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authorSagi Grimberg <sagi@grimberg.me>2019-07-25 11:56:57 -0700
committerSagi Grimberg <sagi@grimberg.me>2019-07-31 18:01:56 -0700
commit0157ec8dad3c8fc9bc9790f76e0831ffdaf2e7f0 (patch)
tree96d89f275edb83e05601330df200da3b72f32e69 /drivers/nvme/host/core.c
parentnvme-rdma: fix possible use-after-free in connect error flow (diff)
downloadlinux-dev-0157ec8dad3c8fc9bc9790f76e0831ffdaf2e7f0.tar.xz
linux-dev-0157ec8dad3c8fc9bc9790f76e0831ffdaf2e7f0.zip
nvme: fix controller removal race with scan work
With multipath enabled, nvme_scan_work() can read from the device (through nvme_mpath_add_disk()) and hang [1]. However, with fabrics, once ctrl->state is set to NVME_CTRL_DELETING, the reads will hang (see nvmf_check_ready()) and the mpath stack device make_request will block if head->list is not empty. However, when the head->list consistst of only DELETING/DEAD controllers, we should actually not block, but rather fail immediately. In addition, before we go ahead and remove the namespaces, make sure to clear the current path and kick the requeue list so that the request will fast fail upon requeuing. [1]: -- INFO: task kworker/u4:3:166 blocked for more than 120 seconds. Not tainted 5.2.0-rc6-vmlocalyes-00005-g808c8c2dc0cf #316 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:3 D 0 166 2 0x80004000 Workqueue: nvme-wq nvme_scan_work Call Trace: __schedule+0x851/0x1400 schedule+0x99/0x210 io_schedule+0x21/0x70 do_read_cache_page+0xa57/0x1330 read_cache_page+0x4a/0x70 read_dev_sector+0xbf/0x380 amiga_partition+0xc4/0x1230 check_partition+0x30f/0x630 rescan_partitions+0x19a/0x980 __blkdev_get+0x85a/0x12f0 blkdev_get+0x2a5/0x790 __device_add_disk+0xe25/0x1250 device_add_disk+0x13/0x20 nvme_mpath_set_live+0x172/0x2b0 nvme_update_ns_ana_state+0x130/0x180 nvme_set_ns_ana_state+0x9a/0xb0 nvme_parse_ana_log+0x1c3/0x4a0 nvme_mpath_add_disk+0x157/0x290 nvme_validate_ns+0x1017/0x1bd0 nvme_scan_work+0x44d/0x6a0 process_one_work+0x7d7/0x1240 worker_thread+0x8e/0xff0 kthread+0x2c3/0x3b0 ret_from_fork+0x35/0x40 INFO: task kworker/u4:1:1034 blocked for more than 120 seconds. Not tainted 5.2.0-rc6-vmlocalyes-00005-g808c8c2dc0cf #316 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:1 D 0 1034 2 0x80004000 Workqueue: nvme-delete-wq nvme_delete_ctrl_work Call Trace: __schedule+0x851/0x1400 schedule+0x99/0x210 schedule_timeout+0x390/0x830 wait_for_completion+0x1a7/0x310 __flush_work+0x241/0x5d0 flush_work+0x10/0x20 nvme_remove_namespaces+0x85/0x3d0 nvme_do_delete_ctrl+0xb4/0x1e0 nvme_delete_ctrl_work+0x15/0x20 process_one_work+0x7d7/0x1240 worker_thread+0x8e/0xff0 kthread+0x2c3/0x3b0 ret_from_fork+0x35/0x40 -- Reported-by: Logan Gunthorpe <logang@deltatee.com> Tested-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Diffstat (limited to '')
-rw-r--r--drivers/nvme/host/core.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 88b8dfd7928a..c258a1ce4b28 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3577,6 +3577,13 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
struct nvme_ns *ns, *next;
LIST_HEAD(ns_list);
+ /*
+ * make sure to requeue I/O to all namespaces as these
+ * might result from the scan itself and must complete
+ * for the scan_work to make progress
+ */
+ nvme_mpath_clear_ctrl_paths(ctrl);
+
/* prevent racing with ns scanning */
flush_work(&ctrl->scan_work);