From patchwork Mon Nov 24 09:07:01 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 5364141 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D8604C11AC for ; Mon, 24 Nov 2014 09:09:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A99A52034A for ; Mon, 24 Nov 2014 09:09:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81A6B202FF for ; Mon, 24 Nov 2014 09:09:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753038AbaKXJJU (ORCPT ); Mon, 24 Nov 2014 04:09:20 -0500 Received: from cn.fujitsu.com ([59.151.112.132]:33070 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752931AbaKXJJQ (ORCPT ); Mon, 24 Nov 2014 04:09:16 -0500 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="43879628" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 24 Nov 2014 17:05:57 +0800 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id sAO98t7D012236 for ; Mon, 24 Nov 2014 17:08:55 +0800 Received: from localhost.localdomain (10.167.226.33) by G08CNEXCHPEKD02.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Mon, 24 Nov 2014 17:09:15 +0800 From: Qu Wenruo To: Subject: [PATCH 2/6] btrfs-progs: Import btrfs_insert/del/lookup_extref() functions. Date: Mon, 24 Nov 2014 17:07:01 +0800 Message-ID: <1416820025-10373-3-git-send-email-quwenruo@cn.fujitsu.com> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1416820025-10373-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1416820025-10373-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.33] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Import btrfs_insert/del/lookup_extref() functions form kernel for the incoming btrfs_add_link() and btrfs_unlink() functions. As the base of incoming btrfs 'lost+found' recovery mechanism. Signed-off-by: Qu Wenruo --- ctree.h | 14 ++++ inode-item.c | 206 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 220 insertions(+) diff --git a/ctree.h b/ctree.h index 89036de..e185e7a 100644 --- a/ctree.h +++ b/ctree.h @@ -2389,6 +2389,20 @@ int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *location, int mod); +struct btrfs_inode_extref +*btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans, + struct btrfs_path *path, struct btrfs_root *root, + u64 ino, u64 parent_ino, u64 index, const char *name, + int namelen, int ins_len); +int btrfs_del_inode_extref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + const char *name, int name_len, + u64 inode_objectid, u64 ref_objectid, + u64 *index); +int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + const char *name, int name_len, + u64 inode_objectid, u64 ref_objectid, u64 index); /* file-item.c */ int btrfs_del_csums(struct btrfs_trans_handle *trans, diff --git a/inode-item.c b/inode-item.c index 8cc98c6..7337ac9 100644 --- a/inode-item.c +++ b/inode-item.c @@ -19,6 +19,7 @@ #include "ctree.h" #include "disk-io.h" #include "transaction.h" +#include "crc32c.h" static int find_name_in_backref(struct btrfs_path *path, const char * name, int name_len, struct btrfs_inode_ref **ref_ret) @@ -145,3 +146,208 @@ int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root sizeof(*inode_item)); return ret; } + +static inline u64 btrfs_extref_hash(u64 parent_ino, const char *name, + int namelen) +{ + return (u64) btrfs_crc32c(parent_ino, name, namelen); +} + +static int +btrfs_find_name_in_ext_backref(struct btrfs_path *path, + u64 parent_ino, const char *name, + int namelen, + struct btrfs_inode_extref **extref_ret) +{ + struct extent_buffer *node; + struct btrfs_inode_extref *extref; + unsigned long ptr; + unsigned long name_ptr; + u32 item_size; + u32 cur_offset = 0; + int ref_name_len; + int slot; + + node = path->nodes[0]; + slot = path->slots[0]; + item_size = btrfs_item_size_nr(node, slot); + ptr = btrfs_item_ptr_offset(node, slot); + + /* + * Search all extended backrefs in this item. We're only + * looking through any collisions so most of the time this is + * just going to compare against one buffer. If all is well, + * we'll return success and the inode ref object. + */ + while (cur_offset < item_size) { + extref = (struct btrfs_inode_extref *) (ptr + cur_offset); + name_ptr = (unsigned long)(&extref->name); + ref_name_len = btrfs_inode_extref_name_len(node, extref); + + if (ref_name_len == namelen && + btrfs_inode_extref_parent(node, extref) == parent_ino && + (memcmp_extent_buffer(node, name, name_ptr, + namelen) == 0)) { + if (extref_ret) + *extref_ret = extref; + return 1; + } + + cur_offset += ref_name_len + sizeof(*extref); + } + return 0; +} + +struct btrfs_inode_extref +*btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans, + struct btrfs_path *path, struct btrfs_root *root, + u64 ino, u64 parent_ino, u64 index, const char *name, + int namelen, int ins_len) +{ + struct btrfs_key key; + struct btrfs_inode_extref *extref; + int ret = 0; + + key.objectid = ino; + key.type = BTRFS_INODE_EXTREF_KEY; + key.offset = btrfs_extref_hash(parent_ino, name, namelen); + + ret = btrfs_search_slot(trans, root, &key, path, ins_len, + ins_len ? 1 : 0); + if (ret < 0) + return ERR_PTR(ret); + if (ret > 0) + return NULL; + if (!btrfs_find_name_in_ext_backref(path, parent_ino, name, + namelen, &extref)) + return NULL; + return extref; +} + +int btrfs_del_inode_extref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + const char *name, int name_len, + u64 inode_objectid, u64 ref_objectid, + u64 *index) +{ + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_inode_extref *extref; + struct extent_buffer *leaf; + int ret; + int del_len = name_len + sizeof(*extref); + unsigned long ptr; + unsigned long item_start; + u32 item_size; + + key.objectid = inode_objectid; + key.type = BTRFS_INODE_EXTREF_KEY; + key.offset = btrfs_extref_hash(ref_objectid, name, name_len); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret > 0) + ret = -ENOENT; + if (ret < 0) + goto out; + + /* + * Sanity check - did we find the right item for this name? + * This should always succeed so error here will make the FS + * readonly. + */ + if (!btrfs_find_name_in_ext_backref(path, ref_objectid, + name, name_len, &extref)) { + ret = -ENOENT; + goto out; + } + + leaf = path->nodes[0]; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + if (index) + *index = btrfs_inode_extref_index(leaf, extref); + + if (del_len == item_size) { + /* + * Common case only one ref in the item, remove the + * whole item. + */ + ret = btrfs_del_item(trans, root, path); + goto out; + } + + ptr = (unsigned long)extref; + item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); + + memmove_extent_buffer(leaf, ptr, ptr + del_len, + item_size - (ptr + del_len - item_start)); + + btrfs_truncate_item(trans, root, path, item_size - del_len, 1); + +out: + btrfs_free_path(path); + + return ret; +} + +/* + * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree. + * + * The caller must have checked against BTRFS_LINK_MAX already. + */ +int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + const char *name, int name_len, + u64 inode_objectid, u64 ref_objectid, u64 index) +{ + struct btrfs_inode_extref *extref; + int ret; + int ins_len = name_len + sizeof(*extref); + unsigned long ptr; + struct btrfs_path *path; + struct btrfs_key key; + struct extent_buffer *leaf; + struct btrfs_item *item; + + key.objectid = inode_objectid; + key.type = BTRFS_INODE_EXTREF_KEY; + key.offset = btrfs_extref_hash(ref_objectid, name, name_len); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_insert_empty_item(trans, root, path, &key, + ins_len); + if (ret == -EEXIST) { + if (btrfs_find_name_in_ext_backref(path, ref_objectid, + name, name_len, NULL)) + goto out; + + btrfs_extend_item(trans, root, path, ins_len); + ret = 0; + } + if (ret < 0) + goto out; + + leaf = path->nodes[0]; + item = btrfs_item_nr(path->slots[0]); + ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char); + ptr += btrfs_item_size(leaf, item) - ins_len; + extref = (struct btrfs_inode_extref *)ptr; + + btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len); + btrfs_set_inode_extref_index(path->nodes[0], extref, index); + btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid); + + ptr = (unsigned long)&extref->name; + write_extent_buffer(path->nodes[0], name, ptr, name_len); + btrfs_mark_buffer_dirty(path->nodes[0]); + +out: + btrfs_free_path(path); + return ret; +}