2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-15 16:53:54 +08:00

ext4: support xattr gnu.* namespace for the Hurd

The Hurd gained[0] support for moving the translator and author
fields out of the inode and into the "gnu.*" xattr namespace.

In anticipation of that, an xattr INDEX was reserved[1].  The Hurd has
now been brought into compliance[2] with that.

This patch adds support for reading and writing such attributes from
Linux; you can now do something like

    mkdir -p hurd-root/servers/socket
    touch hurd-root/servers/socket/1
    setfattr --name=gnu.translator --value='"/hurd/pflocal\0"' \
        hurd-root/servers/socket/1
    getfattr --name=gnu.translator hurd-root/servers/socket/1
    # file: 1
    gnu.translator="/hurd/pflocal"

to setup a pipe translator, which is being used to create[3] a
vm-image for the Hurd from GNU Guix.

[0] https://summerofcode.withgoogle.com/projects/#5869799859027968
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3980bd3b406addb327d858aebd19e229ea340b9a
[2] https://git.savannah.gnu.org/cgit/hurd/hurd.git/commit/?id=a04c7bf83172faa7cb080fbe3b6c04a8415ca645
[3] https://git.savannah.gnu.org/cgit/guix.git/log/?h=wip-hurd-vm

Signed-off-by: Jan Nieuwenhuizen <janneke@gnu.org>
Link: https://lore.kernel.org/r/20200525193940.878-1-janneke@gnu.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Jan (janneke) Nieuwenhuizen 2020-05-25 21:39:40 +02:00 committed by Theodore Ts'o
parent 8119853653
commit 88ee9d571b
5 changed files with 60 additions and 1 deletions

View File

@ -9,7 +9,8 @@ ext4-y := balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \
extents_status.o file.o fsmap.o fsync.o hash.o ialloc.o \
indirect.o inline.o inode.o ioctl.o mballoc.o migrate.o \
mmp.o move_extent.o namei.o page-io.o readpage.o resize.o \
super.o symlink.o sysfs.o xattr.o xattr_trusted.o xattr_user.o
super.o symlink.o sysfs.o xattr.o xattr_hurd.o xattr_trusted.o \
xattr_user.o
ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o
ext4-$(CONFIG_EXT4_FS_SECURITY) += xattr_security.o

View File

@ -93,6 +93,7 @@ static const struct xattr_handler * const ext4_xattr_handler_map[] = {
#ifdef CONFIG_EXT4_FS_SECURITY
[EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler,
#endif
[EXT4_XATTR_INDEX_HURD] = &ext4_xattr_hurd_handler,
};
const struct xattr_handler *ext4_xattr_handlers[] = {
@ -105,6 +106,7 @@ const struct xattr_handler *ext4_xattr_handlers[] = {
#ifdef CONFIG_EXT4_FS_SECURITY
&ext4_xattr_security_handler,
#endif
&ext4_xattr_hurd_handler,
NULL
};

View File

@ -124,6 +124,7 @@ struct ext4_xattr_inode_array {
extern const struct xattr_handler ext4_xattr_user_handler;
extern const struct xattr_handler ext4_xattr_trusted_handler;
extern const struct xattr_handler ext4_xattr_security_handler;
extern const struct xattr_handler ext4_xattr_hurd_handler;
#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"

51
fs/ext4/xattr_hurd.c Normal file
View File

@ -0,0 +1,51 @@
// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/ext4/xattr_hurd.c
* Handler for extended gnu attributes for the Hurd.
*
* Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
* Copyright (C) 2020 by Jan (janneke) Nieuwenhuizen, <janneke@gnu.org>
*/
#include <linux/init.h>
#include <linux/string.h>
#include "ext4.h"
#include "xattr.h"
static bool
ext4_xattr_hurd_list(struct dentry *dentry)
{
return test_opt(dentry->d_sb, XATTR_USER);
}
static int
ext4_xattr_hurd_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *name, void *buffer, size_t size)
{
if (!test_opt(inode->i_sb, XATTR_USER))
return -EOPNOTSUPP;
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_HURD,
name, buffer, size);
}
static int
ext4_xattr_hurd_set(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *name, const void *value,
size_t size, int flags)
{
if (!test_opt(inode->i_sb, XATTR_USER))
return -EOPNOTSUPP;
return ext4_xattr_set(inode, EXT4_XATTR_INDEX_HURD,
name, value, size, flags);
}
const struct xattr_handler ext4_xattr_hurd_handler = {
.prefix = XATTR_HURD_PREFIX,
.list = ext4_xattr_hurd_list,
.get = ext4_xattr_hurd_get,
.set = ext4_xattr_hurd_set,
};

View File

@ -7,6 +7,7 @@
Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved.
Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
Copyright (c) 2020 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
*/
#include <linux/libc-compat.h>
@ -31,6 +32,9 @@
#define XATTR_BTRFS_PREFIX "btrfs."
#define XATTR_BTRFS_PREFIX_LEN (sizeof(XATTR_BTRFS_PREFIX) - 1)
#define XATTR_HURD_PREFIX "gnu."
#define XATTR_HURD_PREFIX_LEN (sizeof(XATTR_HURD_PREFIX) - 1)
#define XATTR_SECURITY_PREFIX "security."
#define XATTR_SECURITY_PREFIX_LEN (sizeof(XATTR_SECURITY_PREFIX) - 1)