diff options
| -rw-r--r-- | mm/huge_memory.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 05ca01ef97f7..14cd0ef33b62 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1022,6 +1022,19 @@ int do_huge_pmd_wp_page(struct fault_env *fe, pmd_t orig_pmd) * We can only reuse the page if nobody else maps the huge page or it's * part. */ + if (!trylock_page(page)) { + get_page(page); + spin_unlock(fe->ptl); + lock_page(page); + spin_lock(fe->ptl); + if (unlikely(!pmd_same(*fe->pmd, orig_pmd))) { + unlock_page(page); + put_page(page); + goto out_unlock; + } + put_page(page); + } + if (page_trans_huge_mapcount(page, NULL) == 1) { pmd_t entry; entry = pmd_mkyoung(orig_pmd); @@ -1029,8 +1042,10 @@ int do_huge_pmd_wp_page(struct fault_env *fe, pmd_t orig_pmd) if (pmdp_set_access_flags(vma, haddr, fe->pmd, entry, 1)) update_mmu_cache_pmd(vma, fe->address, fe->pmd); ret |= VM_FAULT_WRITE; + unlock_page(page); goto out_unlock; } + unlock_page(page); get_page(page); spin_unlock(fe->ptl); alloc: |