122 lines
3.0 KiB
C
122 lines
3.0 KiB
C
/* Extended attribute handling for AFS. We use xattrs to get and set metadata
|
|
* instead of providing pioctl().
|
|
*
|
|
* Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public Licence
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the Licence, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/slab.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/xattr.h>
|
|
#include "internal.h"
|
|
|
|
static const char afs_xattr_list[] =
|
|
"afs.cell\0"
|
|
"afs.fid\0"
|
|
"afs.volume";
|
|
|
|
/*
|
|
* Retrieve a list of the supported xattrs.
|
|
*/
|
|
ssize_t afs_listxattr(struct dentry *dentry, char *buffer, size_t size)
|
|
{
|
|
if (size == 0)
|
|
return sizeof(afs_xattr_list);
|
|
if (size < sizeof(afs_xattr_list))
|
|
return -ERANGE;
|
|
memcpy(buffer, afs_xattr_list, sizeof(afs_xattr_list));
|
|
return sizeof(afs_xattr_list);
|
|
}
|
|
|
|
/*
|
|
* Get the name of the cell on which a file resides.
|
|
*/
|
|
static int afs_xattr_get_cell(const struct xattr_handler *handler,
|
|
struct dentry *dentry,
|
|
struct inode *inode, const char *name,
|
|
void *buffer, size_t size)
|
|
{
|
|
struct afs_vnode *vnode = AFS_FS_I(inode);
|
|
struct afs_cell *cell = vnode->volume->cell;
|
|
size_t namelen;
|
|
|
|
namelen = cell->name_len;
|
|
if (size == 0)
|
|
return namelen;
|
|
if (namelen > size)
|
|
return -ERANGE;
|
|
memcpy(buffer, cell->name, size);
|
|
return namelen;
|
|
}
|
|
|
|
static const struct xattr_handler afs_xattr_afs_cell_handler = {
|
|
.name = "afs.cell",
|
|
.get = afs_xattr_get_cell,
|
|
};
|
|
|
|
/*
|
|
* Get the volume ID, vnode ID and vnode uniquifier of a file as a sequence of
|
|
* hex numbers separated by colons.
|
|
*/
|
|
static int afs_xattr_get_fid(const struct xattr_handler *handler,
|
|
struct dentry *dentry,
|
|
struct inode *inode, const char *name,
|
|
void *buffer, size_t size)
|
|
{
|
|
struct afs_vnode *vnode = AFS_FS_I(inode);
|
|
char text[8 + 1 + 8 + 1 + 8 + 1];
|
|
size_t len;
|
|
|
|
len = sprintf(text, "%llx:%llx:%x",
|
|
vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
|
|
if (size == 0)
|
|
return len;
|
|
if (len > size)
|
|
return -ERANGE;
|
|
memcpy(buffer, text, len);
|
|
return len;
|
|
}
|
|
|
|
static const struct xattr_handler afs_xattr_afs_fid_handler = {
|
|
.name = "afs.fid",
|
|
.get = afs_xattr_get_fid,
|
|
};
|
|
|
|
/*
|
|
* Get the name of the volume on which a file resides.
|
|
*/
|
|
static int afs_xattr_get_volume(const struct xattr_handler *handler,
|
|
struct dentry *dentry,
|
|
struct inode *inode, const char *name,
|
|
void *buffer, size_t size)
|
|
{
|
|
struct afs_vnode *vnode = AFS_FS_I(inode);
|
|
const char *volname = vnode->volume->name;
|
|
size_t namelen;
|
|
|
|
namelen = strlen(volname);
|
|
if (size == 0)
|
|
return namelen;
|
|
if (namelen > size)
|
|
return -ERANGE;
|
|
memcpy(buffer, volname, size);
|
|
return namelen;
|
|
}
|
|
|
|
static const struct xattr_handler afs_xattr_afs_volume_handler = {
|
|
.name = "afs.volume",
|
|
.get = afs_xattr_get_volume,
|
|
};
|
|
|
|
const struct xattr_handler *afs_xattr_handlers[] = {
|
|
&afs_xattr_afs_cell_handler,
|
|
&afs_xattr_afs_fid_handler,
|
|
&afs_xattr_afs_volume_handler,
|
|
NULL
|
|
};
|