Commit 85d9fc89 authored by KAMEZAWA Hiroyuki's avatar KAMEZAWA Hiroyuki Committed by Linus Torvalds
Browse files

memcg: fix refcnt handling at swapoff



Now, at swapoff, even while try_charge() fails, commit is executed.  This
is a bug which turns the refcnt of cgroup_subsys_state negative.
Reported-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Tested-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Tested-by: default avatarDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: default avatarDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7460db56
......@@ -698,8 +698,10 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
pte_t *pte;
int ret = 1;
if (mem_cgroup_try_charge_swapin(vma->vm_mm, page, GFP_KERNEL, &ptr))
if (mem_cgroup_try_charge_swapin(vma->vm_mm, page, GFP_KERNEL, &ptr)) {
ret = -ENOMEM;
goto out_nolock;
}
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
if (unlikely(!pte_same(*pte, swp_entry_to_pte(entry)))) {
......@@ -723,6 +725,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
activate_page(page);
out:
pte_unmap_unlock(pte, ptl);
out_nolock:
return ret;
}
......
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