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Diffstat (limited to 'fs/dax.c')
-rw-r--r--fs/dax.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/fs/dax.c b/fs/dax.c
index 93bf2f990ace..bcfb14bfc1e4 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -119,7 +119,8 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
size_t len;
if (pos == max) {
unsigned blkbits = inode->i_blkbits;
- sector_t block = pos >> blkbits;
+ long page = pos >> PAGE_SHIFT;
+ sector_t block = page << (PAGE_SHIFT - blkbits);
unsigned first = pos - (block << blkbits);
long size;
@@ -568,8 +569,20 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
if (!buffer_size_valid(&bh) || bh.b_size < PMD_SIZE)
goto fallback;
+ sector = bh.b_blocknr << (blkbits - 9);
+
if (buffer_unwritten(&bh) || buffer_new(&bh)) {
int i;
+
+ length = bdev_direct_access(bh.b_bdev, sector, &kaddr, &pfn,
+ bh.b_size);
+ if (length < 0) {
+ result = VM_FAULT_SIGBUS;
+ goto out;
+ }
+ if ((length < PMD_SIZE) || (pfn & PG_PMD_COLOUR))
+ goto fallback;
+
for (i = 0; i < PTRS_PER_PMD; i++)
clear_pmem(kaddr + i * PAGE_SIZE, PAGE_SIZE);
wmb_pmem();
@@ -622,7 +635,6 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
result = VM_FAULT_NOPAGE;
spin_unlock(ptl);
} else {
- sector = bh.b_blocknr << (blkbits - 9);
length = bdev_direct_access(bh.b_bdev, sector, &kaddr, &pfn,
bh.b_size);
if (length < 0) {