1 files changed, 61 insertions, 0 deletions

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 11e9b4caa54f..b984647c24db 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1753,11 +1753,72 @@ xfs_vm_readpages(
         return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
 }
 
+/*
+ * This is basically a copy of __set_page_dirty_buffers() with one
+ * small tweak: buffers beyond EOF do not get marked dirty. If we mark them
+ * dirty, we'll never be able to clean them because we don't write buffers
+ * beyond EOF, and that means we can't invalidate pages that span EOF
+ * that have been marked dirty. Further, the dirty state can leak into
+ * the file interior if the file is extended, resulting in all sorts of
+ * bad things happening as the state does not match the underlying data.
+ *
+ * XXX: this really indicates that bufferheads in XFS need to die. Warts like
+ * this only exist because of bufferheads and how the generic code manages them.
+ */
+STATIC int
+xfs_vm_set_page_dirty(
+        struct page             *page)
+{
+        struct address_space    *mapping = page->mapping;
+        struct inode            *inode = mapping->host;
+        loff_t                  end_offset;
+        loff_t                  offset;
+        int                     newly_dirty;
+
+        if (unlikely(!mapping))
+                return !TestSetPageDirty(page);
+
+        end_offset = i_size_read(inode);
+        offset = page_offset(page);
+
+        spin_lock(&mapping->private_lock);
+        if (page_has_buffers(page)) {
+                struct buffer_head *head = page_buffers(page);
+                struct buffer_head *bh = head;
+
+                do {
+                        if (offset < end_offset)
+                                set_buffer_dirty(bh);
+                        bh = bh->b_this_page;
+                        offset += 1 << inode->i_blkbits;
+                } while (bh != head);
+        }
+        newly_dirty = !TestSetPageDirty(page);
+        spin_unlock(&mapping->private_lock);
+
+        if (newly_dirty) {
+                /* sigh - __set_page_dirty() is static, so copy it here, too */
+                unsigned long flags;
+
+                spin_lock_irqsave(&mapping->tree_lock, flags);
+                if (page->mapping) {    /* Race with truncate? */
+                        WARN_ON_ONCE(!PageUptodate(page));
+                        account_page_dirtied(page, mapping);
+                        radix_tree_tag_set(&mapping->page_tree,
+                                        page_index(page), PAGECACHE_TAG_DIRTY);
+                }
+                spin_unlock_irqrestore(&mapping->tree_lock, flags);
+                __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
+        }
+        return newly_dirty;
+}
+
 const struct address_space_operations xfs_address_space_operations = {
         .readpage               = xfs_vm_readpage,
         .readpages              = xfs_vm_readpages,
         .writepage              = xfs_vm_writepage,
         .writepages             = xfs_vm_writepages,
+        .set_page_dirty         = xfs_vm_set_page_dirty,
         .releasepage            = xfs_vm_releasepage,
         .invalidatepage         = xfs_vm_invalidatepage,
         .write_begin            = xfs_vm_write_begin,