commit c4703ce11c23423d4b46e3d59aef7979814fd608 upstream.

Users have reported intermittent occurrences of DIMM initialization failures due to duplicate allocations of address capacity detected in the labels, or errors of the form below, both have the same root cause.

nd namespace1.4: failed to track label: 0 WARNING: CPU: 17 PID: 1381 at drivers/nvdimm/label.c:863

RIP: 0010:__pmem_label_update+0x56c/0x590 [libnvdimm] Call Trace: ? nd_pmem_namespace_label_update+0xd6/0x160 [libnvdimm] nd_pmem_namespace_label_update+0xd6/0x160 [libnvdimm] uuid_store+0x17e/0x190 [libnvdimm] kernfs_fop_write+0xf0/0x1a0 vfs_write+0xb7/0x1b0 ksys_write+0x57/0xd0 do_syscall_64+0x60/0x210

Unfortunately those reports were typically with a busy parallel namespace creation / destruction loop making it difficult to see the components of the bug. However, Jane provided a simple reproducer using the work-in-progress sub-section implementation.

When ndctl is reconfiguring a namespace it may take an existing defunct / disabled namespace and reconfigure it with a new uuid and other parameters. Critically namespace_update_uuid() takes existing address resources and renames them for the new namespace to use / reconfigure as it sees fit. The bug is that this rename only happens in the resource tracking tree. Existing labels with the old uuid are not reaped leading to a scenario where multiple active labels reference the same span of address range.

Teach namespace_update_uuid() to flag any references to the old uuid for reaping at the next label update attempt.

Cc: stable@vger.kernel.org Fixes: bf9bccc14c05 ("libnvdimm: pmem label sets and namespace instantiation") Link: https://github.com/pmem/ndctl/issues/91 Reported-by: Jane Chu jane.chu@oracle.com Reported-by: Jeff Moyer jmoyer@redhat.com Reported-by: Erwin Tsaur erwin.tsaur@oracle.com Cc: Johannes Thumshirn jthumshirn@suse.de Signed-off-by: Dan Williams dan.j.williams@intel.com --- drivers/nvdimm/label.c | 29 ++++++++++++++++------------- drivers/nvdimm/namespace_devs.c | 15 +++++++++++++++ drivers/nvdimm/nd.h | 4 ++++ 3 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c index 184149a49b02..6a16017cc0d9 100644 --- a/drivers/nvdimm/label.c +++ b/drivers/nvdimm/label.c @@ -614,6 +614,17 @@ static const guid_t *to_abstraction_guid(enum nvdimm_claim_class claim_class, return &guid_null; }

+static void reap_victim(struct nd_mapping *nd_mapping, + struct nd_label_ent *victim) +{ + struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); + u32 slot = to_slot(ndd, victim->label); + + dev_dbg(ndd->dev, "free: %d\n", slot); + nd_label_free_slot(ndd, slot); + victim->label = NULL; +} + static int __pmem_label_update(struct nd_region *nd_region, struct nd_mapping *nd_mapping, struct nd_namespace_pmem *nspm, int pos, unsigned long flags) @@ -621,9 +632,9 @@ static int __pmem_label_update(struct nd_region *nd_region, struct nd_namespace_common *ndns = &nspm->nsio.common; struct nd_interleave_set *nd_set = nd_region->nd_set; struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); - struct nd_label_ent *label_ent, *victim = NULL; struct nd_namespace_label *nd_label; struct nd_namespace_index *nsindex; + struct nd_label_ent *label_ent; struct nd_label_id label_id; struct resource *res; unsigned long *free; @@ -692,18 +703,10 @@ static int __pmem_label_update(struct nd_region *nd_region, list_for_each_entry(label_ent, &nd_mapping->labels, list) { if (!label_ent->label) continue; - if (memcmp(nspm->uuid, label_ent->label->uuid, - NSLABEL_UUID_LEN) != 0) - continue; - victim = label_ent; - list_move_tail(&victim->list, &nd_mapping->labels); - break; - } - if (victim) { - dev_dbg(ndd->dev, "%s: free: %d\n", __func__, slot); - slot = to_slot(ndd, victim->label); - nd_label_free_slot(ndd, slot); - victim->label = NULL; + if (test_and_clear_bit(ND_LABEL_REAP, &label_ent->flags) + || memcmp(nspm->uuid, label_ent->label->uuid, + NSLABEL_UUID_LEN) == 0) + reap_victim(nd_mapping, label_ent); }

/* update index */ diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index e3f228af59d1..ace9958f2905 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -1229,12 +1229,27 @@ static int namespace_update_uuid(struct nd_region *nd_region, for (i = 0; i < nd_region->ndr_mappings; i++) { struct nd_mapping *nd_mapping = &nd_region->mapping[i]; struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); + struct nd_label_ent *label_ent; struct resource *res;

for_each_dpa_resource(ndd, res) if (strcmp(res->name, old_label_id.id) == 0) sprintf((void *) res->name, "%s", new_label_id.id); + + mutex_lock(&nd_mapping->lock); + list_for_each_entry(label_ent, &nd_mapping->labels, list) { + struct nd_namespace_label *nd_label = label_ent->label; + struct nd_label_id label_id; + + if (!nd_label) + continue; + nd_label_gen_id(&label_id, nd_label->uuid, + __le32_to_cpu(nd_label->flags)); + if (strcmp(old_label_id.id, label_id.id) == 0) + set_bit(ND_LABEL_REAP, &label_ent->flags); + } + mutex_unlock(&nd_mapping->lock); } kfree(*old_uuid); out: diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h index 156be00e1f76..e3f060f0b83e 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -120,8 +120,12 @@ struct nd_percpu_lane { spinlock_t lock; };

+enum nd_label_flags { + ND_LABEL_REAP, +}; struct nd_label_ent { struct list_head list; + unsigned long flags; struct nd_namespace_label *label; };