xattrs, flags, acl - Linux fs options

[Steven French]

A couple quick opinion questions ...

ext2/ext3/reiserfs have two ioctls needed for the chattr command to work
(chflags on bsd and MacOS).  Are these reasonable to support remotely (they
seem fine to me, the extensions to Samba are minor?   The valid flags are
easy enough to mask against the supported list from the server (with minor
tweak to the server in my, samba, case).   I may want to make this a build
or mount option though (not sure what the precedent is on the name of such
a mount option).   There is some reasonable overlap it seems between bsd
and linux on these flags - and there are intriguing possibilities to use
this optionally to change dos attributes to windows server (perhaps limited
to archive? system? read-only? bits - since they are vaguely similar to
some of the chattr flags)

2nd quick question - user_xattr is an ext2/ext3/reiserfs specific mount
option (similar to acl in that it enables something which is otherwise
disabled).   Although I support xattr and acls over the wire - not sure
that it makes sense to default them turned off (in cifs) as ext2/ext3
apparently do.  Today xattrs are a build option (not a mount option) in
cifs vfs - and if xattrs are enabled acls are a mount option (ie specifying
"acl" or "noacl" default is on ie "acl").   Looks like I need to allow for
users to disable xattrs at mount time.


Steve French
Senior Software Engineer
Linux Technology Center - IBM Austin
phone: 512-838-2294
email: sfrench at-sign us dot ibm dot com