diff mbox series

[v11,32/34] scsi: sd: Fix sshdr use in cache_type_store

Message ID 20230905231547.83945-33-michael.christie@oracle.com (mailing list archive)
State Changes Requested
Headers show
Series [v11,01/34] scsi: Add helper to prep sense during error handling | expand

Commit Message

Mike Christie Sept. 5, 2023, 11:15 p.m. UTC 
If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
---
 drivers/scsi/sd.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Comments

Martin Wilck Sept. 15, 2023, 9:44 p.m. UTC | #1 
On Tue, 2023-09-05 at 18:15 -0500, Mike Christie wrote:
> If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so
> we
> shouldn't access the sshdr. If it returns 0, then the cmd executed
> successfully, so there is no need to check the sshdr. This has us
> access
> the sshdr when we get a return value > 0.
> 
> Signed-off-by: Mike Christie <michael.christie@oracle.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: John Garry <john.g.garry@oracle.com>

While all these "fix sshdr use" patches are correct, I start wondering
whether we shouldn't simply execute "

        if (sshdr) 
                sshdr->response_code = 0;

early in scsi_execute_cmd(). That way we could skip all those (ret > 0)
clauses.

Anyway,

Reviewed-by: Martin Wilck <mwilck@suse.com>
diff mbox series

Patch

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 781df1fefa84..a5c67129b0c3 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -143,7 +143,7 @@  cache_type_store(struct device *dev, struct device_attribute *attr,
 	struct scsi_mode_data data;
 	struct scsi_sense_hdr sshdr;
 	static const char temp[] = "temporary ";
-	int len;
+	int len, ret;
 
 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
 		/* no cache control on RBC devices; theoretically they
@@ -190,9 +190,10 @@  cache_type_store(struct device *dev, struct device_attribute *attr,
 	 */
 	data.device_specific = 0;
 
-	if (scsi_mode_select(sdp, 1, sp, buffer_data, len, SD_TIMEOUT,
-			     sdkp->max_retries, &data, &sshdr)) {
-		if (scsi_sense_valid(&sshdr))
+	ret = scsi_mode_select(sdp, 1, sp, buffer_data, len, SD_TIMEOUT,
+			       sdkp->max_retries, &data, &sshdr);
+	if (ret) {
+		if (ret > 0 && scsi_sense_valid(&sshdr))
 			sd_print_sense_hdr(sdkp, &sshdr);
 		return -EINVAL;
 	}