io_uring: IORING_OP_F[GS]ETXATTR is fine with REQ_F_FIXED_FILE

Rejection of IOSQE_FIXED_FILE combined with IORING_OP_[GS]ETXATTR
is fine - these do not take a file descriptor, so such combination
makes no sense.  The checks are misplaced, though - as it is, they
triggers on IORING_OP_F[GS]ETXATTR as well, and those do take
a file reference, no matter the origin.

Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Al Viro <[email protected]>

Author: axboe

io_uring/xattr.c

@@ -48,9 +48,6 @@ static int __io_getxattr_prep(struct io_kiocb *req,
 	const char __user *name;
 	int ret;
 
-	if (unlikely(req->flags & REQ_F_FIXED_FILE))
-		return -EBADF;
-
 	ix->filename = NULL;
 	ix->ctx.kvalue = NULL;
 	name = u64_to_user_ptr(READ_ONCE(sqe->addr));
@@ -90,6 +87,9 @@ int io_getxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	const char __user *path;
 	int ret;
 
+	if (unlikely(req->flags & REQ_F_FIXED_FILE))
+		return -EBADF;
+
 	ret = __io_getxattr_prep(req, sqe);
 	if (ret)
 		return ret;
@@ -152,9 +152,6 @@ static int __io_setxattr_prep(struct io_kiocb *req,
 	const char __user *name;
 	int ret;
 
-	if (unlikely(req->flags & REQ_F_FIXED_FILE))
-		return -EBADF;
-
 	ix->filename = NULL;
 	name = u64_to_user_ptr(READ_ONCE(sqe->addr));
 	ix->ctx.cvalue = u64_to_user_ptr(READ_ONCE(sqe->addr2));
@@ -183,6 +180,9 @@ int io_setxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	const char __user *path;
 	int ret;
 
+	if (unlikely(req->flags & REQ_F_FIXED_FILE))
+		return -EBADF;
+
 	ret = __io_setxattr_prep(req, sqe);
 	if (ret)
 		return ret;