ? file_fdatawait_range+0x30/0x30 kernel: read_cache_page+0x12/0x20 kernel: read_dev_sector+0x27/0xc0 kernel: read_lba+0xc1/0x220 kernel: ? kmem_cache_alloc_trace+0x19c/0x230 kernel: efi_partition+0x1e6/0x708 kernel: ? vsnprintf+0x39e/0x4e0 kernel: ? snprintf+0x49/0x60 kernel: check_partition+0x154/0x244 kernel: rescan_partitions+0xae/0x280 kernel: __blkdev_get+0x40f/0x560 kernel: blkdev_get+0x3d/0x140 kernel: __device_add_disk+0x388/0x480 kernel: device_add_disk+0x13/0x20 kernel: nvme_mpath_set_live+0x119/0x140 [nvme_core] kernel: nvme_update_ns_ana_state+0x5c/0x60 [nvme_core] kernel: nvme_set_ns_ana_state+0x1e/0x30 [nvme_core] kernel: nvme_parse_ana_log+0xa1/0x180 [nvme_core] kernel: ? nvme_update_ns_ana_state+0x60/0x60 [nvme_core] kernel: nvme_mpath_add_disk+0x47/0x90 [nvme_core] kernel: nvme_validate_ns+0x396/0x940 [nvme_core] kernel: ? blk_mq_free_request+0xd2/0x100 kernel: nvme_scan_work+0x24f/0x380 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x249/0x400 kernel: kthread+0x104/0x140 kernel: ? process_one_work+0x380/0x380 kernel: ? kthread_park+0x80/0x80 kernel: ret_from_fork+0x1f/0x40 --
Fixes: fab7772bfbcf ("nvme-multipath: revalidate nvme_ns_head gendisk in nvme_validate_ns") Signed-off-by: Anton Eidelman anton@lightbitslabs.com Signed-off-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/core.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index faa7feebb6095..84fcfcdb8ba5f 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1599,7 +1599,6 @@ static void __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id) if (ns->head->disk) { nvme_update_disk_info(ns->head->disk, ns, id); blk_queue_stack_limits(ns->head->disk->queue, ns->queue); - revalidate_disk(ns->head->disk); } #endif }