From 85d9fc89fb0f0703df6444f260187c088a8d59ff Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Thu, 29 Jan 2009 14:25:13 -0800 Subject: 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: Li Zefan Tested-by: Li Zefan Tested-by: Daisuke Nishimura Signed-off-by: KAMEZAWA Hiroyuki Reviewed-by: Daisuke Nishimura Cc: Balbir Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index f48b831e5e5c..7e6304dfafab 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -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; } -- cgit v1.2.3