> On Thu, Feb 11, 2010 at 09:08:36AM +0530, Manish Katiyar wrote: > > > > Is this design somewhere on net so that we can read/lookup it up ? > > Not yet, but the basic idea is to do the compression in userspace, > using libz with regular resync points every 64k or 128k of > uncompressed data. An array, indexed by each fixed-block of > uncompressed data, is located at the beginning of the file indicating > where each compressed block begins. The file is stored on-disk > written by the installer in a compressed format, and then the > installer flips an attribute bit which marks the file as containing > compressed data, and which also makes the file immutable. (Any > attempt to open the file read/write will result in an error.) From the first reading, this sounds like what zisofs is doing. The reading part is already implemented in kernel in fs/isofs/compress.c so that might be lifted to a generic level and used for ext4 as well.. Honza -- Jan Kara <jack@xxxxxxx> SuSE CR Labs -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
