ocfs2: Add extended attribute support

This patch implements storing extended attributes both in inode or a single
external block. We only store EA's in-inode when blocksize > 512 or that
inode block has free space for it. When an EA's value is larger than 80
bytes, we will store the value via b-tree outside inode or block.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 94 insertions, 0 deletions

diff --git a/fs/ocfs2/xattr_user.c b/fs/ocfs2/xattr_user.c
new file mode 100644
index 000000000000..93ba71637788
--- /dev/null
+++ b/fs/ocfs2/xattr_user.c
@@ -0,0 +1,94 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * xattr_user.c
+ *
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ *
+ * CREDITS:
+ * Lots of code in this file is taken from ext3.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#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"
+
+#define XATTR_USER_PREFIX "user."
+
+static size_t ocfs2_xattr_user_list(struct inode *inode, char *list,
+                                    size_t list_size, const char *name,
+                                    size_t name_len)
+{
+        const size_t prefix_len = sizeof(XATTR_USER_PREFIX) - 1;
+        const size_t total_len = prefix_len + name_len + 1;
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+        if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
+                return 0;
+
+        if (list && total_len <= list_size) {
+                memcpy(list, XATTR_USER_PREFIX, prefix_len);
+                memcpy(list + prefix_len, name, name_len);
+                list[prefix_len + name_len] = '\0';
+        }
+        return total_len;
+}
+
+static int ocfs2_xattr_user_get(struct inode *inode, const char *name,
+                                void *buffer, size_t size)
+{
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
+                return -EOPNOTSUPP;
+        return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_USER, name,
+                               buffer, size);
+}
+
+static int ocfs2_xattr_user_set(struct inode *inode, const char *name,
+                                const void *value, size_t size, int flags)
+{
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
+                return -EOPNOTSUPP;
+
+        return ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_USER, name, value,
+                               size, flags);
+}
+
+struct xattr_handler ocfs2_xattr_user_handler = {
+        .prefix = XATTR_USER_PREFIX,
+        .list   = ocfs2_xattr_user_list,
+        .get    = ocfs2_xattr_user_get,
+        .set    = ocfs2_xattr_user_set,
+};