On Tue, 2018-07-24 at 15:07 -0600, Keith Busch wrote: > This patch will find the max contiguous area to determine the largest > pmem namespace size that can be created. If the requested size exceeds > the largest available, ENOSPC error will be returned. > > This fixes the allocation underrun error and wrong error return code > that have otherwise been observed as the following kernel warning: > > WARNING: CPU: <CPU> PID: <PID> at drivers/nvdimm/namespace_devs.c:913 size_store > > Fixes: a1f3e4d6a0c3 ("libnvdimm, region: update nd_region_available_dpa() for multi-pmem support") > Cc: <stable@xxxxxxxxxxxxxxx> > Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx> > --- > v3 -> v4: > > Actually constrain the reserved pmem to the region under consideration > rather than the mapping's dimm. This is done by directly calling > __reserve_free_pmem with the region's device instead of walking the > parent devices children. Thanks to Vishal Verma for reporting how > to trigger the incorrect reportings. > > Fixed a possible NULL deref, from Gustavo A. R. Silva. Looks good to me. Feel free to add: Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxx> > > drivers/nvdimm/dimm_devs.c | 31 +++++++++++++++++++++++++++++++ > drivers/nvdimm/namespace_devs.c | 6 +++--- > drivers/nvdimm/nd-core.h | 8 ++++++++ > drivers/nvdimm/region_devs.c | 24 ++++++++++++++++++++++++ > 4 files changed, 66 insertions(+), 3 deletions(-) > > diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c > index 8d348b22ba45..863cabc35215 100644 > --- a/drivers/nvdimm/dimm_devs.c > +++ b/drivers/nvdimm/dimm_devs.c > @@ -536,6 +536,37 @@ resource_size_t nd_blk_available_dpa(struct nd_region *nd_region) > return info.available; > } > > +/** > + * nd_pmem_max_contiguous_dpa - For the given dimm+region, return the max > + * contiguous unallocated dpa range. > + * @nd_region: constrain available space check to this reference region > + * @nd_mapping: container of dpa-resource-root + labels > + */ > +resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region, > + struct nd_mapping *nd_mapping) > +{ > + struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); > + struct nvdimm_bus *nvdimm_bus; > + resource_size_t max = 0; > + struct resource *res; > + > + /* if a dimm is disabled the available capacity is zero */ > + if (!ndd) > + return 0; > + > + nvdimm_bus = walk_to_nvdimm_bus(ndd->dev); > + if (__reserve_free_pmem(&nd_region->dev, nd_mapping->nvdimm)) > + return 0; > + for_each_dpa_resource(ndd, res) { > + if (strcmp(res->name, "pmem-reserve") != 0) > + continue; > + if (resource_size(res) > max) > + max = resource_size(res); > + } > + release_free_pmem(nvdimm_bus, nd_mapping); > + return max; > +} > + > /** > * nd_pmem_available_dpa - for the given dimm+region account unallocated dpa > * @nd_mapping: container of dpa-resource-root + labels > diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c > index cb322f2bc605..4a4266250c28 100644 > --- a/drivers/nvdimm/namespace_devs.c > +++ b/drivers/nvdimm/namespace_devs.c > @@ -799,7 +799,7 @@ static int merge_dpa(struct nd_region *nd_region, > return 0; > } > > -static int __reserve_free_pmem(struct device *dev, void *data) > +int __reserve_free_pmem(struct device *dev, void *data) > { > struct nvdimm *nvdimm = data; > struct nd_region *nd_region; > @@ -836,7 +836,7 @@ static int __reserve_free_pmem(struct device *dev, void *data) > return 0; > } > > -static void release_free_pmem(struct nvdimm_bus *nvdimm_bus, > +void release_free_pmem(struct nvdimm_bus *nvdimm_bus, > struct nd_mapping *nd_mapping) > { > struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); > @@ -1032,7 +1032,7 @@ static ssize_t __size_store(struct device *dev, unsigned long long val) > > allocated += nvdimm_allocated_dpa(ndd, &label_id); > } > - available = nd_region_available_dpa(nd_region); > + available = nd_region_allocatable_dpa(nd_region); > > if (val > available + allocated) > return -ENOSPC; > diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h > index 79274ead54fb..ac68072fb8cd 100644 > --- a/drivers/nvdimm/nd-core.h > +++ b/drivers/nvdimm/nd-core.h > @@ -100,6 +100,14 @@ struct nd_region; > struct nvdimm_drvdata; > struct nd_mapping; > void nd_mapping_free_labels(struct nd_mapping *nd_mapping); > + > +int __reserve_free_pmem(struct device *dev, void *data); > +void release_free_pmem(struct nvdimm_bus *nvdimm_bus, > + struct nd_mapping *nd_mapping); > + > +resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region, > + struct nd_mapping *nd_mapping); > +resource_size_t nd_region_allocatable_dpa(struct nd_region *nd_region); > resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region, > struct nd_mapping *nd_mapping, resource_size_t *overlap); > resource_size_t nd_blk_available_dpa(struct nd_region *nd_region); > diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c > index ec3543b83330..c30d5af02cc2 100644 > --- a/drivers/nvdimm/region_devs.c > +++ b/drivers/nvdimm/region_devs.c > @@ -389,6 +389,30 @@ resource_size_t nd_region_available_dpa(struct nd_region *nd_region) > return available; > } > > +resource_size_t nd_region_allocatable_dpa(struct nd_region *nd_region) > +{ > + resource_size_t available = 0; > + int i; > + > + if (is_memory(&nd_region->dev)) > + available = PHYS_ADDR_MAX; > + > + WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev)); > + for (i = 0; i < nd_region->ndr_mappings; i++) { > + struct nd_mapping *nd_mapping = &nd_region->mapping[i]; > + > + if (is_memory(&nd_region->dev)) > + available = min(available, > + nd_pmem_max_contiguous_dpa(nd_region, > + nd_mapping)); > + else if (is_nd_blk(&nd_region->dev)) > + available += nd_blk_available_dpa(nd_region); > + } > + if (is_memory(&nd_region->dev)) > + return available * nd_region->ndr_mappings; > + return available; > +} > + > static ssize_t available_size_show(struct device *dev, > struct device_attribute *attr, char *buf) > {