diff options
Diffstat (limited to 'io_uring/io_uring.c')
| -rw-r--r-- | io_uring/io_uring.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index f359e24b46c3..62d1f55fde55 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -609,7 +609,7 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force) io_cq_lock(ctx); while (!list_empty(&ctx->cq_overflow_list)) { - struct io_uring_cqe *cqe = io_get_cqe(ctx); + struct io_uring_cqe *cqe = io_get_cqe_overflow(ctx, true); struct io_overflow_cqe *ocqe; if (!cqe && !force) @@ -736,12 +736,19 @@ bool io_req_cqe_overflow(struct io_kiocb *req) * control dependency is enough as we're using WRITE_ONCE to * fill the cq entry */ -struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx) +struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx, bool overflow) { struct io_rings *rings = ctx->rings; unsigned int off = ctx->cached_cq_tail & (ctx->cq_entries - 1); unsigned int free, queued, len; + /* + * Posting into the CQ when there are pending overflowed CQEs may break + * ordering guarantees, which will affect links, F_MORE users and more. + * Force overflow the completion. + */ + if (!overflow && (ctx->check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))) + return NULL; /* userspace may cheat modifying the tail, be safe and do min */ queued = min(__io_cqring_events(ctx), ctx->cq_entries); @@ -2394,6 +2401,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, if (ret < 0) return ret; io_cqring_overflow_flush(ctx); + if (io_cqring_events(ctx) >= min_events) return 0; } while (ret > 0); |