vfs_acl_xattr and Linux memory fragmentation

[Christoph Hellwig]

On Fri, Apr 07, 2017 at 11:18:20AM +0300, Uri Simchoni via samba-technical wrote:
> 2. In older Linux (prior to 3.4), getxattr() used to require a
> physically-contiguous (kmalloc'd) buffer whose size equals the max size
> requested by the user. So even though no Linux in-tree file system
> supports EA's larger than 4K, the getxattr() system call would try to
> allocate 64K if Samba passes this number.

XFS supports larger than 4k xattr values.

That beeing said a 4k try after 1k seems inherently reasonable to me.