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/*
* fs/generic_acl.c
*
* (C) 2005 Andreas Gruenbacher <agruen@suse.de>
*
* This file is released under the GPL.
*/
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/generic_acl.h>
/**
* generic_acl_list - Generic xattr_handler->list() operation
* @ops: Filesystem specific getacl and setacl callbacks
*/
size_t
generic_acl_list(struct inode *inode, struct generic_acl_operations *ops,
int type, char *list, size_t list_size)
{
struct posix_acl *acl;
const char *name;
size_t size;
acl = ops->getacl(inode, type);
if (!acl)
return 0;
posix_acl_release(acl);
switch(type) {
case ACL_TYPE_ACCESS:
name = POSIX_ACL_XATTR_ACCESS;
break;
case ACL_TYPE_DEFAULT:
name = POSIX_ACL_XATTR_DEFAULT;
break;
default:
return 0;
}
size = strlen(name) + 1;
if (list && size <= list_size)
memcpy(list, name, size);
return size;
}
/**
* generic_acl_get - Generic xattr_handler->get() operation
* @ops: Filesystem specific getacl and setacl callbacks
*/
int
generic_acl_get(struct inode *inode, struct generic_acl_operations *ops,
int type, void *buffer, size_t size)
{
struct posix_acl *acl;
int error;
acl = ops->getacl(inode, type);
if (!acl)
return -ENODATA;
error = posix_acl_to_xattr(acl, buffer, size);
posix_acl_release(acl);
return error;
}
/**
* generic_acl_set - Generic xattr_handler->set() operation
* @ops: Filesystem specific getacl and setacl callbacks
*/
int
generic_acl_set(struct inode *inode, struct generic_acl_operations *ops,
int type, const void *value, size_t size)
{
struct posix_acl *acl = NULL;
int error;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
if (!is_owner_or_cap(inode))
return -EPERM;
if (value) {
acl = posix_acl_from_xattr(value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
if (acl) {
mode_t mode;
error = posix_acl_valid(acl);
if (error)
goto failed;
switch(type) {
case ACL_TYPE_ACCESS:
mode = inode->i_mode;
error = posix_acl_equiv_mode(acl, &mode);
if (error < 0)
goto failed;
inode->i_mode = mode;
if (error == 0) {
posix_acl_release(acl);
acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode)) {
error = -EINVAL;
goto failed;
}
break;
}
}
ops->setacl(inode, type, acl);
error = 0;
failed:
posix_acl_release(acl);
return error;
}
/**
* generic_acl_init - Take care of acl inheritance at @inode create time
* @ops: Filesystem specific getacl and setacl callbacks
*
* Files created inside a directory with a default ACL inherit the
* directory's default ACL.
*/
int
generic_acl_init(struct inode *inode, struct inode *dir,
struct generic_acl_operations *ops)
{
struct posix_acl *acl = NULL;
mode_t mode = inode->i_mode;
int error;
inode->i_mode = mode & ~current->fs->umask;
if (!S_ISLNK(inode->i_mode))
acl = ops->getacl(dir, ACL_TYPE_DEFAULT);
if (acl) {
struct posix_acl *clone;
if (S_ISDIR(inode->i_mode)) {
clone = posix_acl_clone(acl, GFP_KERNEL);
error = -ENOMEM;
if (!clone)
goto cleanup;
ops->setacl(inode, ACL_TYPE_DEFAULT, clone);
posix_acl_release(clone);
}
clone = posix_acl_clone(acl, GFP_KERNEL);
error = -ENOMEM;
if (!clone)
goto cleanup;
error = posix_acl_create_masq(clone, &mode);
if (error >= 0) {
inode->i_mode = mode;
if (error > 0)
ops->setacl(inode, ACL_TYPE_ACCESS, clone);
}
posix_acl_release(clone);
}
error = 0;
cleanup:
posix_acl_release(acl);
return error;
}
/**
* generic_acl_chmod - change the access acl of @inode upon chmod()
* @ops: FIlesystem specific getacl and setacl callbacks
*
* A chmod also changes the permissions of the owner, group/mask, and
* other ACL entries.
*/
int
generic_acl_chmod(struct inode *inode, struct generic_acl_operations *ops)
{
struct posix_acl *acl, *clone;
int error = 0;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
acl = ops->getacl(inode, ACL_TYPE_ACCESS);
if (acl) {
clone = posix_acl_clone(acl, GFP_KERNEL);
posix_acl_release(acl);
if (!clone)
return -ENOMEM;
error = posix_acl_chmod_masq(clone, inode->i_mode);
if (!error)
ops->setacl(inode, ACL_TYPE_ACCESS, clone);
posix_acl_release(clone);
}
return error;
}
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