afs: Fix afs_launder_page to not clear PG_writeback

Fix afs_launder_page() to not clear PG_writeback on the page it is
laundering as the flag isn't set in this case.

Fixes: 4343d008 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/internal.h

@@ -812,6 +812,7 @@ struct afs_operation {
 			pgoff_t		last;		/* last page in mapping to deal with */
 			unsigned	first_offset;	/* offset into mapping[first] */
 			unsigned	last_to;	/* amount of mapping[last] */
+			bool		laundering;	/* Laundering page, PG_writeback not set */
 		} store;
 		struct {
 			struct iattr	*attr;

fs/afs/write.c

@@ -396,7 +396,8 @@ static void afs_store_data_success(struct afs_operation *op)
 	op->ctime = op->file[0].scb.status.mtime_client;
 	afs_vnode_commit_status(op, &op->file[0]);
 	if (op->error == 0) {
-		afs_pages_written_back(vnode, op->store.first, op->store.last);
+		if (!op->store.laundering)
+			afs_pages_written_back(vnode, op->store.first, op->store.last);
 		afs_stat_v(vnode, n_stores);
 		atomic_long_add((op->store.last * PAGE_SIZE + op->store.last_to) -
 				(op->store.first * PAGE_SIZE + op->store.first_offset),
@@ -415,7 +416,7 @@ static const struct afs_operation_ops afs_store_data_operation = {
  */
 static int afs_store_data(struct address_space *mapping,
 			  pgoff_t first, pgoff_t last,
-			  unsigned offset, unsigned to)
+			  unsigned offset, unsigned to, bool laundering)
 {
 	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
 	struct afs_operation *op;
@@ -448,6 +449,7 @@ static int afs_store_data(struct address_space *mapping,
 	op->store.last = last;
 	op->store.first_offset = offset;
 	op->store.last_to = to;
+	op->store.laundering = laundering;
 	op->mtime = vnode->vfs_inode.i_mtime;
 	op->flags |= AFS_OPERATION_UNINTR;
 	op->ops = &afs_store_data_operation;
@@ -601,7 +603,7 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
 	if (end > i_size)
 		to = i_size & ~PAGE_MASK;
 
-	ret = afs_store_data(mapping, first, last, offset, to);
+	ret = afs_store_data(mapping, first, last, offset, to, false);
 	switch (ret) {
 	case 0:
 		ret = count;
@@ -921,7 +923,7 @@ int afs_launder_page(struct page *page)
 
 		trace_afs_page_dirty(vnode, tracepoint_string("launder"),
 				     page->index, priv);
-		ret = afs_store_data(mapping, page->index, page->index, t, f);
+		ret = afs_store_data(mapping, page->index, page->index, t, f, true);
 	}
 
 	trace_afs_page_dirty(vnode, tracepoint_string("laundered"),