diff options
author | Christoph Hellwig <hch@lst.de> | 2017-01-10 09:41:43 +0100 |
---|---|---|
committer | Tejun Heo <tj@kernel.org> | 2017-01-10 10:55:38 -0500 |
commit | aa18da8b7ec57f6ff255634746aed6266a01b315 (patch) | |
tree | 1c193773476d8d410c8caca5ee239562074661ad | |
parent | fb1b8b117531f217e7d332bdc5cbdf8ebb077ea5 (diff) | |
download | linux-aa18da8b7ec57f6ff255634746aed6266a01b315.tar.bz2 |
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 <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
-rw-r--r-- | drivers/ata/libata-scsi.c | 46 |
1 files changed, 22 insertions, 24 deletions
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; } |