From: James Morris <jmorris@redhat.com>
This patch adds xattr support to tmpfs, and a security xattr handler. The
purpose of this is to allow udev to be mounted on tmpfs, as used currently by
Fedora.
Original patch from: Luke Kenneth Casson Leighton <lkcl@lkcl.net>.
Signed-off-by: James Morris <jmorris@redhat.com>
Signed-off-by: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/Kconfig | 21 ++++++++++++
25-akpm/mm/shmem.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 111 insertions(+)
diff -puN fs/Kconfig~xattr-consolidation-v3-tmpfs fs/Kconfig
--- 25/fs/Kconfig~xattr-consolidation-v3-tmpfs 2004-09-23 00:09:02.466579600 -0700
+++ 25-akpm/fs/Kconfig 2004-09-23 00:09:02.473578536 -0700
@@ -944,6 +944,27 @@ config TMPFS
See <file:Documentation/filesystems/tmpfs.txt> for details.
+config TMPFS_XATTR
+ bool "tmpfs Extended Attributes"
+ depends on TMPFS
+ help
+ Extended attributes are name:value pairs associated with inodes by
+ the kernel or by users (see the attr(5) manual page, or visit
+ <http://acl.bestbits.at/> for details).
+
+ If unsure, say N.
+
+config TMPFS_SECURITY
+ bool "tmpfs Security Labels"
+ depends on TMPFS_XATTR
+ help
+ Security labels support alternative access control models
+ implemented by security modules like SELinux. This option
+ enables an extended attribute handler for file security
+ labels in the tmpfs filesystem.
+ If you are not using a security module that requires using
+ extended attributes for file security labels, say N.
+
config HUGETLBFS
bool "HugeTLB file system support"
depends X86 || IA64 || PPC64 || SPARC64 || SUPERH || X86_64 || BROKEN
diff -puN mm/shmem.c~xattr-consolidation-v3-tmpfs mm/shmem.c
--- 25/mm/shmem.c~xattr-consolidation-v3-tmpfs 2004-09-23 00:09:02.468579296 -0700
+++ 25-akpm/mm/shmem.c 2004-09-23 00:09:02.476578080 -0700
@@ -10,6 +10,10 @@
* Copyright (C) 2002-2004 VERITAS Software Corporation.
* Copyright (C) 2004 Andi Kleen, SuSE Labs
*
+ * Extended attribute support for tmpfs:
+ * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net>
+ * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
+ *
* This file is released under the GPL.
*/
@@ -41,6 +45,7 @@
#include <linux/swapops.h>
#include <linux/mempolicy.h>
#include <linux/namei.h>
+#include <linux/xattr.h>
#include <asm/uaccess.h>
#include <asm/div64.h>
#include <asm/pgtable.h>
@@ -171,6 +176,7 @@ static struct address_space_operations s
static struct file_operations shmem_file_operations;
static struct inode_operations shmem_inode_operations;
static struct inode_operations shmem_dir_inode_operations;
+static struct inode_operations shmem_special_inode_operations;
static struct vm_operations_struct shmem_vm_ops;
static struct backing_dev_info shmem_backing_dev_info = {
@@ -1235,6 +1241,7 @@ shmem_get_inode(struct super_block *sb,
switch (mode & S_IFMT) {
default:
+ inode->i_op = &shmem_special_inode_operations;
init_special_inode(inode, mode, dev);
break;
case S_IFREG:
@@ -1756,6 +1763,12 @@ static void shmem_put_link(struct dentry
static struct inode_operations shmem_symlink_inline_operations = {
.readlink = generic_readlink,
.follow_link = shmem_follow_link_inline,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
+#endif
};
static struct inode_operations shmem_symlink_inode_operations = {
@@ -1763,6 +1776,12 @@ static struct inode_operations shmem_sym
.readlink = generic_readlink,
.follow_link = shmem_follow_link,
.put_link = shmem_put_link,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
+#endif
};
static int shmem_parse_options(char *options, int *mode, uid_t *uid, gid_t *gid, unsigned long *blocks, unsigned long *inodes)
@@ -1862,6 +1881,12 @@ static void shmem_put_super(struct super
sb->s_fs_info = NULL;
}
+#ifdef CONFIG_TMPFS_XATTR
+static struct xattr_handler *shmem_xattr_handlers[];
+#else
+#define shmem_xattr_handlers NULL
+#endif
+
static int shmem_fill_super(struct super_block *sb,
void *data, int silent)
{
@@ -1904,6 +1929,7 @@ static int shmem_fill_super(struct super
sbinfo->max_inodes = inodes;
sbinfo->free_inodes = inodes;
}
+ sb->s_xattr = shmem_xattr_handlers;
#endif
sb->s_maxbytes = SHMEM_MAX_BYTES;
@@ -1995,6 +2021,12 @@ static struct file_operations shmem_file
static struct inode_operations shmem_inode_operations = {
.truncate = shmem_truncate,
.setattr = shmem_notify_change,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
+#endif
};
static struct inode_operations shmem_dir_inode_operations = {
@@ -2008,6 +2040,21 @@ static struct inode_operations shmem_dir
.rmdir = shmem_rmdir,
.mknod = shmem_mknod,
.rename = shmem_rename,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
+#endif
+#endif
+};
+
+static struct inode_operations shmem_special_inode_operations = {
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
#endif
};
@@ -2032,6 +2079,49 @@ static struct vm_operations_struct shmem
#endif
};
+
+#ifdef CONFIG_TMPFS_SECURITY
+
+static size_t shmem_xattr_security_list(struct inode *inode, char *list, size_t list_len,
+ const char *name, size_t name_len)
+{
+ return security_inode_listsecurity(inode, list, name_len);
+}
+
+static int shmem_xattr_security_get(struct inode *inode, const char *name, void *buffer, size_t size)
+{
+ if (strcmp(name, "") == 0)
+ return -EINVAL;
+ return security_inode_getsecurity(inode, name, buffer, size);
+}
+
+static int shmem_xattr_security_set(struct inode *inode, const char *name, const void *value, size_t size, int flags)
+{
+ if (strcmp(name, "") == 0)
+ return -EINVAL;
+ return security_inode_setsecurity(inode, name, value, size, flags);
+}
+
+struct xattr_handler shmem_xattr_security_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .list = shmem_xattr_security_list,
+ .get = shmem_xattr_security_get,
+ .set = shmem_xattr_security_set,
+};
+
+#endif /* CONFIG_TMPFS_SECURITY */
+
+#ifdef CONFIG_TMPFS_XATTR
+
+static struct xattr_handler *shmem_xattr_handlers[] = {
+#ifdef CONFIG_TMPFS_SECURITY
+ &shmem_xattr_security_handler,
+#endif
+ NULL
+};
+
+#endif /* CONFIG_TMPFS_XATTR */
+
static struct super_block *shmem_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
_