diff options
author | Jan (janneke) Nieuwenhuizen <janneke@gnu.org> | 2020-05-25 21:39:40 +0200 |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2020-06-12 13:23:34 -0400 |
commit | 88ee9d571b6d8ed345f877e05f685814412e359b (patch) | |
tree | 936b3248c3a5eed5b54eeda3e6c04e210c73399f | |
parent | 811985365378df01386c3cfb7ff716e74ca376d5 (diff) | |
download | linux-88ee9d571b6d8ed345f877e05f685814412e359b.tar.bz2 |
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>
-rw-r--r-- | fs/ext4/Makefile | 3 | ||||
-rw-r--r-- | fs/ext4/xattr.c | 2 | ||||
-rw-r--r-- | fs/ext4/xattr.h | 1 | ||||
-rw-r--r-- | fs/ext4/xattr_hurd.c | 51 | ||||
-rw-r--r-- | include/uapi/linux/xattr.h | 4 |
5 files changed, 60 insertions, 1 deletions
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile index 4ccb3c9189d8..2e42f47a7f98 100644 --- a/fs/ext4/Makefile +++ b/fs/ext4/Makefile @@ -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 diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 9b29a40738ac..7d2f6576d954 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -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 }; diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index ffe21ac77f78..730b91fa0dd7 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -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" diff --git a/fs/ext4/xattr_hurd.c b/fs/ext4/xattr_hurd.c new file mode 100644 index 000000000000..8cfa74a56361 --- /dev/null +++ b/fs/ext4/xattr_hurd.c @@ -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, +}; diff --git a/include/uapi/linux/xattr.h b/include/uapi/linux/xattr.h index c1395b5bd432..9463db2dfa9d 100644 --- a/include/uapi/linux/xattr.h +++ b/include/uapi/linux/xattr.h @@ -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) |