Fix up CIFS for "test_clear_page_dirty()" removal

This also adds he required page "writeback" flag handling, that cifs
hasn't been doing and that the page dirty flag changes made obvious.

Acked-by: Steve French <smfltc@us.ibm.com>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 23 insertions, 3 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 0f05cab5d24a..8a49b2e77d37 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1245,14 +1245,21 @@ retry:
                                 wait_on_page_writeback(page);
 
                         if (PageWriteback(page) ||
-                                        !test_clear_page_dirty(page)) {
+                                        !clear_page_dirty_for_io(page)) {
                                 unlock_page(page);
                                 break;
                         }
 
+                        /*
+                         * This actually clears the dirty bit in the radix tree.
+                         * See cifs_writepage() for more commentary.
+                         */
+                        set_page_writeback(page);
+
                         if (page_offset(page) >= mapping->host->i_size) {
                                 done = 1;
                                 unlock_page(page);
+                                end_page_writeback(page);
                                 break;
                         }
 
@@ -1316,6 +1323,7 @@ retry:
                                         SetPageError(page);
                                 kunmap(page);
                                 unlock_page(page);
+                                end_page_writeback(page);
                                 page_cache_release(page);
                         }
                         if ((wbc->nr_to_write -= n_iov) <= 0)
@@ -1352,11 +1360,23 @@ static int cifs_writepage(struct page* page, struct writeback_control *wbc)
         if (!PageUptodate(page)) {
                 cFYI(1, ("ppw - page not up to date"));
         }
-        
+
+        /*
+         * Set the "writeback" flag, and clear "dirty" in the radix tree.
+         *
+         * A writepage() implementation always needs to do either this,
+         * or re-dirty the page with "redirty_page_for_writepage()" in
+         * the case of a failure.
+         *
+         * Just unlocking the page will cause the radix tree tag-bits
+         * to fail to update with the state of the page correctly.
+         */
+        set_page_writeback(page);               
         rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
         SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
         unlock_page(page);
-        page_cache_release(page);       
+        end_page_writeback(page);
+        page_cache_release(page);
         FreeXid(xid);
         return rc;
 }