diff --git a/fs/aio.c b/fs/aio.c
index f8e52a1..a793f70 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -278,11 +278,11 @@
 	return 0;
 }
 
-static void aio_ring_remap(struct file *file, struct vm_area_struct *vma)
+static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	struct kioctx_table *table;
-	int i;
+	int i, res = -EINVAL;
 
 	spin_lock(&mm->ioctx_lock);
 	rcu_read_lock();
@@ -292,13 +292,17 @@
 
 		ctx = table->table[i];
 		if (ctx && ctx->aio_ring_file == file) {
-			ctx->user_id = ctx->mmap_base = vma->vm_start;
+			if (!atomic_read(&ctx->dead)) {
+				ctx->user_id = ctx->mmap_base = vma->vm_start;
+				res = 0;
+			}
 			break;
 		}
 	}
 
 	rcu_read_unlock();
 	spin_unlock(&mm->ioctx_lock);
+	return res;
 }
 
 static const struct file_operations aio_ring_fops = {
@@ -727,6 +731,9 @@
 err_cleanup:
 	aio_nr_sub(ctx->max_reqs);
 err_ctx:
+	atomic_set(&ctx->dead, 1);
+	if (ctx->mmap_size)
+		vm_munmap(ctx->mmap_base, ctx->mmap_size);
 	aio_free_ring(ctx);
 err:
 	mutex_unlock(&ctx->ring_lock);
@@ -748,11 +755,12 @@
 {
 	struct kioctx_table *table;
 
-	if (atomic_xchg(&ctx->dead, 1))
-		return -EINVAL;
-
-
 	spin_lock(&mm->ioctx_lock);
+	if (atomic_xchg(&ctx->dead, 1)) {
+		spin_unlock(&mm->ioctx_lock);
+		return -EINVAL;
+	}
+
 	table = rcu_dereference_raw(mm->ioctx_table);
 	WARN_ON(ctx != table->table[ctx->id]);
 	table->table[ctx->id] = NULL;
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 46e0d4e..ba1790e 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2394,7 +2394,6 @@
 		/*
 		 * for completing the rest of the request.
 		 */
-		*ppos += written;
 		count -= written;
 		written_buffered = generic_perform_write(file, from, *ppos);
 		/*
@@ -2409,7 +2408,6 @@
 			goto out_dio;
 		}
 
-		iocb->ki_pos = *ppos + written_buffered;
 		/* We need to ensure that the page cache pages are written to
 		 * disk and invalidated to preserve the expected O_DIRECT
 		 * semantics.
@@ -2418,6 +2416,7 @@
 		ret = filemap_write_and_wait_range(file->f_mapping, *ppos,
 				endbyte);
 		if (ret == 0) {
+			iocb->ki_pos = *ppos + written_buffered;
 			written += written_buffered;
 			invalidate_mapping_pages(mapping,
 					*ppos >> PAGE_CACHE_SHIFT,
@@ -2440,10 +2439,14 @@
 	/* buffered aio wouldn't have proper lock coverage today */
 	BUG_ON(ret == -EIOCBQUEUED && !(file->f_flags & O_DIRECT));
 
+	if (unlikely(written <= 0))
+		goto no_sync;
+
 	if (((file->f_flags & O_DSYNC) && !direct_io) || IS_SYNC(inode) ||
 	    ((file->f_flags & O_DIRECT) && !direct_io)) {
-		ret = filemap_fdatawrite_range(file->f_mapping, *ppos,
-					       *ppos + count - 1);
+		ret = filemap_fdatawrite_range(file->f_mapping,
+					       iocb->ki_pos - written,
+					       iocb->ki_pos - 1);
 		if (ret < 0)
 			written = ret;
 
@@ -2454,10 +2457,12 @@
 		}
 
 		if (!ret)
-			ret = filemap_fdatawait_range(file->f_mapping, *ppos,
-						      *ppos + count - 1);
+			ret = filemap_fdatawait_range(file->f_mapping,
+						      iocb->ki_pos - written,
+						      iocb->ki_pos - 1);
 	}
 
+no_sync:
 	/*
 	 * deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io
 	 * function pointer which is called when o_direct io completes so that
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f4131e8..52cc4492 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1549,7 +1549,7 @@
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
-	void (*mremap)(struct file *, struct vm_area_struct *);
+	int (*mremap)(struct file *, struct vm_area_struct *);
 	int (*open) (struct inode *, struct file *);
 	int (*flush) (struct file *, fl_owner_t id);
 	int (*release) (struct inode *, struct file *);
diff --git a/mm/mremap.c b/mm/mremap.c
index 57dadc0..2dc44b1 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -286,8 +286,14 @@
 		old_len = new_len;
 		old_addr = new_addr;
 		new_addr = -ENOMEM;
-	} else if (vma->vm_file && vma->vm_file->f_op->mremap)
-		vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
+	} else if (vma->vm_file && vma->vm_file->f_op->mremap) {
+		err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
+		if (err < 0) {
+			move_page_tables(new_vma, new_addr, vma, old_addr,
+					 moved_len, true);
+			return err;
+		}
+	}
 
 	/* Conceal VM_ACCOUNT so old reservation is not undone */
 	if (vm_flags & VM_ACCOUNT) {