1 files changed, 13 insertions, 20 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 061dd202979d..23f645657488 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -842,13 +842,13 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
 	struct buffer_head *bh, *head;
 	gfp_t gfp = GFP_NOFS | __GFP_ACCOUNT;
 	long offset;
-	struct mem_cgroup *memcg;
+	struct mem_cgroup *memcg, *old_memcg;
 
 	if (retry)
 		gfp |= __GFP_NOFAIL;
 
 	memcg = get_mem_cgroup_from_page(page);
-	memalloc_use_memcg(memcg);
+	old_memcg = set_active_memcg(memcg);
 
 	head = NULL;
 	offset = PAGE_SIZE;
@@ -867,7 +867,7 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
 		set_bh_page(bh, page, offset);
 	}
 out:
-	memalloc_unuse_memcg();
+	set_active_memcg(old_memcg);
 	mem_cgroup_put(memcg);
 	return head;
 /*
@@ -1958,7 +1958,7 @@ iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh,
 		 */
 		set_buffer_new(bh);
 		set_buffer_unwritten(bh);
-		/* FALLTHRU */
+		fallthrough;
 	case IOMAP_MAPPED:
 		if ((iomap->flags & IOMAP_F_NEW) ||
 		    offset >= i_size_read(inode))
@@ -2771,16 +2771,6 @@ int nobh_writepage(struct page *page, get_block_t *get_block,
 	/* Is the page fully outside i_size? (truncate in progress) */
 	offset = i_size & (PAGE_SIZE-1);
 	if (page->index >= end_index+1 || !offset) {
-		/*
-		 * The page may have dirty, unmapped buffers.  For example,
-		 * they may have been added in ext3_writepage().  Make them
-		 * freeable here, so the page does not leak.
-		 */
-#if 0
-		/* Not really sure about this  - do we need this ? */
-		if (page->mapping->a_ops->invalidatepage)
-			page->mapping->a_ops->invalidatepage(page, offset);
-#endif
 		unlock_page(page);
 		return 0; /* don't care */
 	}
@@ -2975,12 +2965,6 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
 	/* Is the page fully outside i_size? (truncate in progress) */
 	offset = i_size & (PAGE_SIZE-1);
 	if (page->index >= end_index+1 || !offset) {
-		/*
-		 * The page may have dirty, unmapped buffers.  For example,
-		 * they may have been added in ext3_writepage().  Make them
-		 * freeable here, so the page does not leak.
-		 */
-		do_invalidatepage(page, 0, PAGE_SIZE);
 		unlock_page(page);
 		return 0; /* don't care */
 	}
@@ -3157,6 +3141,15 @@ int __sync_dirty_buffer(struct buffer_head *bh, int op_flags)
 	WARN_ON(atomic_read(&bh->b_count) < 1);
 	lock_buffer(bh);
 	if (test_clear_buffer_dirty(bh)) {
+		/*
+		 * The bh should be mapped, but it might not be if the
+		 * device was hot-removed. Not much we can do but fail the I/O.
+		 */
+		if (!buffer_mapped(bh)) {
+			unlock_buffer(bh);
+			return -EIO;
+		}
+
 		get_bh(bh);
 		bh->b_end_io = end_buffer_write_sync;
 		ret = submit_bh(REQ_OP_WRITE, op_flags, bh);