Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423560AbWJaQ23 (ORCPT ); Tue, 31 Oct 2006 11:28:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423559AbWJaQ23 (ORCPT ); Tue, 31 Oct 2006 11:28:29 -0500 Received: from palinux.external.hp.com ([192.25.206.14]:52611 "EHLO mail.parisc-linux.org") by vger.kernel.org with ESMTP id S1423549AbWJaQ22 (ORCPT ); Tue, 31 Oct 2006 11:28:28 -0500 Date: Tue, 31 Oct 2006 09:28:25 -0700 From: Matthew Wilcox To: Holden Karau Cc: Josef Sipek , hirofumi@mail.parknet.co.jp, linux-kernel@vger.kernel.org, "akpm@osdl.org" , linux-fsdevel@vger.kernel.org, holden@pigscanfly.ca, holden.karau@gmail.com, Nick Piggin , J?rn Engel Subject: Re: [PATCH 1/1] fat: improve sync performance by grouping writes revised Message-ID: <20061031162825.GD26964@parisc-linux.org> References: <454765AC.1050905@xandros.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <454765AC.1050905@xandros.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2230 Lines: 62 On Tue, Oct 31, 2006 at 10:03:08AM -0500, Holden Karau wrote: > @@ -343,52 +344,65 @@ int fat_ent_read(struct inode *inode, st > return ops->ent_get(fatent); > } > > -/* FIXME: We can write the blocks as more big chunk. */ > -static int fat_mirror_bhs(struct super_block *sb, struct buffer_head **bhs, > - int nr_bhs) > + > +static int fat_mirror_bhs_optw(struct super_block *sb, struct buffer_head **bhs, > + int nr_bhs , int wait) > { > struct msdos_sb_info *sbi = MSDOS_SB(sb); > - struct buffer_head *c_bh; > + struct buffer_head *c_bh[nr_bhs*(sbi->fats)]; > int err, n, copy; > > + /* Always wait if mounted -o sync */ > + if (sb->s_flags & MS_SYNCHRONOUS ) > + wait = 1; > err = 0; > for (copy = 1; copy < sbi->fats; copy++) { > sector_t backup_fat = sbi->fat_length * copy; > - > - for (n = 0; n < nr_bhs; n++) { > - c_bh = sb_getblk(sb, backup_fat + bhs[n]->b_blocknr); > - if (!c_bh) { > + for (n = 0 ; n < nr_bhs ; n++ ) { > + c_bh[(copy-1)*nr_bhs+n] = sb_getblk(sb, backup_fat + bhs[n]->b_blocknr); > + if (!c_bh[(copy-1)*nr_bhs+n]) { > + printk(KERN_CRIT "fat: out of memory while copying backup fat. possible data loss\n"); I don't like that at all. > err = -ENOMEM; > goto error; > } > - memcpy(c_bh->b_data, bhs[n]->b_data, sb->s_blocksize); > - set_buffer_uptodate(c_bh); > - mark_buffer_dirty(c_bh); > - if (sb->s_flags & MS_SYNCHRONOUS) > - err = sync_dirty_buffer(c_bh); > - brelse(c_bh); > - if (err) > - goto error; > + memcpy(c_bh[(copy-1)*nr_bhs+n]->b_data, bhs[n]->b_data, sb->s_blocksize); > + set_buffer_uptodate(c_bh[(copy-1)*nr_bhs+n]); > + mark_buffer_dirty(c_bh[(copy-1)*nr_bhs+n]); > } > } > + > + if (wait) { > + for (n = 0 ; n < nr_bhs ; n++) { > + printk("copying to %d to %d\n" ,n, nr_bhs*(sbi->fats-1)+n); Is this the right version of the patch? The printk should never be left in. Plus, as far as I can tell, that whole loop is actually just memcpy(). - 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/