linux-imx

/*

 * fs/kernfs/inode.c - kernfs inode implementation

 *

 * Copyright (c) 2001-3 Patrick Mochel

 * Copyright (c) 2007 SUSE Linux Products GmbH

 * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org>

 *

 * This file is released under the GPLv2.

 */

​

#include <linux/pagemap.h>

#include <linux/backing-dev.h>

#include <linux/capability.h>

#include <linux/errno.h>

#include <linux/slab.h>

#include <linux/xattr.h>

#include <linux/security.h>

​

#include "kernfs-internal.h"

​

static const struct address_space_operations kernfs_aops = {

    .readpage   = simple_readpage,

    .write_begin    = simple_write_begin,

    .write_end  = simple_write_end,

};

​

static const struct inode_operations kernfs_iops = {

    .permission = kernfs_iop_permission,

    .setattr    = kernfs_iop_setattr,

    .getattr    = kernfs_iop_getattr,

    .listxattr  = kernfs_iop_listxattr,

};

​

static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)

{

    static DEFINE_MUTEX(iattr_mutex);

    struct kernfs_iattrs *ret;

    struct iattr *iattrs;

​

    mutex_lock(&iattr_mutex);

​

    if (kn->iattr)

        goto out_unlock;

​

    kn->iattr = kmem_cache_zalloc(kernfs_iattrs_cache, GFP_KERNEL);

    if (!kn->iattr)

        goto out_unlock;

    iattrs = &kn->iattr->ia_iattr;

​

    /* assign default attributes */

    iattrs->ia_mode = kn->mode;

    iattrs->ia_uid = GLOBAL_ROOT_UID;

    iattrs->ia_gid = GLOBAL_ROOT_GID;

​

    ktime_get_real_ts64(&iattrs->ia_atime);

    iattrs->ia_mtime = iattrs->ia_atime;

    iattrs->ia_ctime = iattrs->ia_atime;

​

    simple_xattrs_init(&kn->iattr->xattrs);

out_unlock:

    ret = kn->iattr;

    mutex_unlock(&iattr_mutex);

    return ret;

}

​

int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)

{

    struct kernfs_iattrs *attrs;

    struct iattr *iattrs;

    unsigned int ia_valid = iattr->ia_valid;

​

    attrs = kernfs_iattrs(kn);

    if (!attrs)

        return -ENOMEM;

​

    iattrs = &attrs->ia_iattr;

​

    if (ia_valid & ATTR_UID)

        iattrs->ia_uid = iattr->ia_uid;

    if (ia_valid & ATTR_GID)

        iattrs->ia_gid = iattr->ia_gid;

    if (ia_valid & ATTR_ATIME)

        iattrs->ia_atime = iattr->ia_atime;

    if (ia_valid & ATTR_MTIME)

        iattrs->ia_mtime = iattr->ia_mtime;

    if (ia_valid & ATTR_CTIME)

        iattrs->ia_ctime = iattr->ia_ctime;

    if (ia_valid & ATTR_MODE) {

        umode_t mode = iattr->ia_mode;

        iattrs->ia_mode = kn->mode = mode;

    }

    return 0;