Commit 1143be17 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/rw: don't mask in f_iocb_flags 



A previous commit changed overwriting kiocb->ki_flags with
->f_iocb_flags with masking it in. This breaks for retry situations,
where we don't necessarily want to retain previously set flags, like
IOCB_NOWAIT.

The use case needs IOCB_HAS_METADATA to be persistent, but the change
makes all flags persistent, which is an issue. Add a request flag to
track whether the request has metadata or not, as that is persistent
across issues.

Fixes: 59a7d12a ("io_uring: introduce attributes for read/write and PI support")
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ce946408

include/linux/io_uring_types.h

+3 −0
Original line number Diff line number Diff line
@@ -480,6 +480,7 @@ enum { 
	REQ_F_BL_NO_RECYCLE_BIT,

	REQ_F_BUFFERS_COMMIT_BIT,

	REQ_F_BUF_NODE_BIT,

	REQ_F_HAS_METADATA_BIT,



	/* not a real bit, just to check we're not overflowing the space */

	__REQ_F_LAST_BIT,
@@ -560,6 +561,8 @@ enum { 
	REQ_F_BUFFERS_COMMIT	= IO_REQ_FLAG(REQ_F_BUFFERS_COMMIT_BIT),

	/* buf node is valid */

	REQ_F_BUF_NODE		= IO_REQ_FLAG(REQ_F_BUF_NODE_BIT),

	/* request has read/write metadata assigned */

	REQ_F_HAS_METADATA	= IO_REQ_FLAG(REQ_F_HAS_METADATA_BIT),

};



typedef void (*io_req_tw_func_t)(struct io_kiocb *req, struct io_tw_state *ts);

io_uring/rw.c

+9 −9
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ static int io_prep_rw_pi(struct io_kiocb *req, struct io_rw *rw, int ddir, 
			  pi_attr.len, &io->meta.iter);

	if (unlikely(ret < 0))

		return ret;

	rw->kiocb.ki_flags |= IOCB_HAS_METADATA;

	req->flags |= REQ_F_HAS_METADATA;

	io_meta_save_state(io);

	return ret;

}
@@ -787,18 +787,17 @@ static bool io_rw_should_retry(struct io_kiocb *req) 
	struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);

	struct kiocb *kiocb = &rw->kiocb;



	/* never retry for NOWAIT, we just complete with -EAGAIN */

	if (req->flags & REQ_F_NOWAIT)

	/*

	 * Never retry for NOWAIT or a request with metadata, we just complete

	 * with -EAGAIN.

	 */

	if (req->flags & (REQ_F_NOWAIT | REQ_F_HAS_METADATA))

		return false;



	/* Only for buffered IO */

	if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))

		return false;



	/* never retry for meta io */

	if (kiocb->ki_flags & IOCB_HAS_METADATA)

		return false;



	/*

	 * just use poll if we can, and don't attempt if the fs doesn't

	 * support callback based unlocks
@@ -849,7 +848,7 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type) 
	if (!(req->flags & REQ_F_FIXED_FILE))

		req->flags |= io_file_get_flags(file);



	kiocb->ki_flags |= file->f_iocb_flags;

	kiocb->ki_flags = file->f_iocb_flags;

	ret = kiocb_set_rw_flags(kiocb, rw->flags, rw_type);

	if (unlikely(ret))

		return ret;
@@ -883,7 +882,7 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type) 
		kiocb->ki_complete = io_complete_rw;

	}



	if (kiocb->ki_flags & IOCB_HAS_METADATA) {

	if (req->flags & REQ_F_HAS_METADATA) {

		struct io_async_rw *io = req->async_data;



		/*
@@ -892,6 +891,7 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type) 
		 */

		if (!(req->file->f_flags & O_DIRECT))

			return -EOPNOTSUPP;

		kiocb->ki_flags |= IOCB_HAS_METADATA;

		kiocb->private = &io->meta;

	}