[PATCH v2] cgroup: fix to allow mounting a hierarchy by name

From: Li Zefan
Date: Tue Dec 27 2011 - 01:23:47 EST

If we mount a hierarchy with a specified name, the name is unique,
and we can use it to mount the hierarchy without specifying its
set of subsystem names. This feature is documented is
Documentation/cgroups/cgroups.txt section 2.3

Here's an example:

# mount -t cgroup -o cpuset,name=myhier xxx /cgroup1
# mount -t cgroup -o name=myhier xxx /cgroup2

But it was broken by commit 32a8cf235e2f192eb002755076994525cdbaa35a
(cgroup: make the mount options parsing more accurate)

This fixes the regression.

Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>

v2: fix code comment s/or/and


diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1042b3c..8e412fd 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1193,10 +1193,10 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)

* If the 'all' option was specified select all the subsystems,
- * otherwise 'all, 'none' and a subsystem name options were not
- * specified, let's default to 'all'
+ * otherwise if 'none', 'name=' and a subsystem name options
+ * were not specified, let's default to 'all'
- if (all_ss || (!all_ss && !one_ss && !opts->none)) {
+ if (all_ss || (!one_ss && !opts->none && !opts->name)) {
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
struct cgroup_subsys *ss = subsys[i];
if (ss == NULL)
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/