block: Catch possible entries missing from rqf_name[]

Add a BUILD_BUG_ON() call to ensure that we are not missing entries in
rqf_name[].
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240719112912.3830443-16-john.g.garry@oracle.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-debugfs.c

@@ -282,6 +282,7 @@ int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 	const char *op_str = blk_op_str(op);
 
 	BUILD_BUG_ON(ARRAY_SIZE(cmd_flag_name) != __REQ_NR_BITS);
+	BUILD_BUG_ON(ARRAY_SIZE(rqf_name) != __RQF_BITS);
 
 	seq_printf(m, "%p {.op=", rq);
 	if (strcmp(op_str, "UNKNOWN") == 0)

include/linux/blk-mq.h

@@ -27,6 +27,7 @@ typedef enum rq_end_io_ret (rq_end_io_fn)(struct request *, blk_status_t);
  * request flags */
 typedef __u32 __bitwise req_flags_t;
 
+/* Keep rqf_name[] in sync with the definitions below */
 enum {
 	/* drive already may have started this one */
 	__RQF_STARTED,