[PATCH 1/7] io_uring/uring_cmd: only cancel requests of the given task

[Jens Axboe <axboe@kernel.dk>]

io_uring_try_cancel_uring_cmd() ignores the task it is asked to cancel
on behalf of as soon as cancel_all is true, and cancels every cancelable
command on the ring instead. That differs from how other requests are
matched, where a valid task always restricts matching to that task's
requests and cancel_all simply lifts the REQ_F_INFLIGHT restriction.

So far the only caller passing both a task and cancel_all is exec, where
tearing down another task's commands on a shared ring is somewhat
impolite. The exit path is about to do the same for every exiting
process though, so bring it in line. Match on the task if one is given,
and cancel everything only for ring teardown, which passes NULL. This
leaves cancel_all as useless, hence drop it.

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

diff --git a/io_uring/cancel.c b/io_uring/cancel.c
index 7d7820eab878..5ee94246c43c 100644
--- a/io_uring/cancel.c
+++ b/io_uring/cancel.c
@@ -560,7 +560,7 @@ __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
 	ret |= io_poll_remove_all(ctx, tctx, cancel_all);
 	ret |= io_waitid_remove_all(ctx, tctx, cancel_all);
 	ret |= io_futex_remove_all(ctx, tctx, cancel_all);
-	ret |= io_uring_try_cancel_uring_cmd(ctx, tctx, cancel_all);
+	ret |= io_uring_try_cancel_uring_cmd(ctx, tctx);
 	ret |= io_kill_timeouts(ctx, tctx, cancel_all);
 	mutex_unlock(&ctx->uring_lock);
 	if (tctx)
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 726a659f38c3..28a87480626c 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -49,7 +49,7 @@ void io_uring_cmd_cleanup(struct io_kiocb *req)
 }
 
 bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
-				   struct io_uring_task *tctx, bool cancel_all)
+				   struct io_uring_task *tctx)
 {
 	struct hlist_node *tmp;
 	struct io_kiocb *req;
@@ -63,7 +63,7 @@ bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
 				struct io_uring_cmd);
 		struct file *file = req->file;
 
-		if (!cancel_all && req->tctx != tctx)
+		if (tctx && req->tctx != tctx)
 			continue;
 
 		if (cmd->flags & IORING_URING_CMD_CANCELABLE) {
diff --git a/io_uring/uring_cmd.h b/io_uring/uring_cmd.h
index 041aef8a8aa3..a5cb3f2ee1c5 100644
--- a/io_uring/uring_cmd.h
+++ b/io_uring/uring_cmd.h
@@ -14,7 +14,7 @@ void io_uring_cmd_sqe_copy(struct io_kiocb *req);
 void io_uring_cmd_cleanup(struct io_kiocb *req);
 
 bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
-				   struct io_uring_task *tctx, bool cancel_all);
+				   struct io_uring_task *tctx);
 
 bool io_uring_cmd_post_mshot_cqe32(struct io_uring_cmd *cmd,
 				   unsigned int issue_flags,
-- 
2.55.0