dax: fix conversion of holes to PMDs

[linux-drm-fsl-dcu.git] / fs / dax.c

diff --git a/fs/dax.c b/fs/dax.c
index 513bba5f1e024149b1554e627c071d31e2bdf038..5b84a46201c2a6d6df977a8d5142f89b9ae5a253 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -589,6 +589,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
        bool write = flags & FAULT_FLAG_WRITE;
        struct block_device *bdev;
        pgoff_t size, pgoff;
+       loff_t lstart, lend;
        sector_t block;
        int result = 0;
 
@@ -643,15 +644,13 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
                goto fallback;
        }
 
-       /*
-        * If we allocated new storage, make sure no process has any
-        * zero pages covering this hole
-        */
-       if (buffer_new(&bh)) {
-               i_mmap_unlock_read(mapping);
-               unmap_mapping_range(mapping, pgoff << PAGE_SHIFT, PMD_SIZE, 0);
-               i_mmap_lock_read(mapping);
-       }
+       /* make sure no process has any zero pages covering this hole */
+       lstart = pgoff << PAGE_SHIFT;
+       lend = lstart + PMD_SIZE - 1; /* inclusive */
+       i_mmap_unlock_read(mapping);
+       unmap_mapping_range(mapping, lstart, PMD_SIZE, 0);
+       truncate_inode_pages_range(mapping, lstart, lend);
+       i_mmap_lock_read(mapping);
 
        /*
         * If a truncate happened while we were allocating blocks, we may
@@ -665,7 +664,8 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
                goto out;
        }
        if ((pgoff | PG_PMD_COLOUR) >= size) {
-               dax_pmd_dbg(&bh, address, "pgoff unaligned");
+               dax_pmd_dbg(&bh, address,
+                               "offset + huge page size > file size");
                goto fallback;
        }