SATA: Is "DPO and FUA" ever supported?

[Michael Tokarev <mjt@tls.msk.ru>]

On each and every machine out there, and on every dmesg
output posted on numerous mailinglists, I see messages
similar to this:

scsi 0:0:0:0: Direct-Access     ATA      ST3250620NS      3.AE PQ: 0 ANSI: 5
SCSI device sda: 488397168 512-byte hdwr sectors (250059 MB)
SCSI device sda: write cache: enabled, read cache: enabled, doesn't support DPO or FUA

for SATA disk drives.  And I wonder -- are those features
supported at all by linux, and/or are there disk drives
out there which supports it as well?

For my Seagate ST3250620NS SATA drive (it's a "server" drive,
whatever it means), I can see -- at least --

           *    Mandatory FLUSH_CACHE
           *    FLUSH_CACHE_EXT

reported by hdparm -I.  I wonder what "FLUSH CACHE EXT" means,
and whenever it can be used to support DPO and/or FUA...

Thanks.

/mjt