From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/fs/fuse/cuse.c | 134 +++++++++++++++++++++++---------------------
1 files changed, 70 insertions(+), 64 deletions(-)
diff --git a/kernel/fs/fuse/cuse.c b/kernel/fs/fuse/cuse.c
index e10e2b6..a37528b 100644
--- a/kernel/fs/fuse/cuse.c
+++ b/kernel/fs/fuse/cuse.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* CUSE: Character device in Userspace
*
* Copyright (C) 2008-2009 SUSE Linux Products GmbH
* Copyright (C) 2008-2009 Tejun Heo <tj@kernel.org>
- *
- * This file is released under the GPLv2.
*
* CUSE enables character devices to be implemented from userland much
* like FUSE allows filesystems. On initialization /dev/cuse is
@@ -33,6 +32,8 @@
* closed.
*/
+#define pr_fmt(fmt) "CUSE: " fmt
+
#include <linux/fuse.h>
#include <linux/cdev.h>
#include <linux/device.h>
@@ -56,6 +57,7 @@
struct cuse_conn {
struct list_head list; /* linked on cuse_conntbl */
+ struct fuse_mount fm; /* Dummy mount referencing fc */
struct fuse_conn fc; /* fuse connection */
struct cdev *cdev; /* associated character device */
struct device *dev; /* device representing @cdev */
@@ -133,7 +135,7 @@
* Generic permission check is already done against the chrdev
* file, proceed to open.
*/
- rc = fuse_do_open(&cc->fc, 0, file, 0);
+ rc = fuse_do_open(&cc->fm, 0, file, 0);
if (rc)
fuse_conn_put(&cc->fc);
return rc;
@@ -142,10 +144,10 @@
static int cuse_release(struct inode *inode, struct file *file)
{
struct fuse_file *ff = file->private_data;
- struct fuse_conn *fc = ff->fc;
+ struct fuse_mount *fm = ff->fm;
- fuse_sync_release(ff, file->f_flags);
- fuse_conn_put(fc);
+ fuse_sync_release(NULL, ff, file->f_flags);
+ fuse_conn_put(fm->fc);
return 0;
}
@@ -154,7 +156,7 @@
unsigned long arg)
{
struct fuse_file *ff = file->private_data;
- struct cuse_conn *cc = fc_to_cc(ff->fc);
+ struct cuse_conn *cc = fc_to_cc(ff->fm->fc);
unsigned int flags = 0;
if (cc->unrestricted_ioctl)
@@ -167,7 +169,7 @@
unsigned long arg)
{
struct fuse_file *ff = file->private_data;
- struct cuse_conn *cc = fc_to_cc(ff->fc);
+ struct cuse_conn *cc = fc_to_cc(ff->fm->fc);
unsigned int flags = FUSE_IOCTL_COMPAT;
if (cc->unrestricted_ioctl)
@@ -224,7 +226,7 @@
return 0;
if (end[-1] != '\0') {
- printk(KERN_ERR "CUSE: info not properly terminated\n");
+ pr_err("info not properly terminated\n");
return -EINVAL;
}
@@ -241,7 +243,7 @@
key = strstrip(key);
if (!strlen(key)) {
- printk(KERN_ERR "CUSE: zero length info key specified\n");
+ pr_err("zero length info key specified\n");
return -EINVAL;
}
@@ -269,7 +271,7 @@
static int cuse_parse_devinfo(char *p, size_t len, struct cuse_devinfo *devinfo)
{
char *end = p + len;
- char *uninitialized_var(key), *uninitialized_var(val);
+ char *key, *val;
int rc;
while (true) {
@@ -281,12 +283,11 @@
if (strcmp(key, "DEVNAME") == 0)
devinfo->name = val;
else
- printk(KERN_WARNING "CUSE: unknown device info \"%s\"\n",
- key);
+ pr_warn("unknown device info \"%s\"\n", key);
}
if (!devinfo->name || !strlen(devinfo->name)) {
- printk(KERN_ERR "CUSE: DEVNAME unspecified\n");
+ pr_err("DEVNAME unspecified\n");
return -EINVAL;
}
@@ -298,6 +299,14 @@
kfree(dev);
}
+struct cuse_init_args {
+ struct fuse_args_pages ap;
+ struct cuse_init_in in;
+ struct cuse_init_out out;
+ struct page *page;
+ struct fuse_page_desc desc;
+};
+
/**
* cuse_process_init_reply - finish initializing CUSE channel
*
@@ -305,21 +314,23 @@
* required data structures for it. Please read the comment at the
* top of this file for high level overview.
*/
-static void cuse_process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
+static void cuse_process_init_reply(struct fuse_mount *fm,
+ struct fuse_args *args, int error)
{
+ struct fuse_conn *fc = fm->fc;
+ struct cuse_init_args *ia = container_of(args, typeof(*ia), ap.args);
+ struct fuse_args_pages *ap = &ia->ap;
struct cuse_conn *cc = fc_to_cc(fc), *pos;
- struct cuse_init_out *arg = req->out.args[0].value;
- struct page *page = req->pages[0];
+ struct cuse_init_out *arg = &ia->out;
+ struct page *page = ap->pages[0];
struct cuse_devinfo devinfo = { };
struct device *dev;
struct cdev *cdev;
dev_t devt;
int rc, i;
- if (req->out.h.error ||
- arg->major != FUSE_KERNEL_VERSION || arg->minor < 11) {
+ if (error || arg->major != FUSE_KERNEL_VERSION || arg->minor < 11)
goto err;
- }
fc->minor = arg->minor;
fc->max_read = max_t(unsigned, arg->max_read, 4096);
@@ -328,7 +339,7 @@
/* parse init reply */
cc->unrestricted_ioctl = arg->flags & CUSE_UNRESTRICTED_IOCTL;
- rc = cuse_parse_devinfo(page_address(page), req->out.args[1].size,
+ rc = cuse_parse_devinfo(page_address(page), ap->args.out_args[1].size,
&devinfo);
if (rc)
goto err;
@@ -340,7 +351,7 @@
else
rc = register_chrdev_region(devt, 1, devinfo.name);
if (rc) {
- printk(KERN_ERR "CUSE: failed to register chrdev region\n");
+ pr_err("failed to register chrdev region\n");
goto err;
}
@@ -395,7 +406,7 @@
dev_set_uevent_suppress(dev, 0);
kobject_uevent(&dev->kobj, KOBJ_ADD);
out:
- kfree(arg);
+ kfree(ia);
__free_page(page);
return;
@@ -407,62 +418,56 @@
err_region:
unregister_chrdev_region(devt, 1);
err:
- fuse_abort_conn(fc, false);
+ fuse_abort_conn(fc);
goto out;
}
static int cuse_send_init(struct cuse_conn *cc)
{
int rc;
- struct fuse_req *req;
struct page *page;
- struct fuse_conn *fc = &cc->fc;
- struct cuse_init_in *arg;
- void *outarg;
+ struct fuse_mount *fm = &cc->fm;
+ struct cuse_init_args *ia;
+ struct fuse_args_pages *ap;
BUILD_BUG_ON(CUSE_INIT_INFO_MAX > PAGE_SIZE);
-
- req = fuse_get_req_for_background(fc, 1);
- if (IS_ERR(req)) {
- rc = PTR_ERR(req);
- goto err;
- }
rc = -ENOMEM;
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (!page)
- goto err_put_req;
+ goto err;
- outarg = kzalloc(sizeof(struct cuse_init_out), GFP_KERNEL);
- if (!outarg)
+ ia = kzalloc(sizeof(*ia), GFP_KERNEL);
+ if (!ia)
goto err_free_page;
- arg = &req->misc.cuse_init_in;
- arg->major = FUSE_KERNEL_VERSION;
- arg->minor = FUSE_KERNEL_MINOR_VERSION;
- arg->flags |= CUSE_UNRESTRICTED_IOCTL;
- req->in.h.opcode = CUSE_INIT;
- req->in.numargs = 1;
- req->in.args[0].size = sizeof(struct cuse_init_in);
- req->in.args[0].value = arg;
- req->out.numargs = 2;
- req->out.args[0].size = sizeof(struct cuse_init_out);
- req->out.args[0].value = outarg;
- req->out.args[1].size = CUSE_INIT_INFO_MAX;
- req->out.argvar = 1;
- req->out.argpages = 1;
- req->pages[0] = page;
- req->page_descs[0].length = req->out.args[1].size;
- req->num_pages = 1;
- req->end = cuse_process_init_reply;
- fuse_request_send_background(fc, req);
+ ap = &ia->ap;
+ ia->in.major = FUSE_KERNEL_VERSION;
+ ia->in.minor = FUSE_KERNEL_MINOR_VERSION;
+ ia->in.flags |= CUSE_UNRESTRICTED_IOCTL;
+ ap->args.opcode = CUSE_INIT;
+ ap->args.in_numargs = 1;
+ ap->args.in_args[0].size = sizeof(ia->in);
+ ap->args.in_args[0].value = &ia->in;
+ ap->args.out_numargs = 2;
+ ap->args.out_args[0].size = sizeof(ia->out);
+ ap->args.out_args[0].value = &ia->out;
+ ap->args.out_args[1].size = CUSE_INIT_INFO_MAX;
+ ap->args.out_argvar = true;
+ ap->args.out_pages = true;
+ ap->num_pages = 1;
+ ap->pages = &ia->page;
+ ap->descs = &ia->desc;
+ ia->page = page;
+ ia->desc.length = ap->args.out_args[1].size;
+ ap->args.end = cuse_process_init_reply;
- return 0;
-
+ rc = fuse_simple_background(fm, &ap->args, GFP_KERNEL);
+ if (rc) {
+ kfree(ia);
err_free_page:
- __free_page(page);
-err_put_req:
- fuse_put_request(fc, req);
+ __free_page(page);
+ }
err:
return rc;
}
@@ -503,9 +508,10 @@
* Limit the cuse channel to requests that can
* be represented in file->f_cred->user_ns.
*/
- fuse_conn_init(&cc->fc, file->f_cred->user_ns);
+ fuse_conn_init(&cc->fc, &cc->fm, file->f_cred->user_ns,
+ &fuse_dev_fiq_ops, NULL);
- fud = fuse_dev_alloc(&cc->fc);
+ fud = fuse_dev_alloc_install(&cc->fc);
if (!fud) {
kfree(cc);
return -ENOMEM;
@@ -587,7 +593,7 @@
{
struct cuse_conn *cc = dev_get_drvdata(dev);
- fuse_abort_conn(&cc->fc, false);
+ fuse_abort_conn(&cc->fc);
return count;
}
static DEVICE_ATTR(abort, 0200, NULL, cuse_class_abort_store);
--
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