[5/7] xattr consolidation - devpts

From: James Morris
Date: Mon Aug 23 2004 - 13:34:02 EST

Next message: James Morris: "[PATCH][6/7] add xattr support to tmpfs"
Previous message: Andi Kleen: "Re: DTrace-like analysis possible with future Linux kernels?"
In reply to: James Morris: "[PATCH][4/7] xattr consolidation - ext2"
Next in thread: James Morris: "[PATCH][6/7] add xattr support to tmpfs"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

This patch updates the devpts xattr handler code to the new libs API, also
adds a GPL notice, author and copyright details.

fs/devpts/xattr.c | 171 +++++++++------------------------------------
fs/devpts/xattr.h | 16 ----
fs/devpts/xattr_security.c | 34 +++++---
3 files changed, 58 insertions(+), 163 deletions(-)

Signed-off-by: James Morris <jmorris@xxxxxxxxxx>
Signed-off-by: Stephen Smalley <sds@xxxxxxxxxxxxxx>

diff -purN -X dontdiff linux-2.6.8.1-mm2.p/fs/devpts/xattr.c linux-2.6.8.1-mm2.w/fs/devpts/xattr.c
--- linux-2.6.8.1-mm2.p/fs/devpts/xattr.c 2004-08-23 01:23:25.470272608 -0400
+++ linux-2.6.8.1-mm2.w/fs/devpts/xattr.c 2004-08-23 01:25:08.832559152 -0400
@@ -1,97 +1,24 @@
/*
- File: fs/devpts/xattr.c
-
- Derived from fs/ext3/xattr.c, changed in the following ways:
- drop everything related to persistent storage of EAs
- pass dentry rather than inode to internal methods
- only presently define a handler for security modules
-*/
-
+ * Pseudo xattr support for devpts.
+ *
+ * Originally derived from fs/ext3/xattr.c, changed in the following ways:
+ * drop everything related to persistent storage of EAs
+ * only presently define a handler for security modules
+ *
+ * Author: Stephen Smalley <sds@xxxxxxxxxxxxxx>
+ * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
#include <linux/init.h>
#include <linux/fs.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-#include <asm/semaphore.h>
#include "xattr.h"

-static struct devpts_xattr_handler *devpts_xattr_handlers[DEVPTS_XATTR_INDEX_MAX];
-static rwlock_t devpts_handler_lock = RW_LOCK_UNLOCKED;
-
-int
-devpts_xattr_register(int name_index, struct devpts_xattr_handler *handler)
-{
- int error = -EINVAL;
-
- if (name_index > 0 && name_index <= DEVPTS_XATTR_INDEX_MAX) {
- write_lock(&devpts_handler_lock);
- if (!devpts_xattr_handlers[name_index-1]) {
- devpts_xattr_handlers[name_index-1] = handler;
- error = 0;
- }
- write_unlock(&devpts_handler_lock);
- }
- return error;
-}
-
-void
-devpts_xattr_unregister(int name_index, struct devpts_xattr_handler *handler)
-{
- if (name_index > 0 || name_index <= DEVPTS_XATTR_INDEX_MAX) {
- write_lock(&devpts_handler_lock);
- devpts_xattr_handlers[name_index-1] = NULL;
- write_unlock(&devpts_handler_lock);
- }
-}
-
-static inline const char *
-strcmp_prefix(const char *a, const char *a_prefix)
-{
- while (*a_prefix && *a == *a_prefix) {
- a++;
- a_prefix++;
- }
- return *a_prefix ? NULL : a;
-}
-
-/*
- * Decode the extended attribute name, and translate it into
- * the name_index and name suffix.
- */
-static inline struct devpts_xattr_handler *
-devpts_xattr_resolve_name(const char **name)
-{
- struct devpts_xattr_handler *handler = NULL;
- int i;
-
- if (!*name)
- return NULL;
- read_lock(&devpts_handler_lock);
- for (i=0; i<DEVPTS_XATTR_INDEX_MAX; i++) {
- if (devpts_xattr_handlers[i]) {
- const char *n = strcmp_prefix(*name,
- devpts_xattr_handlers[i]->prefix);
- if (n) {
- handler = devpts_xattr_handlers[i];
- *name = n;
- break;
- }
- }
- }
- read_unlock(&devpts_handler_lock);
- return handler;
-}
-
-static inline struct devpts_xattr_handler *
-devpts_xattr_handler(int name_index)
-{
- struct devpts_xattr_handler *handler = NULL;
- if (name_index > 0 && name_index <= DEVPTS_XATTR_INDEX_MAX) {
- read_lock(&devpts_handler_lock);
- handler = devpts_xattr_handlers[name_index-1];
- read_unlock(&devpts_handler_lock);
- }
- return handler;
-}
+static struct simple_xattr_handler *devpts_xattr_handlers[SIMPLE_XATTR_MAX];
+static struct simple_xattr_info devpts_xattr_info;

/*
* Inode operation getxattr()
@@ -102,12 +29,13 @@ ssize_t
devpts_getxattr(struct dentry *dentry, const char *name,
void *buffer, size_t size)
{
- struct devpts_xattr_handler *handler;
+ struct simple_xattr_handler *handler;
+ struct inode *inode = dentry->d_inode;

- handler = devpts_xattr_resolve_name(&name);
+ handler = simple_xattr_resolve_name(&devpts_xattr_info, &name);
if (!handler)
return -EOPNOTSUPP;
- return handler->get(dentry, name, buffer, size);
+ return handler->get(inode, name, buffer, size);
}

/*
@@ -116,41 +44,9 @@ devpts_getxattr(struct dentry *dentry, c
* dentry->d_inode->i_sem down
*/
ssize_t
-devpts_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+devpts_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
- struct devpts_xattr_handler *handler = NULL;
- int i, error = 0;
- unsigned int size = 0;
- char *buf;
-
- read_lock(&devpts_handler_lock);
-
- for (i=0; i<DEVPTS_XATTR_INDEX_MAX; i++) {
- handler = devpts_xattr_handlers[i];
- if (handler)
- size += handler->list(dentry, NULL);
- }
-
- if (!buffer) {
- error = size;
- goto out;
- } else {
- error = -ERANGE;
- if (size > buffer_size)
- goto out;
- }
-
- buf = buffer;
- for (i=0; i<DEVPTS_XATTR_INDEX_MAX; i++) {
- handler = devpts_xattr_handlers[i];
- if (handler)
- buf += handler->list(dentry, buf);
- }
- error = size;
-
-out:
- read_unlock(&devpts_handler_lock);
- return size;
+ return simple_xattr_list(&devpts_xattr_info, dentry, buffer, size);
}

/*
@@ -162,14 +58,15 @@ int
devpts_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
- struct devpts_xattr_handler *handler;
+ struct simple_xattr_handler *handler;
+ struct inode *inode = dentry->d_inode;

if (size == 0)
value = ""; /* empty EA, do not remove */
- handler = devpts_xattr_resolve_name(&name);
+ handler = simple_xattr_resolve_name(&devpts_xattr_info, &name);
if (!handler)
return -EOPNOTSUPP;
- return handler->set(dentry, name, value, size, flags);
+ return handler->set(inode, name, value, size, flags);
}

/*
@@ -180,12 +77,13 @@ devpts_setxattr(struct dentry *dentry, c
int
devpts_removexattr(struct dentry *dentry, const char *name)
{
- struct devpts_xattr_handler *handler;
+ struct simple_xattr_handler *handler;
+ struct inode *inode = dentry->d_inode;

- handler = devpts_xattr_resolve_name(&name);
+ handler = simple_xattr_resolve_name(&devpts_xattr_info, &name);
if (!handler)
return -EOPNOTSUPP;
- return handler->set(dentry, name, NULL, 0, XATTR_REPLACE);
+ return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
}

int __init
@@ -193,8 +91,12 @@ init_devpts_xattr(void)
{
#ifdef CONFIG_DEVPTS_FS_SECURITY
int err;
+
+ devpts_xattr_info.lock = RW_LOCK_UNLOCKED;
+ devpts_xattr_info.handlers = devpts_xattr_handlers;

- err = devpts_xattr_register(DEVPTS_XATTR_INDEX_SECURITY,
+ err = simple_xattr_register(&devpts_xattr_info,
+ DEVPTS_XATTR_INDEX_SECURITY,
&devpts_xattr_security_handler);
if (err)
return err;
@@ -207,7 +109,8 @@ void
exit_devpts_xattr(void)
{
#ifdef CONFIG_DEVPTS_FS_SECURITY
- devpts_xattr_unregister(DEVPTS_XATTR_INDEX_SECURITY,
+ simple_xattr_unregister(&devpts_xattr_info,
+ DEVPTS_XATTR_INDEX_SECURITY,
&devpts_xattr_security_handler);
#endif

diff -purN -X dontdiff linux-2.6.8.1-mm2.p/fs/devpts/xattr.h linux-2.6.8.1-mm2.w/fs/devpts/xattr.h
--- linux-2.6.8.1-mm2.p/fs/devpts/xattr.h 2004-08-23 01:23:25.471272456 -0400
+++ linux-2.6.8.1-mm2.w/fs/devpts/xattr.h 2004-08-23 01:19:12.341753992 -0400
@@ -3,7 +3,6 @@

Derived from fs/ext3/xattr.h, changed in the following ways:
drop everything related to persistent storage of EAs
- pass dentry rather than inode to internal methods
only presently define a handler for security modules
*/

@@ -11,23 +10,10 @@
#include <linux/xattr.h>

/* Name indexes */
-#define DEVPTS_XATTR_INDEX_MAX 10
#define DEVPTS_XATTR_INDEX_SECURITY 1

# ifdef CONFIG_DEVPTS_FS_XATTR

-struct devpts_xattr_handler {
- char *prefix;
- size_t (*list)(struct dentry *dentry, char *buffer);
- int (*get)(struct dentry *dentry, const char *name, void *buffer,
- size_t size);
- int (*set)(struct dentry *dentry, const char *name, const void *buffer,
- size_t size, int flags);
-};
-
-extern int devpts_xattr_register(int, struct devpts_xattr_handler *);
-extern void devpts_xattr_unregister(int, struct devpts_xattr_handler *);
-
extern int devpts_setxattr(struct dentry *, const char *, const void *, size_t, int);
extern ssize_t devpts_getxattr(struct dentry *, const char *, void *, size_t);
extern ssize_t devpts_listxattr(struct dentry *, char *, size_t);
@@ -55,5 +41,5 @@ exit_devpts_xattr(void)

# endif /* CONFIG_DEVPTS_FS_XATTR */

-extern struct devpts_xattr_handler devpts_xattr_security_handler;
+extern struct simple_xattr_handler devpts_xattr_security_handler;

diff -purN -X dontdiff linux-2.6.8.1-mm2.p/fs/devpts/xattr_security.c linux-2.6.8.1-mm2.w/fs/devpts/xattr_security.c
--- linux-2.6.8.1-mm2.p/fs/devpts/xattr_security.c 2004-08-23 01:23:25.472272304 -0400
+++ linux-2.6.8.1-mm2.w/fs/devpts/xattr_security.c 2004-08-23 01:25:07.312790192 -0400
@@ -1,38 +1,44 @@
/*
- * File: fs/devpts/xattr_security.c
+ * Security xattr support for devpts.
+ *
+ * Author: Stephen Smalley <sds@xxxxxxxxxxxxxx>
+ * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
*/
-
#include <linux/module.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/security.h>
#include "xattr.h"

-static size_t
-devpts_xattr_security_list(struct dentry *dentry, char *buffer)
+static size_t devpts_xattr_security_list(struct inode *inode, char *list,
+ const char *name, int name_len)
+
{
- return security_inode_listsecurity(dentry, buffer);
+ return security_inode_listsecurity(inode, list);
}

-static int
-devpts_xattr_security_get(struct dentry *dentry, const char *name,
- void *buffer, size_t size)
+static int devpts_xattr_security_get(struct inode *inode, const char *name,
+ void *buffer, size_t size)
{
if (strcmp(name, "") == 0)
return -EINVAL;
- return security_inode_getsecurity(dentry, name, buffer, size);
+ return security_inode_getsecurity(inode, name, buffer, size);
}

-static int
-devpts_xattr_security_set(struct dentry *dentry, const char *name,
- const void *value, size_t size, int flags)
+static int devpts_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(dentry, name, value, size, flags);
+ return security_inode_setsecurity(inode, name, value, size, flags);
}

-struct devpts_xattr_handler devpts_xattr_security_handler = {
+struct simple_xattr_handler devpts_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.list = devpts_xattr_security_list,
.get = devpts_xattr_security_get,

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: James Morris: "[PATCH][6/7] add xattr support to tmpfs"
Previous message: Andi Kleen: "Re: DTrace-like analysis possible with future Linux kernels?"
In reply to: James Morris: "[PATCH][4/7] xattr consolidation - ext2"
Next in thread: James Morris: "[PATCH][6/7] add xattr support to tmpfs"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]