Now that the documentation section is expanding, I can make a not-so-ill-informed comment about zfs and the Mac OS. If I'm reading the documentation correctly, the news is unfortunately bad.
The "problem" with Mac support is that the Mac stored all of its display-related information in the directory itself. By this I refer to things like the icon's position within its directory window, the "type and creator" flags that are an analog to a file extension, and even things like window sizing, position and scroll location for folders. The idea here was that on a floppy, which the FS was targetted for way back when, a single pass over the flat-file directory would give you EVERYTHING you needed to draw the display. Given the extremely limited bandwidth, this was an extremely practical decision, if potentially limiting. For the interested, here's the info needed: http://developer.apple.com/technotes/tn/tn1150.html#FinderInfo It's a pair of four-byte strings, three 2x16-bit Points and potentially a 32-bit Rect, and a couple of flags, the vast majority of which are no longer used or are duplicated in zfs's directory ZAP anyway. Now generally the Unix nerds would suggest hanging the Mac's extra information in the xattrs.The problem here is that zfs stores all xattrs separately from the ZAP directory entry. So while it is physically possible to make another ACE for the Mac info and hang it off the xattr "inode" (ZAP), this means that drawing a window in the Finder will require a file system walk! This just isn't going to work, Mac users won't accept PC-slow directory displays -- I know I wouldn't. What I don't understand is why this disturbingly inflexible design was chosen. Note that the ACL ACE is built in order to store up to six entries in-line, which likely serves 95% of all cases. Why an identical solution was not used for xattrs absolutely baffles me. An identical six entry with overflow ACE dir would work wonderfully for xattrs, and in this particular case, would store all the needed Mac-related goodness. So can anyone tell me why xattrs weren't handled in the same way as ACLs? It smells of inside-the-box-thinking, but I'm no FS expert and there may very well be a good reason. And if there isn't a good reason, is it simply too late to fix this? If xattr were moved below gid and used up the pad[4], that would at least give us something useful. Maury This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list [EMAIL PROTECTED] http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
