io_uring: add req flag invariant build assertion

isilence · axboe · commit 697b2876ac03 · 2025-03-31T07:07:34.000-06:00
We're caching some of file related request flags in a tricky way, put a build check to make sure flags don't get reshuffled. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9877577b83c25dd78224a8274f799187e7ec7639.1743407551.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
@@ -1643,6 +1643,8 @@ io_req_flags_t io_file_get_flags(struct file *file)
 {
 	io_req_flags_t res = 0;
 
+	BUILD_BUG_ON(REQ_F_ISREG_BIT != REQ_F_SUPPORT_NOWAIT_BIT + 1);
+
 	if (S_ISREG(file_inode(file)->i_mode))
 		res |= REQ_F_ISREG;
 	if ((file->f_flags & O_NONBLOCK) || (file->f_mode & FMODE_NOWAIT))

Original file line number	Diff line number	Diff line change
`@@ -1643,6 +1643,8 @@ io_req_flags_t io_file_get_flags(struct file *file)`
`1643`	`1643`	`{`
`1644`	`1644`	`io_req_flags_t res = 0;`
`1645`	`1645`
	`1646`	`+ BUILD_BUG_ON(REQ_F_ISREG_BIT != REQ_F_SUPPORT_NOWAIT_BIT + 1);`
	`1647`	`+`
`1646`	`1648`	`if (S_ISREG(file_inode(file)->i_mode))`
`1647`	`1649`	`res \|= REQ_F_ISREG;`
`1648`	`1650`	`if ((file->f_flags & O_NONBLOCK) \|\| (file->f_mode & FMODE_NOWAIT))`