ARM: dts: vf610: lpuart: Add eDMA support

[cascardo/linux.git] / mm / memory-failure.c

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index b25ed32..4f08a2d 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -856,14 +856,14 @@ static int page_action(struct page_state *ps, struct page *p,
  * the pages and send SIGBUS to the processes if the data was dirty.
  */
 static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
-                                 int trapno, int flags)
+                                 int trapno, int flags, struct page **hpagep)
 {
        enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
        struct address_space *mapping;
        LIST_HEAD(tokill);
        int ret;
        int kill = 1, forcekill;
-       struct page *hpage = compound_head(p);
+       struct page *hpage = *hpagep;
        struct page *ppage;
 
        if (PageReserved(p) || PageSlab(p))
@@ -942,11 +942,14 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
                         * We pinned the head page for hwpoison handling,
                         * now we split the thp and we are interested in
                         * the hwpoisoned raw page, so move the refcount
-                        * to it.
+                        * to it. Similarly, page lock is shifted.
                         */
                        if (hpage != p) {
                                put_page(hpage);
                                get_page(p);
+                               lock_page(p);
+                               unlock_page(hpage);
+                               *hpagep = p;
                        }
                        /* THP is split, so ppage should be the real poisoned page. */
                        ppage = p;
@@ -964,17 +967,11 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
        if (kill)
                collect_procs(ppage, &tokill);
 
-       if (hpage != ppage)
-               lock_page(ppage);
-
        ret = try_to_unmap(ppage, ttu);
        if (ret != SWAP_SUCCESS)
                printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
                                pfn, page_mapcount(ppage));
 
-       if (hpage != ppage)
-               unlock_page(ppage);
-
        /*
         * Now that the dirty bit has been propagated to the
         * struct page and all unmaps done we can decide if
@@ -1193,8 +1190,12 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
        /*
         * Now take care of user space mappings.
         * Abort on fail: __delete_from_page_cache() assumes unmapped page.
+        *
+        * When the raw error page is thp tail page, hpage points to the raw
+        * page after thp split.
         */
-       if (hwpoison_user_mappings(p, pfn, trapno, flags) != SWAP_SUCCESS) {
+       if (hwpoison_user_mappings(p, pfn, trapno, flags, &hpage)
+           != SWAP_SUCCESS) {
                printk(KERN_ERR "MCE %#lx: cannot unmap page, give up\n", pfn);
                res = -EBUSY;
                goto out;