On May 05, 2006 13:18 +0200, Erik Mouw wrote: > Andreas, care to elaborate? AFAICS resetting ->i_mode to 0000, setting > ->i_links_count to 0, and setting ->i_dtime should be enough to > uniquely mark an inode as deleted. Doing so would make an occasional > undelete much easier to recover for Joe Sixpack (and for us a lot less > work to reconstruct files by scavenging the whole partition for clues). Yes, while this would mark the _inode_ unused, it does nothing to mark the blocks unused in the block bitmaps (of which there may be many thousand/million in a single file). So ext3 needs to be able to mark these bitmap blocks unused when the file is unlinked/truncated. Otherwise each crash would leak blocks that can't be recovered except by full e2fsck. There is another mechanism ext3 could potentially use, wherein it walks the whole inode in advance of the truncate and creates a (potentially) very large transaction handle to do the bitmap updates in a single shot (and also reducing the amount of IO needed for an unlink by 96%), but nobody has ever cared enough about it to work on implementing this. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. - 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
