Reading >4kB xattrs (from ZFS) = input/output error

[Jeremy Allison]

On Wed, Feb 12, 2025 at 04:38:40PM +0100, Peter B. via samba-technical wrote:
>Hi everyone :)
>
>I've recently set a >40kB binary metadata as xattrs on ZFS, using 
>`setfattr` locally.
>Works fine, and I can read/write data like that without issues.
>
>But when I try to access such "larger" xattrs over Samba using 
>`getfattr`, I get the following error:
>
>`getfattr: bigdata.test: Input/output error`
>
>I've tried increasing the log-level on the server's smb.conf, but I 
>couldn't make out relevant information telling me more about this.

What does strace show when reading that xattr ?