Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5512320c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'fsdax-fix-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 

Pull fsdax fix from Dan Williams:
 "A single filesystem-dax fix. It has been lingering in -next for a long
  while and there are no other fsdax fixes on the horizon:

   - Avoid a crash scenario with architectures like powerpc that require
     'pgtable_deposit' for the zero page"

* tag 'fsdax-fix-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  fs/dax: Deposit pagetable even when installing zero page
parents dc4060a5 11cf9d86

fs/dax.c

+15 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/sizes.h>

#include <linux/mmu_notifier.h>

#include <linux/iomap.h>

#include <asm/pgalloc.h>

#include "internal.h"



#define CREATE_TRACE_POINTS
@@ -1407,7 +1408,9 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, 
{

	struct address_space *mapping = vmf->vma->vm_file->f_mapping;

	unsigned long pmd_addr = vmf->address & PMD_MASK;

	struct vm_area_struct *vma = vmf->vma;

	struct inode *inode = mapping->host;

	pgtable_t pgtable = NULL;

	struct page *zero_page;

	spinlock_t *ptl;

	pmd_t pmd_entry;
@@ -1422,12 +1425,22 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, 
	*entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn,

			DAX_PMD | DAX_ZERO_PAGE, false);



	if (arch_needs_pgtable_deposit()) {

		pgtable = pte_alloc_one(vma->vm_mm);

		if (!pgtable)

			return VM_FAULT_OOM;

	}



	ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd);

	if (!pmd_none(*(vmf->pmd))) {

		spin_unlock(ptl);

		goto fallback;

	}



	if (pgtable) {

		pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable);

		mm_inc_nr_ptes(vma->vm_mm);

	}

	pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot);

	pmd_entry = pmd_mkhuge(pmd_entry);

	set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry);
@@ -1436,6 +1449,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, 
	return VM_FAULT_NOPAGE;



fallback:

	if (pgtable)

		pte_free(vma->vm_mm, pgtable);

	trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry);

	return VM_FAULT_FALLBACK;

}