mm: fix data corruption due to stale mmap reads

[sfrench/cifs-2.6.git] / fs / dax.c

diff --git a/fs/dax.c b/fs/dax.c
index 66d79067eedfd25b942a37b2ba7188941df48cf2..123d9903c77d859c1ecfa79022ef66c68ce294c2 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -460,35 +460,6 @@ int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index)
        return ret;
 }
 
-/*
- * Invalidate exceptional DAX entry if easily possible. This handles DAX
- * entries for invalidate_inode_pages() so we evict the entry only if we can
- * do so without blocking.
- */
-int dax_invalidate_mapping_entry(struct address_space *mapping, pgoff_t index)
-{
-       int ret = 0;
-       void *entry, **slot;
-       struct radix_tree_root *page_tree = &mapping->page_tree;
-
-       spin_lock_irq(&mapping->tree_lock);
-       entry = __radix_tree_lookup(page_tree, index, NULL, &slot);
-       if (!entry || !radix_tree_exceptional_entry(entry) ||
-           slot_locked(mapping, slot))
-               goto out;
-       if (radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_DIRTY) ||
-           radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE))
-               goto out;
-       radix_tree_delete(page_tree, index);
-       mapping->nrexceptional--;
-       ret = 1;
-out:
-       spin_unlock_irq(&mapping->tree_lock);
-       if (ret)
-               dax_wake_mapping_entry_waiter(mapping, index, entry, true);
-       return ret;
-}
-
 /*
  * Invalidate exceptional DAX entry if it is clean.
  */
@@ -1044,7 +1015,7 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
         * into page tables. We have to tear down these mappings so that data
         * written by write(2) is visible in mmap.
         */
-       if ((iomap->flags & IOMAP_F_NEW) && inode->i_mapping->nrpages) {
+       if (iomap->flags & IOMAP_F_NEW) {
                invalidate_inode_pages2_range(inode->i_mapping,
                                              pos >> PAGE_SHIFT,
                                              (end - 1) >> PAGE_SHIFT);