linux/fs/configfs/inode.c
Thomas Gleixner 328970de0e treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 145
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 021110 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 84 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190524100844.756442981@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:25:18 -07:00

269 lines
6.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* inode.c - basic inode and dentry operations.
*
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
* configfs Copyright (C) 2005 Oracle. All rights reserved.
*
* Please see Documentation/filesystems/configfs/configfs.txt for more
* information.
*/
#undef DEBUG
#include <linux/pagemap.h>
#include <linux/namei.h>
#include <linux/backing-dev.h>
#include <linux/capability.h>
#include <linux/sched.h>
#include <linux/lockdep.h>
#include <linux/slab.h>
#include <linux/configfs.h>
#include "configfs_internal.h"
#ifdef CONFIG_LOCKDEP
static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
#endif
static const struct address_space_operations configfs_aops = {
.readpage = simple_readpage,
.write_begin = simple_write_begin,
.write_end = simple_write_end,
};
static const struct inode_operations configfs_inode_operations ={
.setattr = configfs_setattr,
};
int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
{
struct inode * inode = d_inode(dentry);
struct configfs_dirent * sd = dentry->d_fsdata;
struct iattr * sd_iattr;
unsigned int ia_valid = iattr->ia_valid;
int error;
if (!sd)
return -EINVAL;
sd_iattr = sd->s_iattr;
if (!sd_iattr) {
/* setting attributes for the first time, allocate now */
sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
if (!sd_iattr)
return -ENOMEM;
/* assign default attributes */
sd_iattr->ia_mode = sd->s_mode;
sd_iattr->ia_uid = GLOBAL_ROOT_UID;
sd_iattr->ia_gid = GLOBAL_ROOT_GID;
sd_iattr->ia_atime = sd_iattr->ia_mtime =
sd_iattr->ia_ctime = current_time(inode);
sd->s_iattr = sd_iattr;
}
/* attributes were changed atleast once in past */
error = simple_setattr(dentry, iattr);
if (error)
return error;
if (ia_valid & ATTR_UID)
sd_iattr->ia_uid = iattr->ia_uid;
if (ia_valid & ATTR_GID)
sd_iattr->ia_gid = iattr->ia_gid;
if (ia_valid & ATTR_ATIME)
sd_iattr->ia_atime = timespec64_trunc(iattr->ia_atime,
inode->i_sb->s_time_gran);
if (ia_valid & ATTR_MTIME)
sd_iattr->ia_mtime = timespec64_trunc(iattr->ia_mtime,
inode->i_sb->s_time_gran);
if (ia_valid & ATTR_CTIME)
sd_iattr->ia_ctime = timespec64_trunc(iattr->ia_ctime,
inode->i_sb->s_time_gran);
if (ia_valid & ATTR_MODE) {
umode_t mode = iattr->ia_mode;
if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
mode &= ~S_ISGID;
sd_iattr->ia_mode = sd->s_mode = mode;
}
return error;
}
static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
{
inode->i_mode = mode;
inode->i_atime = inode->i_mtime =
inode->i_ctime = current_time(inode);
}
static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
{
inode->i_mode = iattr->ia_mode;
inode->i_uid = iattr->ia_uid;
inode->i_gid = iattr->ia_gid;
inode->i_atime = iattr->ia_atime;
inode->i_mtime = iattr->ia_mtime;
inode->i_ctime = iattr->ia_ctime;
}
struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
struct super_block *s)
{
struct inode * inode = new_inode(s);
if (inode) {
inode->i_ino = get_next_ino();
inode->i_mapping->a_ops = &configfs_aops;
inode->i_op = &configfs_inode_operations;
if (sd->s_iattr) {
/* sysfs_dirent has non-default attributes
* get them for the new inode from persistent copy
* in sysfs_dirent
*/
set_inode_attr(inode, sd->s_iattr);
} else
set_default_inode_attr(inode, mode);
}
return inode;
}
#ifdef CONFIG_LOCKDEP
static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
struct inode *inode)
{
int depth = sd->s_depth;
if (depth > 0) {
if (depth <= ARRAY_SIZE(default_group_class)) {
lockdep_set_class(&inode->i_rwsem,
&default_group_class[depth - 1]);
} else {
/*
* In practice the maximum level of locking depth is
* already reached. Just inform about possible reasons.
*/
pr_info("Too many levels of inodes for the locking correctness validator.\n");
pr_info("Spurious warnings may appear.\n");
}
}
}
#else /* CONFIG_LOCKDEP */
static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
struct inode *inode)
{
}
#endif /* CONFIG_LOCKDEP */
int configfs_create(struct dentry * dentry, umode_t mode, void (*init)(struct inode *))
{
int error = 0;
struct inode *inode = NULL;
struct configfs_dirent *sd;
struct inode *p_inode;
if (!dentry)
return -ENOENT;
if (d_really_is_positive(dentry))
return -EEXIST;
sd = dentry->d_fsdata;
inode = configfs_new_inode(mode, sd, dentry->d_sb);
if (!inode)
return -ENOMEM;
p_inode = d_inode(dentry->d_parent);
p_inode->i_mtime = p_inode->i_ctime = current_time(p_inode);
configfs_set_inode_lock_class(sd, inode);
init(inode);
if (S_ISDIR(mode) || S_ISLNK(mode)) {
/*
* ->symlink(), ->mkdir(), configfs_register_subsystem() or
* create_default_group() - already hashed.
*/
d_instantiate(dentry, inode);
dget(dentry); /* pin link and directory dentries in core */
} else {
/* ->lookup() */
d_add(dentry, inode);
}
return error;
}
/*
* Get the name for corresponding element represented by the given configfs_dirent
*/
const unsigned char * configfs_get_name(struct configfs_dirent *sd)
{
struct configfs_attribute *attr;
BUG_ON(!sd || !sd->s_element);
/* These always have a dentry, so use that */
if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
return sd->s_dentry->d_name.name;
if (sd->s_type & (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)) {
attr = sd->s_element;
return attr->ca_name;
}
return NULL;
}
/*
* Unhashes the dentry corresponding to given configfs_dirent
* Called with parent inode's i_mutex held.
*/
void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
{
struct dentry * dentry = sd->s_dentry;
if (dentry) {
spin_lock(&dentry->d_lock);
if (simple_positive(dentry)) {
dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
simple_unlink(d_inode(parent), dentry);
} else
spin_unlock(&dentry->d_lock);
}
}
void configfs_hash_and_remove(struct dentry * dir, const char * name)
{
struct configfs_dirent * sd;
struct configfs_dirent * parent_sd = dir->d_fsdata;
if (d_really_is_negative(dir))
/* no inode means this hasn't been made visible yet */
return;
inode_lock(d_inode(dir));
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
if (!sd->s_element)
continue;
if (!strcmp(configfs_get_name(sd), name)) {
spin_lock(&configfs_dirent_lock);
list_del_init(&sd->s_sibling);
spin_unlock(&configfs_dirent_lock);
configfs_drop_dentry(sd, dir);
configfs_put(sd);
break;
}
}
inode_unlock(d_inode(dir));
}