The sequence number of the timeout req (req->sequence) indicate the
expected completion request. Because of each timeout req consume a
sequence number, so the sequence of each timeout req on the timeout
list shouldn't be the same. But now, we may get the same number (also
incorrect) if we insert a new entry before the last one, such as submit
such two timeout reqs on a new ring instance below.
req->sequence
req_1 (count = 2): 2
req_2 (count = 1): 2
Then, if we submit a nop req, req_2 will still timeout even the nop req
finished. This patch fix this problem by adjust the sequence number of
each reordered reqs when inserting a new entry.
Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx>
---
fs/io_uring.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index e7a856392a23..4a395a7a36c1 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1912,6 +1912,7 @@ static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe)
struct io_ring_ctx *ctx = req->ctx;
struct list_head *entry;
struct timespec64 ts;
+ unsigned span = 0;
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
@@ -1960,9 +1961,17 @@ static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe)
if (ctx->cached_sq_head < nxt_sq_head)
tmp += UINT_MAX;
- if (tmp >= tmp_nxt)
+ if (tmp > tmp_nxt)
break;
+
+ /*
+ * Sequence of reqs after the insert one and itself should
+ * be adjusted because each timeout req consumes a slot.
+ */
+ span++;
+ nxt->sequence++;
}
+ req->sequence -= span;
list_add(&req->list, entry);
spin_unlock_irq(&ctx->completion_lock);
--
2.17.2
