Merge branch 'akpm' (updates from Andrew Morton)

Merge first patch-bomb from Andrew Morton:
 - various misc bits
 - I'm been patchmonkeying ocfs2 for a while, as Joel and Mark have been
   distracted.  There has been quite a bit of activity.
 - About half the MM queue
 - Some backlight bits
 - Various lib/ updates
 - checkpatch updates
 - zillions more little rtc patches
 - ptrace
 - signals
 - exec
 - procfs
 - rapidio
 - nbd
 - aoe
 - pps
 - memstick
 - tools/testing/selftests updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (445 commits)
  tools/testing/selftests: don't assume the x bit is set on scripts
  selftests: add .gitignore for kcmp
  selftests: fix clean target in kcmp Makefile
  selftests: add .gitignore for vm
  selftests: add hugetlbfstest
  self-test: fix make clean
  selftests: exit 1 on failure
  kernel/resource.c: remove the unneeded assignment in function __find_resource
  aio: fix wrong comment in aio_complete()
  drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test mode
  drivers/memstick/host/r592.c: convert to module_pci_driver
  drivers/memstick/host/jmb38x_ms: convert to module_pci_driver
  pps-gpio: add device-tree binding and support
  drivers/pps/clients/pps-gpio.c: convert to module_platform_driver
  drivers/pps/clients/pps-gpio.c: convert to devm_* helpers
  drivers/parport/share.c: use kzalloc
  Documentation/accounting/getdelays.c: avoid strncpy in accounting tool
  aoe: update internal version number to v83
  aoe: update copyright date
  aoe: perform I/O completions in parallel
  ...

1 files changed, 34 insertions, 0 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index f93392e2df12..4d7433534f5c 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -83,6 +83,40 @@ void unlock_buffer(struct buffer_head *bh)
 EXPORT_SYMBOL(unlock_buffer);
 
 /*
+ * Returns if the page has dirty or writeback buffers. If all the buffers
+ * are unlocked and clean then the PageDirty information is stale. If
+ * any of the pages are locked, it is assumed they are locked for IO.
+ */
+void buffer_check_dirty_writeback(struct page *page,
+                                     bool *dirty, bool *writeback)
+{
+        struct buffer_head *head, *bh;
+        *dirty = false;
+        *writeback = false;
+
+        BUG_ON(!PageLocked(page));
+
+        if (!page_has_buffers(page))
+                return;
+
+        if (PageWriteback(page))
+                *writeback = true;
+
+        head = page_buffers(page);
+        bh = head;
+        do {
+                if (buffer_locked(bh))
+                        *writeback = true;
+
+                if (buffer_dirty(bh))
+                        *dirty = true;
+
+                bh = bh->b_this_page;
+        } while (bh != head);
+}
+EXPORT_SYMBOL(buffer_check_dirty_writeback);
+
+/*
  * Block until a buffer comes unlocked.  This doesn't stop it
  * from becoming locked again - you have to lock it yourself
  * if you want to preserve its state.