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/*
* linux/fs/ext2/acl.c
*
* Copyright (C) 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*/
/*
* This file will contain the Access Control Lists management for the
* second extended file system.
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/sched.h>
#include <linux/stat.h>
/*
* ext2_permission ()
*
* Check for access rights
*/
int ext2_permission (struct inode * inode, int mask)
{
unsigned short mode = inode->i_mode;
/*
* Nobody gets write access to a file on a readonly-fs
*/
if ((mask & S_IWOTH) &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
IS_RDONLY(inode))
return -EROFS;
/*
* Nobody gets write access to an immutable file
*/
if ((mask & S_IWOTH) && IS_IMMUTABLE(inode))
return -EACCES;
/*
* If no ACL, checks using the file mode
*/
else if (current->fsuid == inode->i_uid)
mode >>= 6;
else if (in_group_p (inode->i_gid))
mode >>= 3;
/*
* Access is always granted for root. We now check last,
* though, for BSD process accounting correctness
*/
if (((mode & mask & S_IRWXO) == mask) || capable(CAP_DAC_OVERRIDE))
return 0;
if ((mask == S_IROTH) ||
(S_ISDIR(mode) && !(mask & ~(S_IROTH | S_IXOTH))))
if (capable(CAP_DAC_READ_SEARCH))
return 0;
return -EACCES;
}
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