mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 21:36:44 +07:00
7736e8cc51
fuse_ctl_cleanup is only called by __exit fuse_exit Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
355 lines
7.9 KiB
C
355 lines
7.9 KiB
C
/*
|
|
FUSE: Filesystem in Userspace
|
|
Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
|
|
|
|
This program can be distributed under the terms of the GNU GPL.
|
|
See the file COPYING.
|
|
*/
|
|
|
|
#include "fuse_i.h"
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
|
|
#define FUSE_CTL_SUPER_MAGIC 0x65735543
|
|
|
|
/*
|
|
* This is non-NULL when the single instance of the control filesystem
|
|
* exists. Protected by fuse_mutex
|
|
*/
|
|
static struct super_block *fuse_control_sb;
|
|
|
|
static struct fuse_conn *fuse_ctl_file_conn_get(struct file *file)
|
|
{
|
|
struct fuse_conn *fc;
|
|
mutex_lock(&fuse_mutex);
|
|
fc = file_inode(file)->i_private;
|
|
if (fc)
|
|
fc = fuse_conn_get(fc);
|
|
mutex_unlock(&fuse_mutex);
|
|
return fc;
|
|
}
|
|
|
|
static ssize_t fuse_conn_abort_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
|
|
if (fc) {
|
|
fuse_abort_conn(fc);
|
|
fuse_conn_put(fc);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static ssize_t fuse_conn_waiting_read(struct file *file, char __user *buf,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
char tmp[32];
|
|
size_t size;
|
|
|
|
if (!*ppos) {
|
|
long value;
|
|
struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
|
|
if (!fc)
|
|
return 0;
|
|
|
|
value = atomic_read(&fc->num_waiting);
|
|
file->private_data = (void *)value;
|
|
fuse_conn_put(fc);
|
|
}
|
|
size = sprintf(tmp, "%ld\n", (long)file->private_data);
|
|
return simple_read_from_buffer(buf, len, ppos, tmp, size);
|
|
}
|
|
|
|
static ssize_t fuse_conn_limit_read(struct file *file, char __user *buf,
|
|
size_t len, loff_t *ppos, unsigned val)
|
|
{
|
|
char tmp[32];
|
|
size_t size = sprintf(tmp, "%u\n", val);
|
|
|
|
return simple_read_from_buffer(buf, len, ppos, tmp, size);
|
|
}
|
|
|
|
static ssize_t fuse_conn_limit_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos, unsigned *val,
|
|
unsigned global_limit)
|
|
{
|
|
unsigned long t;
|
|
unsigned limit = (1 << 16) - 1;
|
|
int err;
|
|
|
|
if (*ppos)
|
|
return -EINVAL;
|
|
|
|
err = kstrtoul_from_user(buf, count, 0, &t);
|
|
if (err)
|
|
return err;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
limit = min(limit, global_limit);
|
|
|
|
if (t > limit)
|
|
return -EINVAL;
|
|
|
|
*val = t;
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t fuse_conn_max_background_read(struct file *file,
|
|
char __user *buf, size_t len,
|
|
loff_t *ppos)
|
|
{
|
|
struct fuse_conn *fc;
|
|
unsigned val;
|
|
|
|
fc = fuse_ctl_file_conn_get(file);
|
|
if (!fc)
|
|
return 0;
|
|
|
|
val = fc->max_background;
|
|
fuse_conn_put(fc);
|
|
|
|
return fuse_conn_limit_read(file, buf, len, ppos, val);
|
|
}
|
|
|
|
static ssize_t fuse_conn_max_background_write(struct file *file,
|
|
const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned uninitialized_var(val);
|
|
ssize_t ret;
|
|
|
|
ret = fuse_conn_limit_write(file, buf, count, ppos, &val,
|
|
max_user_bgreq);
|
|
if (ret > 0) {
|
|
struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
|
|
if (fc) {
|
|
fc->max_background = val;
|
|
fuse_conn_put(fc);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t fuse_conn_congestion_threshold_read(struct file *file,
|
|
char __user *buf, size_t len,
|
|
loff_t *ppos)
|
|
{
|
|
struct fuse_conn *fc;
|
|
unsigned val;
|
|
|
|
fc = fuse_ctl_file_conn_get(file);
|
|
if (!fc)
|
|
return 0;
|
|
|
|
val = fc->congestion_threshold;
|
|
fuse_conn_put(fc);
|
|
|
|
return fuse_conn_limit_read(file, buf, len, ppos, val);
|
|
}
|
|
|
|
static ssize_t fuse_conn_congestion_threshold_write(struct file *file,
|
|
const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned uninitialized_var(val);
|
|
ssize_t ret;
|
|
|
|
ret = fuse_conn_limit_write(file, buf, count, ppos, &val,
|
|
max_user_congthresh);
|
|
if (ret > 0) {
|
|
struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
|
|
if (fc) {
|
|
fc->congestion_threshold = val;
|
|
fuse_conn_put(fc);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations fuse_ctl_abort_ops = {
|
|
.open = nonseekable_open,
|
|
.write = fuse_conn_abort_write,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
static const struct file_operations fuse_ctl_waiting_ops = {
|
|
.open = nonseekable_open,
|
|
.read = fuse_conn_waiting_read,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
static const struct file_operations fuse_conn_max_background_ops = {
|
|
.open = nonseekable_open,
|
|
.read = fuse_conn_max_background_read,
|
|
.write = fuse_conn_max_background_write,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
static const struct file_operations fuse_conn_congestion_threshold_ops = {
|
|
.open = nonseekable_open,
|
|
.read = fuse_conn_congestion_threshold_read,
|
|
.write = fuse_conn_congestion_threshold_write,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
|
|
struct fuse_conn *fc,
|
|
const char *name,
|
|
int mode, int nlink,
|
|
const struct inode_operations *iop,
|
|
const struct file_operations *fop)
|
|
{
|
|
struct dentry *dentry;
|
|
struct inode *inode;
|
|
|
|
BUG_ON(fc->ctl_ndents >= FUSE_CTL_NUM_DENTRIES);
|
|
dentry = d_alloc_name(parent, name);
|
|
if (!dentry)
|
|
return NULL;
|
|
|
|
fc->ctl_dentry[fc->ctl_ndents++] = dentry;
|
|
inode = new_inode(fuse_control_sb);
|
|
if (!inode)
|
|
return NULL;
|
|
|
|
inode->i_ino = get_next_ino();
|
|
inode->i_mode = mode;
|
|
inode->i_uid = fc->user_id;
|
|
inode->i_gid = fc->group_id;
|
|
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
|
|
/* setting ->i_op to NULL is not allowed */
|
|
if (iop)
|
|
inode->i_op = iop;
|
|
inode->i_fop = fop;
|
|
set_nlink(inode, nlink);
|
|
inode->i_private = fc;
|
|
d_add(dentry, inode);
|
|
return dentry;
|
|
}
|
|
|
|
/*
|
|
* Add a connection to the control filesystem (if it exists). Caller
|
|
* must hold fuse_mutex
|
|
*/
|
|
int fuse_ctl_add_conn(struct fuse_conn *fc)
|
|
{
|
|
struct dentry *parent;
|
|
char name[32];
|
|
|
|
if (!fuse_control_sb)
|
|
return 0;
|
|
|
|
parent = fuse_control_sb->s_root;
|
|
inc_nlink(parent->d_inode);
|
|
sprintf(name, "%u", fc->dev);
|
|
parent = fuse_ctl_add_dentry(parent, fc, name, S_IFDIR | 0500, 2,
|
|
&simple_dir_inode_operations,
|
|
&simple_dir_operations);
|
|
if (!parent)
|
|
goto err;
|
|
|
|
if (!fuse_ctl_add_dentry(parent, fc, "waiting", S_IFREG | 0400, 1,
|
|
NULL, &fuse_ctl_waiting_ops) ||
|
|
!fuse_ctl_add_dentry(parent, fc, "abort", S_IFREG | 0200, 1,
|
|
NULL, &fuse_ctl_abort_ops) ||
|
|
!fuse_ctl_add_dentry(parent, fc, "max_background", S_IFREG | 0600,
|
|
1, NULL, &fuse_conn_max_background_ops) ||
|
|
!fuse_ctl_add_dentry(parent, fc, "congestion_threshold",
|
|
S_IFREG | 0600, 1, NULL,
|
|
&fuse_conn_congestion_threshold_ops))
|
|
goto err;
|
|
|
|
return 0;
|
|
|
|
err:
|
|
fuse_ctl_remove_conn(fc);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* Remove a connection from the control filesystem (if it exists).
|
|
* Caller must hold fuse_mutex
|
|
*/
|
|
void fuse_ctl_remove_conn(struct fuse_conn *fc)
|
|
{
|
|
int i;
|
|
|
|
if (!fuse_control_sb)
|
|
return;
|
|
|
|
for (i = fc->ctl_ndents - 1; i >= 0; i--) {
|
|
struct dentry *dentry = fc->ctl_dentry[i];
|
|
dentry->d_inode->i_private = NULL;
|
|
d_drop(dentry);
|
|
dput(dentry);
|
|
}
|
|
drop_nlink(fuse_control_sb->s_root->d_inode);
|
|
}
|
|
|
|
static int fuse_ctl_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
struct tree_descr empty_descr = {""};
|
|
struct fuse_conn *fc;
|
|
int err;
|
|
|
|
err = simple_fill_super(sb, FUSE_CTL_SUPER_MAGIC, &empty_descr);
|
|
if (err)
|
|
return err;
|
|
|
|
mutex_lock(&fuse_mutex);
|
|
BUG_ON(fuse_control_sb);
|
|
fuse_control_sb = sb;
|
|
list_for_each_entry(fc, &fuse_conn_list, entry) {
|
|
err = fuse_ctl_add_conn(fc);
|
|
if (err) {
|
|
fuse_control_sb = NULL;
|
|
mutex_unlock(&fuse_mutex);
|
|
return err;
|
|
}
|
|
}
|
|
mutex_unlock(&fuse_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct dentry *fuse_ctl_mount(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *raw_data)
|
|
{
|
|
return mount_single(fs_type, flags, raw_data, fuse_ctl_fill_super);
|
|
}
|
|
|
|
static void fuse_ctl_kill_sb(struct super_block *sb)
|
|
{
|
|
struct fuse_conn *fc;
|
|
|
|
mutex_lock(&fuse_mutex);
|
|
fuse_control_sb = NULL;
|
|
list_for_each_entry(fc, &fuse_conn_list, entry)
|
|
fc->ctl_ndents = 0;
|
|
mutex_unlock(&fuse_mutex);
|
|
|
|
kill_litter_super(sb);
|
|
}
|
|
|
|
static struct file_system_type fuse_ctl_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "fusectl",
|
|
.mount = fuse_ctl_mount,
|
|
.kill_sb = fuse_ctl_kill_sb,
|
|
};
|
|
MODULE_ALIAS_FS("fusectl");
|
|
|
|
int __init fuse_ctl_init(void)
|
|
{
|
|
return register_filesystem(&fuse_ctl_fs_type);
|
|
}
|
|
|
|
void __exit fuse_ctl_cleanup(void)
|
|
{
|
|
unregister_filesystem(&fuse_ctl_fs_type);
|
|
}
|