linux-kernel - [RFC v2 08/11] io_uring/rsrc: add imu flags

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Message-ID: <25a416c7f2673d39ae31bfe8bddcfc7eef710e71.1763725388.git.asml.silence@gmail.com>
Date: Sun, 23 Nov 2025 22:51:28 +0000
From: Pavel Begunkov <asml.silence@...il.com>
To: linux-block@...r.kernel.org,
	io-uring@...r.kernel.org
Cc: Vishal Verma <vishal1.verma@...el.com>,
	tushar.gohad@...el.com,
	Keith Busch <kbusch@...nel.org>,
	Jens Axboe <axboe@...nel.dk>,
	Christoph Hellwig <hch@....de>,
	Sagi Grimberg <sagi@...mberg.me>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Christian Brauner <brauner@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Sumit Semwal <sumit.semwal@...aro.org>,
	Christian König <christian.koenig@....com>,
	Pavel Begunkov <asml.silence@...il.com>,
	linux-kernel@...r.kernel.org,
	linux-nvme@...ts.infradead.org,
	linux-fsdevel@...r.kernel.org,
	linux-media@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	linaro-mm-sig@...ts.linaro.org
Subject: [RFC v2 08/11] io_uring/rsrc: add imu flags

Replace is_kbuf with a flags field in io_mapped_ubuf. There will be new
flags shortly, and bit fields are often not as convenient to work with.

Signed-off-by: Pavel Begunkov <asml.silence@...il.com>
---
 io_uring/rsrc.c | 12 ++++++------
 io_uring/rsrc.h |  6 +++++-
 io_uring/rw.c   |  3 ++-
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 3765a50329a8..21548942e80d 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -828,7 +828,7 @@ static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx,
 	imu->folio_shift = PAGE_SHIFT;
 	imu->release = io_release_ubuf;
 	imu->priv = imu;
-	imu->is_kbuf = false;
+	imu->flags = 0;
 	imu->dir = IO_IMU_DEST | IO_IMU_SOURCE;
 	if (coalesced)
 		imu->folio_shift = data.folio_shift;
@@ -985,7 +985,7 @@ int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
 	refcount_set(&imu->refs, 1);
 	imu->release = release;
 	imu->priv = rq;
-	imu->is_kbuf = true;
+	imu->flags = IO_IMU_F_KBUF;
 	imu->dir = 1 << rq_data_dir(rq);
 
 	rq_for_each_bvec(bv, rq, rq_iter)
@@ -1020,7 +1020,7 @@ int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, unsigned int index,
 		ret = -EINVAL;
 		goto unlock;
 	}
-	if (!node->buf->is_kbuf) {
+	if (!(node->buf->flags & IO_IMU_F_KBUF)) {
 		ret = -EBUSY;
 		goto unlock;
 	}
@@ -1086,7 +1086,7 @@ static int io_import_fixed(int ddir, struct iov_iter *iter,
 
 	offset = buf_addr - imu->ubuf;
 
-	if (imu->is_kbuf)
+	if (imu->flags & IO_IMU_F_KBUF)
 		return io_import_kbuf(ddir, iter, imu, len, offset);
 
 	/*
@@ -1511,7 +1511,7 @@ int io_import_reg_vec(int ddir, struct iov_iter *iter,
 	iovec_off = vec->nr - nr_iovs;
 	iov = vec->iovec + iovec_off;
 
-	if (imu->is_kbuf) {
+	if (imu->flags & IO_IMU_F_KBUF) {
 		int ret = io_kern_bvec_size(iov, nr_iovs, imu, &nr_segs);
 
 		if (unlikely(ret))
@@ -1549,7 +1549,7 @@ int io_import_reg_vec(int ddir, struct iov_iter *iter,
 		req->flags |= REQ_F_NEED_CLEANUP;
 	}
 
-	if (imu->is_kbuf)
+	if (imu->flags & IO_IMU_F_KBUF)
 		return io_vec_fill_kern_bvec(ddir, iter, imu, iov, nr_iovs, vec);
 
 	return io_vec_fill_bvec(ddir, iter, imu, iov, nr_iovs, vec);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index d603f6a47f5e..7c1128a856ec 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -28,6 +28,10 @@ enum {
 	IO_IMU_SOURCE	= 1 << ITER_SOURCE,
 };
 
+enum {
+	IO_IMU_F_KBUF			= 1,
+};
+
 struct io_mapped_ubuf {
 	u64		ubuf;
 	unsigned int	len;
@@ -37,7 +41,7 @@ struct io_mapped_ubuf {
 	unsigned long	acct_pages;
 	void		(*release)(void *);
 	void		*priv;
-	bool		is_kbuf;
+	u8		flags;
 	u8		dir;
 	struct bio_vec	bvec[] __counted_by(nr_bvecs);
 };
diff --git a/io_uring/rw.c b/io_uring/rw.c
index a7b568c3dfe8..a3eb4e7bf992 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -706,7 +706,8 @@ static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter)
 	if ((kiocb->ki_flags & IOCB_NOWAIT) &&
 	    !(kiocb->ki_filp->f_flags & O_NONBLOCK))
 		return -EAGAIN;
-	if ((req->flags & REQ_F_BUF_NODE) && req->buf_node->buf->is_kbuf)
+	if ((req->flags & REQ_F_BUF_NODE) &&
+	    (req->buf_node->buf->flags & IO_IMU_F_KBUF))
 		return -EFAULT;
 
 	ppos = io_kiocb_ppos(kiocb);
-- 
2.52.0