On Mon, Apr 23, 2007 at 09:58:49PM +0530, Suparna Bhattacharya wrote: > On Mon, Apr 23, 2007 at 06:21:34AM -0500, Amit Gud wrote: > > > > This is an initial implementation of ChunkFS technique, briefly discussed > > at: http://lwn.net/Articles/190222 and > > http://cis.ksu.edu/~gud/docs/chunkfs-hotdep-val-arjan-gud-zach.pdf > > > > This implementation is done within ext2 driver. Every chunk is an > > independent ext2 file system. The knowledge about chunks is kept within > > ext2 and 'continuation inodes', which are used to allow files and > > directories span across multiple chunks, are managed within ext2. > > > > At mount time, super blocks for all the chunks are created and linked with > > the global super_blocks list maintained by VFS. This allows independent > > behavior or individual chunks and also helps writebacks to happen > > seamlessly. > > > > Apart from this, chunkfs code in ext2 effectively only provides knowledge > > of: > > > > - what inode's which block number to look for, for a given file's logical > > block number > > - in which chunk to allocate next inode / block > > - number of inodes to scan when a directory is being read > > > > To maintain the ext2's inode number uniqueness property, 8 msb bits of > > inode number are used to indicate the chunk number in which it resides. > > > > As said, this is a preliminary implementation and lots of changes are > > expected before this code is even sanely usable. Some known issues and > > obvious optimizations are listed in the TODO file in the chunkfs patch. > > > > http://cis.ksu.edu/~gud/patches/chunkfs-v0.0.8.patch > > - one big patch > > - applies to 2.6.18 > > > Could you send this out as a patch to ext2 codebase, so we can just look > at the changes for chunkfs ? That might also make it small enough > to inline your patch in email for review. Sorry, I missed the part about ext2-chunkfs-diff below. Regards suparna > > What kind of results are you planning to gather to evaluate/optimize this ? > > Regards > Suparna > > > > > Attached - ext2-chunkfs-diff.patch.gz > > - since the code is a spin-off of ext2, this patch explains better what > > has changed from the ext2. > > > > git://cislinux.cis.ksu.edu/chunkfs-tools > > - mkfs, and fsck for chunkfs. > > > > http://cis.ksu.edu/~gud/patches/config-chunkfs-2.6.18-uml > > - config file used; tested mostly on UML with loopback file systems. > > > > NOTE: No xattrs and xips yet, CONFIG_EXT2_FS_XATTR and CONFIG_EXT2_FS_XIP > > should be "no" for clean compile. > > > > > > Please comment, suggest, criticize. Patches most welcome. > > > > > > Best, > > AG > > -- > > May the source be with you. > > http://www.cis.ksu.edu/~gud > > > > -- > Suparna Bhattacharya (suparna@xxxxxxxxxx) > Linux Technology Center > IBM Software Lab, India > -- Suparna Bhattacharya (suparna@xxxxxxxxxx) Linux Technology Center IBM Software Lab, India - 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
