The patch titled Subject: cgroups: don't attach task to subsystem if migration failed has been removed from the -mm tree. Its filename was cgroups-fix-ordering-of-calls-in-cgroup_attach_proc.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ From: Ben Blum <bblum@xxxxxxxxxxxxxx> Subject: cgroups: don't attach task to subsystem if migration failed If a task has exited to the point it has called cgroup_exit() already, then we can't migrate it to another cgroup anymore. This can happen when we are attaching a task to a new cgroup between the call to ->can_attach_task() on subsystems and the migration that is eventually tried in cgroup_task_migrate(). In this case cgroup_task_migrate() returns -ESRCH and we don't want to attach the task to the subsystems because the attachment to the new cgroup itself failed. Fix this by only calling ->attach_task() on the subsystems if the cgroup migration succeeded. Reported-by: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Ben Blum <bblum@xxxxxxxxxxxxxx> Acked-by: Paul Menage <paul@xxxxxxxxxxxxxx> Cc: Li Zefan <lizf@xxxxxxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/cgroup.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff -puN kernel/cgroup.c~cgroups-fix-ordering-of-calls-in-cgroup_attach_proc kernel/cgroup.c --- a/kernel/cgroup.c~cgroups-fix-ordering-of-calls-in-cgroup_attach_proc +++ a/kernel/cgroup.c @@ -2135,14 +2135,17 @@ int cgroup_attach_proc(struct cgroup *cg oldcgrp = task_cgroup_from_root(tsk, root); if (cgrp == oldcgrp) continue; - /* attach each task to each subsystem */ - for_each_subsys(root, ss) { - if (ss->attach_task) - ss->attach_task(cgrp, tsk); - } /* if the thread is PF_EXITING, it can just get skipped. */ retval = cgroup_task_migrate(cgrp, oldcgrp, tsk, true); - BUG_ON(retval != 0 && retval != -ESRCH); + if (retval == 0) { + /* attach each task to each subsystem */ + for_each_subsys(root, ss) { + if (ss->attach_task) + ss->attach_task(cgrp, tsk); + } + } else { + BUG_ON(retval != -ESRCH); + } } /* nothing is sensitive to fork() after this point. */ _ Patches currently in -mm which might be from bblum@xxxxxxxxxxxxxx are origin.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html