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| author | Pavel Begunkov <asml.silence@gmail.com> | 2024-11-04 16:12:04 +0000 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2024-11-11 14:34:21 +0100 |
| commit | df3b8ca604f224eb4cd51669416ad4d607682273 (patch) | |
| tree | 45a904dc05cc644fe83b89d1be23b5ded5534bd2 | |
| parent | 1cc86aeadafd667c381c588a84fdef2d5e8093a5 (diff) | |
| download | lwn-df3b8ca604f224eb4cd51669416ad4d607682273.tar.gz lwn-df3b8ca604f224eb4cd51669416ad4d607682273.zip | |
io_uring/cmd: let cmds to know about dying task
When the taks that submitted a request is dying, a task work for that
request might get run by a kernel thread or even worse by a half
dismantled task. We can't just cancel the task work without running the
callback as the cmd might need to do some clean up, so pass a flag
instead. If set, it's not safe to access any task resources and the
callback is expected to cancel the cmd ASAP.
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | include/linux/io_uring_types.h | 1 | ||||
| -rw-r--r-- | io_uring/uring_cmd.c | 6 |
2 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index 4b9ba523978d..2ee5dc105b58 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -37,6 +37,7 @@ enum io_uring_cmd_flags { /* set when uring wants to cancel a previously issued command */ IO_URING_F_CANCEL = (1 << 11), IO_URING_F_COMPAT = (1 << 12), + IO_URING_F_TASK_DEAD = (1 << 13), }; struct io_wq_work_node { diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 39c3c816ec78..e2e8485932d6 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -119,9 +119,13 @@ EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable); static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts) { struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); + unsigned int flags = IO_URING_F_COMPLETE_DEFER; + + if (current->flags & (PF_EXITING | PF_KTHREAD)) + flags |= IO_URING_F_TASK_DEAD; /* task_work executor checks the deffered list completion */ - ioucmd->task_work_cb(ioucmd, IO_URING_F_COMPLETE_DEFER); + ioucmd->task_work_cb(ioucmd, flags); } void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd, |