Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756152AbXL2EvQ (ORCPT ); Fri, 28 Dec 2007 23:51:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754632AbXL2EvF (ORCPT ); Fri, 28 Dec 2007 23:51:05 -0500 Received: from e6.ny.us.ibm.com ([32.97.182.146]:51487 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754513AbXL2EvE (ORCPT ); Fri, 28 Dec 2007 23:51:04 -0500 Subject: Re: [PATCH] jfs: clear PAGECACHE_TAG_DIRTY for no-write pages From: Dave Kleikamp To: Fengguang Wu Cc: Peter Zijlstra , Andrew Morton , Linux Kernel Mailing List , jfs-discussion@lists.sourceforge.net, Nick Piggin In-Reply-To: References: <1198841626.6821.92.camel@twins> <1198859101.13075.10.camel@norville.austin.ibm.com> <1198860794.13075.15.camel@norville.austin.ibm.com> Content-Type: text/plain Date: Fri, 28 Dec 2007 22:50:59 -0600 Message-Id: <1198903859.6353.7.camel@norville.austin.ibm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2825 Lines: 89 On Sat, 2007-12-29 at 10:21 +0800, Fengguang Wu wrote: > On Fri, Dec 28, 2007 at 10:53:14AM -0600, Dave Kleikamp wrote: > > > > --- > > > > diff -Nurp linux-2.6.24-rc6-git5/fs/jfs/jfs_metapage.c linux/fs/jfs/jfs_metapage.c > > --- linux-2.6.24-rc6-git5/fs/jfs/jfs_metapage.c 2007-12-28 10:28:33.000000000 -0600 > > +++ linux/fs/jfs/jfs_metapage.c 2007-12-28 10:37:30.000000000 -0600 > > @@ -360,6 +360,7 @@ static int metapage_writepage(struct pag > > struct metapage *mp; > > int redirty = 0; > > sector_t lblock; > > + int nr_underway = 0; > > sector_t pblock; > > sector_t next_block = 0; > > sector_t page_start; > > @@ -371,6 +372,7 @@ static int metapage_writepage(struct pag > > (PAGE_CACHE_SHIFT - inode->i_blkbits); > > BUG_ON(!PageLocked(page)); > > BUG_ON(PageWriteback(page)); > > This line should be moved below: > > + set_page_writeback(page); No. set_page_writeback() needs to be called before submit_bio() is called. I don't think there is any harm in calling set_page_writeback(), redirty_page_for_writeback() and end_page_writeback() in the case where there is no I/O to submit, and some dirty data cannot be written. It is consistent with what happens in __block_write_full_page(). It's also possible that some part of the page was written, and another part cannot be, causing the page to be redirtied. > > > > for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { > > mp = page_to_mp(page, offset); > > @@ -413,11 +415,10 @@ static int metapage_writepage(struct pag > > if (!bio->bi_size) > > goto dump_bio; > > submit_bio(WRITE, bio); > > + nr_underway++; > > bio = NULL; > > - } else { > > - set_page_writeback(page); > > + } else > > inc_io(page); > > - } > > xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits; > > pblock = metapage_get_blocks(inode, lblock, &xlen); > > if (!pblock) { > > @@ -449,12 +450,16 @@ static int metapage_writepage(struct pag > > goto dump_bio; > > > > submit_bio(WRITE, bio); > > + nr_underway++; > > } > > if (redirty) > > redirty_page_for_writepage(wbc, page); > + else > + set_page_writeback(page); > > > > unlock_page(page); > > > > + if (nr_underway == 0) > + if (nr_underway == 0 && redirty == 0) > > > + end_page_writeback(page); > > + > > return 0; > > add_failed: > > /* We should never reach here, since we're only adding one vec */ > > Otherwise looks pretty good. > > Reviewed-by: Fengguang Wu > -- David Kleikamp IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/