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Commit 20f14172 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 

Pull libnvdimm fixes from Dan Williams:
 "A 4.16 regression fix, three fixes for -stable, and a cleanup fix:

   - During the merge window support for the new ACPI NVDIMM Platform
     Capabilities structure disabled support for "deep flush", a
     force-unit- access like mechanism for persistent memory. Restore
     that mechanism.

   - VFIO like RDMA is yet one more memory registration / pinning
     interface that is incompatible with Filesystem-DAX. Disable long
     term pins of Filesystem-DAX mappings via VFIO.

   - The Filesystem-DAX detection to prevent long terms pins mistakenly
     also disabled Device-DAX pins which are not subject to the same
     block- map collision concerns.

   - Similar to the setup path, softlockup warnings can trigger in the
     shutdown path for large persistent memory namespaces. Teach
     for_each_device_pfn() to perform cond_resched() in all cases.

   - Boaz noticed that the might_sleep() in dax_direct_access() is stale
     as of the v4.15 kernel.

  These have received a build success notification from the 0day robot,
  and the longterm pin fixes have appeared in -next. However, I recently
  rebased the tree to remove some other fixes that need to be reworked
  after review feedback.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  memremap: fix softlockup reports at teardown
  libnvdimm: re-enable deep flush for pmem devices via fsync()
  vfio: disable filesystem-dax page pinning
  dax: fix vma_is_fsdax() helper
  dax: ->direct_access does not sleep anymore
parents 0eb3412a 949b9325

drivers/dax/super.c

+0 −6
Original line number Diff line number Diff line
@@ -246,12 +246,6 @@ long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 
{

	long avail;



	/*

	 * The device driver is allowed to sleep, in order to make the

	 * memory directly accessible.

	 */

	might_sleep();



	if (!dax_dev)

		return -EOPNOTSUPP;

drivers/nvdimm/pmem.c

+1 −2
Original line number Diff line number Diff line
@@ -335,8 +335,7 @@ static int pmem_attach_disk(struct device *dev, 
		dev_warn(dev, "unable to guarantee persistence of writes\n");

		fua = 0;

	}

	wbc = nvdimm_has_cache(nd_region) &&

		!test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags);

	wbc = nvdimm_has_cache(nd_region);



	if (!devm_request_mem_region(dev, res->start, resource_size(res),

				dev_name(&ndns->dev))) {

drivers/vfio/vfio_iommu_type1.c

+15 −3
Original line number Diff line number Diff line
@@ -338,11 +338,12 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, 
{

	struct page *page[1];

	struct vm_area_struct *vma;

	struct vm_area_struct *vmas[1];

	int ret;



	if (mm == current->mm) {

		ret = get_user_pages_fast(vaddr, 1, !!(prot & IOMMU_WRITE),

					  page);

		ret = get_user_pages_longterm(vaddr, 1, !!(prot & IOMMU_WRITE),

					      page, vmas);

	} else {

		unsigned int flags = 0;
@@ -351,7 +352,18 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, 


		down_read(&mm->mmap_sem);

		ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page,

					    NULL, NULL);

					    vmas, NULL);

		/*

		 * The lifetime of a vaddr_get_pfn() page pin is

		 * userspace-controlled. In the fs-dax case this could

		 * lead to indefinite stalls in filesystem operations.

		 * Disallow attempts to pin fs-dax pages via this

		 * interface.

		 */

		if (ret > 0 && vma_is_fsdax(vmas[0])) {

			ret = -EOPNOTSUPP;

			put_page(page[0]);

		}

		up_read(&mm->mmap_sem);

	}

include/linux/fs.h

+1 −1
Original line number Diff line number Diff line
@@ -3198,7 +3198,7 @@ static inline bool vma_is_fsdax(struct vm_area_struct *vma) 
	if (!vma_is_dax(vma))

		return false;

	inode = file_inode(vma->vm_file);

	if (inode->i_mode == S_IFCHR)

	if (S_ISCHR(inode->i_mode))

		return false; /* device-dax */

	return true;

}

kernel/memremap.c

+10 −5
Original line number Diff line number Diff line
@@ -275,8 +275,15 @@ static unsigned long pfn_end(struct dev_pagemap *pgmap) 
	return (res->start + resource_size(res)) >> PAGE_SHIFT;

}



static unsigned long pfn_next(unsigned long pfn)

{

	if (pfn % 1024 == 0)

		cond_resched();

	return pfn + 1;

}



#define for_each_device_pfn(pfn, map) \

	for (pfn = pfn_first(map); pfn < pfn_end(map); pfn++)

	for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn))



static void devm_memremap_pages_release(void *data)

{
@@ -337,10 +344,10 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 
	resource_size_t align_start, align_size, align_end;

	struct vmem_altmap *altmap = pgmap->altmap_valid ?

			&pgmap->altmap : NULL;

	struct resource *res = &pgmap->res;

	unsigned long pfn, pgoff, order;

	pgprot_t pgprot = PAGE_KERNEL;

	int error, nid, is_ram, i = 0;

	struct resource *res = &pgmap->res;

	int error, nid, is_ram;



	align_start = res->start & ~(SECTION_SIZE - 1);

	align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
@@ -409,8 +416,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 
		list_del(&page->lru);

		page->pgmap = pgmap;

		percpu_ref_get(pgmap->ref);

		if (!(++i % 1024))

			cond_resched();

	}



	devm_add_action(dev, devm_memremap_pages_release, pgmap);