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| author | Jackie Liu <liuyun01@kylinos.cn> | 2019-08-14 17:35:22 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-08-15 11:21:39 -0600 |
| commit | a982eeb09b6030e567b8b815277c8c9197168040 (patch) | |
| tree | 1086aec4590f89b11422f491c0887e38cb5864e0 | |
| parent | 7b6620d7db566a46f49b4b9deab9fa061fd4b59b (diff) | |
| download | linux-a982eeb09b6030e567b8b815277c8c9197168040.tar.bz2 | |
io_uring: fix an issue when IOSQE_IO_LINK is inserted into defer list
This patch may fix two issues:
First, when IOSQE_IO_DRAIN set, the next IOs need to be inserted into
defer list to delay execution, but link io will be actively scheduled to
run by calling io_queue_sqe.
Second, when multiple LINK_IOs are inserted together with defer_list,
the LINK_IO is no longer keep order.
|-------------|
| LINK_IO | ----> insert to defer_list -----------
|-------------| |
| LINK_IO | ----> insert to defer_list ----------|
|-------------| |
| LINK_IO | ----> insert to defer_list ----------|
|-------------| |
| NORMAL_IO | ----> insert to defer_list ----------|
|-------------| |
|
queue_work at same time <-----|
Fixes: 9e645e1105c ("io_uring: add support for sqe links")
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io_uring.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index aa25b5bbd4ae..24bbe3cb7ad4 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2023,6 +2023,15 @@ static int io_queue_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, { int ret; + ret = io_req_defer(ctx, req, s->sqe); + if (ret) { + if (ret != -EIOCBQUEUED) { + io_free_req(req); + io_cqring_add_event(ctx, s->sqe->user_data, ret); + } + return 0; + } + ret = __io_submit_sqe(ctx, req, s, true); if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) { struct io_uring_sqe *sqe_copy; @@ -2095,13 +2104,6 @@ err: return; } - ret = io_req_defer(ctx, req, s->sqe); - if (ret) { - if (ret != -EIOCBQUEUED) - goto err_req; - return; - } - /* * If we already have a head request, queue this one for async * submittal once the head completes. If we don't have a head but |