security: new security_inode_init_security API adds function callback

This patch changes the security_inode_init_security API by adding a
filesystem specific callback to write security extended attributes.
This change is in preparation for supporting the initialization of
multiple LSM xattrs and the EVM xattr.  Initially the callback function
walks an array of xattrs, writing each xattr separately, but could be
optimized to write multiple xattrs at once.

For existing security_inode_init_security() calls, which have not yet
been converted to use the new callback function, such as those in
reiserfs and ocfs2, this patch defines security_old_inode_init_security().

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>

1 files changed, 28 insertions, 29 deletions

diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index 24838f1eeee5..e982509292f8 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -1091,38 +1091,37 @@ int jfs_removexattr(struct dentry *dentry, const char *name)
 }
 
 #ifdef CONFIG_JFS_SECURITY
-int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
-		      const struct qstr *qstr)
+int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+		   void *fs_info)
 {
-	int rc;
-	size_t len;
-	void *value;
-	char *suffix;
+	const struct xattr *xattr;
+	tid_t *tid = fs_info;
 	char *name;
-
-	rc = security_inode_init_security(inode, dir, qstr, &suffix, &value,
-					  &len);
-	if (rc) {
-		if (rc == -EOPNOTSUPP)
-			return 0;
-		return rc;
-	}
-	name = kmalloc(XATTR_SECURITY_PREFIX_LEN + 1 + strlen(suffix),
-		       GFP_NOFS);
-	if (!name) {
-		rc = -ENOMEM;
-		goto kmalloc_failed;
+	int err = 0;
+
+	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+		name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
+			       strlen(xattr->name) + 1, GFP_NOFS);
+		if (!name) {
+			err = -ENOMEM;
+			break;
+		}
+		strcpy(name, XATTR_SECURITY_PREFIX);
+		strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
+
+		err = __jfs_setxattr(*tid, inode, name,
+				     xattr->value, xattr->value_len, 0);
+		kfree(name);
+		if (err < 0)
+			break;
 	}
-	strcpy(name, XATTR_SECURITY_PREFIX);
-	strcpy(name + XATTR_SECURITY_PREFIX_LEN, suffix);
-
-	rc = __jfs_setxattr(tid, inode, name, value, len, 0);
-
-	kfree(name);
-kmalloc_failed:
-	kfree(suffix);
-	kfree(value);
+	return err;
+}
 
-	return rc;
+int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
+		      const struct qstr *qstr)
+{
+	return security_inode_init_security(inode, dir, qstr,
+					    &jfs_initxattrs, &tid);
 }
 #endif