From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 26 May 2002 16:40:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 26 May 2002 16:39:02 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:43792 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id ; Sun, 26 May 2002 16:37:54 -0400 Message-ID: <3CF14860.30A48829@zip.com.au> Date: Sun, 26 May 2002 13:41:04 -0700 From: Andrew Morton X-Mailer: Mozilla 4.79 [en] (X11; U; Linux 2.4.19-pre8 i686) X-Accept-Language: en MIME-Version: 1.0 To: Linus Torvalds CC: lkml Subject: [patch 6/18] relax nr_to_write requirements Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Relax the requirements on the writeback_mapping a_op. This function is passed the number of pages which it should write. The current fs-writeback.c code will get confused if the address_space writes back more pages than it was asked to. With this change the address_space may write more pages than required if that is convenient. Extent-based fileystems may wish to do this. ===================================== --- 2.5.18/fs/fs-writeback.c~relax-nr-to_write Sat May 25 23:26:46 2002 +++ 2.5.18-akpm/fs/fs-writeback.c Sun May 26 00:50:19 2002 @@ -257,7 +257,7 @@ static void sync_sb_inodes(struct super_ if (current_is_pdflush()) writeback_release(bdi); - if (nr_to_write && *nr_to_write == 0) + if (nr_to_write && *nr_to_write <= 0) break; } out: @@ -301,7 +301,7 @@ void writeback_unlocked_inodes(int *nr_t older_than_this); spin_lock(&sb_lock); } - if (nr_to_write && *nr_to_write == 0) + if (nr_to_write && *nr_to_write <= 0) break; } spin_unlock(&sb_lock); --- 2.5.18/Documentation/filesystems/Locking~relax-nr-to_write Sat May 25 23:26:46 2002 +++ 2.5.18-akpm/Documentation/filesystems/Locking Sun May 26 00:50:22 2002 @@ -179,11 +179,12 @@ existing instances of this method ->sync well-defined... ->writeback_mapping() is used for periodic writeback and for -systemcall-initiated sync operations. The address_space should start -I/O against at least *nr_to_write pages. *nr_to_write must be decremented -for each page which is written. *nr_to_write must not go negative (this -will be relaxed later). If nr_to_write is NULL, all dirty pages must -be written. +systemcall-initiated sync operations. The address_space should start +I/O against at least *nr_to_write pages. *nr_to_write must be +decremented for each page which is written. The address_space +implementation may write more (or less) pages than *nr_to_write asks +for, but it should try to be reasonably close. If nr_to_write is NULL, +all dirty pages must be written. ->vm_writeback() is called from the VM. The address_space should start I/O against at least *nr_to_write pages, including the passed page. As -