afs: Don't wait for page writeback with the page lock held

Drop the page lock before waiting for page writeback.

Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/afs/write.c b/fs/afs/write.c
index e5f150b..2d2fccd 100644 (file)
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -518,17 +518,16 @@ static int afs_writepages_region(struct address_space *mapping,
                 */
                lock_page(page);
 
-               if (page->mapping != mapping) {
+               if (page->mapping != mapping || !PageDirty(page)) {
                        unlock_page(page);
                        put_page(page);
                        continue;
                }
 
-               if (wbc->sync_mode != WB_SYNC_NONE)
-                       wait_on_page_writeback(page);
-
-               if (PageWriteback(page) || !PageDirty(page)) {
+               if (PageWriteback(page)) {
                        unlock_page(page);
+                       if (wbc->sync_mode != WB_SYNC_NONE)
+                               wait_on_page_writeback(page);
                        put_page(page);
                        continue;
                }