There is no CONFIG_EXT4_FS_XATTR option on .config

jl4c · 2014-01-29 01:38:05

Hi guys, am new here and this is my first post. I need support to write extended attributes on a ext4 partition on my ARCH server, but the default kernel doesn't have support for it.
Am trying to build (ABS) my own kernel to include this feature, but sadly the CONFIG_EXT4_FS_XATTR option is not in the .config file. Please help.

Last edited by jl4c (2014-01-29 01:38:58)

karol · 2014-01-29 02:01:36

http://git.kernel.org/cgit/linux/kernel … c177000e96

The savings if you disable CONFIG_EXT4_FS_XATTR is only 27k, which isn't much in the grand scheme of things. Since no one seems to be testing this configuration except for some automated compile farms, on balance we are better removing this config option, and so that it is effectively always enabled.

jl4c · 2014-01-29 02:08:36

karol wrote:

http://git.kernel.org/cgit/linux/kernel … c177000e96
The savings if you disable CONFIG_EXT4_FS_XATTR is only 27k, which isn't much in the grand scheme of things. Since no one seems to be testing this configuration except for some automated compile farms, on balance we are better removing this config option, and so that it is effectively always enabled.

Thanks karol for the answer, but my question is how to build a new kernel, ABS, to support xattr on ext4.

karol · 2014-01-29 02:09:42

Are you sure the stock config doesn't support it?

Edit: I found the commit that removed it: https://projects.archlinux.org/svntogit … a686cf2cb2
If the stock config doesn't enable it by default, you can add it back and see what happens.

Last edited by karol (2014-01-29 02:11:34)

jl4c · 2014-01-29 02:13:51

karol wrote:

Are you sure the stock config doesn't support it?
Edit: I found the commit that removed it: https://projects.archlinux.org/svntogit … a686cf2cb2
If the stock config doesn't enable it by default, you can add it back and see what happens.

Sorry, but how can i do that?

this is the output of zcat /proc/config.gz | grep XATTR

CONFIG_REISERFS_FS_XATTR=y
CONFIG_TMPFS_XATTR=y
# CONFIG_JFFS2_FS_XATTR is not set
CONFIG_SQUASHFS_XATTR=y
CONFIG_F2FS_FS_XATTR=y
CONFIG_CIFS_XATTR=y

Last edited by jl4c (2014-01-29 02:14:42)

karol · 2014-01-29 02:15:17

Are you sure that the current config doesn't support extended attributes for ext4? How did you test it?
Edit: You've only checked the config file. If I understand it right, the config line was removed, but that doesn't mean that it's not set - on the contrary, it is set by default.
Does some application that needs the extended attributes doesn't work? What is the problem you're having?

The wiki has an article about patching and building with ABS.

Last edited by karol (2014-01-29 02:17:56)

jl4c · 2014-01-29 02:35:19

Yes, am sure. The arch machine is my NFS server and using it to backup an OS X client. This is the output when am try to copy any file to the sever:

cp: /Volumes/DATA/Desktop/test.copy: could not copy extended attributes to /Volumes/BACKUPs/test.copy: Operation not permitted

Last edited by jl4c (2014-01-29 02:40:50)

karol · 2014-01-29 02:42:30

I'm not sure if you still need any special mount options, but what are the mount options on your ext4 partitions?

According to http://forums.gentoo.org/viewtopic-t-97 … art-0.html xattr for ext4 are enabled by default, as I thought.

jl4c · 2014-01-29 03:18:40

No, there is no need any special mount option for xattr. I just need help to build my own kernel to include the CONFIG_EXT4_FS_XATTR=y option.

karol · 2014-01-29 03:20:44

What happens if you just add the line and compile it?

jl4c · 2014-01-29 03:39:05

md5sums fails on config.x86_64

karol · 2014-01-29 03:41:46

Ummm, yes, that's expected, as you've changed the file. Update the checksums and try again.

Edit: Read https://wiki.archlinux.org/index.php/Patching_in_ABS and https://wiki.archlinux.org/index.php/Ke … ild_System , as I already suggested.

Last edited by karol (2014-01-29 03:44:05)

jl4c · 2014-01-29 03:57:46

done, but still there is no xattr ext4 option on menuconfig gui...

Last edited by jl4c (2014-01-29 03:58:10)

WonderWoofy · 2014-01-29 04:53:48

karol wrote:

http://git.kernel.org/cgit/linux/kernel … c177000e96
The savings if you disable CONFIG_EXT4_FS_XATTR is only 27k, which isn't much in the grand scheme of things. Since no one seems to be testing this configuration except for some automated compile farms, on balance we are better removing this config option, and so that it is effectively always enabled.

Please read this commit message. You are chasing a config option that doesn't exist and is now always turned on.

jl4c · 2014-01-29 05:46:31

Thanks WonderWoofy

But why i can't write xattr on disk?.

check this output:

sudo tune2fs -l /dev/sdb1 | grep "Default mount options:"
Default mount options: user_xattr acl

WonderWoofy · 2014-01-29 05:50:53

jl4c wrote:

But why i can't write xattr on disk?.

Considering the fact that you haven't even really given any kind of reasonable explanation of what you are doing and how... I don't know... black magic?

jl4c · 2014-01-29 05:57:31

Am just trying to copy some files from an OS X (EXTENDED ATTRIBUTES) machine with Finder to my NFS server (ARCHLINUX) through network, but this is what i get:

cp: /Volumes/DATA/Desktop/test.copy: could not copy extended attributes to /Volumes/BACKUPs/test.copy: Operation not permitted

But when i copy the same file without extended attributes (-X option), the copy end successfully

jasonwryan · 2014-01-29 06:06:47

Please provide some more information: the file systems your are a copying from and to would be a good start.

This whole thread is a classic X-Y problem...

Moving to NC.

jl4c · 2014-01-29 06:17:10

Thanks Jason,

Am just trying to copy some files from MAC OS X (HFS+) client to ARCHLINUX (EXT4) server with extended atributes.

Slithery · 2014-01-29 07:20:53

You're looking at this all wrong.

The config option CONFIG_EXT4_FS_XATTR is enabled by default, in fact the option to disable it doesn't exist anymore.

The problem you're having isn't that your ext4 filesystem doesn't support extended attributes (it does), it's that NFS doesn't properly support extended attributes.

I don't use a Mac so none of the results make much sense to me but Googling for 'NFS extended attributes' should give you a starting place to look for solutions.

Last edited by Slithery (2014-01-29 08:32:24)

TheGrudge · 2014-05-26 18:54:50

I'm also not able to use user_xattr on any ext4 partition. I use the stock kernel, when I check my partiton with tun2fs, I get this:

Default mount options: (none)

If I try to mount the partiton with user_xattr, nothing happens:

mount -o remount,user_xattr /mnt/data

Putting it in /etc/fstab doesn't help either

LABEL=data /mnt/data ext4 defaults,user_xattr 0 1

Something seems to be wrong with my setup, but I don't know what it is. I use the standard kernel (on an x64 system).
When I call "mount", I get the following output:

/dev/mapper/Group00-data on /mnt/data type ext4 (rw,relatime,data=ordered)

Any ideas?

Last edited by TheGrudge (2014-05-26 18:55:54)

loqs · 2014-05-26 19:33:56

@TheGrudge

on /home type ext4 (rw,relatime,data=ordered)

done as a normal user

$ touch testfile
$ getfattr -n user.comment testfile
testfile: user.comment: No such attribute
$ getfattr testfile
$ setfattr -n user.comment -v "this is a comment" testfile
$ getfattr testfile
# file: testfile
user.comment

$ getfattr -n user.comment testfile
# file: testfile
user.comment="this is a comment"

$ setfattr -x user.comment testfile
$ getfattr testfile

Arch Linux

#1 2014-01-29 01:38:05

There is no CONFIG_EXT4_FS_XATTR option on .config

#2 2014-01-29 02:01:36

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#3 2014-01-29 02:08:36

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#4 2014-01-29 02:09:42

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#5 2014-01-29 02:13:51

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#6 2014-01-29 02:15:17

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#7 2014-01-29 02:35:19

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#8 2014-01-29 02:42:30

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#9 2014-01-29 03:18:40

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#10 2014-01-29 03:20:44

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#11 2014-01-29 03:39:05

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#12 2014-01-29 03:41:46

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#13 2014-01-29 03:57:46

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#14 2014-01-29 04:53:48

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#15 2014-01-29 05:46:31

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#16 2014-01-29 05:50:53

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#17 2014-01-29 05:57:31

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#18 2014-01-29 06:06:47

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#19 2014-01-29 06:17:10

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#20 2014-01-29 07:20:53

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#21 2014-05-26 18:54:50

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

#22 2014-05-26 19:33:56

Re: There is no CONFIG_EXT4_FS_XATTR option on .config

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