* [PATCH] xen: add error handling for xenbus_printf
@ 2018-06-12 3:44 Zhouyang Jia
2018-06-14 21:57 ` Boris Ostrovsky
2018-06-14 23:34 ` [PATCH v2] " Zhouyang Jia
0 siblings, 2 replies; 5+ messages in thread
From: Zhouyang Jia @ 2018-06-12 3:44 UTC (permalink / raw)
Cc: Zhouyang Jia, Boris Ostrovsky, Juergen Gross, xen-devel, linux-kernel
When xenbus_printf fails, the lack of error-handling code may
cause unexpected results.
This patch adds error-handling code after calling xenbus_printf.
Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
---
drivers/xen/manage.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 8835065..159694d 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -289,8 +289,15 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path,
return;
}
- if (sysrq_key != '\0')
- xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
+ if (sysrq_key != '\0') {
+ err = xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
+ if (err) {
+ pr_err("Error %d writing sysrq code in control/sysrq\n",
+ err);
+ xenbus_transaction_end(xbt, 1);
+ return;
+ }
+ }
err = xenbus_transaction_end(xbt, 0);
if (err == -EAGAIN)
@@ -342,7 +349,11 @@ static int setup_shutdown_watcher(void)
continue;
snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
shutdown_handlers[idx].command);
- xenbus_printf(XBT_NIL, "control", node, "%u", 1);
+ err = xenbus_printf(XBT_NIL, "control", node, "%u", 1);
+ if (err) {
+ pr_err("Error %d writing %s\n", err, node);
+ return err;
+ }
}
return 0;
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] xen: add error handling for xenbus_printf
2018-06-12 3:44 [PATCH] xen: add error handling for xenbus_printf Zhouyang Jia
@ 2018-06-14 21:57 ` Boris Ostrovsky
2018-06-14 23:34 ` [PATCH v2] " Zhouyang Jia
1 sibling, 0 replies; 5+ messages in thread
From: Boris Ostrovsky @ 2018-06-14 21:57 UTC (permalink / raw)
To: Zhouyang Jia; +Cc: Juergen Gross, xen-devel, linux-kernel
On 06/11/2018 11:44 PM, Zhouyang Jia wrote:
> When xenbus_printf fails, the lack of error-handling code may
> cause unexpected results.
>
> This patch adds error-handling code after calling xenbus_printf.
>
> Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
> ---
> drivers/xen/manage.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
> index 8835065..159694d 100644
> --- a/drivers/xen/manage.c
> +++ b/drivers/xen/manage.c
> @@ -289,8 +289,15 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path,
> return;
> }
>
> - if (sysrq_key != '\0')
> - xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
> + if (sysrq_key != '\0') {
> + err = xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
> + if (err) {
> + pr_err("Error %d writing sysrq code in control/sysrq\n",
> + err);
> + xenbus_transaction_end(xbt, 1);
> + return;
> + }
> + }
>
> err = xenbus_transaction_end(xbt, 0);
> if (err == -EAGAIN)
> @@ -342,7 +349,11 @@ static int setup_shutdown_watcher(void)
> continue;
> snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
> shutdown_handlers[idx].command);
> - xenbus_printf(XBT_NIL, "control", node, "%u", 1);
> + err = xenbus_printf(XBT_NIL, "control", node, "%u", 1);
> + if (err) {
> + pr_err("Error %d writing %s\n", err, node);
Adding __func__ will make it it easier trying to understand where the
error is coming from. And for consistency, I'd add it to the one above
as well.
-boris
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2] xen: add error handling for xenbus_printf
2018-06-12 3:44 [PATCH] xen: add error handling for xenbus_printf Zhouyang Jia
2018-06-14 21:57 ` Boris Ostrovsky
@ 2018-06-14 23:34 ` Zhouyang Jia
2018-06-15 12:54 ` Boris Ostrovsky
2018-06-19 13:02 ` Juergen Gross
1 sibling, 2 replies; 5+ messages in thread
From: Zhouyang Jia @ 2018-06-14 23:34 UTC (permalink / raw)
Cc: Zhouyang Jia, Boris Ostrovsky, Juergen Gross, xen-devel, linux-kernel
When xenbus_printf fails, the lack of error-handling code may
cause unexpected results.
This patch adds error-handling code after calling xenbus_printf.
Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
---
v1->v2:
- Add __func__.
---
drivers/xen/manage.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 8835065..c93d8ef 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -289,8 +289,15 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path,
return;
}
- if (sysrq_key != '\0')
- xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
+ if (sysrq_key != '\0') {
+ err = xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
+ if (err) {
+ pr_err("%s: Error %d writing sysrq in control/sysrq\n",
+ __func__, err);
+ xenbus_transaction_end(xbt, 1);
+ return;
+ }
+ }
err = xenbus_transaction_end(xbt, 0);
if (err == -EAGAIN)
@@ -342,7 +349,12 @@ static int setup_shutdown_watcher(void)
continue;
snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
shutdown_handlers[idx].command);
- xenbus_printf(XBT_NIL, "control", node, "%u", 1);
+ err = xenbus_printf(XBT_NIL, "control", node, "%u", 1);
+ if (err) {
+ pr_err("%s: Error %d writing %s\n", __func__,
+ err, node);
+ return err;
+ }
}
return 0;
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2] xen: add error handling for xenbus_printf
2018-06-14 23:34 ` [PATCH v2] " Zhouyang Jia
@ 2018-06-15 12:54 ` Boris Ostrovsky
2018-06-19 13:02 ` Juergen Gross
1 sibling, 0 replies; 5+ messages in thread
From: Boris Ostrovsky @ 2018-06-15 12:54 UTC (permalink / raw)
To: Zhouyang Jia; +Cc: Juergen Gross, xen-devel, linux-kernel
On 06/14/2018 07:34 PM, Zhouyang Jia wrote:
> When xenbus_printf fails, the lack of error-handling code may
> cause unexpected results.
>
> This patch adds error-handling code after calling xenbus_printf.
>
> Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
(I wasn't asking you to use xenbus_dev_error() for this patch. Only for
the other two patches --- for scsi front and back).
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] xen: add error handling for xenbus_printf
2018-06-14 23:34 ` [PATCH v2] " Zhouyang Jia
2018-06-15 12:54 ` Boris Ostrovsky
@ 2018-06-19 13:02 ` Juergen Gross
1 sibling, 0 replies; 5+ messages in thread
From: Juergen Gross @ 2018-06-19 13:02 UTC (permalink / raw)
To: Zhouyang Jia; +Cc: Boris Ostrovsky, xen-devel, linux-kernel
On 15/06/18 01:34, Zhouyang Jia wrote:
> When xenbus_printf fails, the lack of error-handling code may
> cause unexpected results.
>
> This patch adds error-handling code after calling xenbus_printf.
>
> Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
Pushed to xen/tip.git for-linus-4.18
Juergen
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-06-19 13:03 UTC | newest]
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2018-06-12 3:44 [PATCH] xen: add error handling for xenbus_printf Zhouyang Jia
2018-06-14 21:57 ` Boris Ostrovsky
2018-06-14 23:34 ` [PATCH v2] " Zhouyang Jia
2018-06-15 12:54 ` Boris Ostrovsky
2018-06-19 13:02 ` Juergen Gross
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