ocfs2: add POSIX ACL API
This patch adds POSIX ACL(access control lists) APIs in ocfs2. We convert
struct posix_acl to many ocfs2_acl_entry and regard them as an extended
attribute entry.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
new file mode 100644
index 0000000..62d0faa
--- /dev/null
+++ b/fs/ocfs2/acl.c
@@ -0,0 +1,378 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * acl.c
+ *
+ * Copyright (C) 2004, 2008 Oracle. All rights reserved.
+ *
+ * CREDITS:
+ * Lots of code in this file is copy from linux/fs/ext3/acl.c.
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#define MLOG_MASK_PREFIX ML_INODE
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+#include "alloc.h"
+#include "dlmglue.h"
+#include "file.h"
+#include "ocfs2_fs.h"
+
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Convert from xattr value to acl struct.
+ */
+static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
+{
+ int n, count;
+ struct posix_acl *acl;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(struct posix_acl_entry))
+ return ERR_PTR(-EINVAL);
+
+ count = size / sizeof(struct posix_acl_entry);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+
+ acl = posix_acl_alloc(count, GFP_NOFS);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+ for (n = 0; n < count; n++) {
+ struct ocfs2_acl_entry *entry =
+ (struct ocfs2_acl_entry *)value;
+
+ acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
+ acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
+ acl->a_entries[n].e_id = le32_to_cpu(entry->e_id);
+ value += sizeof(struct posix_acl_entry);
+
+ }
+ return acl;
+}
+
+/*
+ * Convert acl struct to xattr value.
+ */
+static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
+{
+ struct ocfs2_acl_entry *entry = NULL;
+ char *ocfs2_acl;
+ size_t n;
+
+ *size = acl->a_count * sizeof(struct posix_acl_entry);
+
+ ocfs2_acl = kmalloc(*size, GFP_NOFS);
+ if (!ocfs2_acl)
+ return ERR_PTR(-ENOMEM);
+
+ entry = (struct ocfs2_acl_entry *)ocfs2_acl;
+ for (n = 0; n < acl->a_count; n++, entry++) {
+ entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
+ entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
+ entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
+ }
+ return ocfs2_acl;
+}
+
+static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
+ int type,
+ struct buffer_head *di_bh)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ int name_index;
+ char *value = NULL;
+ struct posix_acl *acl;
+ int retval;
+
+ if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
+ return NULL;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
+ if (retval > 0) {
+ value = kmalloc(retval, GFP_NOFS);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
+ "", value, retval);
+ }
+
+ if (retval > 0)
+ acl = ocfs2_acl_from_xattr(value, retval);
+ else if (retval == -ENODATA || retval == 0)
+ acl = NULL;
+ else
+ acl = ERR_PTR(retval);
+
+ kfree(value);
+
+ return acl;
+}
+
+
+/*
+ * Get posix acl.
+ */
+static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct buffer_head *di_bh = NULL;
+ struct posix_acl *acl;
+ int ret;
+
+ if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
+ return NULL;
+
+ ret = ocfs2_inode_lock(inode, &di_bh, 0);
+ if (ret < 0) {
+ mlog_errno(ret);
+ acl = ERR_PTR(ret);
+ return acl;
+ }
+
+ acl = ocfs2_get_acl_nolock(inode, type, di_bh);
+
+ ocfs2_inode_unlock(inode, 0);
+
+ brelse(di_bh);
+
+ return acl;
+}
+
+/*
+ * Set the access or default ACL of an inode.
+ */
+static int ocfs2_set_acl(handle_t *handle,
+ struct inode *inode,
+ struct buffer_head *di_bh,
+ int type,
+ struct posix_acl *acl,
+ struct ocfs2_alloc_context *meta_ac,
+ struct ocfs2_alloc_context *data_ac)
+{
+ int name_index;
+ void *value = NULL;
+ size_t size = 0;
+ int ret;
+
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
+ if (acl) {
+ mode_t mode = inode->i_mode;
+ ret = posix_acl_equiv_mode(acl, &mode);
+ if (ret < 0)
+ return ret;
+ else {
+ inode->i_mode = mode;
+ if (ret == 0)
+ acl = NULL;
+ }
+ }
+ break;
+ case ACL_TYPE_DEFAULT:
+ name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (acl) {
+ value = ocfs2_acl_to_xattr(acl, &size);
+ if (IS_ERR(value))
+ return (int)PTR_ERR(value);
+ }
+
+ if (handle)
+ ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
+ "", value, size, 0,
+ meta_ac, data_ac);
+ else
+ ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
+
+ kfree(value);
+
+ return ret;
+}
+
+static size_t ocfs2_xattr_list_acl_access(struct inode *inode,
+ char *list,
+ size_t list_len,
+ const char *name,
+ size_t name_len)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
+
+ if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
+ return 0;
+
+ if (list && size <= list_len)
+ memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
+ return size;
+}
+
+static size_t ocfs2_xattr_list_acl_default(struct inode *inode,
+ char *list,
+ size_t list_len,
+ const char *name,
+ size_t name_len)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
+
+ if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
+ return 0;
+
+ if (list && size <= list_len)
+ memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
+ return size;
+}
+
+static int ocfs2_xattr_get_acl(struct inode *inode,
+ int type,
+ void *buffer,
+ size_t size)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct posix_acl *acl;
+ int ret;
+
+ if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
+ return -EOPNOTSUPP;
+
+ acl = ocfs2_get_acl(inode, type);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl == NULL)
+ return -ENODATA;
+ ret = posix_acl_to_xattr(acl, buffer, size);
+ posix_acl_release(acl);
+
+ return ret;
+}
+
+static int ocfs2_xattr_get_acl_access(struct inode *inode,
+ const char *name,
+ void *buffer,
+ size_t size)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return ocfs2_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
+}
+
+static int ocfs2_xattr_get_acl_default(struct inode *inode,
+ const char *name,
+ void *buffer,
+ size_t size)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return ocfs2_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
+}
+
+static int ocfs2_xattr_set_acl(struct inode *inode,
+ int type,
+ const void *value,
+ size_t size)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct posix_acl *acl;
+ int ret = 0;
+
+ if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
+ return -EOPNOTSUPP;
+
+ if (!is_owner_or_cap(inode))
+ return -EPERM;
+
+ if (value) {
+ acl = posix_acl_from_xattr(value, size);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ else if (acl) {
+ ret = posix_acl_valid(acl);
+ if (ret)
+ goto cleanup;
+ }
+ } else
+ acl = NULL;
+
+ ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
+
+cleanup:
+ posix_acl_release(acl);
+ return ret;
+}
+
+static int ocfs2_xattr_set_acl_access(struct inode *inode,
+ const char *name,
+ const void *value,
+ size_t size,
+ int flags)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return ocfs2_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int ocfs2_xattr_set_acl_default(struct inode *inode,
+ const char *name,
+ const void *value,
+ size_t size,
+ int flags)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return ocfs2_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+struct xattr_handler ocfs2_xattr_acl_access_handler = {
+ .prefix = POSIX_ACL_XATTR_ACCESS,
+ .list = ocfs2_xattr_list_acl_access,
+ .get = ocfs2_xattr_get_acl_access,
+ .set = ocfs2_xattr_set_acl_access,
+};
+
+struct xattr_handler ocfs2_xattr_acl_default_handler = {
+ .prefix = POSIX_ACL_XATTR_DEFAULT,
+ .list = ocfs2_xattr_list_acl_default,
+ .get = ocfs2_xattr_get_acl_default,
+ .set = ocfs2_xattr_set_acl_default,
+};