From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zheng Liu Subject: Re: [PATCH 16/29] ext4: Improve writepage credit estimate for files with indirect blocks Date: Tue, 7 May 2013 13:39:27 +0800 Message-ID: <20130507053927.GA17637@gmail.com> References: <1365456754-29373-1-git-send-email-jack@suse.cz> <1365456754-29373-17-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ted Tso , linux-ext4@vger.kernel.org To: Jan Kara Return-path: Received: from mail-pb0-f42.google.com ([209.85.160.42]:39748 "EHLO mail-pb0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753506Ab3EGFVr (ORCPT ); Tue, 7 May 2013 01:21:47 -0400 Received: by mail-pb0-f42.google.com with SMTP id up7so136192pbc.29 for ; Mon, 06 May 2013 22:21:46 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1365456754-29373-17-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Apr 08, 2013 at 11:32:21PM +0200, Jan Kara wrote: > ext4_ind_trans_blocks() wrongly used 'chunk' argument to decide whether > blocks mapped are logically continguous. That is wrong since the argument > informs whether the blocks are physically continguous. As the blocks > mapped are always logically continguous and that's all > ext4_ind_trans_blocks() cares about, just remove the 'chunk' argument. > > Signed-off-by: Jan Kara Reviewed-by: Zheng Liu Regards, - Zheng > --- > fs/ext4/ext4.h | 2 +- > fs/ext4/indirect.c | 27 +++++++++------------------ > fs/ext4/inode.c | 2 +- > 3 files changed, 11 insertions(+), 20 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 3575fdb..d3a54f2 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -2093,7 +2093,7 @@ extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb, > const struct iovec *iov, loff_t offset, > unsigned long nr_segs); > extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock); > -extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk); > +extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks); > extern void ext4_ind_truncate(struct inode *inode); > extern int ext4_ind_punch_hole(struct file *file, loff_t offset, loff_t length); > > diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c > index b505a14..197b202 100644 > --- a/fs/ext4/indirect.c > +++ b/fs/ext4/indirect.c > @@ -913,27 +913,18 @@ int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock) > return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1; > } > > -int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk) > +/* > + * Calculate number of indirect blocks touched by mapping @nrblocks logically > + * continguous blocks > + */ > +int ext4_ind_trans_blocks(struct inode *inode, int nrblocks) > { > - int indirects; > - > - /* if nrblocks are contiguous */ > - if (chunk) { > - /* > - * With N contiguous data blocks, we need at most > - * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks, > - * 2 dindirect blocks, and 1 tindirect block > - */ > - return DIV_ROUND_UP(nrblocks, > - EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4; > - } > /* > - * if nrblocks are not contiguous, worse case, each block touch > - * a indirect block, and each indirect block touch a double indirect > - * block, plus a triple indirect block > + * With N contiguous data blocks, we need at most > + * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks, > + * 2 dindirect blocks, and 1 tindirect block > */ > - indirects = nrblocks * 2 + 1; > - return indirects; > + return DIV_ROUND_UP(nrblocks, EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4; > } > > /* > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index f4dc4a1..aa26f4c 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -4399,7 +4399,7 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, > static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk) > { > if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) > - return ext4_ind_trans_blocks(inode, nrblocks, chunk); > + return ext4_ind_trans_blocks(inode, nrblocks); > return ext4_ext_index_trans_blocks(inode, nrblocks, chunk); > } > > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html