The patch titled
cgroup: fix root_count when mount fails due to busy subsystem
has been added to the -mm tree. Its filename is
cgroup-fix-root_count-when-mount-fails-due-to-busy-subsystem.patch
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------------------------------------------------------
Subject: cgroup: fix root_count when mount fails due to busy subsystem
From: Paul Menage <menage@xxxxxxxxxx>
root_count was being incremented in cgroup_get_sb() after all error
checking was complete, but decremented in cgroup_kill_sb(), which can be
called on a superblock that we gave up on due to an error. This patch
changes cgroup_kill_sb() to only decrement root_count if the root was
previously linked into the list of roots.
Signed-off-by: Paul Menage <menage@xxxxxxxxxx>
Tested-by: Serge Hallyn <serue@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/cgroup.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff -puN kernel/cgroup.c~cgroup-fix-root_count-when-mount-fails-due-to-busy-subsystem kernel/cgroup.c
--- a/kernel/cgroup.c~cgroup-fix-root_count-when-mount-fails-due-to-busy-subsystem
+++ a/kernel/cgroup.c
@@ -1115,8 +1115,10 @@ static void cgroup_kill_sb(struct super_
}
write_unlock(&css_set_lock);
- list_del(&root->root_list);
- root_count--;
+ if (!list_empty(&root->root_list)) {
+ list_del(&root->root_list);
+ root_count--;
+ }
mutex_unlock(&cgroup_mutex);
_
Patches currently in -mm which might be from menage@xxxxxxxxxx are
cgroups-use-hierarchy-mutex-in-creation-failure-path.patch
memcg-get-put-parents-at-create-free.patch
memcg-get-put-parents-at-create-free-fix.patch
cgroups-fix-lock-inconsistency-in-cgroup_clone.patch
cgroups-add-cpu_relax-calls-in-css_tryget-and-cgroup_clear_css_refs.patch
cgroup-fix-root_count-when-mount-fails-due-to-busy-subsystem.patch
linux-next.patch
cgroups-fix-cgrouph-comments.patch
relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups.patch
cpuset-fix-allocating-page-cache-slab-object-on-the-unallowed-node-when-memory-spread-is-set.patch
cpuset-fix-allocating-page-cache-slab-object-on-the-unallowed-node-when-memory-spread-is-set-checkpatch-fixes.patch
add-a-refcount-check-in-dput.patch
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