|author||Dylan Yudaken <firstname.lastname@example.org>||2022-07-21 06:13:25 -0700|
|committer||Jens Axboe <email@example.com>||2022-07-21 08:31:31 -0600|
io_uring: do not recycle buffer in READVio_uring-5.19-2022-07-21io_uring-5.19
READV cannot recycle buffers as it would lose some of the data required to reimport that buffer. Reported-by: Ammar Faizi <firstname.lastname@example.org> Fixes: b66e65f41426 ("io_uring: never call io_buffer_select() for a buffer re-select") Signed-off-by: Dylan Yudaken <email@example.com> Link: https://firstname.lastname@example.org Signed-off-by: Jens Axboe <email@example.com>
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 2b7bb62c7805..e8e769be9ed0 100644
@@ -1738,6 +1738,14 @@ static void io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
+ * READV uses fields in `struct io_rw` (len/addr) to stash the selected
+ * buffer data. However if that buffer is recycled the original request
+ * data stored in addr is lost. Therefore forbid recycling for now.
+ if (req->opcode == IORING_OP_READV)
* We don't need to recycle for REQ_F_BUFFER_RING, we can just clear
* the flag and hence ensure that bl->head doesn't get incremented.
* If the tail has already been incremented, hang on to it.