From 2dd2a1740ee19cd2636d247276cf27bfa434b0e2 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 20 Nov 2020 08:50:07 -0800 Subject: [PATCH] libnvdimm/namespace: Fix reaping of invalidated block-window-namespace labels A recent change to ndctl to attempt to reconfigure namespaces in place uncovered a label accounting problem in block-window-type namespaces. The ndctl "create.sh" test is able to trigger this signature: WARNING: CPU: 34 PID: 9167 at drivers/nvdimm/label.c:1100 __blk_label_update+0x9a3/0xbc0 [libnvdimm] [..] RIP: 0010:__blk_label_update+0x9a3/0xbc0 [libnvdimm] [..] Call Trace: uuid_store+0x21b/0x2f0 [libnvdimm] kernfs_fop_write+0xcf/0x1c0 vfs_write+0xcc/0x380 ksys_write+0x68/0xe0 When allocated capacity for a namespace is renamed (new UUID) the labels with the old UUID need to be deleted. The ndctl behavior to always destroy namespaces on reconfiguration hid this problem. The immediate impact of this bug is limited since block-window-type namespaces only seem to exist in the specification and not in any shipping products. However, the label handling code is being reused for other technologies like CXL region labels, so there is a benefit to making sure both vertical labels sets (block-window) and horizontal label sets (pmem) have a functional reference implementation in libnvdimm. Fixes: c4703ce11c23 ("libnvdimm/namespace: Fix label tracking error") Cc: Cc: Vishal Verma Cc: Dave Jiang Cc: Ira Weiny Signed-off-by: Dan Williams --- drivers/nvdimm/label.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c index 47a4828..6f2be7a 100644 --- a/drivers/nvdimm/label.c +++ b/drivers/nvdimm/label.c @@ -980,6 +980,15 @@ static int __blk_label_update(struct nd_region *nd_region, } } + /* release slots associated with any invalidated UUIDs */ + mutex_lock(&nd_mapping->lock); + list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) + if (test_and_clear_bit(ND_LABEL_REAP, &label_ent->flags)) { + reap_victim(nd_mapping, label_ent); + list_move(&label_ent->list, &list); + } + mutex_unlock(&nd_mapping->lock); + /* * Find the resource associated with the first label in the set * per the v1.2 namespace specification. -- 2.7.4