On Mon, Apr 30, 2007 at 01:26:24PM -0400, Theodore Tso wrote: > On Sun, Apr 29, 2007 at 08:40:42PM -0500, Matt Mackall wrote: > > chunkfs. The other is reverse maps (aka back pointers) for blocks -> > > inodes and inodes -> directories that obviate the need to have large > > amounts of memory to check for collisions. > > Yes, I missed the fact that you had back pointers for blocks as well > as inodes. So the block table in the tile header gets used for > determing if a block is free, much like is done with FAT, right? We could eliminate the block bitmap, but I don't think there's much reason to. It improves allocator performance with negligible footprint and improves redundancy. > That's a clever system; I like it. It does mean that there is a lot > more metadata updates, but since you're not journaling, that should > counter that effect to some extent. I had actually envisioned this as working with or without a journal. I suspect there are ways to keep the performance downside here low. > IMHO, it's definitely worth a try to see how well it works! I'm not much of an FS hacker and I've got a lot of other projects in the air, but I may give it a shot. Any help on this front would be appreciated. -- Mathematics is the supreme nostalgia of our time. - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
