From b4bb1900c12e6a0fe11ff51e1aa6eea19a4ad635 Mon Sep 17 00:00:00 2001
From: Tony Solomonik <tony.solomonik@gmail.com>
Date: Fri, 2 Feb 2024 14:17:24 +0200
Subject: [PATCH] io_uring: add support for ftruncate
Adds support for doing truncate through io_uring, eliminating
the need for applications to roll their own thread pool or offload
mechanism to be able to do non-blocking truncates.
Signed-off-by: Tony Solomonik <tony.solomonik@gmail.com>
Link: https://lore.kernel.org/r/20240202121724.17461-3-tony.solomonik@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/uapi/linux/io_uring.h | 1 +
io_uring/Makefile | 2 +-
io_uring/opdef.c | 10 ++++++++
io_uring/truncate.c | 48 +++++++++++++++++++++++++++++++++++
io_uring/truncate.h | 4 +++
5 files changed, 64 insertions(+), 1 deletion(-)
create mode 100644 io_uring/truncate.c
create mode 100644 io_uring/truncate.h
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 7a673b52827b1..fb812f1b6bb5a 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -255,6 +255,7 @@ enum io_uring_op {
IORING_OP_FUTEX_WAKE,
IORING_OP_FUTEX_WAITV,
IORING_OP_FIXED_FD_INSTALL,
+ IORING_OP_FTRUNCATE,
/* this goes last, obviously */
IORING_OP_LAST,
diff --git a/io_uring/Makefile b/io_uring/Makefile
index 2cdc518254053..42afe4a1ff318 100644
--- a/io_uring/Makefile
+++ b/io_uring/Makefile
@@ -8,6 +8,6 @@ obj-$(CONFIG_IO_URING) += io_uring.o xattr.o nop.o fs.o splice.o \
statx.o net.o msg_ring.o timeout.o \
sqpoll.o fdinfo.o tctx.o poll.o \
cancel.o kbuf.o rsrc.o rw.o opdef.o \
- notif.o waitid.o register.o
+ notif.o waitid.o register.o truncate.o
obj-$(CONFIG_IO_WQ) += io-wq.o
obj-$(CONFIG_FUTEX) += futex.o
diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index b1ee3a9c38072..9c080aadc5a66 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -35,6 +35,7 @@
#include "rw.h"
#include "waitid.h"
#include "futex.h"
+#include "truncate.h"
static int io_no_issue(struct io_kiocb *req, unsigned int issue_flags)
{
@@ -474,6 +475,12 @@ const struct io_issue_def io_issue_defs[] = {
.prep = io_install_fixed_fd_prep,
.issue = io_install_fixed_fd,
},
+ [IORING_OP_FTRUNCATE] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .prep = io_ftruncate_prep,
+ .issue = io_ftruncate,
+ },
};
const struct io_cold_def io_cold_defs[] = {
@@ -712,6 +719,9 @@ const struct io_cold_def io_cold_defs[] = {
[IORING_OP_FIXED_FD_INSTALL] = {
.name = "FIXED_FD_INSTALL",
},
+ [IORING_OP_FTRUNCATE] = {
+ .name = "FTRUNCATE",
+ },
};
const char *io_uring_get_opcode(u8 opcode)
diff --git a/io_uring/truncate.c b/io_uring/truncate.c
new file mode 100644
index 0000000000000..62ee73d34d72b
--- /dev/null
+++ b/io_uring/truncate.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "../fs/internal.h"
+
+#include "io_uring.h"
+#include "truncate.h"
+
+struct io_ftrunc {
+ struct file *file;
+ loff_t len;
+};
+
+int io_ftruncate_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_ftrunc *ft = io_kiocb_to_cmd(req, struct io_ftrunc);
+
+ if (sqe->rw_flags || sqe->addr || sqe->len || sqe->buf_index ||
+ sqe->splice_fd_in || sqe->addr3)
+ return -EINVAL;
+
+ ft->len = READ_ONCE(sqe->off);
+
+ req->flags |= REQ_F_FORCE_ASYNC;
+ return 0;
+}
+
+int io_ftruncate(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ftrunc *ft = io_kiocb_to_cmd(req, struct io_ftrunc);
+ int ret;
+
+ WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
+
+ ret = do_ftruncate(req->file, ft->len, 1);
+
+ io_req_set_res(req, ret, 0);
+ return IOU_OK;
+}
diff --git a/io_uring/truncate.h b/io_uring/truncate.h
new file mode 100644
index 0000000000000..ec088293a4787
--- /dev/null
+++ b/io_uring/truncate.h
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+
+int io_ftruncate_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
+int io_ftruncate(struct io_kiocb *req, unsigned int issue_flags);
--
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