mirror of
https://github.com/torvalds/linux.git
synced 2024-11-14 08:02:07 +00:00
6af4ea0ba7
same story as with oprofilefs_mkdir() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
290 lines
6.5 KiB
C
290 lines
6.5 KiB
C
/**
|
|
* @file oprofilefs.c
|
|
*
|
|
* @remark Copyright 2002 OProfile authors
|
|
* @remark Read the file COPYING
|
|
*
|
|
* @author John Levon
|
|
*
|
|
* A simple filesystem for configuration and
|
|
* access of oprofile.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/oprofile.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/pagemap.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
#include "oprof.h"
|
|
|
|
#define OPROFILEFS_MAGIC 0x6f70726f
|
|
|
|
DEFINE_RAW_SPINLOCK(oprofilefs_lock);
|
|
|
|
static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode)
|
|
{
|
|
struct inode *inode = new_inode(sb);
|
|
|
|
if (inode) {
|
|
inode->i_ino = get_next_ino();
|
|
inode->i_mode = mode;
|
|
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
|
|
}
|
|
return inode;
|
|
}
|
|
|
|
|
|
static const struct super_operations s_ops = {
|
|
.statfs = simple_statfs,
|
|
.drop_inode = generic_delete_inode,
|
|
};
|
|
|
|
|
|
ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset)
|
|
{
|
|
return simple_read_from_buffer(buf, count, offset, str, strlen(str));
|
|
}
|
|
|
|
|
|
#define TMPBUFSIZE 50
|
|
|
|
ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset)
|
|
{
|
|
char tmpbuf[TMPBUFSIZE];
|
|
size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val);
|
|
if (maxlen > TMPBUFSIZE)
|
|
maxlen = TMPBUFSIZE;
|
|
return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen);
|
|
}
|
|
|
|
|
|
/*
|
|
* Note: If oprofilefs_ulong_from_user() returns 0, then *val remains
|
|
* unchanged and might be uninitialized. This follows write syscall
|
|
* implementation when count is zero: "If count is zero ... [and if]
|
|
* no errors are detected, 0 will be returned without causing any
|
|
* other effect." (man 2 write)
|
|
*/
|
|
int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
|
|
{
|
|
char tmpbuf[TMPBUFSIZE];
|
|
unsigned long flags;
|
|
|
|
if (!count)
|
|
return 0;
|
|
|
|
if (count > TMPBUFSIZE - 1)
|
|
return -EINVAL;
|
|
|
|
memset(tmpbuf, 0x0, TMPBUFSIZE);
|
|
|
|
if (copy_from_user(tmpbuf, buf, count))
|
|
return -EFAULT;
|
|
|
|
raw_spin_lock_irqsave(&oprofilefs_lock, flags);
|
|
*val = simple_strtoul(tmpbuf, NULL, 0);
|
|
raw_spin_unlock_irqrestore(&oprofilefs_lock, flags);
|
|
return count;
|
|
}
|
|
|
|
|
|
static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
|
|
{
|
|
unsigned long *val = file->private_data;
|
|
return oprofilefs_ulong_to_user(*val, buf, count, offset);
|
|
}
|
|
|
|
|
|
static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset)
|
|
{
|
|
unsigned long value;
|
|
int retval;
|
|
|
|
if (*offset)
|
|
return -EINVAL;
|
|
|
|
retval = oprofilefs_ulong_from_user(&value, buf, count);
|
|
if (retval <= 0)
|
|
return retval;
|
|
|
|
retval = oprofile_set_ulong(file->private_data, value);
|
|
if (retval)
|
|
return retval;
|
|
|
|
return count;
|
|
}
|
|
|
|
|
|
static const struct file_operations ulong_fops = {
|
|
.read = ulong_read_file,
|
|
.write = ulong_write_file,
|
|
.open = simple_open,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
|
|
static const struct file_operations ulong_ro_fops = {
|
|
.read = ulong_read_file,
|
|
.open = simple_open,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
|
|
static int __oprofilefs_create_file(struct dentry *root, char const *name,
|
|
const struct file_operations *fops, int perm, void *priv)
|
|
{
|
|
struct dentry *dentry;
|
|
struct inode *inode;
|
|
|
|
mutex_lock(&root->d_inode->i_mutex);
|
|
dentry = d_alloc_name(root, name);
|
|
if (!dentry) {
|
|
mutex_unlock(&root->d_inode->i_mutex);
|
|
return -ENOMEM;
|
|
}
|
|
inode = oprofilefs_get_inode(root->d_sb, S_IFREG | perm);
|
|
if (!inode) {
|
|
dput(dentry);
|
|
mutex_unlock(&root->d_inode->i_mutex);
|
|
return -ENOMEM;
|
|
}
|
|
inode->i_fop = fops;
|
|
inode->i_private = priv;
|
|
d_add(dentry, inode);
|
|
mutex_unlock(&root->d_inode->i_mutex);
|
|
return 0;
|
|
}
|
|
|
|
|
|
int oprofilefs_create_ulong(struct dentry *root,
|
|
char const *name, unsigned long *val)
|
|
{
|
|
return __oprofilefs_create_file(root, name,
|
|
&ulong_fops, 0644, val);
|
|
}
|
|
|
|
|
|
int oprofilefs_create_ro_ulong(struct dentry *root,
|
|
char const *name, unsigned long *val)
|
|
{
|
|
return __oprofilefs_create_file(root, name,
|
|
&ulong_ro_fops, 0444, val);
|
|
}
|
|
|
|
|
|
static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
|
|
{
|
|
atomic_t *val = file->private_data;
|
|
return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
|
|
}
|
|
|
|
|
|
static const struct file_operations atomic_ro_fops = {
|
|
.read = atomic_read_file,
|
|
.open = simple_open,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
|
|
int oprofilefs_create_ro_atomic(struct dentry *root,
|
|
char const *name, atomic_t *val)
|
|
{
|
|
return __oprofilefs_create_file(root, name,
|
|
&atomic_ro_fops, 0444, val);
|
|
}
|
|
|
|
|
|
int oprofilefs_create_file(struct dentry *root,
|
|
char const *name, const struct file_operations *fops)
|
|
{
|
|
return __oprofilefs_create_file(root, name, fops, 0644, NULL);
|
|
}
|
|
|
|
|
|
int oprofilefs_create_file_perm(struct dentry *root,
|
|
char const *name, const struct file_operations *fops, int perm)
|
|
{
|
|
return __oprofilefs_create_file(root, name, fops, perm, NULL);
|
|
}
|
|
|
|
|
|
struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name)
|
|
{
|
|
struct dentry *dentry;
|
|
struct inode *inode;
|
|
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
dentry = d_alloc_name(parent, name);
|
|
if (!dentry) {
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
return NULL;
|
|
}
|
|
inode = oprofilefs_get_inode(parent->d_sb, S_IFDIR | 0755);
|
|
if (!inode) {
|
|
dput(dentry);
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
return NULL;
|
|
}
|
|
inode->i_op = &simple_dir_inode_operations;
|
|
inode->i_fop = &simple_dir_operations;
|
|
d_add(dentry, inode);
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
return dentry;
|
|
}
|
|
|
|
|
|
static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
struct inode *root_inode;
|
|
|
|
sb->s_blocksize = PAGE_CACHE_SIZE;
|
|
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
|
|
sb->s_magic = OPROFILEFS_MAGIC;
|
|
sb->s_op = &s_ops;
|
|
sb->s_time_gran = 1;
|
|
|
|
root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
|
|
if (!root_inode)
|
|
return -ENOMEM;
|
|
root_inode->i_op = &simple_dir_inode_operations;
|
|
root_inode->i_fop = &simple_dir_operations;
|
|
sb->s_root = d_make_root(root_inode);
|
|
if (!sb->s_root)
|
|
return -ENOMEM;
|
|
|
|
oprofile_create_files(sb->s_root);
|
|
|
|
// FIXME: verify kill_litter_super removes our dentries
|
|
return 0;
|
|
}
|
|
|
|
|
|
static struct dentry *oprofilefs_mount(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data)
|
|
{
|
|
return mount_single(fs_type, flags, data, oprofilefs_fill_super);
|
|
}
|
|
|
|
|
|
static struct file_system_type oprofilefs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "oprofilefs",
|
|
.mount = oprofilefs_mount,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
MODULE_ALIAS_FS("oprofilefs");
|
|
|
|
|
|
int __init oprofilefs_register(void)
|
|
{
|
|
return register_filesystem(&oprofilefs_type);
|
|
}
|
|
|
|
|
|
void __exit oprofilefs_unregister(void)
|
|
{
|
|
unregister_filesystem(&oprofilefs_type);
|
|
}
|