diff options
Diffstat (limited to 'arch/s390/mm/gup.c')
| -rw-r--r-- | arch/s390/mm/gup.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c index 45b405ca2567..65cb06e2af4e 100644 --- a/arch/s390/mm/gup.c +++ b/arch/s390/mm/gup.c @@ -52,7 +52,7 @@ static inline int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { unsigned long mask, result; - struct page *head, *page; + struct page *head, *page, *tail; int refs; result = write ? 0 : _SEGMENT_ENTRY_RO; @@ -64,6 +64,7 @@ static inline int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr, refs = 0; head = pmd_page(pmd); page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT); + tail = page; do { VM_BUG_ON(compound_head(page) != head); pages[*nr] = page; @@ -81,6 +82,17 @@ static inline int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr, *nr -= refs; while (refs--) put_page(head); + return 0; + } + + /* + * Any tail page need their mapcount reference taken before we + * return. + */ + while (refs--) { + if (PageTail(tail)) + get_huge_page_tail(tail); + tail++; } return 1; |