summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2018-03-04 01:32:00 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-03-04 01:32:00 +0300
commit20f14172cbb8d711a47d336355fa947631444f60 (patch)
tree4991434323d5568d72037e7d9557ff4a0cdc70e3
parent0eb3412a68c354c0aa4adc4a24ec533154bd2172 (diff)
parent949b93250a566cc7a578b4f829cf76b70d19a62c (diff)
downloadlinux-20f14172cbb8d711a47d336355fa947631444f60.tar.xz
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
-rw-r--r--drivers/dax/super.c6
-rw-r--r--drivers/nvdimm/pmem.c3
-rw-r--r--drivers/vfio/vfio_iommu_type1.c18
-rw-r--r--include/linux/fs.h2
-rw-r--r--kernel/memremap.c15
5 files changed, 27 insertions, 17 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 473af694ad1c..ecdc292aa4e4 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -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;
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 10041ac4032c..06f8dcc52ca6 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -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))) {
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index e30e29ae4819..45657e2b1ff7 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -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);
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2a815560fda0..79c413985305 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -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;
}
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 4849be5f9b3c..4dd4274cabe2 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -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);