From: "Aneesh Kumar K.V" Subject: Re: [PATCH 1/6 ]Ext4 credits caclulation cleanup and fix that for nonextent writepage Date: Wed, 13 Aug 2008 14:01:32 +0530 Message-ID: <20080813083132.GA6439@skywalker> References: <48841077.500@cse.unsw.edu.au> <20080721082010.GC8788@skywalker> <1216774311.6505.4.camel@mingming-laptop> <20080723074226.GA15091@skywalker> <1217032947.6394.2.camel@mingming-laptop> <1218558190.6766.37.camel@mingming-laptop> <1218558354.6766.40.camel@mingming-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: tytso , linux-ext4@vger.kernel.org, Andreas Dilger To: Mingming Cao Return-path: Received: from E23SMTP03.au.ibm.com ([202.81.18.172]:51074 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755278AbYHMIhA (ORCPT ); Wed, 13 Aug 2008 04:37:00 -0400 Received: from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225]) by e23smtp03.au.ibm.com (8.13.1/8.13.1) with ESMTP id m7D8ZppJ015048 for ; Wed, 13 Aug 2008 18:35:51 +1000 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v9.0) with ESMTP id m7D8VtWE159426 for ; Wed, 13 Aug 2008 18:31:55 +1000 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m7D8VtNQ022294 for ; Wed, 13 Aug 2008 18:31:55 +1000 Content-Disposition: inline In-Reply-To: <1218558354.6766.40.camel@mingming-laptop> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Aug 12, 2008 at 09:25:54AM -0700, Mingming Cao wrote: .... > - * and dindirect block, and the "5" above becomes "3". > + * Also account for superblock, inode, quota and xattr blocks > + */ > +int ext4_meta_trans_blocks(struct inode* inode, int nrblocks, int idxblocks) > +{ > + int groups, gdpblocks; > + int ret = 0; > + > + groups = nrblocks + idxblocks; > + gdpblocks = groups; > + if (groups > EXT4_SB(inode->i_sb)->s_groups_count) > + groups = EXT4_SB(inode->i_sb)->s_groups_count; > + if (groups > EXT4_SB(inode->i_sb)->s_gdb_count) > + gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count; > + > + /* bitmaps and block group descriptor blocks */ > + ret += groups + gdpblocks; ret = groups + gdpblocks; > + > + ret += idxblocks; > + > + /* journalled mode, include buffer to modify data blocks */ > + if (ext4_should_journal_data(inode)) > + ret += nrblocks; > + > + /* Blocks for super block, inode, quota and xattr blocks */ > + ret += EXT4_META_TRANS_BLOCKS(inode->i_sb); > + > + return ret; > +} > + > +static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks, > + int chunk) > +{ ..... ..... > > +/* > + * Define the number of metadata blocks we need to account to modify data. > + * > + * This include super block, inode block, quota blocks and xattr blocks > + */ > +#define EXT4_META_TRANS_BLOCKS(sb) (EXT4_XATTR_TRANS_BLOCKS + \ > + 2*EXT4_QUOTA_TRANS_BLOCKS(sb)) > + Do EXT4_XATTR_TRANS_BLOCKS blocks really account for super block and inode block ? Looking at EXT4_DATA_TRANS_BLOCKS which also use EXT4_XATTR_TRANS_BLOCKS I think it doesn't. But the comment above EXT4_XATTR_TRANS_BLOCKS is confusing. I guess we would need a +2 here. -aneesh