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| author | Gao feng <gaofeng@cn.fujitsu.com> | 2012-12-03 09:28:18 +0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2012-12-03 08:33:11 -0800 |
| commit | 7083d0378a1746f2b45729cae494c6b92e75d73f (patch) | |
| tree | bc2a732ffe1e9b4337a55b3fb7cc215a27159053 /kernel | |
| parent | 879a3d9dbbde823ac77d39131e7a287f31b8296f (diff) | |
| download | linux-7083d0378a1746f2b45729cae494c6b92e75d73f.tar.bz2 | |
cgroup: remove subsystem files when remounting cgroup
cgroup_clear_directroy is called by cgroup_d_remove_dir
and cgroup_remount.
when we call cgroup_remount to remount the cgroup,the subsystem
may be unlinked from cgroupfs_root->subsys_list in rebind_subsystem,this
subsystem's files will not be removed in cgroup_clear_directroy.
And the system will panic when we try to access these files.
this patch removes subsystems's files before rebind_subsystems,
if rebind_subsystems failed, repopulate these removed files.
With help from Tejun.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index e1293a9189b6..5cc37241a6fb 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1349,14 +1349,21 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) goto out_unlock; } + /* + * Clear out the files of subsystems that should be removed, do + * this before rebind_subsystems, since rebind_subsystems may + * change this hierarchy's subsys_list. + */ + cgroup_clear_directory(cgrp->dentry, false, removed_mask); + ret = rebind_subsystems(root, opts.subsys_mask); if (ret) { + /* rebind_subsystems failed, re-populate the removed files */ + cgroup_populate_dir(cgrp, false, removed_mask); drop_parsed_module_refcounts(opts.subsys_mask); goto out_unlock; } - /* clear out any existing files and repopulate subsystem files */ - cgroup_clear_directory(cgrp->dentry, false, removed_mask); /* re-populate subsystem files */ cgroup_populate_dir(cgrp, false, added_mask); |