On 2019/10/9 9:19, Jackie Liu wrote:
__io_get_deferred_req is used to get all defer lists, including defer_list
and timeout_list, but io_sequence_defer should be only cares about the sequence.
Signed-off-by: Jackie Liu <liuyun01@xxxxxxxxxx>
---
fs/io_uring.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 8a0381f1a43b..8ec2443eb019 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -418,9 +418,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
static inline bool io_sequence_defer(struct io_ring_ctx *ctx,
struct io_kiocb *req)
{
- /* timeout requests always honor sequence */
- if (!(req->flags & REQ_F_TIMEOUT) &&
- (req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN)
+ if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN)
return false;
return req->sequence != ctx->cached_cq_tail + ctx->rings->sq_dropped;
@@ -435,12 +433,11 @@ static struct io_kiocb *__io_get_deferred_req(struct io_ring_ctx *ctx,
return NULL;
req = list_first_entry(list, struct io_kiocb, list);
- if (!io_sequence_defer(ctx, req)) {
- list_del_init(&req->list);
- return req;
- }
+ if (!(req->flags & REQ_F_TIMEOUT) && io_sequence_defer(ctx, req))
+ return NULL;
Hi,
For timeout req, we should also compare the sequence to determine to
return NULL or the req. But now we will return req directly. Actually,
no need to compare req->flags with REQ_F_TIMEOUT.
Another problem, before this change, a timeout req can also drain the
sqe(io_queue_sqe->io_req_defer and add to refer list), i am not sure is
it a right or wrong logic, but your patch fix that.
Thanks,
Kun.
- return NULL;
+ list_del_init(&req->list);
+ return req;
}
static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)
