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authorChristoph Hellwig <hch@lst.de>2017-01-10 09:41:43 +0100
committerTejun Heo <tj@kernel.org>2017-01-10 10:55:38 -0500
commitaa18da8b7ec57f6ff255634746aed6266a01b315 (patch)
tree1c193773476d8d410c8caca5ee239562074661ad /drivers/ata
parentfb1b8b117531f217e7d332bdc5cbdf8ebb077ea5 (diff)
downloadlinux-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>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libata-scsi.c46
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;
}