6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hannes Reinecke hare@kernel.org
[ Upstream commit 3b97f5a05cfc55e7729ff3769f63eef64e2178bb ]
During repetitive namespace remapping operations on the target the namespace might have changed between the time the initial scan was performed, and partition scan was invoked by device_add_disk() in nvme_mpath_set_live(). We then end up with a stuck scanning process:
[<0>] folio_wait_bit_common+0x12a/0x310 [<0>] filemap_read_folio+0x97/0xd0 [<0>] do_read_cache_folio+0x108/0x390 [<0>] read_part_sector+0x31/0xa0 [<0>] read_lba+0xc5/0x160 [<0>] efi_partition+0xd9/0x8f0 [<0>] bdev_disk_changed+0x23d/0x6d0 [<0>] blkdev_get_whole+0x78/0xc0 [<0>] bdev_open+0x2c6/0x3b0 [<0>] bdev_file_open_by_dev+0xcb/0x120 [<0>] disk_scan_partitions+0x5d/0x100 [<0>] device_add_disk+0x402/0x420 [<0>] nvme_mpath_set_live+0x4f/0x1f0 [nvme_core] [<0>] nvme_mpath_add_disk+0x107/0x120 [nvme_core] [<0>] nvme_alloc_ns+0xac6/0xe60 [nvme_core] [<0>] nvme_scan_ns+0x2dd/0x3e0 [nvme_core] [<0>] nvme_scan_work+0x1a3/0x490 [nvme_core]
This happens when we have several paths, some of which are inaccessible, and the active paths are removed first. Then nvme_find_path() will requeue I/O in the ns_head (as paths are present), but the requeue list is never triggered as all remaining paths are inactive.
This patch checks for NVME_NSHEAD_DISK_LIVE in nvme_available_path(), and requeue I/O after NVME_NSHEAD_DISK_LIVE has been cleared once the last path has been removed to properly terminate pending I/O.
Signed-off-by: Hannes Reinecke hare@kernel.org Reviewed-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Keith Busch kbusch@kernel.org Stable-dep-of: 5dd18f09ce73 ("nvme/multipath: Fix RCU list traversal to use SRCU primitive") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/multipath.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 2fa137738ac8d..989d1e50fb8cc 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -420,6 +420,9 @@ static bool nvme_available_path(struct nvme_ns_head *head) { struct nvme_ns *ns;
+ if (!test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) + return NULL; + list_for_each_entry_rcu(ns, &head->list, siblings) { if (test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ns->ctrl->flags)) continue; @@ -996,8 +999,7 @@ void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) { if (!head->disk) return; - kblockd_schedule_work(&head->requeue_work); - if (test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { + if (test_and_clear_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { nvme_cdev_del(&head->cdev, &head->cdev_device); /* * requeue I/O after NVME_NSHEAD_DISK_LIVE has been cleared @@ -1007,6 +1009,12 @@ void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) kblockd_schedule_work(&head->requeue_work); del_gendisk(head->disk); } + /* + * requeue I/O after NVME_NSHEAD_DISK_LIVE has been cleared + * to allow multipath to fail all I/O. + */ + synchronize_srcu(&head->srcu); + kblockd_schedule_work(&head->requeue_work); }
void nvme_mpath_remove_disk(struct nvme_ns_head *head)