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authorLinus Torvalds <torvalds@linux-foundation.org>2019-04-16 00:10:20 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2019-04-16 00:10:20 +0200
commit5512320c9f6f2acd7972c05400473c2338325339 (patch)
tree42e053788513385401abf94fb57bf13aa53d4658 /fs
parentLinux 5.1-rc5 (diff)
parentfs/dax: Deposit pagetable even when installing zero page (diff)
downloadlinux-5512320c9f6f2acd7972c05400473c2338325339.tar.xz
linux-5512320c9f6f2acd7972c05400473c2338325339.zip
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
Diffstat (limited to 'fs')
-rw-r--r--fs/dax.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/dax.c b/fs/dax.c
index ca0671d55aa6..e5e54da1715f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -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;
}