From: James Morris 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 . Signed-off-by: James Morris Signed-off-by: Stephen Smalley Signed-off-by: Andrew Morton --- 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 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 + 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 + * Copyright (c) 2004 Red Hat, Inc., James Morris + * * This file is released under the GPL. */ @@ -41,6 +45,7 @@ #include #include #include +#include #include #include #include @@ -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) { _