Commit 2ec33a6c authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/rw: ensure kiocb_end_write() is always called 



A previous commit moved the notifications and end-write handling, but
it is now missing a few spots where we also want to call both of those.
Without that, we can potentially be missing file notifications, and
more importantly, have an imbalance in the super_block writers sem
accounting.

Fixes: b000145e ("io_uring/rw: defer fsnotify calls to task context")
Reported-by: default avatarDave Chinner <david@fromorbit.com>
Link: https://lore.kernel.org/all/20221010050319.GC2703033@dread.disaster.area/


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 00927931

io_uring/rw.c

+29 −9
Original line number Diff line number Diff line
@@ -234,11 +234,34 @@ static void kiocb_end_write(struct io_kiocb *req) 
	}

}



/*

 * Trigger the notifications after having done some IO, and finish the write

 * accounting, if any.

 */

static void io_req_io_end(struct io_kiocb *req)

{

	struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);



	WARN_ON(!in_task());



	if (rw->kiocb.ki_flags & IOCB_WRITE) {

		kiocb_end_write(req);

		fsnotify_modify(req->file);

	} else {

		fsnotify_access(req->file);

	}

}



static bool __io_complete_rw_common(struct io_kiocb *req, long res)

{

	if (unlikely(res != req->cqe.res)) {

		if ((res == -EAGAIN || res == -EOPNOTSUPP) &&

		    io_rw_should_reissue(req)) {

			/*

			 * Reissue will start accounting again, finish the

			 * current cycle.

			 */

			io_req_io_end(req);

			req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO;

			return true;

		}
@@ -264,15 +287,7 @@ static inline int io_fixup_rw_res(struct io_kiocb *req, long res) 


static void io_req_rw_complete(struct io_kiocb *req, bool *locked)

{

	struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);



	if (rw->kiocb.ki_flags & IOCB_WRITE) {

		kiocb_end_write(req);

		fsnotify_modify(req->file);

	} else {

		fsnotify_access(req->file);

	}



	io_req_io_end(req);

	io_req_task_complete(req, locked);

}
@@ -317,6 +332,11 @@ static int kiocb_done(struct io_kiocb *req, ssize_t ret, 
		req->file->f_pos = rw->kiocb.ki_pos;

	if (ret >= 0 && (rw->kiocb.ki_complete == io_complete_rw)) {

		if (!__io_complete_rw_common(req, ret)) {

			/*

			 * Safe to call io_end from here as we're inline

			 * from the submission path.

			 */

			io_req_io_end(req);

			io_req_set_res(req, final_ret,

				       io_put_kbuf(req, issue_flags));

			return IOU_OK;