1 files changed, 27 insertions, 6 deletions

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 2b2691b73428..596ec71da00e 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -725,6 +725,25 @@ xfs_convert_page(
 			(xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
 			i_size_read(inode));
 
+	/*
+	 * If the current map does not span the entire page we are about to try
+	 * to write, then give up. The only way we can write a page that spans
+	 * multiple mappings in a single writeback iteration is via the
+	 * xfs_vm_writepage() function. Data integrity writeback requires the
+	 * entire page to be written in a single attempt, otherwise the part of
+	 * the page we don't write here doesn't get written as part of the data
+	 * integrity sync.
+	 *
+	 * For normal writeback, we also don't attempt to write partial pages
+	 * here as it simply means that write_cache_pages() will see it under
+	 * writeback and ignore the page until some point in the future, at
+	 * which time this will be the only page in the file that needs
+	 * writeback.  Hence for more optimal IO patterns, we should always
+	 * avoid partial page writeback due to multiple mappings on a page here.
+	 */
+	if (!xfs_imap_valid(inode, imap, end_offset))
+		goto fail_unlock_page;
+
 	len = 1 << inode->i_blkbits;
 	p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1),
 					PAGE_CACHE_SIZE);
@@ -824,10 +843,12 @@ xfs_cluster_write(
 STATIC void
 xfs_vm_invalidatepage(
 	struct page		*page,
-	unsigned long		offset)
+	unsigned int		offset,
+	unsigned int		length)
 {
-	trace_xfs_invalidatepage(page->mapping->host, page, offset);
-	block_invalidatepage(page, offset);
+	trace_xfs_invalidatepage(page->mapping->host, page, offset,
+				 length);
+	block_invalidatepage(page, offset, length);
 }
 
 /*
@@ -891,7 +912,7 @@ next_buffer:
 
 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 out_invalidate:
-	xfs_vm_invalidatepage(page, 0);
+	xfs_vm_invalidatepage(page, 0, PAGE_CACHE_SIZE);
 	return;
 }
 
@@ -921,7 +942,7 @@ xfs_vm_writepage(
 	int			count = 0;
 	int			nonblocking = 0;
 
-	trace_xfs_writepage(inode, page, 0);
+	trace_xfs_writepage(inode, page, 0, 0);
 
 	ASSERT(page_has_buffers(page));
 
@@ -1152,7 +1173,7 @@ xfs_vm_releasepage(
 {
 	int			delalloc, unwritten;
 
-	trace_xfs_releasepage(page->mapping->host, page, 0);
+	trace_xfs_releasepage(page->mapping->host, page, 0, 0);
 
 	xfs_count_page_state(page, &delalloc, &unwritten);