Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753489Ab0K3V7A (ORCPT ); Tue, 30 Nov 2010 16:59:00 -0500 Received: from mail-pv0-f174.google.com ([74.125.83.174]:48572 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752915Ab0K3V6Q (ORCPT ); Tue, 30 Nov 2010 16:58:16 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=RlFk7BrdxJQFXlcSYcmCnrlEx7zMHAeDP0fqpfS+pJHdZKv5DMMk0UEka8VnCGUrDG 3YwujbQ55gY/RHU4yOTRnNWgcOvMMSLuItjMEFm8MY4o8iftYXdM8MiGkomAGXJ5Slcs DCT0qUCI/eyCU/428rlp3qTcLgBXzvvQ+3BL0= From: Charles Manning To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Charles Manning Subject: [PATCH 6/8] Add yaffs2 file system: xattrib code Date: Wed, 1 Dec 2010 10:57:32 +1300 Message-Id: <1291154254-22533-7-git-send-email-cdhmanning@gmail.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1291154254-22533-1-git-send-email-cdhmanning@gmail.com> References: <1291154254-22533-1-git-send-email-cdhmanning@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6546 Lines: 257 Signed-off-by: Charles Manning --- fs/yaffs2/yaffs_nameval.c | 201 +++++++++++++++++++++++++++++++++++++++++++++ fs/yaffs2/yaffs_nameval.h | 28 ++++++ 2 files changed, 229 insertions(+), 0 deletions(-) create mode 100644 fs/yaffs2/yaffs_nameval.c create mode 100644 fs/yaffs2/yaffs_nameval.h diff --git a/fs/yaffs2/yaffs_nameval.c b/fs/yaffs2/yaffs_nameval.c new file mode 100644 index 0000000..d8c548a --- /dev/null +++ b/fs/yaffs2/yaffs_nameval.c @@ -0,0 +1,201 @@ +/* + * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. + * + * Copyright (C) 2002-2010 Aleph One Ltd. + * for Toby Churchill Ltd and Brightstar Engineering + * + * Created by Charles Manning + * + * 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 simple implementation of a name-value store assumes a small number of values and fits + * into a small finite buffer. + * + * Each attribute is stored as a record: + * sizeof(int) bytes record size. + * strnlen+1 bytes name null terminated. + * nbytes value. + * ---------- + * total size stored in record size + * + * This code has not been tested with unicode yet. + */ + +#include "yaffs_nameval.h" + +#include "yportenv.h" + +static int nval_find(const char *xb, int xb_size, const YCHAR * name, + int *exist_size) +{ + int pos = 0; + int size; + + memcpy(&size, xb, sizeof(int)); + while (size > 0 && (size < xb_size) && (pos + size < xb_size)) { + if (yaffs_strncmp + ((YCHAR *) (xb + pos + sizeof(int)), name, size) == 0) { + if (exist_size) + *exist_size = size; + return pos; + } + pos += size; + if (pos < xb_size - sizeof(int)) + memcpy(&size, xb + pos, sizeof(int)); + else + size = 0; + } + if (exist_size) + *exist_size = 0; + return -1; +} + +static int nval_used(const char *xb, int xb_size) +{ + int pos = 0; + int size; + + memcpy(&size, xb + pos, sizeof(int)); + while (size > 0 && (size < xb_size) && (pos + size < xb_size)) { + pos += size; + if (pos < xb_size - sizeof(int)) + memcpy(&size, xb + pos, sizeof(int)); + else + size = 0; + } + return pos; +} + +int nval_del(char *xb, int xb_size, const YCHAR * name) +{ + int pos = nval_find(xb, xb_size, name, NULL); + int size; + + if (pos >= 0 && pos < xb_size) { + /* Find size, shift rest over this record, then zero out the rest of buffer */ + memcpy(&size, xb + pos, sizeof(int)); + memcpy(xb + pos, xb + pos + size, xb_size - (pos + size)); + memset(xb + (xb_size - size), 0, size); + return 0; + } else { + return -ENODATA; + } +} + +int nval_set(char *xb, int xb_size, const YCHAR * name, const char *buf, + int bsize, int flags) +{ + int pos; + int namelen = yaffs_strnlen(name, xb_size); + int reclen; + int size_exist = 0; + int space; + int start; + + pos = nval_find(xb, xb_size, name, &size_exist); + + if (flags & XATTR_CREATE && pos >= 0) + return -EEXIST; + if (flags & XATTR_REPLACE && pos < 0) + return -ENODATA; + + start = nval_used(xb, xb_size); + space = xb_size - start + size_exist; + + reclen = (sizeof(int) + namelen + 1 + bsize); + + if (reclen > space) + return -ENOSPC; + + if (pos >= 0) { + nval_del(xb, xb_size, name); + start = nval_used(xb, xb_size); + } + + pos = start; + + memcpy(xb + pos, &reclen, sizeof(int)); + pos += sizeof(int); + yaffs_strncpy((YCHAR *) (xb + pos), name, reclen); + pos += (namelen + 1); + memcpy(xb + pos, buf, bsize); + return 0; +} + +int nval_get(const char *xb, int xb_size, const YCHAR * name, char *buf, + int bsize) +{ + int pos = nval_find(xb, xb_size, name, NULL); + int size; + + if (pos >= 0 && pos < xb_size) { + + memcpy(&size, xb + pos, sizeof(int)); + pos += sizeof(int); /* advance past record length */ + size -= sizeof(int); + + /* Advance over name string */ + while (xb[pos] && size > 0 && pos < xb_size) { + pos++; + size--; + } + /*Advance over NUL */ + pos++; + size--; + + if (size <= bsize) { + memcpy(buf, xb + pos, size); + return size; + } + + } + if (pos >= 0) + return -ERANGE; + else + return -ENODATA; +} + +int nval_list(const char *xb, int xb_size, char *buf, int bsize) +{ + int pos = 0; + int size; + int name_len; + int ncopied = 0; + int filled = 0; + + memcpy(&size, xb + pos, sizeof(int)); + while (size > sizeof(int) && size <= xb_size && (pos + size) < xb_size + && !filled) { + pos += sizeof(int); + size -= sizeof(int); + name_len = yaffs_strnlen((YCHAR *) (xb + pos), size); + if (ncopied + name_len + 1 < bsize) { + memcpy(buf, xb + pos, name_len * sizeof(YCHAR)); + buf += name_len; + *buf = '\0'; + buf++; + if (sizeof(YCHAR) > 1) { + *buf = '\0'; + buf++; + } + ncopied += (name_len + 1); + } else { + filled = 1; + } + pos += size; + if (pos < xb_size - sizeof(int)) + memcpy(&size, xb + pos, sizeof(int)); + else + size = 0; + } + return ncopied; +} + +int nval_hasvalues(const char *xb, int xb_size) +{ + return nval_used(xb, xb_size) > 0; +} diff --git a/fs/yaffs2/yaffs_nameval.h b/fs/yaffs2/yaffs_nameval.h new file mode 100644 index 0000000..2bb02b6 --- /dev/null +++ b/fs/yaffs2/yaffs_nameval.h @@ -0,0 +1,28 @@ +/* + * YAFFS: Yet another Flash File System . A NAND-flash specific file system. + * + * Copyright (C) 2002-2010 Aleph One Ltd. + * for Toby Churchill Ltd and Brightstar Engineering + * + * Created by Charles Manning + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License version 2.1 as + * published by the Free Software Foundation. + * + * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL. + */ + +#ifndef __NAMEVAL_H__ +#define __NAMEVAL_H__ + +#include "yportenv.h" + +int nval_del(char *xb, int xb_size, const YCHAR * name); +int nval_set(char *xb, int xb_size, const YCHAR * name, const char *buf, + int bsize, int flags); +int nval_get(const char *xb, int xb_size, const YCHAR * name, char *buf, + int bsize); +int nval_list(const char *xb, int xb_size, char *buf, int bsize); +int nval_hasvalues(const char *xb, int xb_size); +#endif -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/