[RFC PATCH 3/5] scsi:scsi_debug: make command timeout if timeout error is injected

From: Wenchao Hao
Date: Tue Nov 08 2022 - 21:44:11 EST


If a timeout error is injected for specific scsi command, just return
0 in queuecommand to make it timeout.

For example, the following command would inject timeout error for
inquiry(0x12) command for 10 times:
echo "0 -10 0x12" >/sys/block/sdb/device/error_inject/error

Signed-off-by: Wenchao Hao <haowenchao@xxxxxxxxxx>
---
drivers/scsi/scsi_debug.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 06e3150812fa..761e1e3bcb9a 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -7784,6 +7784,30 @@ const struct attribute_group *sdebug_sdev_groups[] = {
NULL
};

+static int sdebug_timeout_cmd(struct scsi_cmnd *cmnd)
+{
+ struct scsi_device *sdp = cmnd->device;
+ struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;
+ struct sdebug_err_inject *err;
+ unsigned char *cmd = cmnd->cmnd;
+ int ret = 0;
+
+ if (devip == NULL)
+ return 0;
+
+ list_for_each_entry(err, &devip->inject_err_list, list) {
+ if (err->type == ERR_TMOUT_CMD &&
+ (err->cmd == cmd[0] || err->cmd == 0xff)) {
+ ret = !!err->cnt;
+ if (err->cnt < 0)
+ err->cnt++;
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
static int scsi_debug_queuecommand(struct Scsi_Host *shost,
struct scsi_cmnd *scp)
{
@@ -7842,6 +7866,12 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost,
if (NULL == devip)
goto err_out;
}
+
+ if (sdebug_timeout_cmd(scp)) {
+ scmd_printk(KERN_INFO, scp, "timeout command 0x%x\n", opcode);
+ return 0;
+ }
+
if (unlikely(inject_now && !atomic_read(&sdeb_inject_pending)))
atomic_set(&sdeb_inject_pending, 1);

--
2.35.3