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Commit cf780b7d authored by Vladimir Davydov's avatar Vladimir Davydov Committed by Tejun Heo
Browse files

cgroup: fix idr_preload usage 



It does not make much sense to call idr_preload with the same gfp mask
as the following idr_alloc, but this is what we do in cgroup_idr_alloc.
This patch fixes the idr_preload usage by making cgroup_idr_alloc call
idr_alloc w/o __GFP_WAIT. Since it is now safe to call cgroup_idr_alloc
with GFP_KERNEL, the patch also fixes all its callers appropriately.

Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 917d8e2d

kernel/cgroup.c

+4 −4
Original line number Diff line number Diff line
@@ -210,7 +210,7 @@ static int cgroup_idr_alloc(struct idr *idr, void *ptr, int start, int end, 


	idr_preload(gfp_mask);

	spin_lock_bh(&cgroup_idr_lock);

	ret = idr_alloc(idr, ptr, start, end, gfp_mask);

	ret = idr_alloc(idr, ptr, start, end, gfp_mask & ~__GFP_WAIT);

	spin_unlock_bh(&cgroup_idr_lock);

	idr_preload_end();

	return ret;
@@ -1669,7 +1669,7 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask) 


	lockdep_assert_held(&cgroup_mutex);



	ret = cgroup_idr_alloc(&root->cgroup_idr, root_cgrp, 1, 2, GFP_NOWAIT);

	ret = cgroup_idr_alloc(&root->cgroup_idr, root_cgrp, 1, 2, GFP_KERNEL);

	if (ret < 0)

		goto out;

	root_cgrp->id = ret;
@@ -4582,7 +4582,7 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss, 
	if (err)

		goto err_free_css;



	err = cgroup_idr_alloc(&ss->css_idr, NULL, 2, 0, GFP_NOWAIT);

	err = cgroup_idr_alloc(&ss->css_idr, NULL, 2, 0, GFP_KERNEL);

	if (err < 0)

		goto err_free_percpu_ref;

	css->id = err;
@@ -4659,7 +4659,7 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, 
	 * Temporarily set the pointer to NULL, so idr_find() won't return

	 * a half-baked cgroup.

	 */

	cgrp->id = cgroup_idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_NOWAIT);

	cgrp->id = cgroup_idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_KERNEL);

	if (cgrp->id < 0) {

		ret = -ENOMEM;

		goto out_cancel_ref;