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| author | Pavel Begunkov <asml.silence@gmail.com> | 2020-11-06 01:31:37 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-11-06 01:36:40 +0300 |
| commit | 9a472ef7a3690ac0b77ebfb04c88fa795de2adea (patch) | |
| tree | 52601c2f161cccd8057364f971a070a03211d023 | |
| parent | 6b47ab81c9a9b56a94882815e9949d40e4207c92 (diff) | |
| download | linux-9a472ef7a3690ac0b77ebfb04c88fa795de2adea.tar.xz | |
io_uring: fix link lookup racing with link timeout
We can't just go over linked requests because it may race with linked
timeouts. Take ctx->completion_lock in that case.
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io_uring.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 29f1417690d5..8018c7076b25 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8470,7 +8470,21 @@ static bool io_timeout_remove_link(struct io_ring_ctx *ctx, static bool io_cancel_link_cb(struct io_wq_work *work, void *data) { - return io_match_link(container_of(work, struct io_kiocb, work), data); + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + bool ret; + + if (req->flags & REQ_F_LINK_TIMEOUT) { + unsigned long flags; + struct io_ring_ctx *ctx = req->ctx; + + /* protect against races with linked timeouts */ + spin_lock_irqsave(&ctx->completion_lock, flags); + ret = io_match_link(req, data); + spin_unlock_irqrestore(&ctx->completion_lock, flags); + } else { + ret = io_match_link(req, data); + } + return ret; } static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req) |