AFS: further write support fixes

Further fixes for AFS write support:

 (1) The afs_send_pages() outer loop must do an extra iteration if it ends
     with 'first == last' because 'last' is inclusive in the page set
     otherwise it fails to send the last page and complete the RxRPC op under
     some circumstances.

 (2) Similarly, the outer loop in afs_pages_written_back() must also do an
     extra iteration if it ends with 'first == last', otherwise it fails to
     clear PG_writeback on the last page under some circumstances.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/afs/rxrpc.c

@@ -294,7 +294,7 @@ int afs_send_pages(struct afs_call *call, struct msghdr *msg, struct kvec *iov)
 			put_page(pages[loop]);
 		if (ret < 0)
 			break;
-	} while (first < last);
+	} while (first <= last);
 
 	_leave(" = %d", ret);
 	return ret;

fs/afs/write.c

@@ -669,7 +669,7 @@ void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
 	pagevec_init(&pv, 0);
 
 	do {
-		_debug("attach %lx-%lx", first, last);
+		_debug("done %lx-%lx", first, last);
 
 		count = last - first + 1;
 		if (count > PAGEVEC_SIZE)
@@ -701,7 +701,7 @@ void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
 		}
 
 		__pagevec_release(&pv);
-	} while (first < last);
+	} while (first <= last);
 
 	_leave("");
 }