1 files changed, 77 insertions, 0 deletions

diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index 11b1c15ac697..3470d4e8f0cb 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -10,8 +10,25 @@ static int cachefiles_ondemand_fd_release(struct inode *inode,
 	struct cachefiles_object *object = file->private_data;
 	struct cachefiles_cache *cache = object->volume->cache;
 	int object_id = object->ondemand_id;
+	struct cachefiles_req *req;
+	XA_STATE(xas, &cache->reqs, 0);
 
+	xa_lock(&cache->reqs);
 	object->ondemand_id = CACHEFILES_ONDEMAND_ID_CLOSED;
+
+	/*
+	 * Flush all pending READ requests since their completion depends on
+	 * anon_fd.
+	 */
+	xas_for_each(&xas, req, ULONG_MAX) {
+		if (req->msg.opcode == CACHEFILES_OP_READ) {
+			req->error = -EIO;
+			complete(&req->done);
+			xas_store(&xas, NULL);
+		}
+	}
+	xa_unlock(&cache->reqs);
+
 	xa_erase(&cache->ondemand_ids, object_id);
 	cachefiles_put_object(object, cachefiles_obj_put_ondemand_fd);
 	cachefiles_put_unbind_pincount(cache);
@@ -57,11 +74,35 @@ static loff_t cachefiles_ondemand_fd_llseek(struct file *filp, loff_t pos,
 	return vfs_llseek(file, pos, whence);
 }
 
+static long cachefiles_ondemand_fd_ioctl(struct file *filp, unsigned int ioctl,
+					 unsigned long arg)
+{
+	struct cachefiles_object *object = filp->private_data;
+	struct cachefiles_cache *cache = object->volume->cache;
+	struct cachefiles_req *req;
+	unsigned long id;
+
+	if (ioctl != CACHEFILES_IOC_READ_COMPLETE)
+		return -EINVAL;
+
+	if (!test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags))
+		return -EOPNOTSUPP;
+
+	id = arg;
+	req = xa_erase(&cache->reqs, id);
+	if (!req)
+		return -EINVAL;
+
+	complete(&req->done);
+	return 0;
+}
+
 static const struct file_operations cachefiles_ondemand_fd_fops = {
 	.owner		= THIS_MODULE,
 	.release	= cachefiles_ondemand_fd_release,
 	.write_iter	= cachefiles_ondemand_fd_write_iter,
 	.llseek		= cachefiles_ondemand_fd_llseek,
+	.unlocked_ioctl	= cachefiles_ondemand_fd_ioctl,
 };
 
 /*
@@ -388,6 +429,32 @@ static int cachefiles_ondemand_init_close_req(struct cachefiles_req *req,
 	return 0;
 }
 
+struct cachefiles_read_ctx {
+	loff_t off;
+	size_t len;
+};
+
+static int cachefiles_ondemand_init_read_req(struct cachefiles_req *req,
+					     void *private)
+{
+	struct cachefiles_object *object = req->object;
+	struct cachefiles_read *load = (void *)req->msg.data;
+	struct cachefiles_read_ctx *read_ctx = private;
+	int object_id = object->ondemand_id;
+
+	/* Stop enqueuing requests when daemon has closed anon_fd. */
+	if (object_id <= 0) {
+		WARN_ON_ONCE(object_id == 0);
+		pr_info_once("READ: anonymous fd closed prematurely.\n");
+		return -EIO;
+	}
+
+	req->msg.object_id = object_id;
+	load->off = read_ctx->off;
+	load->len = read_ctx->len;
+	return 0;
+}
+
 int cachefiles_ondemand_init_object(struct cachefiles_object *object)
 {
 	struct fscache_cookie *cookie = object->cookie;
@@ -417,3 +484,13 @@ void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
 	cachefiles_ondemand_send_req(object, CACHEFILES_OP_CLOSE, 0,
 			cachefiles_ondemand_init_close_req, NULL);
 }
+
+int cachefiles_ondemand_read(struct cachefiles_object *object,
+			     loff_t pos, size_t len)
+{
+	struct cachefiles_read_ctx read_ctx = {pos, len};
+
+	return cachefiles_ondemand_send_req(object, CACHEFILES_OP_READ,
+			sizeof(struct cachefiles_read),
+			cachefiles_ondemand_init_read_req, &read_ctx);
+}