[PATCH v2] io-wq: expose IO_WQ_ACCT_* enumeration items to UAPI

[Eugene Syromiatnikov <esyr@redhat.com>]

These are used to index elements in the argument
of IORING_REGISTER_IOWQ_MAX_WORKERS io_uring_register command,
so they are to be exposed in UAPI.

Complements: 2e480058ddc21ec5 ("io-wq: provide a way to limit max number of workers")
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
---
v2:
 - IO_WQ_ACCT_NR is no longer exposed directly in UAPI, per Jens Axboe's
   suggestion.

v1: https://lore.kernel.org/lkml/20210912122411.GA27679@asgard.redhat.com/
---
 fs/io-wq.c                    | 5 ++---
 include/uapi/linux/io_uring.h | 8 ++++++++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 6c55362..eb5162d 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -14,6 +14,7 @@
 #include <linux/rculist_nulls.h>
 #include <linux/cpu.h>
 #include <linux/tracehook.h>
+#include <uapi/linux/io_uring.h>
 
 #include "io-wq.h"
 
@@ -78,9 +79,7 @@ struct io_wqe_acct {
 };
 
 enum {
-	IO_WQ_ACCT_BOUND,
-	IO_WQ_ACCT_UNBOUND,
-	IO_WQ_ACCT_NR,
+	IO_WQ_ACCT_NR = __IO_WQ_ACCT_MAX
 };
 
 /*
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 59ef351..dae1841 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -324,6 +324,14 @@ enum {
 	IORING_REGISTER_LAST
 };
 
+/* io-wq worker limit categories */
+enum {
+	IO_WQ_ACCT_BOUND,
+	IO_WQ_ACCT_UNBOUND,
+
+	__IO_WQ_ACCT_MAX /* Non-UAPI */
+};
+
 /* deprecated, see struct io_uring_rsrc_update */
 struct io_uring_files_update {
 	__u32 offset;
-- 
2.1.4