[PATCH] dax: Fix use of zero page
by Matthew Wilcox
This patch got caught in the crossfire and didn't make it into 4.18
as planned. Can it make 4.19 please?
---- >8 ----
Use my_zero_pfn instead of ZERO_PAGE, and pass the vaddr to it so it
works on MIPS and s390.
Signed-off-by: Matthew Wilcox <willy(a)infradead.org>
Reviewed-by: Ross Zwisler <ross.zwisler(a)linux.intel.com>
---
fs/dax.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 467601a134bc..c7917b46a75b 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1093,21 +1093,12 @@ static vm_fault_t dax_load_hole(struct address_space *mapping, void *entry,
{
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
- vm_fault_t ret = VM_FAULT_NOPAGE;
- struct page *zero_page;
- pfn_t pfn;
-
- zero_page = ZERO_PAGE(0);
- if (unlikely(!zero_page)) {
- ret = VM_FAULT_OOM;
- goto out;
- }
+ pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr));
+ vm_fault_t ret;
- pfn = page_to_pfn_t(zero_page);
dax_insert_mapping_entry(mapping, vmf, entry, pfn, RADIX_DAX_ZERO_PAGE,
false);
ret = vmf_insert_mixed(vmf->vma, vaddr, pfn);
-out:
trace_dax_load_hole(inode, vmf, ret);
return ret;
}
--
2.17.1
3 years, 8 months
[PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
by Dave Jiang
It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
This can be triggered by:
1. Boot with memmap=4G!8G
2. build ndctl with destructive flag on
3. make TESTS=device-dax check
[ +0.000675] kernel BUG at mm/huge_memory.c:824!
Applying the same change that was applied to vmf_insert_pfn_pmd() in the
original patch.
Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax")
Reported-by: Vishal Verma <vishal.l.verma(a)intel.com>
Signed-off-by: Dave Jiang <dave.jiang(a)intel.com>
---
mm/huge_memory.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c3bc7e9c9a2a..533f9b00147d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
* but we need to be consistent with PTEs and architectures that
* can't support a 'special' bit.
*/
- BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+ BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
+ !pfn_t_devmap(pfn));
BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
(VM_PFNMAP|VM_MIXEDMAP));
BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
- BUG_ON(!pfn_t_devmap(pfn));
if (addr < vma->vm_start || addr >= vma->vm_end)
return VM_FAULT_SIGBUS;
3 years, 8 months
[PATCH] device-dax: Convert variable to vm_fault_t type
by Souptick Joarder
As part of commit 226ab561075f ("device-dax: Convert to
vmf_insert_mixed and vm_fault_t") in 4.19-rc1,
'rc' was not converted to vm_fault_t. Now converted.
Signed-off-by: Souptick Joarder <jrdr.linux(a)gmail.com>
---
drivers/dax/device.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 6fd4608..bbe4d72 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -392,7 +392,8 @@ static vm_fault_t dev_dax_huge_fault(struct vm_fault *vmf,
{
struct file *filp = vmf->vma->vm_file;
unsigned long fault_size;
- int rc, id;
+ vm_fault_t rc = VM_FAULT_SIGBUS;
+ int id;
pfn_t pfn;
struct dev_dax *dev_dax = filp->private_data;
--
1.9.1
3 years, 8 months
