From c1ca757bd6f4632c510714631ddcc2d13030fe1e Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 25 Dec 2019 22:18:28 -0700
Subject: [PATCH] io_uring: add IORING_OP_MADVISE
This adds support for doing madvise(2) through io_uring. We assume that
any operation can block, and hence punt everything async. This could be
improved, but hard to make bullet proof. The async punt ensures it's
safe.
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 59 +++++++++++++++++++++++++++++++++++
include/uapi/linux/io_uring.h | 1 +
2 files changed, 60 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9ca12b900b425..17a199c99c7cc 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -408,6 +408,13 @@ struct io_fadvise {
u32 advice;
};
+struct io_madvise {
+ struct file *file;
+ u64 addr;
+ u32 len;
+ u32 advice;
+};
+
struct io_async_connect {
struct sockaddr_storage address;
};
@@ -461,6 +468,7 @@ struct io_kiocb {
struct io_close close;
struct io_files_update files_update;
struct io_fadvise fadvise;
+ struct io_madvise madvise;
};
struct io_async_ctx *io;
@@ -680,6 +688,10 @@ static const struct io_op_def io_op_defs[] = {
/* IORING_OP_FADVISE */
.needs_file = 1,
},
+ {
+ /* IORING_OP_MADVISE */
+ .needs_mm = 1,
+ },
};
static void io_wq_submit_work(struct io_wq_work **workptr);
@@ -2449,6 +2461,42 @@ static int io_openat(struct io_kiocb *req, struct io_kiocb **nxt,
return 0;
}
+static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
+ if (sqe->ioprio || sqe->buf_index || sqe->off)
+ return -EINVAL;
+
+ req->madvise.addr = READ_ONCE(sqe->addr);
+ req->madvise.len = READ_ONCE(sqe->len);
+ req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_madvise(struct io_kiocb *req, struct io_kiocb **nxt,
+ bool force_nonblock)
+{
+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
+ struct io_madvise *ma = &req->madvise;
+ int ret;
+
+ if (force_nonblock)
+ return -EAGAIN;
+
+ ret = do_madvise(ma->addr, ma->len, ma->advice);
+ if (ret < 0)
+ req_set_fail_links(req);
+ io_cqring_add_event(req, ret);
+ io_put_req_find_next(req, nxt);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
if (sqe->ioprio || sqe->buf_index || sqe->addr)
@@ -3766,6 +3814,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
case IORING_OP_FADVISE:
ret = io_fadvise_prep(req, sqe);
break;
+ case IORING_OP_MADVISE:
+ ret = io_madvise_prep(req, sqe);
+ break;
default:
printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
req->opcode);
@@ -3970,6 +4021,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
}
ret = io_fadvise(req, nxt, force_nonblock);
break;
+ case IORING_OP_MADVISE:
+ if (sqe) {
+ ret = io_madvise_prep(req, sqe);
+ if (ret)
+ break;
+ }
+ ret = io_madvise(req, nxt, force_nonblock);
+ break;
default:
ret = -EINVAL;
break;
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index f86d1c7760787..8ad3cece54408 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -88,6 +88,7 @@ enum {
IORING_OP_READ,
IORING_OP_WRITE,
IORING_OP_FADVISE,
+ IORING_OP_MADVISE,
/* this goes last, obviously */
IORING_OP_LAST,
--
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