On Wed, Mar 23, 2016 at 12:01 PM, Jeremy Allison <jra@xxxxxxxxx> wrote: > On Wed, Mar 23, 2016 at 09:45:07AM -0500, Steve French wrote: >> One of the arguments in favor of additional interfaces (ioctl or >> openat) for accessing alternate data streams which may not be obvious >> to Windows users is that while alternate data streams can be opened >> just like regular files in Windows (and thus over SMB3 mounts), in >> Linux it is hard to allow opening a stream and still support files >> with the ':' (colon) character in their file name since colon is used >> a separator for the stream name in Windows (and is a reserved >> character), but is a valid character in POSIX. When we use a cifs >> or smb3 mount to Windows or Mac we typically map characters (into the >> Unicode remap range just above 0xF000) like ':' the same way the Mac >> does (and Windows services for Mac does as well). This is enabled >> with mount option "mapposix" >> >> So without an ioctl to query the stream contents (or a new syscall), >> you have to choose whether to either allow : in a filename or allow >> opening streams. >> >> There is some additional information on some of the more important >> uses in Windows for alternate data streams at the end of the article >> in this link: https://blogs.technet.microsoft.com/askcore/2013/03/24/alternate-data-streams-in-ntfs/ > > Sorry Steve, but none of the uses in there can be called "important". > > I personally have an intense dislike for streams in a filesystem, > and was very disappointed when Microsoft re-added them to the > previously streamless ReFS (probably for backwards compatibility > stuff like this). > > There's no way to transfer stream-riddled files over the Internet, > and the amount of code complexity we have in Samba having to deal > with them is nasty and has lead to more than one security hole in > the past. > > Please don't add this to Linux. Well, I can avoid setting them, but I do have to be able to query them for backup. -- Thanks, Steve -- 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
