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/*
* linux/fs/attr.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
* changes by Thomas Schoebel-Theuer
*/
#include <linux/stat.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <asm/system.h>
/* Taken over from the old code... */
/* POSIX UID/GID verification for setting inode attributes. */
int inode_change_ok(struct inode *inode, struct iattr *attr)
{
int retval = -EPERM;
unsigned int ia_valid = attr->ia_valid;
/* If force is set do it anyway. */
if (ia_valid & ATTR_FORCE)
goto fine;
/* Make sure a caller can chown. */
if ((ia_valid & ATTR_UID) &&
(current->fsuid != inode->i_uid ||
attr->ia_uid != inode->i_uid) && !fsuser())
goto error;
/* Make sure caller can chgrp. */
if ((ia_valid & ATTR_GID) &&
(!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid) &&
!fsuser())
goto error;
/* Make sure a caller can chmod. */
if (ia_valid & ATTR_MODE) {
if ((current->fsuid != inode->i_uid) && !fsuser())
goto error;
/* Also check the setgid bit! */
if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
inode->i_gid) && !fsuser())
attr->ia_mode &= ~S_ISGID;
}
/* Check for setting the inode time. */
if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET)) {
if (current->fsuid != inode->i_uid && !fsuser())
goto error;
}
fine:
retval = 0;
error:
return retval;
}
void inode_setattr(struct inode * inode, struct iattr * attr)
{
unsigned int ia_valid = attr->ia_valid;
if (ia_valid & ATTR_UID)
inode->i_uid = attr->ia_uid;
if (ia_valid & ATTR_GID)
inode->i_gid = attr->ia_gid;
if (ia_valid & ATTR_SIZE)
inode->i_size = attr->ia_size;
if (ia_valid & ATTR_ATIME)
inode->i_atime = attr->ia_atime;
if (ia_valid & ATTR_MTIME)
inode->i_mtime = attr->ia_mtime;
if (ia_valid & ATTR_CTIME)
inode->i_ctime = attr->ia_ctime;
if (ia_valid & ATTR_MODE) {
inode->i_mode = attr->ia_mode;
if (!in_group_p(inode->i_gid) && !fsuser())
inode->i_mode &= ~S_ISGID;
}
mark_inode_dirty(inode);
}
int notify_change(struct dentry * dentry, struct iattr * attr)
{
struct inode *inode = dentry->d_inode;
int error;
time_t now = CURRENT_TIME;
unsigned int ia_valid = attr->ia_valid;
attr->ia_ctime = now;
if (!(ia_valid & ATTR_ATIME_SET))
attr->ia_atime = now;
if (!(ia_valid & ATTR_MTIME_SET))
attr->ia_mtime = now;
if (inode->i_sb && inode->i_sb->s_op &&
inode->i_sb->s_op->notify_change)
error = inode->i_sb->s_op->notify_change(dentry, attr);
else {
error = inode_change_ok(inode, attr);
if (!error)
inode_setattr(inode, attr);
}
return error;
}
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