[PATCH 4/6] io_uring/cancel: add generic cancel helper

Jens Axboe
2025-02-05T20:26:50Z

Any opcode that is cancelable ends up defining its own cancel helper
for finding and canceling a specific request. Add a generic helper that
can be used for this purpose.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
io_uring/cancel.c | 21 +++++++++++++++++++++
io_uring/cancel.h | 4 ++++
2 files changed, 25 insertions(+)

diff --git a/io_uring/cancel.c b/io_uring/cancel.c
index 0565dc0d7611..4ff3771131c2 100644
--- a/io_uring/cancel.c
+++ b/io_uring/cancel.c
@@ -361,3 +361,24 @@ bool io_cancel_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx,

return found;
}
+
+int io_cancel_remove(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
+ unsigned int issue_flags, struct hlist_head *list,
+ bool (*cancel)(struct io_kiocb *))
+{
+ struct hlist_node *tmp;
+ struct io_kiocb *req;
+ int nr = 0;
+
+ io_ring_submit_lock(ctx, issue_flags);
+ hlist_for_each_entry_safe(req, tmp, list, hash_node) {
+ if (!io_cancel_req_match(req, cd))
+ continue;
+ if (cancel(req))
+ nr++;
+ if (!(cd->flags & IORING_ASYNC_CANCEL_ALL))
+ break;
+ }
+ io_ring_submit_unlock(ctx, issue_flags);
+ return nr ?: -ENOENT;
+}
diff --git a/io_uring/cancel.h b/io_uring/cancel.h
index 80734a0a2b26..43e9bb74e9d1 100644
--- a/io_uring/cancel.h
+++ b/io_uring/cancel.h
@@ -28,6 +28,10 @@ bool io_cancel_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx,
struct hlist_head *list, bool cancel_all,
bool (*cancel)(struct io_kiocb *));

+int io_cancel_remove(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
+ unsigned int issue_flags, struct hlist_head *list,
+ bool (*cancel)(struct io_kiocb *));
+
static inline bool io_cancel_match_sequence(struct io_kiocb *req, int sequence)
{
if (req->cancel_seq_set && sequence == req->work.cancel_seq)
--
2.47.2