[v9,17/33] scsi: sd: Fix sshdr use in sd_suspend_common

Commit Message

Mike Christie July 11, 2023, 9:46 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. To avoid where
sd_suspend_common will access the sshdr but scsi_execute_cmd has
not initialized it and to allow sd_sync_cache to convert
device/host/status errors to -EXYZ values, this has sd_sync_cache
convert ILLEGAL_REQUEST to -EOPNOTSUPP. sd_suspend_common can then
check for that error instead of using a sshdr.

Signed-off-by: Mike Christie <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
---
 drivers/scsi/sd.c | 37 +++++++++++++++++--------------------
 1 file changed, 17 insertions(+), 20 deletions(-)

Patch

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index e67a3d163b24..bb2e5885e41b 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1604,24 +1604,21 @@  static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
 	return disk_changed ? DISK_EVENT_MEDIA_CHANGE : 0;
 }
 
-static int sd_sync_cache(struct scsi_disk *sdkp, struct scsi_sense_hdr *sshdr)
+static int sd_sync_cache(struct scsi_disk *sdkp)
 {
 	int retries, res;
 	struct scsi_device *sdp = sdkp->device;
 	const int timeout = sdp->request_queue->rq_timeout
 		* SD_FLUSH_TIMEOUT_MULTIPLIER;
-	struct scsi_sense_hdr my_sshdr;
+	struct scsi_sense_hdr sshdr;
 	const struct scsi_exec_args exec_args = {
 		.req_flags = BLK_MQ_REQ_PM,
-		/* caller might not be interested in sense, but we need it */
-		.sshdr = sshdr ? : &my_sshdr,
+		.sshdr = &sshdr,
 	};
 
 	if (!scsi_device_online(sdp))
 		return -ENODEV;
 
-	sshdr = exec_args.sshdr;
-
 	for (retries = 3; retries > 0; --retries) {
 		unsigned char cmd[16] = { 0 };
 
@@ -1646,15 +1643,19 @@  static int sd_sync_cache(struct scsi_disk *sdkp, struct scsi_sense_hdr *sshdr)
 			return res;
 
 		if (scsi_status_is_check_condition(res) &&
-		    scsi_sense_valid(sshdr)) {
-			sd_print_sense_hdr(sdkp, sshdr);
+		    scsi_sense_valid(&sshdr)) {
+			sd_print_sense_hdr(sdkp, &sshdr);
 
 			/* we need to evaluate the error return  */
-			if (sshdr->asc == 0x3a ||	/* medium not present */
-			    sshdr->asc == 0x20 ||	/* invalid command */
-			    (sshdr->asc == 0x74 && sshdr->ascq == 0x71))	/* drive is password locked */
+			if (sshdr.asc == 0x3a ||	/* medium not present */
+			    sshdr.asc == 0x20 ||	/* invalid command */
+			    (sshdr.asc == 0x74 && sshdr.ascq == 0x71))	/* drive is password locked */
 				/* this is no error here */
 				return 0;
+
+			/* This drive doesn't support sync. */
+			if (sshdr.sense_key == ILLEGAL_REQUEST)
+				return -EOPNOTSUPP;
 		}
 
 		switch (host_byte(res)) {
@@ -3849,7 +3850,7 @@  static void sd_shutdown(struct device *dev)
 
 	if (sdkp->WCE && sdkp->media_present) {
 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
-		sd_sync_cache(sdkp, NULL);
+		sd_sync_cache(sdkp);
 	}
 
 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
@@ -3861,7 +3862,6 @@  static void sd_shutdown(struct device *dev)
 static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
 {
 	struct scsi_disk *sdkp = dev_get_drvdata(dev);
-	struct scsi_sense_hdr sshdr;
 	int ret = 0;
 
 	if (!sdkp)	/* E.g.: runtime suspend following sd_remove() */
@@ -3870,21 +3870,18 @@  static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
 	if (sdkp->WCE && sdkp->media_present) {
 		if (!sdkp->device->silence_suspend)
 			sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
-		ret = sd_sync_cache(sdkp, &sshdr);
+		ret = sd_sync_cache(sdkp);
 
 		if (ret) {
 			/* ignore OFFLINE device */
 			if (ret == -ENODEV)
 				return 0;
 
-			if (!scsi_sense_valid(&sshdr) ||
-			    sshdr.sense_key != ILLEGAL_REQUEST)
+			if (ret != -EOPNOTSUPP)
 				return ret;
-
 			/*
-			 * sshdr.sense_key == ILLEGAL_REQUEST means this drive
-			 * doesn't support sync. There's not much to do and
-			 * suspend shouldn't fail.
+			 * The drive doesn't support sync. There's not much to
+			 * do and suspend shouldn't fail.
 			 */
 			ret = 0;
 		}