[systemd-devel] [PATCH] metadata: reflect change in task_cgroup_name

[Hristo Venev]

On Wed, 2014-04-09 at 15:04 +0200, Daniel Mack wrote:
> Eh. Thanks for spotting this. However, I think we should have a compat
> workaround for 3.14, for at least a couple of weeks. We can drop it
> after that. Could you amend your patch for that?

How do I check if the kernel version is 3.14.0 or 3.14.0+?
linux/version.h is the same. I've amended the patch to check for 3.15.0
so it will be broken until the release of 3.15.0-rc1.

> Apart from that, please take care to follow the kernel CodingStyle. In
> particular, we use tabs for indentation, not spaces.

Done.

---
 metadata.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/metadata.c b/metadata.c
index 5b47bb2..1dab96e 100644
--- a/metadata.c
+++ b/metadata.c
@@ -23,6 +23,7 @@
 #include <linux/sizes.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/version.h>
 
 #include "connection.h"
 #include "message.h"
@@ -335,18 +336,29 @@ static int kdbus_meta_append_caps(struct
kdbus_meta *meta)
 #ifdef CONFIG_CGROUPS
 static int kdbus_meta_append_cgroup(struct kdbus_meta *meta)
 {
-	char *tmp;
+	char *buf, *path;
 	int ret;
 
-	tmp = (char *)__get_free_page(GFP_TEMPORARY | __GFP_ZERO);
-	if (!tmp)
+	buf = (char *)__get_free_page(GFP_TEMPORARY | __GFP_ZERO);
+	if (!buf)
 		return -ENOMEM;
 
-	ret = task_cgroup_path(current, tmp, PAGE_SIZE);
-	if (ret >= 0)
-		ret = kdbus_meta_append_str(meta, KDBUS_ITEM_CGROUP, tmp);
+	#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)
+	path = task_cgroup_path(current, buf, PAGE_SIZE);
+	#else
+	ret = task_cgroup_path(current, buf, PAGE_SIZE);
+	if (ret < 0)
+		path = NULL;
+	else
+		path = buf;
+	#endif
 
-	free_page((unsigned long) tmp);
+	if (path)
+		ret = kdbus_meta_append_str(meta, KDBUS_ITEM_CGROUP, path);
+	else
+		ret = -ENAMETOOLONG;
+
+	free_page((unsigned long) buf);
 
 	return ret;
 }
-- 
1.9.1