scsi: ufs: Correct the LUN used in eh_device_reset_handler() callback

Users can initiate resets to specific SCSI device/target/host through
IOCTL. When this happens, the SCSI cmd passed to eh_device/target/host
_reset_handler() callbacks is initialized with a request whose tag is -1.
In this case it is not right for eh_device_reset_handler() callback to
count on the LUN get from hba->lrb[-1]. Fix it by getting LUN from the SCSI
device associated with the SCSI cmd.

Link: https://lore.kernel.org/r/1609157080-26283-1-git-send-email-cang@codeaurora.org
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: Can Guo

drivers/scsi/ufs/ufshcd.c

@@ -6659,19 +6659,16 @@ static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd)
 {
 	struct Scsi_Host *host;
 	struct ufs_hba *hba;
-	unsigned int tag;
 	u32 pos;
 	int err;
-	u8 resp = 0xF;
-	struct ufshcd_lrb *lrbp;
+	u8 resp = 0xF, lun;
 	unsigned long flags;
 
 	host = cmd->device->host;
 	hba = shost_priv(host);
-	tag = cmd->request->tag;
 
-	lrbp = &hba->lrb[tag];
-	err = ufshcd_issue_tm_cmd(hba, lrbp->lun, 0, UFS_LOGICAL_RESET, &resp);
+	lun = ufshcd_scsi_to_upiu_lun(cmd->device->lun);
+	err = ufshcd_issue_tm_cmd(hba, lun, 0, UFS_LOGICAL_RESET, &resp);
 	if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
 		if (!err)
 			err = resp;
@@ -6680,7 +6677,7 @@ static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd)
 
 	/* clear the commands that were pending for corresponding LUN */
 	for_each_set_bit(pos, &hba->outstanding_reqs, hba->nutrs) {
-		if (hba->lrb[pos].lun == lrbp->lun) {
+		if (hba->lrb[pos].lun == lun) {
 			err = ufshcd_clear_cmd(hba, pos);
 			if (err)
 				break;