Further to the thread titled: "[PATCH] SG_SCSI_RESET ioctl should
only perform requested operation" by Jeremy Linton a patch
is presented that adds "no_escalate" versions to the existing
ioctl. This should not break any existing code.
This patches applies to lk 3.7.7 and lk 3.8.0-rc7 . I will extend
sg_reset in the sg3_utils package to use it.
ChangeLog:
- modify SG_SCSI_RESET ioctl so the SG_SCSI_RESET_NO_ESCALATE
value may be added to the existing values. If so the existing
device->target->bus->host escalation does not occur.
- modify scsi_reset_provider() in the scsi_error.c file in a
similar way to support this new functionality.
Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index c1b05a8..4ba79c1 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -2013,8 +2013,18 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
break;
/* FALLTHROUGH */
case SCSI_TRY_RESET_HOST:
+ case SCSI_TRY_RESET_HOST + SCSI_TRY_RESET_NO_ESCALATE:
rtn = scsi_try_host_reset(scmd);
break;
+ case SCSI_TRY_RESET_DEVICE + SCSI_TRY_RESET_NO_ESCALATE:
+ rtn = scsi_try_bus_device_reset(scmd);
+ break;
+ case SCSI_TRY_RESET_TARGET + SCSI_TRY_RESET_NO_ESCALATE:
+ rtn = scsi_try_target_reset(scmd);
+ break;
+ case SCSI_TRY_RESET_BUS + SCSI_TRY_RESET_NO_ESCALATE:
+ rtn = scsi_try_bus_reset(scmd);
+ break;
default:
rtn = FAILED;
}
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
index 06a8790..49d07e9 100644
--- a/include/scsi/scsi_eh.h
+++ b/include/scsi/scsi_eh.h
@@ -62,11 +62,16 @@ extern void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq);
/*
* Reset request from external source
+ * Note: if SCSI_TRY_RESET_DEVICE fails then it will escalate to
+ * SCSI_TRY_RESET_TARGET which if it fails will escalate to
+ * SCSI_TRY_RESET_BUS which if it fails will escalate to SCSI_TRY_RESET_HOST.
+ * To prevent escalation add SCSI_TRY_RESET_NO_ESCALATE.
*/
#define SCSI_TRY_RESET_DEVICE 1
#define SCSI_TRY_RESET_BUS 2
#define SCSI_TRY_RESET_HOST 3
#define SCSI_TRY_RESET_TARGET 4
+#define SCSI_TRY_RESET_NO_ESCALATE 0x100 /* may add to prior defines */
extern int scsi_reset_provider(struct scsi_device *, int);
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index be2c9a6..d9226ec 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -810,7 +810,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
void __user *p = (void __user *)arg;
int __user *ip = p;
- int result, val, read_only;
+ int result, val, val2, read_only;
Sg_device *sdp;
Sg_fd *sfp;
Sg_request *srp;
@@ -1045,27 +1045,32 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
result = get_user(val, ip);
if (result)
return result;
+ if (val >= SG_SCSI_RESET_NO_ESCALATE) {
+ val -= SG_SCSI_RESET_NO_ESCALATE;
+ val2 = SCSI_TRY_RESET_NO_ESCALATE;
+ } else
+ val2 = 0;
if (SG_SCSI_RESET_NOTHING == val)
return 0;
switch (val) {
case SG_SCSI_RESET_DEVICE:
- val = SCSI_TRY_RESET_DEVICE;
+ val2 += SCSI_TRY_RESET_DEVICE;
break;
case SG_SCSI_RESET_TARGET:
- val = SCSI_TRY_RESET_TARGET;
+ val2 += SCSI_TRY_RESET_TARGET;
break;
case SG_SCSI_RESET_BUS:
- val = SCSI_TRY_RESET_BUS;
+ val2 += SCSI_TRY_RESET_BUS;
break;
case SG_SCSI_RESET_HOST:
- val = SCSI_TRY_RESET_HOST;
+ val2 += SCSI_TRY_RESET_HOST;
break;
default:
return -EINVAL;
}
if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
return -EACCES;
- return (scsi_reset_provider(sdp->device, val) ==
+ return (scsi_reset_provider(sdp->device, val2) ==
SUCCESS) ? 0 : -EIO;
case SCSI_IOCTL_SEND_COMMAND:
if (sdp->detached)
diff --git a/include/scsi/sg.h b/include/scsi/sg.h
index a9f3c6f..8207171 100644
--- a/include/scsi/sg.h
+++ b/include/scsi/sg.h
@@ -204,12 +204,15 @@ typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
/* Returns -EBUSY if occupied. 3rd argument pointer to int (see next) */
#define SG_SCSI_RESET 0x2284
-/* Associated values that can be given to SG_SCSI_RESET follow */
+/* Associated values that can be given to SG_SCSI_RESET follow.
+ * SG_SCSI_RESET_NO_ESCALATE may be added to the _DEVICE, _TARGET, _BUS
+ * or _HOST reset value so only that action is attempted. */
#define SG_SCSI_RESET_NOTHING 0
#define SG_SCSI_RESET_DEVICE 1
#define SG_SCSI_RESET_BUS 2
#define SG_SCSI_RESET_HOST 3
#define SG_SCSI_RESET_TARGET 4
+#define SG_SCSI_RESET_NO_ESCALATE 0x100
/* synchronous SCSI command ioctl, (only in version 3 interface) */
#define SG_IO 0x2285 /* similar effect as write() followed by read() */
