On Wed, 17 Sep 2008 16:41:47 +0200, Jörn Engel wrote: > On Mon, 15 September 2008 04:08:22 +0900, Ryusuke Konishi wrote: > > > > This adds the cache of on-disk blocks to be moved in garbage > > collection. The disk blocks are held with dummy inodes (called > > gcinodes), and this file provides lookup function of the dummy inodes, > > and their buffer read function. > > Nice explanation. Can you add it to the comment header at the top of > the file? Unlike the GPL preample, it actually helps non-lawyers. ;) Well, I see. ;) > Using dummy inodes is... unusual. Why can you not use the actual inodes > those blocks belong to? Because we have to treat blocks that belong to a same file but have different checkpoint numbers. (NILFS2 keeps up multiple checkpoints/snapshots across GC) Of course, if the standard inode hash is applicable, I prefer it. ilookup5 or its variant may be applicable for this. If so, the remaining problem would be the lock dependencies as you mentioned before. > Or alternatively a single inode that simply > covers the complete physical device? > > Jörn NILFS2 writes GC blocks per file like other files, so the per file caches (even separate inodes) are convienient for this end. Ryusuke -- 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
