From: Anton Eidelman anton@lightbitslabs.com
[ Upstream commit 489dd102a2c7c94d783a35f9412eb085b8da1aa4 ]
When scan_work calls nvme_mpath_add_disk() this holds ana_lock and invokes nvme_parse_ana_log(), which may issue IO in device_add_disk() and hang waiting for an accessible path. While nvme_mpath_set_live() only called when nvme_state_is_live(), a transition may cause NVME_SC_ANA_TRANSITION and requeue the IO.
In order to recover and complete the IO ana_work on the same ctrl should be able to update the path state and remove NVME_NS_ANA_PENDING.
The deadlock occurs because scan_work keeps holding ana_lock, so ana_work hangs [1].
Fix: Now nvme_mpath_add_disk() uses nvme_parse_ana_log() to obtain a copy of the ANA group desc, and then calls nvme_update_ns_ana_state() without holding ana_lock.
[1]: 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: read_cache_page+0x12/0x20 kernel: read_dev_sector+0x27/0xc0 kernel: read_lba+0xc1/0x220 kernel: efi_partition+0x1e6/0x708 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_mpath_add_disk+0x47/0x90 [nvme_core] kernel: nvme_validate_ns+0x396/0x940 [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: Workqueue: nvme-wq nvme_ana_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: ? __switch_to_asm+0x34/0x70 kernel: ? select_task_rq_fair+0x1aa/0x5c0 kernel: ? kvm_sched_clock_read+0x11/0x20 kernel: ? sched_clock+0x9/0x10 kernel: __mutex_lock_slowpath+0x13/0x20 kernel: mutex_lock+0x2e/0x40 kernel: nvme_read_ana_log+0x3a/0x100 [nvme_core] kernel: nvme_ana_work+0x15/0x20 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x4d/0x400 kernel: kthread+0x104/0x140 kernel: ? process_one_work+0x380/0x380 kernel: ? kthread_park+0x80/0x80 kernel: ret_from_fork+0x35/0x40
Fixes: 0d0b660f214d ("nvme: add ANA support") 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/multipath.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 7cc0ec180d555..18f0a05c74b56 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -639,26 +639,34 @@ static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr, } DEVICE_ATTR_RO(ana_state);
-static int nvme_set_ns_ana_state(struct nvme_ctrl *ctrl, +static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *desc, void *data) { - struct nvme_ns *ns = data; + struct nvme_ana_group_desc *dst = data;
- if (ns->ana_grpid == le32_to_cpu(desc->grpid)) { - nvme_update_ns_ana_state(desc, ns); - return -ENXIO; /* just break out of the loop */ - } + if (desc->grpid != dst->grpid) + return 0;
- return 0; + *dst = *desc; + return -ENXIO; /* just break out of the loop */ }
void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id) { if (nvme_ctrl_use_ana(ns->ctrl)) { + struct nvme_ana_group_desc desc = { + .grpid = id->anagrpid, + .state = 0, + }; + mutex_lock(&ns->ctrl->ana_lock); ns->ana_grpid = le32_to_cpu(id->anagrpid); - nvme_parse_ana_log(ns->ctrl, ns, nvme_set_ns_ana_state); + nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc); mutex_unlock(&ns->ctrl->ana_lock); + if (desc.state) { + /* found the group desc: update */ + nvme_update_ns_ana_state(&desc, ns); + } } else { ns->ana_state = NVME_ANA_OPTIMIZED; nvme_mpath_set_live(ns);