mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 18:41:23 +00:00
bd33d12fba
The file is fs/debugfs/inode.c but the comment says it is file.c. This patch can fix this little mistake. Signed-off-by: Harry Wei <harryxiyou@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
545 lines
15 KiB
C
545 lines
15 KiB
C
/*
|
|
* inode.c - part of debugfs, a tiny little debug file system
|
|
*
|
|
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
|
|
* Copyright (C) 2004 IBM Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License version
|
|
* 2 as published by the Free Software Foundation.
|
|
*
|
|
* debugfs is for people to use instead of /proc or /sys.
|
|
* See Documentation/DocBook/kernel-api for more details.
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kobject.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/fsnotify.h>
|
|
#include <linux/string.h>
|
|
#include <linux/magic.h>
|
|
#include <linux/slab.h>
|
|
|
|
static struct vfsmount *debugfs_mount;
|
|
static int debugfs_mount_count;
|
|
static bool debugfs_registered;
|
|
|
|
static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t dev,
|
|
void *data, const struct file_operations *fops)
|
|
|
|
{
|
|
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;
|
|
switch (mode & S_IFMT) {
|
|
default:
|
|
init_special_inode(inode, mode, dev);
|
|
break;
|
|
case S_IFREG:
|
|
inode->i_fop = fops ? fops : &debugfs_file_operations;
|
|
inode->i_private = data;
|
|
break;
|
|
case S_IFLNK:
|
|
inode->i_op = &debugfs_link_operations;
|
|
inode->i_fop = fops;
|
|
inode->i_private = data;
|
|
break;
|
|
case S_IFDIR:
|
|
inode->i_op = &simple_dir_inode_operations;
|
|
inode->i_fop = fops ? fops : &simple_dir_operations;
|
|
inode->i_private = data;
|
|
|
|
/* directory inodes start off with i_nlink == 2
|
|
* (for "." entry) */
|
|
inc_nlink(inode);
|
|
break;
|
|
}
|
|
}
|
|
return inode;
|
|
}
|
|
|
|
/* SMP-safe */
|
|
static int debugfs_mknod(struct inode *dir, struct dentry *dentry,
|
|
int mode, dev_t dev, void *data,
|
|
const struct file_operations *fops)
|
|
{
|
|
struct inode *inode;
|
|
int error = -EPERM;
|
|
|
|
if (dentry->d_inode)
|
|
return -EEXIST;
|
|
|
|
inode = debugfs_get_inode(dir->i_sb, mode, dev, data, fops);
|
|
if (inode) {
|
|
d_instantiate(dentry, inode);
|
|
dget(dentry);
|
|
error = 0;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode,
|
|
void *data, const struct file_operations *fops)
|
|
{
|
|
int res;
|
|
|
|
mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
|
|
res = debugfs_mknod(dir, dentry, mode, 0, data, fops);
|
|
if (!res) {
|
|
inc_nlink(dir);
|
|
fsnotify_mkdir(dir, dentry);
|
|
}
|
|
return res;
|
|
}
|
|
|
|
static int debugfs_link(struct inode *dir, struct dentry *dentry, int mode,
|
|
void *data, const struct file_operations *fops)
|
|
{
|
|
mode = (mode & S_IALLUGO) | S_IFLNK;
|
|
return debugfs_mknod(dir, dentry, mode, 0, data, fops);
|
|
}
|
|
|
|
static int debugfs_create(struct inode *dir, struct dentry *dentry, int mode,
|
|
void *data, const struct file_operations *fops)
|
|
{
|
|
int res;
|
|
|
|
mode = (mode & S_IALLUGO) | S_IFREG;
|
|
res = debugfs_mknod(dir, dentry, mode, 0, data, fops);
|
|
if (!res)
|
|
fsnotify_create(dir, dentry);
|
|
return res;
|
|
}
|
|
|
|
static inline int debugfs_positive(struct dentry *dentry)
|
|
{
|
|
return dentry->d_inode && !d_unhashed(dentry);
|
|
}
|
|
|
|
static int debug_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
static struct tree_descr debug_files[] = {{""}};
|
|
|
|
return simple_fill_super(sb, DEBUGFS_MAGIC, debug_files);
|
|
}
|
|
|
|
static struct dentry *debug_mount(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name,
|
|
void *data)
|
|
{
|
|
return mount_single(fs_type, flags, data, debug_fill_super);
|
|
}
|
|
|
|
static struct file_system_type debug_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "debugfs",
|
|
.mount = debug_mount,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
|
|
static int debugfs_create_by_name(const char *name, mode_t mode,
|
|
struct dentry *parent,
|
|
struct dentry **dentry,
|
|
void *data,
|
|
const struct file_operations *fops)
|
|
{
|
|
int error = 0;
|
|
|
|
/* If the parent is not specified, we create it in the root.
|
|
* We need the root dentry to do this, which is in the super
|
|
* block. A pointer to that is in the struct vfsmount that we
|
|
* have around.
|
|
*/
|
|
if (!parent)
|
|
parent = debugfs_mount->mnt_sb->s_root;
|
|
|
|
*dentry = NULL;
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
*dentry = lookup_one_len(name, parent, strlen(name));
|
|
if (!IS_ERR(*dentry)) {
|
|
switch (mode & S_IFMT) {
|
|
case S_IFDIR:
|
|
error = debugfs_mkdir(parent->d_inode, *dentry, mode,
|
|
data, fops);
|
|
break;
|
|
case S_IFLNK:
|
|
error = debugfs_link(parent->d_inode, *dentry, mode,
|
|
data, fops);
|
|
break;
|
|
default:
|
|
error = debugfs_create(parent->d_inode, *dentry, mode,
|
|
data, fops);
|
|
break;
|
|
}
|
|
dput(*dentry);
|
|
} else
|
|
error = PTR_ERR(*dentry);
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* debugfs_create_file - create a file in the debugfs filesystem
|
|
* @name: a pointer to a string containing the name of the file to create.
|
|
* @mode: the permission that the file should have.
|
|
* @parent: a pointer to the parent dentry for this file. This should be a
|
|
* directory dentry if set. If this paramater is NULL, then the
|
|
* file will be created in the root of the debugfs filesystem.
|
|
* @data: a pointer to something that the caller will want to get to later
|
|
* on. The inode.i_private pointer will point to this value on
|
|
* the open() call.
|
|
* @fops: a pointer to a struct file_operations that should be used for
|
|
* this file.
|
|
*
|
|
* This is the basic "create a file" function for debugfs. It allows for a
|
|
* wide range of flexibility in creating a file, or a directory (if you want
|
|
* to create a directory, the debugfs_create_dir() function is
|
|
* recommended to be used instead.)
|
|
*
|
|
* This function will return a pointer to a dentry if it succeeds. This
|
|
* pointer must be passed to the debugfs_remove() function when the file is
|
|
* to be removed (no automatic cleanup happens if your module is unloaded,
|
|
* you are responsible here.) If an error occurs, %NULL will be returned.
|
|
*
|
|
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
|
|
* returned.
|
|
*/
|
|
struct dentry *debugfs_create_file(const char *name, mode_t mode,
|
|
struct dentry *parent, void *data,
|
|
const struct file_operations *fops)
|
|
{
|
|
struct dentry *dentry = NULL;
|
|
int error;
|
|
|
|
pr_debug("debugfs: creating file '%s'\n",name);
|
|
|
|
error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
|
|
&debugfs_mount_count);
|
|
if (error)
|
|
goto exit;
|
|
|
|
error = debugfs_create_by_name(name, mode, parent, &dentry,
|
|
data, fops);
|
|
if (error) {
|
|
dentry = NULL;
|
|
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
|
|
goto exit;
|
|
}
|
|
exit:
|
|
return dentry;
|
|
}
|
|
EXPORT_SYMBOL_GPL(debugfs_create_file);
|
|
|
|
/**
|
|
* debugfs_create_dir - create a directory in the debugfs filesystem
|
|
* @name: a pointer to a string containing the name of the directory to
|
|
* create.
|
|
* @parent: a pointer to the parent dentry for this file. This should be a
|
|
* directory dentry if set. If this paramater is NULL, then the
|
|
* directory will be created in the root of the debugfs filesystem.
|
|
*
|
|
* This function creates a directory in debugfs with the given name.
|
|
*
|
|
* This function will return a pointer to a dentry if it succeeds. This
|
|
* pointer must be passed to the debugfs_remove() function when the file is
|
|
* to be removed (no automatic cleanup happens if your module is unloaded,
|
|
* you are responsible here.) If an error occurs, %NULL will be returned.
|
|
*
|
|
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
|
|
* returned.
|
|
*/
|
|
struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
|
|
{
|
|
return debugfs_create_file(name,
|
|
S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
|
|
parent, NULL, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(debugfs_create_dir);
|
|
|
|
/**
|
|
* debugfs_create_symlink- create a symbolic link in the debugfs filesystem
|
|
* @name: a pointer to a string containing the name of the symbolic link to
|
|
* create.
|
|
* @parent: a pointer to the parent dentry for this symbolic link. This
|
|
* should be a directory dentry if set. If this paramater is NULL,
|
|
* then the symbolic link will be created in the root of the debugfs
|
|
* filesystem.
|
|
* @target: a pointer to a string containing the path to the target of the
|
|
* symbolic link.
|
|
*
|
|
* This function creates a symbolic link with the given name in debugfs that
|
|
* links to the given target path.
|
|
*
|
|
* This function will return a pointer to a dentry if it succeeds. This
|
|
* pointer must be passed to the debugfs_remove() function when the symbolic
|
|
* link is to be removed (no automatic cleanup happens if your module is
|
|
* unloaded, you are responsible here.) If an error occurs, %NULL will be
|
|
* returned.
|
|
*
|
|
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
|
|
* returned.
|
|
*/
|
|
struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
|
|
const char *target)
|
|
{
|
|
struct dentry *result;
|
|
char *link;
|
|
|
|
link = kstrdup(target, GFP_KERNEL);
|
|
if (!link)
|
|
return NULL;
|
|
|
|
result = debugfs_create_file(name, S_IFLNK | S_IRWXUGO, parent, link,
|
|
NULL);
|
|
if (!result)
|
|
kfree(link);
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(debugfs_create_symlink);
|
|
|
|
static int __debugfs_remove(struct dentry *dentry, struct dentry *parent)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (debugfs_positive(dentry)) {
|
|
if (dentry->d_inode) {
|
|
dget(dentry);
|
|
switch (dentry->d_inode->i_mode & S_IFMT) {
|
|
case S_IFDIR:
|
|
ret = simple_rmdir(parent->d_inode, dentry);
|
|
break;
|
|
case S_IFLNK:
|
|
kfree(dentry->d_inode->i_private);
|
|
/* fall through */
|
|
default:
|
|
simple_unlink(parent->d_inode, dentry);
|
|
break;
|
|
}
|
|
if (!ret)
|
|
d_delete(dentry);
|
|
dput(dentry);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* debugfs_remove - removes a file or directory from the debugfs filesystem
|
|
* @dentry: a pointer to a the dentry of the file or directory to be
|
|
* removed.
|
|
*
|
|
* This function removes a file or directory in debugfs that was previously
|
|
* created with a call to another debugfs function (like
|
|
* debugfs_create_file() or variants thereof.)
|
|
*
|
|
* This function is required to be called in order for the file to be
|
|
* removed, no automatic cleanup of files will happen when a module is
|
|
* removed, you are responsible here.
|
|
*/
|
|
void debugfs_remove(struct dentry *dentry)
|
|
{
|
|
struct dentry *parent;
|
|
int ret;
|
|
|
|
if (!dentry)
|
|
return;
|
|
|
|
parent = dentry->d_parent;
|
|
if (!parent || !parent->d_inode)
|
|
return;
|
|
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
ret = __debugfs_remove(dentry, parent);
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
if (!ret)
|
|
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
|
|
}
|
|
EXPORT_SYMBOL_GPL(debugfs_remove);
|
|
|
|
/**
|
|
* debugfs_remove_recursive - recursively removes a directory
|
|
* @dentry: a pointer to a the dentry of the directory to be removed.
|
|
*
|
|
* This function recursively removes a directory tree in debugfs that
|
|
* was previously created with a call to another debugfs function
|
|
* (like debugfs_create_file() or variants thereof.)
|
|
*
|
|
* This function is required to be called in order for the file to be
|
|
* removed, no automatic cleanup of files will happen when a module is
|
|
* removed, you are responsible here.
|
|
*/
|
|
void debugfs_remove_recursive(struct dentry *dentry)
|
|
{
|
|
struct dentry *child;
|
|
struct dentry *parent;
|
|
|
|
if (!dentry)
|
|
return;
|
|
|
|
parent = dentry->d_parent;
|
|
if (!parent || !parent->d_inode)
|
|
return;
|
|
|
|
parent = dentry;
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
|
|
while (1) {
|
|
/*
|
|
* When all dentries under "parent" has been removed,
|
|
* walk up the tree until we reach our starting point.
|
|
*/
|
|
if (list_empty(&parent->d_subdirs)) {
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
if (parent == dentry)
|
|
break;
|
|
parent = parent->d_parent;
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
}
|
|
child = list_entry(parent->d_subdirs.next, struct dentry,
|
|
d_u.d_child);
|
|
next_sibling:
|
|
|
|
/*
|
|
* If "child" isn't empty, walk down the tree and
|
|
* remove all its descendants first.
|
|
*/
|
|
if (!list_empty(&child->d_subdirs)) {
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
parent = child;
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
continue;
|
|
}
|
|
__debugfs_remove(child, parent);
|
|
if (parent->d_subdirs.next == &child->d_u.d_child) {
|
|
/*
|
|
* Try the next sibling.
|
|
*/
|
|
if (child->d_u.d_child.next != &parent->d_subdirs) {
|
|
child = list_entry(child->d_u.d_child.next,
|
|
struct dentry,
|
|
d_u.d_child);
|
|
goto next_sibling;
|
|
}
|
|
|
|
/*
|
|
* Avoid infinite loop if we fail to remove
|
|
* one dentry.
|
|
*/
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
break;
|
|
}
|
|
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
|
|
}
|
|
|
|
parent = dentry->d_parent;
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
__debugfs_remove(dentry, parent);
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
|
|
}
|
|
EXPORT_SYMBOL_GPL(debugfs_remove_recursive);
|
|
|
|
/**
|
|
* debugfs_rename - rename a file/directory in the debugfs filesystem
|
|
* @old_dir: a pointer to the parent dentry for the renamed object. This
|
|
* should be a directory dentry.
|
|
* @old_dentry: dentry of an object to be renamed.
|
|
* @new_dir: a pointer to the parent dentry where the object should be
|
|
* moved. This should be a directory dentry.
|
|
* @new_name: a pointer to a string containing the target name.
|
|
*
|
|
* This function renames a file/directory in debugfs. The target must not
|
|
* exist for rename to succeed.
|
|
*
|
|
* This function will return a pointer to old_dentry (which is updated to
|
|
* reflect renaming) if it succeeds. If an error occurs, %NULL will be
|
|
* returned.
|
|
*
|
|
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
|
|
* returned.
|
|
*/
|
|
struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
|
|
struct dentry *new_dir, const char *new_name)
|
|
{
|
|
int error;
|
|
struct dentry *dentry = NULL, *trap;
|
|
const char *old_name;
|
|
|
|
trap = lock_rename(new_dir, old_dir);
|
|
/* Source or destination directories don't exist? */
|
|
if (!old_dir->d_inode || !new_dir->d_inode)
|
|
goto exit;
|
|
/* Source does not exist, cyclic rename, or mountpoint? */
|
|
if (!old_dentry->d_inode || old_dentry == trap ||
|
|
d_mountpoint(old_dentry))
|
|
goto exit;
|
|
dentry = lookup_one_len(new_name, new_dir, strlen(new_name));
|
|
/* Lookup failed, cyclic rename or target exists? */
|
|
if (IS_ERR(dentry) || dentry == trap || dentry->d_inode)
|
|
goto exit;
|
|
|
|
old_name = fsnotify_oldname_init(old_dentry->d_name.name);
|
|
|
|
error = simple_rename(old_dir->d_inode, old_dentry, new_dir->d_inode,
|
|
dentry);
|
|
if (error) {
|
|
fsnotify_oldname_free(old_name);
|
|
goto exit;
|
|
}
|
|
d_move(old_dentry, dentry);
|
|
fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name,
|
|
S_ISDIR(old_dentry->d_inode->i_mode),
|
|
NULL, old_dentry);
|
|
fsnotify_oldname_free(old_name);
|
|
unlock_rename(new_dir, old_dir);
|
|
dput(dentry);
|
|
return old_dentry;
|
|
exit:
|
|
if (dentry && !IS_ERR(dentry))
|
|
dput(dentry);
|
|
unlock_rename(new_dir, old_dir);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(debugfs_rename);
|
|
|
|
/**
|
|
* debugfs_initialized - Tells whether debugfs has been registered
|
|
*/
|
|
bool debugfs_initialized(void)
|
|
{
|
|
return debugfs_registered;
|
|
}
|
|
EXPORT_SYMBOL_GPL(debugfs_initialized);
|
|
|
|
|
|
static struct kobject *debug_kobj;
|
|
|
|
static int __init debugfs_init(void)
|
|
{
|
|
int retval;
|
|
|
|
debug_kobj = kobject_create_and_add("debug", kernel_kobj);
|
|
if (!debug_kobj)
|
|
return -EINVAL;
|
|
|
|
retval = register_filesystem(&debug_fs_type);
|
|
if (retval)
|
|
kobject_put(debug_kobj);
|
|
else
|
|
debugfs_registered = true;
|
|
|
|
return retval;
|
|
}
|
|
core_initcall(debugfs_init);
|
|
|