On Jun 30, 2008 19:01 -0700, Brad Boyer wrote: > What would you expect as reasonable behavior for an FS type that > doesn't have distinct storage for directories? On HFS and HFS+, the > directory information is completely synthetic based on the parent > ID of each file. A directory has no actual data dedicated to it > other than the basic metadata that would be in the inode in ext3, > and readdir just walks the catalog tree and finds all the entries > that say they have the directory you want as a parent. They are > sorted that way, so it's not as bad as it sounds for performance. > > Would it be reasonable for a filesystem like this to just say that > a directory has no extents at all? You can open a directory and > seek to an offset, but that doesn't logically map to any place > on the disk. Is this going to cause problems? Even though the directory data isn't stored in a separate "file", the inodes that make up the "directory" still consume space on disk. If I were writing a FIEMAP handler for such a filesystem, I'd probably return the byte range of the "catalog tree" that match the directory "parent". Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, 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
