Only for hugetlb pages in shared mappings, try_to_unmap should take
semaphore in write mode here. Rework the code to make it clear.
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/memory-failure.c | 34 +++++++++++++++-------------------
1 file changed, 15 insertions(+), 19 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 71bd78279669..78aba0b3e983 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1405,26 +1405,22 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
if (kill)
collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
- if (!PageHuge(hpage)) {
- try_to_unmap(hpage, ttu);
+ if (PageHuge(hpage) && !PageAnon(hpage)) {
+ /*
+ * For hugetlb pages in shared mappings, try_to_unmap
+ * could potentially call huge_pmd_unshare. Because of
+ * this, take semaphore in write mode here and set
+ * TTU_RMAP_LOCKED to indicate we have taken the lock
+ * at this higher level.
+ */
+ mapping = hugetlb_page_mapping_lock_write(hpage);
+ if (mapping) {
+ try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
+ i_mmap_unlock_write(mapping);
+ } else
+ pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn);
} else {
- if (!PageAnon(hpage)) {
- /*
- * For hugetlb pages in shared mappings, try_to_unmap
- * could potentially call huge_pmd_unshare. Because of
- * this, take semaphore in write mode here and set
- * TTU_RMAP_LOCKED to indicate we have taken the lock
- * at this higher level.
- */
- mapping = hugetlb_page_mapping_lock_write(hpage);
- if (mapping) {
- try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
- i_mmap_unlock_write(mapping);
- } else
- pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn);
- } else {
- try_to_unmap(hpage, ttu);
- }
+ try_to_unmap(hpage, ttu);
}
unmap_success = !page_mapped(hpage);
--
2.23.0
