From aa18da8b7ec57f6ff255634746aed6266a01b315 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 10 Jan 2017 09:41:43 +0100 Subject: libata: avoid global response buffer in atapi_qc_complete We only need to look at 4 bytes of the inquiry response for ATAPI devices. Instead of using the global ata_scsi_rbuf just use a a stack buffer. Also factor the fixup into it's own little helper function to make it more readable. Signed-off-by: Christoph Hellwig Signed-off-by: Tejun Heo --- drivers/ata/libata-scsi.c | 46 ++++++++++++++++++++++------------------------ 1 file changed, 22 insertions(+), 24 deletions(-) (limited to 'drivers/ata/libata-scsi.c') diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 1f863e757ee4..031a77aae19d 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -2873,6 +2873,26 @@ static void atapi_request_sense(struct ata_queued_cmd *qc) DPRINTK("EXIT\n"); } +/* + * ATAPI devices typically report zero for their SCSI version, and sometimes + * deviate from the spec WRT response data format. If SCSI version is + * reported as zero like normal, then we make the following fixups: + * 1) Fake MMC-5 version, to indicate to the Linux scsi midlayer this is a + * modern device. + * 2) Ensure response data format / ATAPI information are always correct. + */ +static void atapi_fixup_inquiry(struct scsi_cmnd *cmd) +{ + u8 buf[4]; + + sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, 4); + if (buf[2] == 0) { + buf[2] = 0x5; + buf[3] = 0x32; + } + sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, 4); +} + static void atapi_qc_complete(struct ata_queued_cmd *qc) { struct scsi_cmnd *cmd = qc->scsicmd; @@ -2927,30 +2947,8 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc) */ ata_gen_passthru_sense(qc); } else { - u8 *scsicmd = cmd->cmnd; - - if ((scsicmd[0] == INQUIRY) && ((scsicmd[1] & 0x03) == 0)) { - unsigned long flags; - u8 *buf; - - buf = ata_scsi_rbuf_get(cmd, true, &flags); - - /* ATAPI devices typically report zero for their SCSI version, - * and sometimes deviate from the spec WRT response data - * format. If SCSI version is reported as zero like normal, - * then we make the following fixups: 1) Fake MMC-5 version, - * to indicate to the Linux scsi midlayer this is a modern - * device. 2) Ensure response data format / ATAPI information - * are always correct. - */ - if (buf[2] == 0) { - buf[2] = 0x5; - buf[3] = 0x32; - } - - ata_scsi_rbuf_put(cmd, true, &flags); - } - + if (cmd->cmnd[0] == INQUIRY && (cmd->cmnd[1] & 0x03) == 0) + atapi_fixup_inquiry(cmd); cmd->result = SAM_STAT_GOOD; } -- cgit v1.2.3