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 15:49:43 +0530 Message-ID: <20080813101943.GF6439@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 e28smtp07.in.ibm.com ([59.145.155.7]:51980 "EHLO e28esmtp07.in.ibm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750782AbYHMKT5 (ORCPT ); Wed, 13 Aug 2008 06:19:57 -0400 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by e28esmtp07.in.ibm.com (8.13.1/8.13.1) with ESMTP id m7DAJkYX017199 for ; Wed, 13 Aug 2008 15:49:46 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v9.0) with ESMTP id m7DAJklv1036498 for ; Wed, 13 Aug 2008 15:49:46 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.13.1/8.13.3) with ESMTP id m7DAJjhM015871 for ; Wed, 13 Aug 2008 15:49:45 +0530 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: > +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; I guess we should pass chunk to ext4_meta_trans_blocks also. if (chunk) we should update only one group descriptor and one bitmap block ie, if(chunk) groups = 1 + idxblocks; > + > + /* bitmaps and block group descriptor blocks */ > + 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_writeblocks_trans_credits_old(struct inode *inode, int nrblocks, > + int chunk) > { > - int bpp = ext4_journal_blocks_per_page(inode); > - int indirects = (EXT4_NDIR_BLOCKS % bpp) ? 5 : 3; > + int indirects; > int ret; > > - if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) > - return ext4_ext_writepage_trans_blocks(inode, bpp); > - > - if (ext4_should_journal_data(inode)) > - ret = 3 * (bpp + indirects) + 2; > - else > - ret = 2 * (bpp + indirects) + 2; > + /* > + * How many index blocks need to touch to modify nrblocks? > + * The "Chunk" flag indicating whether the nrblocks is > + * physically contigous on disk > + * > + * For Direct IO and fallocate, they calls get_block to allocate > + * one single extent at a time, so they could set the "Chunk" flag > + */ > + indirects = ext4_indirect_trans_blocks(inode, nrblocks, chunk); > > -#ifdef CONFIG_QUOTA > - /* We know that structure was already allocated during DQUOT_INIT so > - * we will be updating only the data blocks + inodes */ > - ret += 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); > -#endif > + /* Account for block group bitmaps and block groups > + * descriptors.Worse case, the nrblocks+indirects blocks spread > + * over different block groups > + */ > + ret = ext4_meta_trans_blocks(inode, nrblocks, indirects); > > return ret; > } -aneesh