Merge branch 'block' of git://brick.kernel.dk/data/git/linux-2.6-block

* 'block' of git://brick.kernel.dk/data/git/linux-2.6-block: (67 commits)
  [PATCH] blk_queue_start_tag() shared map race fix
  [PATCH] Update axboe@suse.de email address
  [PATCH] fix creating zero sized bio mempools in low memory system
  [PATCH] CONFIG_BLOCK: blk_congestion_wait() fix
  [PATCH] CONFIG_BLOCK internal.h cleanups
  [PATCH] BLOCK: Make USB storage depend on SCSI rather than selecting it [try #6]
  [PATCH] BLOCK: Make it possible to disable the block layer [try #6]
  [PATCH] BLOCK: Remove no-longer necessary linux/buffer_head.h inclusions [try #6]
  [PATCH] BLOCK: Remove no-longer necessary linux/mpage.h inclusions [try #6]
  [PATCH] BLOCK: Move the msdos device ioctl compat stuff to the msdos driver [try #6]
  [PATCH] BLOCK: Move the Ext3 device ioctl compat stuff to the Ext3 driver [try #6]
  [PATCH] BLOCK: Move the Ext2 device ioctl compat stuff to the Ext2 driver [try #6]
  [PATCH] BLOCK: Move the ReiserFS device ioctl compat stuff to the ReiserFS driver [try #6]
  [PATCH] BLOCK: Move common FS-specific ioctls to linux/fs.h [try #6]
  [PATCH] BLOCK: Move the loop device ioctl compat stuff to the loop driver [try #6]
  [PATCH] BLOCK: Move __invalidate_device() to block_dev.c [try #6]
  [PATCH] BLOCK: Dissociate generic_writepages() from mpage stuff [try #6]
  [PATCH] BLOCK: Remove dependence on existence of blockdev_superblock [try #6]
  [PATCH] BLOCK: Move extern declarations out of fs/*.c into header files [try #6]
  [PATCH] BLOCK: Don't call block_sync_page() from AFS [try #6]
  ...

1 files changed, 26 insertions, 0 deletions

diff --git a/mm/truncate.c b/mm/truncate.c
index a654928323dc..8fde6580657e 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -17,6 +17,32 @@
                                    do_invalidatepage */
 
 
+/**
+ * do_invalidatepage - invalidate part of all of a page
+ * @page: the page which is affected
+ * @offset: the index of the truncation point
+ *
+ * do_invalidatepage() is called when all or part of the page has become
+ * invalidated by a truncate operation.
+ *
+ * do_invalidatepage() does not have to release all buffers, but it must
+ * ensure that no dirty buffer is left outside @offset and that no I/O
+ * is underway against any of the blocks which are outside the truncation
+ * point.  Because the caller is about to free (and possibly reuse) those
+ * blocks on-disk.
+ */
+void do_invalidatepage(struct page *page, unsigned long offset)
+{
+        void (*invalidatepage)(struct page *, unsigned long);
+        invalidatepage = page->mapping->a_ops->invalidatepage;
+#ifdef CONFIG_BLOCK
+        if (!invalidatepage)
+                invalidatepage = block_invalidatepage;
+#endif
+        if (invalidatepage)
+                (*invalidatepage)(page, offset);
+}
+
 static inline void truncate_partial_page(struct page *page, unsigned partial)
 {
         memclear_highpage_flush(page, partial, PAGE_CACHE_SIZE-partial);