Re: [PATCH 6.12.y 1/2] ata: libata-scsi: Return residual for emulated SCSI commands

[Greg KH <greg@kroah.com>]

On Fri, Mar 20, 2026 at 05:54:44PM -0400, Sasha Levin wrote:
> From: Damien Le Moal <dlemoal@kernel.org>
> 
> [ Upstream commit 5251ae224d8d3caa21b28d12408062b6e75cffad ]
> 
> The function ata_scsi_rbuf_fill() used to fill the reply buffer of
> emulated SCSI commands always copies the ATA reply buffer
> (ata_scsi_rbuf) up to the size of the SCSI command buffer (the transfer
> length for the command), even if the reply is shorter than the SCSI
> command buffer. This leads to issuers of the SCSI command to always get
> a result without any residual (resid is always 0) despite the
> potentially shorter reply for the command.
> 
> Modify all fill actors used by ata_scsi_rbuf_fill() to return the number
> of bytes filled for the reply and 0 in case of error. Using this value,
> add a call to scsi_set_resid() in ata_scsi_rbuf_fill() to set the
> correct residual for the SCSI command when the reply length is shorter
> than the command buffer.
> 
> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
> Link: https://lore.kernel.org/r/20241022024537.251905-7-dlemoal@kernel.org
> Signed-off-by: Niklas Cassel <cassel@kernel.org>
> Stable-dep-of: e6d7eba23b66 ("ata: libata-scsi: report correct sense field pointer in ata_scsiop_maint_in()")
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  drivers/ata/libata-scsi.c | 81 +++++++++++++++++++++++----------------
>  1 file changed, 47 insertions(+), 34 deletions(-)
> 

BOth of these don't apply :(