[PATCH v3 4/9] cachefiles: use tmpfile_open() helper

[Miklos Szeredi <mszeredi@redhat.com>]

Use the tmpfile_open() helper instead of doing tmpfile creation and opening
separately.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
 fs/cachefiles/namei.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index d3a5884fe5c9..44f575328af4 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -451,18 +451,19 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object)
 	const struct cred *saved_cred;
 	struct dentry *fan = volume->fanout[(u8)object->cookie->key_hash];
 	struct file *file;
-	struct path path;
+	struct path path = { .mnt = cache->mnt, .dentry = fan };
 	uint64_t ni_size;
 	long ret;
 
 
 	cachefiles_begin_secure(cache, &saved_cred);
 
-	path.mnt = cache->mnt;
 	ret = cachefiles_inject_write_error();
 	if (ret == 0) {
-		path.dentry = vfs_tmpfile(&init_user_ns, fan, S_IFREG, O_RDWR);
-		ret = PTR_ERR_OR_ZERO(path.dentry);
+		file = tmpfile_open(&init_user_ns, &path, S_IFREG,
+				    O_RDWR | O_LARGEFILE | O_DIRECT,
+				    cache->cache_cred);
+		ret = PTR_ERR_OR_ZERO(file);
 	}
 	if (ret) {
 		trace_cachefiles_vfs_error(object, d_inode(fan), ret,
@@ -471,12 +472,14 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object)
 			cachefiles_io_error_obj(object, "Failed to create tmpfile");
 		goto err;
 	}
+	/* From now path refers to the tmpfile */
+	path.dentry = file->f_path.dentry;
 
 	trace_cachefiles_tmpfile(object, d_backing_inode(path.dentry));
 
 	ret = -EBUSY;
 	if (!cachefiles_mark_inode_in_use(object, path.dentry))
-		goto err_dput;
+		goto err_fput;
 
 	ret = cachefiles_ondemand_init_object(object);
 	if (ret < 0)
@@ -499,14 +502,6 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object)
 		}
 	}
 
-	file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT,
-				   d_backing_inode(path.dentry), cache->cache_cred);
-	ret = PTR_ERR(file);
-	if (IS_ERR(file)) {
-		trace_cachefiles_vfs_error(object, d_backing_inode(path.dentry),
-					   ret, cachefiles_trace_open_error);
-		goto err_unuse;
-	}
 	ret = -EINVAL;
 	if (unlikely(!file->f_op->read_iter) ||
 	    unlikely(!file->f_op->write_iter)) {
@@ -514,15 +509,14 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object)
 		pr_notice("Cache does not support read_iter and write_iter\n");
 		goto err_unuse;
 	}
-	dput(path.dentry);
 out:
 	cachefiles_end_secure(cache, saved_cred);
 	return file;
 
 err_unuse:
 	cachefiles_do_unmark_inode_in_use(object, path.dentry);
-err_dput:
-	dput(path.dentry);
+err_fput:
+	fput(file);
 err:
 	file = ERR_PTR(ret);
 	goto out;
-- 
2.37.3