[PATCH 2/2] eventfd: simplify eventfd_signal_mask()

From: Christian Brauner
Date: Thu Jul 13 2023 - 06:07:36 EST


The eventfd_signal_mask() helper was introduced for io_uring and similar
to eventfd_signal() it always passed 1 for @n. So don't bother with that
argument at all.

Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
drivers/gpu/drm/i915/gvt/interrupt.c | 2 +-
fs/eventfd.c | 9 +++++----
include/linux/eventfd.h | 9 ++++-----
io_uring/io_uring.c | 4 ++--
4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/interrupt.c b/drivers/gpu/drm/i915/gvt/interrupt.c
index 3d9e09c2add4..31aff6f733d4 100644
--- a/drivers/gpu/drm/i915/gvt/interrupt.c
+++ b/drivers/gpu/drm/i915/gvt/interrupt.c
@@ -435,7 +435,7 @@ static int inject_virtual_interrupt(struct intel_vgpu *vgpu)
*/
if (!test_bit(INTEL_VGPU_STATUS_ATTACHED, vgpu->status))
return -ESRCH;
- if (vgpu->msi_trigger && eventfd_signal(vgpu->msi_trigger) != 1)
+ if (vgpu->msi_trigger && !eventfd_signal(vgpu->msi_trigger))
return -EFAULT;
return 0;
}
diff --git a/fs/eventfd.c b/fs/eventfd.c
index dc9e01053235..077be5da72bd 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -43,9 +43,10 @@ struct eventfd_ctx {
int id;
};

-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask)
+bool eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
{
unsigned long flags;
+ __u64 n = 1;

/*
* Deadlock or stack overflow issues can happen if we recurse here
@@ -68,7 +69,7 @@ __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask)
current->in_eventfd = 0;
spin_unlock_irqrestore(&ctx->wqh.lock, flags);

- return n;
+ return n == 1;
}

/**
@@ -82,9 +83,9 @@ __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask)
*
* Returns the amount by which the counter was incremented.
*/
-__u64 eventfd_signal(struct eventfd_ctx *ctx)
+bool eventfd_signal(struct eventfd_ctx *ctx)
{
- return eventfd_signal_mask(ctx, 1, 0);
+ return eventfd_signal_mask(ctx, 0);
}
EXPORT_SYMBOL_GPL(eventfd_signal);

diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h
index 562089431551..0155ee25f7c8 100644
--- a/include/linux/eventfd.h
+++ b/include/linux/eventfd.h
@@ -35,8 +35,8 @@ void eventfd_ctx_put(struct eventfd_ctx *ctx);
struct file *eventfd_fget(int fd);
struct eventfd_ctx *eventfd_ctx_fdget(int fd);
struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);
-__u64 eventfd_signal(struct eventfd_ctx *ctx);
-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask);
+bool eventfd_signal(struct eventfd_ctx *ctx);
+bool eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait,
__u64 *cnt);
void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt);
@@ -58,13 +58,12 @@ static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
return ERR_PTR(-ENOSYS);
}

-static inline int eventfd_signal(struct eventfd_ctx *ctx)
+static inline bool eventfd_signal(struct eventfd_ctx *ctx)
{
return -ENOSYS;
}

-static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n,
- unsigned mask)
+static inline bool eventfd_signal_mask(struct eventfd_ctx *ctx, unsigned mask)
{
return -ENOSYS;
}
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index e8096d502a7c..a9359ef73935 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -537,7 +537,7 @@ static void io_eventfd_ops(struct rcu_head *rcu)
int ops = atomic_xchg(&ev_fd->ops, 0);

if (ops & BIT(IO_EVENTFD_OP_SIGNAL_BIT))
- eventfd_signal_mask(ev_fd->cq_ev_fd, 1, EPOLL_URING_WAKE);
+ eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE);

/* IO_EVENTFD_OP_FREE_BIT may not be set here depending on callback
* ordering in a race but if references are 0 we know we have to free
@@ -573,7 +573,7 @@ static void io_eventfd_signal(struct io_ring_ctx *ctx)
goto out;

if (likely(eventfd_signal_allowed())) {
- eventfd_signal_mask(ev_fd->cq_ev_fd, 1, EPOLL_URING_WAKE);
+ eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE);
} else {
atomic_inc(&ev_fd->refs);
if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops))

--
2.34.1