On Mon, Dec 22, 2014 at 12:44 PM, Austin S Hemmelgarn <ahferro...@gmail.com> wrote: > On 2014-12-22 15:06, Richard Sharpe wrote: >> >> On Mon, Dec 22, 2014 at 10:43 AM, Chris Murphy <li...@colorremedies.com> >> wrote: >>> >>> On Mon, Dec 22, 2014 at 11:09 AM, Austin S Hemmelgarn >>> <ahferro...@gmail.com> wrote: >>> >>>> Personally, I'd love to see unlimited length xattr's like NTFS and HFS+ >>>> do, >>>> as that would greatly improve interoperability (both Windows and OS X >>>> use >>>> xattrs, although they call them 'alternative data streams' and 'forks' >>>> respectively), and provide a higher likelihood that xattrs would start >>>> getting used more. >>> >>> >>> This is two years old, but it looks like NFS will not support xattr. >>> http://comments.gmane.org/gmane.linux.nfs/53259 >>> >>> It looks like SMB does support xattr (and sometimes requires it) but I >>> have no idea to what degree, including the host/client preservation on >>> different filesystems. [1] It would still be helpful for cp and rsync >>> to be able to preserve xattr, however Apple has moved to a new on-disk >>> format that makes the future of reading OS X volumes on Linux an open >>> question. [2] >> >> >> Those are the old OS 2 XATTRs, better known as EAs, and NTFS says that >> you can support EAs or you can have Reparse Points, but not both >> (basically, they re-used the EA Length field as the reparse tag). >> Also, Windows (of any flavor) does not make it easy to access EAs. >> > But OS/2 style XATTRS are not the same as NTFS Alternative Data Streams,
I agree with you and was not trying to claim that EAs are ADSs. Indeed, they have worse functionality than unix XATTRs, IMO. > which technically (because of Windows backward compatibility interfaces) > don't need a huge amount of support from SMB. They were originally added to > support SFM in NT3.1, so that windows could store resource forks. The two > primary uses on windows today are the file history interface in Win8/8.1 and > the 'zone_identifier' saved with downloads by most modern browsers. They're > actually pretty easy to get to, you just append the ADS name to the end of > the filename with a : separating them, and you can access it like a regular > file (which is part of why : isn't a legal character in a windows filename). > Most people don't know about them because they don't get listed in windows > explorer, even with hidden files and protected OS file visible. The actual > on-disk format for them is actually kind of interesting, the file data > itself (what in the Apple world is called the Data Fork) is actually stored > as an unnamed ADS associated with the filename. > -- Regards, Richard Sharpe (何以解憂？唯有杜康。--曹操) -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
