The patch titled
cgroups: don't change release_agent when remount failed
has been added to the -mm tree. Its filename is
cgroups-dont-change-release_agent-when-remount-failed.patch
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------------------------------------------------------
Subject: cgroups: don't change release_agent when remount failed
From: Li Zefan <lizf@xxxxxxxxxxxxxx>
Remount can fail in either case:
- wrong mount options is specified, or option 'noprefix' is changed.
- a to-be-added subsys is already mounted/active.
When using remount to change 'release_agent', for the above former failure
case, remount will return errno with release_agent unchanged, but for the
latter case, remount will return EBUSY with relase_agent changed, which is
unexpected I think:
# mount -t cgroup -o cpu xxx /cgrp1
# mount -t cgroup -o cpuset,release_agent=agent1 yyy /cgrp2
# cat /cgrp2/release_agent
agent1
# mount -t cgroup -o remount,cpuset,noprefix,release_agent=agent2 yyy /cgrp2
mount: /cgrp2 not mounted already, or bad option
# cat /cgrp2/release_agent
agent1 <-- ok
# mount -t cgroup -o remount,cpu,cpuset,release_agent=agent2 yyy /cgrp2
mount: /cgrp2 is busy
# cat /cgrp2/release_agent
agent2 <-- unexpected!
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Paul Menage <menage@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/cgroup.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff -puN kernel/cgroup.c~cgroups-dont-change-release_agent-when-remount-failed kernel/cgroup.c
--- a/kernel/cgroup.c~cgroups-dont-change-release_agent-when-remount-failed
+++ a/kernel/cgroup.c
@@ -915,10 +915,11 @@ static int cgroup_remount(struct super_b
}
ret = rebind_subsystems(root, opts.subsys_bits);
+ if (ret)
+ goto out_unlock;
/* (re)populate subsystem files */
- if (!ret)
- cgroup_populate_dir(cgrp);
+ cgroup_populate_dir(cgrp);
if (opts.release_agent)
strcpy(root->release_agent_path, opts.release_agent);
_
Patches currently in -mm which might be from lizf@xxxxxxxxxxxxxx are
linux-next.patch
vfs-add-missing-unlock-in-sget.patch
relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups.patch
cgroup-css-id-support.patch
cgroup-fix-frequent-ebusy-at-rmdir.patch
cgroups-more-documentation-for-remount-and-release_agent.patch
cgroups-show-correct-file-mode.patch
cgroups-show-correct-file-mode-fix.patch
cgroups-dont-change-release_agent-when-remount-failed.patch
memcg-use-css-id.patch
memcg-hierarchical-stat.patch
memcg-fix-shrinking-memory-to-return-ebusy-by-fixing-retry-algorithm.patch
memcg-fix-oom-killer-under-memcg.patch
memcg-fix-oom-killer-under-memcg-fix2.patch
memcg-fix-oom-killer-under-memcg-fix.patch
memcg-show-memcg-information-during-oom.patch
memcg-show-memcg-information-during-oom-fix2.patch
memcg-show-memcg-information-during-oom-fix.patch
memcg-show-memcg-information-during-oom-fix-fix.patch
memcg-show-memcg-information-during-oom-fix-fix-checkpatch-fixes.patch
use-css-id-in-swap_cgroup-for-saving-memory-v4.patch
cpuset-fix-possible-races-in-cpu-memory-hotplug.patch
cgroups-add-data-field-to-struct-cgroup_scanner.patch
cpuset-rewrite-update_tasks_nodemask.patch
cpuset-avoid-changing-cpusets-mems-when-errno-returned.patch
cpuset-remove-struct-cpuset_hotplug_scanner.patch
cpusets-allow-cpusets-to-be-configured-built-on-non-smp-systems.patch
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