From: Thadeu Lima de Souza Cascardo Subject: [PATCH] Support for "gnu" extended attributes namespace for ext4 Date: Thu, 12 Jun 2008 13:27:37 -0300 Message-ID: <20080612162737.GC13745@vespa.holoscopio.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: linux-ext4@vger.kernel.org Return-path: Received: from liberdade.minaslivre.org ([72.232.18.203]:41845 "EHLO liberdade.minaslivre.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752512AbYFLRC2 (ORCPT ); Thu, 12 Jun 2008 13:02:28 -0400 Received: from vespa.holoscopio.com (unknown [201.80.63.222]) by liberdade.minaslivre.org (Postfix) with ESMTP id 87B46208D71 for ; Thu, 12 Jun 2008 13:33:15 -0300 (BRT) Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: This support is needed for GNU Hurd, for things like active translators. --- fs/ext4/Makefile | 3 +- fs/ext4/xattr.c | 2 + fs/ext4/xattr.h | 2 + fs/ext4/xattr_gnu.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 68 insertions(+), 1 deletions(-) create mode 100644 fs/ext4/xattr_gnu.c diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile index ac6fa8c..b148ba8 100644 --- a/fs/ext4/Makefile +++ b/fs/ext4/Makefile @@ -8,6 +8,7 @@ ext4dev-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \ ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \ ext4_jbd2.o migrate.o mballoc.o -ext4dev-$(CONFIG_EXT4DEV_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o +ext4dev-$(CONFIG_EXT4DEV_FS_XATTR) += xattr.o xattr_user.o \ + xattr_trusted.o xattr_gnu.o ext4dev-$(CONFIG_EXT4DEV_FS_POSIX_ACL) += acl.o ext4dev-$(CONFIG_EXT4DEV_FS_SECURITY) += xattr_security.o diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index ff08633..6c47327 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -107,6 +107,7 @@ static struct xattr_handler *ext4_xattr_handler_map[] = { #ifdef CONFIG_EXT4DEV_FS_SECURITY [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, #endif + [EXT4_XATTR_INDEX_GNU] = &ext4_xattr_gnu_handler, }; struct xattr_handler *ext4_xattr_handlers[] = { @@ -119,6 +120,7 @@ struct xattr_handler *ext4_xattr_handlers[] = { #ifdef CONFIG_EXT4DEV_FS_SECURITY &ext4_xattr_security_handler, #endif + &ext4_xattr_gnu_handler, NULL }; diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index 5992fe9..bb481b4 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -21,6 +21,7 @@ #define EXT4_XATTR_INDEX_TRUSTED 4 #define EXT4_XATTR_INDEX_LUSTRE 5 #define EXT4_XATTR_INDEX_SECURITY 6 +#define EXT4_XATTR_INDEX_GNU 7 struct ext4_xattr_header { __le32 h_magic; /* magic number for identification */ @@ -70,6 +71,7 @@ extern struct xattr_handler ext4_xattr_trusted_handler; extern struct xattr_handler ext4_xattr_acl_access_handler; extern struct xattr_handler ext4_xattr_acl_default_handler; extern struct xattr_handler ext4_xattr_security_handler; +extern struct xattr_handler ext4_xattr_gnu_handler; extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); diff --git a/fs/ext4/xattr_gnu.c b/fs/ext4/xattr_gnu.c new file mode 100644 index 0000000..039f839 --- /dev/null +++ b/fs/ext4/xattr_gnu.c @@ -0,0 +1,62 @@ +/* + * linux/fs/ext4/xattr_gnu.c + * Handler for gnu extended attributes. + * + * Copyright (C) 2003 by Andreas Gruenbacher, + * Copyright Thadeu Lima de Souza Cascardo + */ + +#include +#include +#include +#include +#include +#include +#include "xattr.h" + +#define XATTR_GNU_PREFIX "gnu." + +static size_t +ext4_xattr_gnu_list(struct inode *inode, char *list, size_t list_size, + const char *name, size_t name_len) +{ + const size_t prefix_len = sizeof(XATTR_GNU_PREFIX)-1; + const size_t total_len = prefix_len + name_len + 1; + + if (!capable(CAP_SYS_ADMIN)) + return 0; + + if (list && total_len <= list_size) { + memcpy(list, XATTR_GNU_PREFIX, prefix_len); + memcpy(list+prefix_len, name, name_len); + list[prefix_len + name_len] = '\0'; + } + return total_len; +} + +static int +ext4_xattr_gnu_get(struct inode *inode, const char *name, + void *buffer, size_t size) +{ + if (strcmp(name, "") == 0) + return -EINVAL; + return ext4_xattr_get(inode, EXT4_XATTR_INDEX_GNU, name, + buffer, size); +} + +static int +ext4_xattr_gnu_set(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + if (strcmp(name, "") == 0) + return -EINVAL; + return ext4_xattr_set(inode, EXT4_XATTR_INDEX_GNU, name, + value, size, flags); +} + +struct xattr_handler ext4_xattr_gnu_handler = { + .prefix = XATTR_GNU_PREFIX, + .list = ext4_xattr_gnu_list, + .get = ext4_xattr_gnu_get, + .set = ext4_xattr_gnu_set, +}; -- 1.5.5.4