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| author | Michal Koutný <mkoutny@suse.com> | 2020-01-24 12:40:15 +0100 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2020-02-12 23:02:53 +0100 |
| commit | 9c974c77246460fa6a92c18554c3311c8c83c160 (patch) | |
| tree | b18bb13e7ddc8ed4522b6bc095ad279ba341ebb1 /include | |
| parent | cgroup: cgroup_procs_next should increase position index (diff) | |
| download | linux-9c974c77246460fa6a92c18554c3311c8c83c160.tar.xz linux-9c974c77246460fa6a92c18554c3311c8c83c160.zip | |
cgroup: Iterate tasks that did not finish do_exit()
PF_EXITING is set earlier than actual removal from css_set when a task
is exitting. This can confuse cgroup.procs readers who see no PF_EXITING
tasks, however, rmdir is checking against css_set membership so it can
transitionally fail with EBUSY.
Fix this by listing tasks that weren't unlinked from css_set active
lists.
It may happen that other users of the task iterator (without
CSS_TASK_ITER_PROCS) spot a PF_EXITING task before cgroup_exit(). This
is equal to the state before commit c03cd7738a83 ("cgroup: Include dying
leaders with live threads in PROCS iterations") but it may be reviewed
later.
Reported-by: Suren Baghdasaryan <surenb@google.com>
Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cgroup.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index d7ddebd0cdec..e75d2191226b 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -62,6 +62,7 @@ struct css_task_iter { struct list_head *mg_tasks_head; struct list_head *dying_tasks_head; + struct list_head *cur_tasks_head; struct css_set *cur_cset; struct css_set *cur_dcset; struct task_struct *cur_task; |