2004-06-30 12:51:10

by Jacky Malcles

Subject: A question about extended attributes of filesystem objects (setfattr command)

I have a question regarding
Attributes of symlinks vs. the files pointed to

If I try to attach name:value pair to object symlink file
then I'll get: "Operation not permitted"

reading the man pages of setfattr (or attr) I thought that it operates
on the attributes of the symbolic link itself.

show:
-----
touch f
ln -s f l
setfattr -n user.filename -v ascii1 f l
setfattr -h -n user.filename -v ascii2 f
getfattr -d f l
setfattr -h -n user.filename -v ascii3 l
setfattr -h --no-dereference -n user.filename -v ascii4 l
getfattr -d f l

so, my question is : what is expected ?
I've
libattr-devel-2.2.0-1
libattr-2.2.0-1
attr-2.2.0-1
and a 2.6.7 kernel

many thanks,
regards,

--
Jacky Malcles B1-403 Email : [email protected]
Bull SA, 1 rue de Provence, B.P 208, 38432 Echirolles CEDEX, FRANCE
Tel : 04.76.29.73.14

2004-06-30 14:03:41

by Jacky Malcles

Subject: Re: A question about extended attributes of filesystem objects (setfattr command)

Michael Kerrisk wrote:
>
> Gidday,
>
> > I have a question regarding
> > Attributes of symlinks vs. the files pointed to
> >
> > If I try to attach name:value pair to object symlink file
> > then I'll get: "Operation not permitted"
>
> What file system are you using? If ext2, ext3 (or patched kernel
> supporting Reiserfs EAs), did you mount with "-o user_xattr?
> (The above error suggests you haven't used this option.)

# mount
/dev/sdb3 on /a type ext3 (rw,acl,user_xattr)
...etc...


>
> > reading the man pages of setfattr (or attr) I thought that it operates
> > on the attributes of the symbolic link itself.
>
> No, these commands follow symbolic links.
>
> > show:
> > -----
> > touch f
> > ln -s f l
> > setfattr -n user.filename -v ascii1 f l
> > setfattr -h -n user.filename -v ascii2 f
> > getfattr -d f l
> > setfattr -h -n user.filename -v ascii3 l
> > setfattr -h --no-dereference -n user.filename -v ascii4 l
> > getfattr -d f l
> >
> > so, my question is : what is expected ?
should have added this:

[root@t20 acl]# show
# file: f
user.filename="ascii2"

# file: l
user.filename="ascii2"

setfattr: l: Operation not permitted
setfattr: l: Operation not permitted
# file: f
user.filename="ascii2"

# file: l
user.filename="ascii2"

[root@t20 acl]#

>
> attr(5) specifically notes that USER EAs are disallowed on
> symbolic links, but this is rather an issu that affects the
> use of lsetxattr(2).
>
> Cheers,
>
> Michael
>
> --
> "Sie haben neue Mails!" - Die GMX Toolbar informiert Sie beim Surfen!
> Jetzt aktivieren unter http://www.gmx.net/info
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
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--
Jacky Malcles B1-403 Email : [email protected]
Bull SA, 1 rue de Provence, B.P 208, 38432 Echirolles CEDEX, FRANCE
Tel : 04.76.29.73.14

2004-06-30 14:21:26

by Jacky Malcles

Subject: Re: A question about extended attributes of filesystem objects (setfattr command)

Michael Kerrisk wrote:
>
> Gidday,
>
> > I have a question regarding
> > Attributes of symlinks vs. the files pointed to
> >
> > If I try to attach name:value pair to object symlink file
> > then I'll get: "Operation not permitted"
>
> What file system are you using? If ext2, ext3 (or patched kernel
> supporting Reiserfs EAs), did you mount with "-o user_xattr?
> (The above error suggests you haven't used this option.)
>
> > reading the man pages of setfattr (or attr) I thought that it operates
> > on the attributes of the symbolic link itself.
>
> No, these commands follow symbolic links.
>
> > show:
> > -----
> > touch f
> > ln -s f l
> > setfattr -n user.filename -v ascii1 f l
> > setfattr -h -n user.filename -v ascii2 f
> > getfattr -d f l
> > setfattr -h -n user.filename -v ascii3 l
> > setfattr -h --no-dereference -n user.filename -v ascii4 l
> > getfattr -d f l
> >
> > so, my question is : what is expected ?
>

thanks Michael,
below is what I was trying to find out !!
> attr(5) specifically notes that USER EAs are disallowed on
> symbolic links, but this is rather an issu that affects the
> use of lsetxattr(2).
>
> Cheers,
>
> Michael
>
> --
> "Sie haben neue Mails!" - Die GMX Toolbar informiert Sie beim Surfen!
> Jetzt aktivieren unter http://www.gmx.net/info
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

--
Jacky Malcles B1-403 Email : [email protected]
Bull SA, 1 rue de Provence, B.P 208, 38432 Echirolles CEDEX, FRANCE
Tel : 04.76.29.73.14