From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH 1/9] extents for ext4 Date: Wed, 9 Aug 2006 23:39:40 -0700 Message-ID: <20060809233940.50162afb.akpm@osdl.org> References: <1155172827.3161.80.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, ext2-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Return-path: To: cmm@us.ibm.com In-Reply-To: <1155172827.3161.80.camel@localhost.localdomain> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: ext2-devel-bounces@lists.sourceforge.net Errors-To: ext2-devel-bounces@lists.sourceforge.net List-Id: linux-fsdevel.vger.kernel.org On Wed, 09 Aug 2006 18:20:26 -0700 Mingming Cao wrote: > > Add extent map support to ext4. Patch from Alex Tomas. > > On disk extents format: > /* > * this is extent on-disk structure > * it's used at the bottom of the tree > */ > struct ext3_extent { > __le32 ee_block; /* first logical block extent covers */ > __le16 ee_len; /* number of blocks covered by extent */ > __le16 ee_start_hi; /* high 16 bits of physical block */ > __le32 ee_start; /* low 32 bigs of physical block */ > }; > >>From a quick scan: - The code is very poorly commented. I'd want to spend a lot of time reviewing this implementation, but not in its present state. - Far, far too many inlines - overly-terse variable naming - There are several places which appear to be putting block numbers into an `int'. - Needs kmalloc()->kzalloc() conversion - replace all brelse() calls with put_bh(). Because brelse() is old-fashioned, has a weird name and neelessly permits a NULL arg. In fact it would be beter to convert JBD and ext3 to put_bh before copying it all over. - The open-coded __clear_bit(BH_New, ...) in ext4_ext_get_blocks is a bit nasty. We can live with nasty, but are we sure that it isn't buggy?? - It has about 7,000 instances of if ((lhs = expression)) { whereas the preferred coding style is lhs = expression; if (lhs) { - The existing comments could benefit from some rework by a native English speaker. ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642