From 7d7230652e7c788ef908536fd79f4cca077f269f Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 12 Nov 2019 22:31:31 -0700 Subject: io_wq: add get/put_work handlers to io_wq_create() For cancellation, we need to ensure that the work item stays valid for as long as ->cur_work is valid. Right now we can't safely dereference the work item even under the wqe->lock, because while the ->cur_work pointer will remain valid, the work could be completing and be freed in parallel. Only invoke ->get/put_work() on items we know that the caller queued themselves. Add IO_WQ_WORK_INTERNAL for io-wq to use, which is needed when we're queueing a flush item, for instance. Signed-off-by: Jens Axboe --- fs/io-wq.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/io-wq.h') diff --git a/fs/io-wq.h b/fs/io-wq.h index cc50754d028c..4b29f922f80c 100644 --- a/fs/io-wq.h +++ b/fs/io-wq.h @@ -10,6 +10,7 @@ enum { IO_WQ_WORK_NEEDS_USER = 8, IO_WQ_WORK_NEEDS_FILES = 16, IO_WQ_WORK_UNBOUND = 32, + IO_WQ_WORK_INTERNAL = 64, IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */ }; @@ -34,8 +35,12 @@ struct io_wq_work { (work)->files = NULL; \ } while (0) \ +typedef void (get_work_fn)(struct io_wq_work *); +typedef void (put_work_fn)(struct io_wq_work *); + struct io_wq *io_wq_create(unsigned bounded, struct mm_struct *mm, - struct user_struct *user); + struct user_struct *user, + get_work_fn *get_work, put_work_fn *put_work); void io_wq_destroy(struct io_wq *wq); void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work); -- cgit