Thanks a ton for the pointers, Erik. The proceedings paper was an excellent source of reference. -HC On 4/29/05, Erik Mouw <J.A.K.Mouw@xxxxxxxxxxxxxx> wrote: > On Fri, Apr 29, 2005 at 02:14:19AM -0700, HC wrote: > > I am trying to port a ext3 COW utility from 2.4 to 2.6. > > One of the major changes I see in the 2.6 ext3 is the use of dx_ > > functions. Looking the source code, I understand that some kind of > > hashing is being done in these functions. It would be great if anyone > > can tell me whats is the basic idea behind these dx_ functions. > > Directory hashing, aka "htree support". From the mke2fs manual page: > > -O feature[,...] > Create filesystem with given features (filesystem options), > > [...] > > The following filesystem options are supported: > > dir_index > Use hashed b-trees to speed up lookups in large > directories. > > For more information, see Daniel Phillips' talk at OLS 2002: > > http://www.linuxsymposium.org/2002/view_txt.php?text=abstract&talk=3 > > His paper is in the proceedings. > > > General pointers on changes to ext3 in 2.6 will be greatly > > appreciated. > > AFAIK the only major change in disk layout is htree support, but ext3 > also got quite some speed ups due to more efficient locking. Right now > there are people working on support for extents, but that code isn't in > yet. > > Erik > > -- > Erik Mouw > J.A.K.Mouw@xxxxxxxxxxxxxx mouw@xxxxxxxxxxxx > > > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
