Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
 "146 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak,
  dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap,
  memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb,
  userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp,
  ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and
  damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits)
  mm/damon: hide kernel pointer from tracepoint event
  mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log
  mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging
  mm/damon/dbgfs: remove an unnecessary variable
  mm/damon: move the implementation of damon_insert_region to damon.h
  mm/damon: add access checking for hugetlb pages
  Docs/admin-guide/mm/damon/usage: update for schemes statistics
  mm/damon/dbgfs: support all DAMOS stats
  Docs/admin-guide/mm/damon/reclaim: document statistics parameters
  mm/damon/reclaim: provide reclamation statistics
  mm/damon/schemes: account how many times quota limit has exceeded
  mm/damon/schemes: account scheme actions that successfully applied
  mm/damon: remove a mistakenly added comment for a future feature
  Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts
  Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning
  Docs/admin-guide/mm/damon/usage: remove redundant information
  Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks
  mm/damon: convert macro functions to static inline functions
  mm/damon: modify damon_rand() macro to static inline function
  mm/damon: move damon_rand() definition into damon.h
  ...

1 files changed, 67 insertions, 24 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index 28d627444a243..66909efd0a1b2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -554,7 +554,7 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
 	struct shmem_inode_info *info;
 	struct page *page;
 	unsigned long batch = sc ? sc->nr_to_scan : 128;
-	int removed = 0, split = 0;
+	int split = 0;
 
 	if (list_empty(&sbinfo->shrinklist))
 		return SHRINK_STOP;
@@ -569,7 +569,6 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
 		/* inode is about to be evicted */
 		if (!inode) {
 			list_del_init(&info->shrinklist);
-			removed++;
 			goto next;
 		}
 
@@ -577,12 +576,12 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
 		if (round_up(inode->i_size, PAGE_SIZE) ==
 				round_up(inode->i_size, HPAGE_PMD_SIZE)) {
 			list_move(&info->shrinklist, &to_remove);
-			removed++;
 			goto next;
 		}
 
 		list_move(&info->shrinklist, &list);
 next:
+		sbinfo->shrinklist_len--;
 		if (!--batch)
 			break;
 	}
@@ -602,7 +601,7 @@ next:
 		inode = &info->vfs_inode;
 
 		if (nr_to_split && split >= nr_to_split)
-			goto leave;
+			goto move_back;
 
 		page = find_get_page(inode->i_mapping,
 				(inode->i_size & HPAGE_PMD_MASK) >> PAGE_SHIFT);
@@ -616,38 +615,44 @@ next:
 		}
 
 		/*
-		 * Leave the inode on the list if we failed to lock
-		 * the page at this time.
+		 * Move the inode on the list back to shrinklist if we failed
+		 * to lock the page at this time.
 		 *
 		 * Waiting for the lock may lead to deadlock in the
 		 * reclaim path.
 		 */
 		if (!trylock_page(page)) {
 			put_page(page);
-			goto leave;
+			goto move_back;
 		}
 
 		ret = split_huge_page(page);
 		unlock_page(page);
 		put_page(page);
 
-		/* If split failed leave the inode on the list */
+		/* If split failed move the inode on the list back to shrinklist */
 		if (ret)
-			goto leave;
+			goto move_back;
 
 		split++;
 drop:
 		list_del_init(&info->shrinklist);
-		removed++;
-leave:
+		goto put;
+move_back:
+		/*
+		 * Make sure the inode is either on the global list or deleted
+		 * from any local list before iput() since it could be deleted
+		 * in another thread once we put the inode (then the local list
+		 * is corrupted).
+		 */
+		spin_lock(&sbinfo->shrinklist_lock);
+		list_move(&info->shrinklist, &sbinfo->shrinklist);
+		sbinfo->shrinklist_len++;
+		spin_unlock(&sbinfo->shrinklist_lock);
+put:
 		iput(inode);
 	}
 
-	spin_lock(&sbinfo->shrinklist_lock);
-	list_splice_tail(&list, &sbinfo->shrinklist);
-	sbinfo->shrinklist_len -= removed;
-	spin_unlock(&sbinfo->shrinklist_lock);
-
 	return split;
 }
 
@@ -1541,8 +1546,7 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp,
 		return NULL;
 
 	shmem_pseudo_vma_init(&pvma, info, hindex);
-	page = alloc_pages_vma(gfp, HPAGE_PMD_ORDER, &pvma, 0, numa_node_id(),
-			       true);
+	page = alloc_pages_vma(gfp, HPAGE_PMD_ORDER, &pvma, 0, true);
 	shmem_pseudo_vma_destroy(&pvma);
 	if (page)
 		prep_transhuge_page(page);
@@ -2439,6 +2443,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
 	struct inode *inode = mapping->host;
 	struct shmem_inode_info *info = SHMEM_I(inode);
 	pgoff_t index = pos >> PAGE_SHIFT;
+	int ret = 0;
 
 	/* i_rwsem is held by caller */
 	if (unlikely(info->seals & (F_SEAL_GROW |
@@ -2449,7 +2454,19 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
 			return -EPERM;
 	}
 
-	return shmem_getpage(inode, index, pagep, SGP_WRITE);
+	ret = shmem_getpage(inode, index, pagep, SGP_WRITE);
+
+	if (ret)
+		return ret;
+
+	if (PageHWPoison(*pagep)) {
+		unlock_page(*pagep);
+		put_page(*pagep);
+		*pagep = NULL;
+		return -EIO;
+	}
+
+	return 0;
 }
 
 static int
@@ -2536,6 +2553,12 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 			if (sgp == SGP_CACHE)
 				set_page_dirty(page);
 			unlock_page(page);
+
+			if (PageHWPoison(page)) {
+				put_page(page);
+				error = -EIO;
+				break;
+			}
 		}
 
 		/*
@@ -3075,7 +3098,8 @@ static const char *shmem_get_link(struct dentry *dentry,
 		page = find_get_page(inode->i_mapping, 0);
 		if (!page)
 			return ERR_PTR(-ECHILD);
-		if (!PageUptodate(page)) {
+		if (PageHWPoison(page) ||
+		    !PageUptodate(page)) {
 			put_page(page);
 			return ERR_PTR(-ECHILD);
 		}
@@ -3083,6 +3107,13 @@ static const char *shmem_get_link(struct dentry *dentry,
 		error = shmem_getpage(inode, 0, &page, SGP_READ);
 		if (error)
 			return ERR_PTR(error);
+		if (!page)
+			return ERR_PTR(-ECHILD);
+		if (PageHWPoison(page)) {
+			unlock_page(page);
+			put_page(page);
+			return ERR_PTR(-ECHILD);
+		}
 		unlock_page(page);
 	}
 	set_delayed_call(done, shmem_put_link, page);
@@ -3733,6 +3764,13 @@ static void shmem_destroy_inodecache(void)
 	kmem_cache_destroy(shmem_inode_cachep);
 }
 
+/* Keep the page in page cache instead of truncating it */
+static int shmem_error_remove_page(struct address_space *mapping,
+				   struct page *page)
+{
+	return 0;
+}
+
 const struct address_space_operations shmem_aops = {
 	.writepage	= shmem_writepage,
 	.set_page_dirty	= __set_page_dirty_no_writeback,
@@ -3743,7 +3781,7 @@ const struct address_space_operations shmem_aops = {
 #ifdef CONFIG_MIGRATION
 	.migratepage	= migrate_page,
 #endif
-	.error_remove_page = generic_error_remove_page,
+	.error_remove_page = shmem_error_remove_page,
 };
 EXPORT_SYMBOL(shmem_aops);
 
@@ -4151,9 +4189,14 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
 	error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE,
 				  gfp, NULL, NULL, NULL);
 	if (error)
-		page = ERR_PTR(error);
-	else
-		unlock_page(page);
+		return ERR_PTR(error);
+
+	unlock_page(page);
+	if (PageHWPoison(page)) {
+		put_page(page);
+		return ERR_PTR(-EIO);
+	}
+
 	return page;
 #else
 	/*