lsetxattr()/lgetxsttr() functions are not working on a ext4 symlink.
But works fine on a regular file.
I tried the following program.. Not sure if I am missing something.
Any help will be appreciated.
--------- simple program -------------
[jvrao]# cat sxl.c
#include <stdio.h>
#include <sys/types.h>
#include <attr/xattr.h>
main()
{
int ha=5;
int ha_out=-1;
int err;
err = lsetxattr("./foo", "user.junk", &ha, sizeof(int),0);
if (err == -1)
perror("lsetxattr failed");
lgetxattr("./foo", "user.junk", &ha_out, sizeof(int));
if (err == -1)
perror("lsetxattr failed");
printf("file:./foo ha:%d ha_out:%d\n", ha, ha_out);
ha_out = -1;
err = lsetxattr("./foo.sl", "user.junk", &ha, sizeof(int),0);
if (err == -1)
perror("lsetxattr failed");
lgetxattr("./foo.sl", "user.junk", &ha_out, sizeof(int));
if (err == -1)
perror("lsetxattr failed");
printf("file:./foo.sl ha:%d ha_out:%d\n", ha, ha_out);
}
------------------------
[jvrao]# ls -l foo*
-rw-r--r--. 1 root root 0 2010-03-31 16:49 foo
lrwxrwxrwx. 1 root root 3 2010-03-31 16:49 foo.sl -> foo
[jvrao]# ./sxl
file:./foo ha:5 ha_out:5
lsetxattr failed: Operation not permitted
lsetxattr failed: Operation not permitted
file:./foo.sl ha:5 ha_out:-1
On Wed, 2010-03-31 at 17:06 -0700, jvrao wrote:
> lsetxattr()/lgetxsttr() functions are not working on a ext4 symlink.
> But works fine on a regular file.
>
> I tried the following program.. Not sure if I am missing something.
> Any help will be appreciated.
>
>
I tried your test program on ext2/3/btrfs, it seems all broken.
Not sure how this not being visible? Thought xattrs are heavily used by
default on some distros.
Mingming
> --------- simple program -------------
> [jvrao]# cat sxl.c
> #include <stdio.h>
> #include <sys/types.h>
> #include <attr/xattr.h>
>
> main()
> {
> int ha=5;
> int ha_out=-1;
> int err;
> err = lsetxattr("./foo", "user.junk", &ha, sizeof(int),0);
> if (err == -1)
> perror("lsetxattr failed");
> lgetxattr("./foo", "user.junk", &ha_out, sizeof(int));
> if (err == -1)
> perror("lsetxattr failed");
> printf("file:./foo ha:%d ha_out:%d\n", ha, ha_out);
>
> ha_out = -1;
> err = lsetxattr("./foo.sl", "user.junk", &ha, sizeof(int),0);
> if (err == -1)
> perror("lsetxattr failed");
> lgetxattr("./foo.sl", "user.junk", &ha_out, sizeof(int));
> if (err == -1)
> perror("lsetxattr failed");
> printf("file:./foo.sl ha:%d ha_out:%d\n", ha, ha_out);
> }
> ------------------------
>
> [jvrao]# ls -l foo*
> -rw-r--r--. 1 root root 0 2010-03-31 16:49 foo
> lrwxrwxrwx. 1 root root 3 2010-03-31 16:49 foo.sl -> foo
>
> [jvrao]# ./sxl
> file:./foo ha:5 ha_out:5
> lsetxattr failed: Operation not permitted
> lsetxattr failed: Operation not permitted
> file:./foo.sl ha:5 ha_out:-1
>
>
>
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Mingming Cao wrote:
> On Wed, 2010-03-31 at 17:06 -0700, jvrao wrote:
>> lsetxattr()/lgetxsttr() functions are not working on a ext4 symlink.
>> But works fine on a regular file.
>>
>> I tried the following program.. Not sure if I am missing something.
>> Any help will be appreciated.
>>
>>
>
>
> I tried your test program on ext2/3/btrfs, it seems all broken.
> Not sure how this not being visible? Thought xattrs are heavily used by
> default on some distros.
xfs as well FWIW.
however, I'm not sure setting user xattrs directly on symlinks is
a common operation...
-Eric
Eric Sandeen wrote:
> Mingming Cao wrote:
>> On Wed, 2010-03-31 at 17:06 -0700, jvrao wrote:
>>> lsetxattr()/lgetxsttr() functions are not working on a ext4 symlink.
>>> But works fine on a regular file.
>>>
>>> I tried the following program.. Not sure if I am missing something.
>>> Any help will be appreciated.
>>>
>>>
>>
>> I tried your test program on ext2/3/btrfs, it seems all broken.
>> Not sure how this not being visible? Thought xattrs are heavily used by
>> default on some distros.
>
> xfs as well FWIW.
>
> however, I'm not sure setting user xattrs directly on symlinks is
> a common operation...
Looking at the attr(5) says user xattrs are not allowed on symlinks and special files.
I guess it is working as designed. :)
- JV
>
> -Eric
>