Deleting files with extended attributes is dead slow

[Christoph Hellwig]

On Fri, Aug 12, 2011 at 08:19:53PM +0200, Bernd Schubert wrote:
> Hi there,
> 
> with FhGFS we may use extended attributes to store file meta data
> and with ext3/ext4 that also works very well and the rate to create
> files and to write those EAs (create() + fsetxattr()  is about 2.5
> to 3 times faster than with a create() + write(). Size of those EA
> data is about 256 bytes depending on the number of storage stripes.
> However, with XFS using extended attributes is *extremely* slow.
> Here are some numbers with ext4 and xfs using a patched [1] bonnie++

Currently XFS uses synchronous transactions when retiring inodes with
xattrs on them.  So far I've not actually found a good reason for that,
so I suspect we can remove it.  I'll do another audit of it, and will
send you a patch for it after doing basic QA.