Re: [PATCH 1/6] io_uring/cancel: add generic remove_all helper

Jens Axboe
2025-02-06T14:07:43Z

On 2/6/25 5:46 AM, lizetao wrote:
>
>
>> -----Original Message-----
>> From: Jens Axboe <axboe@kernel.dk>
>> Sent: Thursday, February 6, 2025 4:26 AM
>> To: io-uring@vger.kernel.org
>> Cc: Jens Axboe <axboe@kernel.dk>
>> Subject: [PATCH 1/6] io_uring/cancel: add generic remove_all helper
>>
>> Any opcode that is cancelable ends up defining its own remove all helper, which
>> iterates the pending list and cancels matches. Add a generic helper for it, which
>> can be used by them.
>>
>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>> ---
>> io_uring/cancel.c | 20 ++++++++++++++++++++ io_uring/cancel.h | 4 ++++
>> 2 files changed, 24 insertions(+)
>>
>> diff --git a/io_uring/cancel.c b/io_uring/cancel.c index
>> 484193567839..0565dc0d7611 100644
>> --- a/io_uring/cancel.c
>> +++ b/io_uring/cancel.c
>> @@ -341,3 +341,23 @@ int io_sync_cancel(struct io_ring_ctx *ctx, void __user
>> *arg)
>> fput(file);
>> return ret;
>> }
>> +
>> +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 *)) {
>> + struct hlist_node *tmp;
>> + struct io_kiocb *req;
>> + bool found = false;
>> +
>> + lockdep_assert_held(&ctx->uring_lock);
>> +
>> + hlist_for_each_entry_safe(req, tmp, list, hash_node) {
>> + if (!io_match_task_safe(req, tctx, cancel_all))
>> + continue;
>
> Should call hlist_del_init(&req->hash_node) here, just like the
> original code logic.

Indeed, good catch! I'll make the change.

--
Jens Axboe