[PATCH 5.14 29/30] io_uring: kill fasync

Greg Kroah-Hartman
2021-10-14T15:06:08Z

From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit 3f008385d46d3cea4a097d2615cd485f2184ba26 ]

We have never supported fasync properly, it would only fire when there
is something polling io_uring making it useless. The original support came
in through the initial io_uring merge for 5.1. Since it's broken and
nobody has reported it, get rid of the fasync bits.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2f7ca3d344d406d34fa6713824198915c41cea86.1633080236.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/io_uring.c | 17 ++---------------
1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 675216f7022d..2f79586c1a7c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -419,7 +419,6 @@ struct io_ring_ctx {
struct wait_queue_head cq_wait;
unsigned cq_extra;
atomic_t cq_timeouts;
- struct fasync_struct *cq_fasync;
unsigned cq_last_tm_flush;
} ____cacheline_aligned_in_smp;

@@ -1448,10 +1447,8 @@ static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
wake_up(&ctx->sq_data->wait);
if (io_should_trigger_evfd(ctx))
eventfd_signal(ctx->cq_ev_fd, 1);
- if (waitqueue_active(&ctx->poll_wait)) {
+ if (waitqueue_active(&ctx->poll_wait))
wake_up_interruptible(&ctx->poll_wait);
- kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
- }
}

static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
@@ -1465,10 +1462,8 @@ static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
}
if (io_should_trigger_evfd(ctx))
eventfd_signal(ctx->cq_ev_fd, 1);
- if (waitqueue_active(&ctx->poll_wait)) {
+ if (waitqueue_active(&ctx->poll_wait))
wake_up_interruptible(&ctx->poll_wait);
- kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
- }
}

/* Returns true if there are no backlogged entries after the flush */
@@ -8779,13 +8774,6 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait)
return mask;
}

-static int io_uring_fasync(int fd, struct file *file, int on)
-{
- struct io_ring_ctx *ctx = file->private_data;
-
- return fasync_helper(fd, file, on, &ctx->cq_fasync);
-}
-
static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
{
const struct cred *creds;
@@ -9571,7 +9559,6 @@ static const struct file_operations io_uring_fops = {
.mmap_capabilities = io_uring_nommu_mmap_capabilities,
#endif
.poll = io_uring_poll,
- .fasync = io_uring_fasync,
#ifdef CONFIG_PROC_FS
.show_fdinfo = io_uring_show_fdinfo,
#endif
--
2.33.0