On 02/11/2015 12:45 PM, Douglas Gilbert wrote:
> On 15-02-11 11:32 AM, Tony Battersby wrote:
>> Fix SCSI generic read() incorrectly returning success after detecting an
>> error.
>>
>> Cc: <stable@xxxxxxxxxxxxxxx>
>> Signed-off-by: Tony Battersby <tonyb@xxxxxxxxxxxxxxx>
>> ---
>>
>> For inclusion in kernel 3.20.
>>
>> --- linux-3.19.0/drivers/scsi/sg.c.orig 2015-02-08 21:54:22.000000000 -0500
>> +++ linux-3.19.0/drivers/scsi/sg.c 2015-02-10 09:26:09.000000000 -0500
>> @@ -546,7 +546,7 @@ static ssize_t
>> sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
>> {
>> sg_io_hdr_t *hp = &srp->header;
>> - int err = 0;
>> + int err = 0, err2;
>> int len;
>>
>> if (count < SZ_SG_IO_HDR) {
>> @@ -575,8 +575,8 @@ sg_new_read(Sg_fd * sfp, char __user *bu
>> goto err_out;
>> }
>> err_out:
>> - err = sg_finish_rem_req(srp);
>> - return (0 == err) ? count : err;
>> + err2 = sg_finish_rem_req(srp);
>> + return err ? : err2 ? : count;
> Tony,
> Your point is well made.
>
> I just don't like that last line, using a gcc extension that
> hasn't even made it into C11 (or C++11). Wouldn't:
> return err ? err : (err2 ? err2 : count);
>
> be a bit better? I think the following snippet makes the intent
> clear but would it generate any more code:
> if (err || err2)
> return err ? err : err2;
> else
> return count;
>
> Doug Gilbert
>
>
>
I checked before submitting, and the foo ? : bar construct is already
used at least 455 times in the kernel, so it is nothing new.
find linux-3.19 -type f -name "*.[ch]" | xargs grep '\? :' | wc -l
455
But you are probably right; I think that with such small variable names
your version is more readable due to the nesting. Updated patch below.
---
Fix SCSI generic read() incorrectly returning success after detecting an
error.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Battersby <tonyb@xxxxxxxxxxxxxxx>
---
--- linux-3.19.0/drivers/scsi/sg.c.orig 2015-02-08 21:54:22.000000000 -0500
+++ linux-3.19.0/drivers/scsi/sg.c 2015-02-11 13:02:56.000000000 -0500
@@ -546,7 +546,7 @@ static ssize_t
sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
{
sg_io_hdr_t *hp = &srp->header;
- int err = 0;
+ int err = 0, err2;
int len;
if (count < SZ_SG_IO_HDR) {
@@ -575,8 +575,8 @@ sg_new_read(Sg_fd * sfp, char __user *bu
goto err_out;
}
err_out:
- err = sg_finish_rem_req(srp);
- return (0 == err) ? count : err;
+ err2 = sg_finish_rem_req(srp);
+ return err ? err : (err2 ? err2 : count);
}
static ssize_t
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
