From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com ([209.85.220.43]:57710 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682Ab3KAGxo (ORCPT ); Fri, 1 Nov 2013 02:53:44 -0400 Received: by mail-pa0-f43.google.com with SMTP id hz1so3644474pad.30 for ; Thu, 31 Oct 2013 23:53:43 -0700 (PDT) Date: Thu, 31 Oct 2013 23:53:41 -0700 From: Kelley Nielsen To: linux-btrfs@vger.kernel.org Cc: opw-kernel@googlegroups.com Subject: [PATCH 1/3] Bootstrap generic btrfs_find_item interface Message-ID: <4a397119c8d634b82198fe728b9ea3ac4690444c.1383287959.git.kelleynnn@gmail.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: There are many btrfs functions that manually search the tree for an item. They all reimplement the same mechanism and differ in the conditions that they use to find the item.__inode_info() is one such example. It has been proposed that a new interface be created to take the place of these functions. This patch is the first step to creating the interface. A new function, btrfs_find_item, has been added to ctree.c and prototyped in ctree.h. It is identical to __inode_info, except that the order of the parameters has been rearranged to more closely those of similar functions elsewhere in the code (now, root and path come first, then the objectid, offset and type, and the key to be filled in last). __inode_info's callers have been set to call this new function instead, and __inode_info itself has been removed. Signed-off-by: Kelley Nielsen Suggested-by: Zach Brown --- fs/btrfs/backref.c | 40 ++++------------------------------------ fs/btrfs/ctree.c | 37 +++++++++++++++++++++++++++++++++++++ fs/btrfs/ctree.h | 2 ++ 3 files changed, 43 insertions(+), 36 deletions(-) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 3775947..595bd1f 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -1107,38 +1107,6 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, return 0; } - -static int __inode_info(u64 inum, u64 ioff, u8 key_type, - struct btrfs_root *fs_root, struct btrfs_path *path, - struct btrfs_key *found_key) -{ - int ret; - struct btrfs_key key; - struct extent_buffer *eb; - - key.type = key_type; - key.objectid = inum; - key.offset = ioff; - - ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); - if (ret < 0) - return ret; - - eb = path->nodes[0]; - if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { - ret = btrfs_next_leaf(fs_root, path); - if (ret) - return ret; - eb = path->nodes[0]; - } - - btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); - if (found_key->type != key.type || found_key->objectid != key.objectid) - return 1; - - return 0; -} - /* * this makes the path point to (inum INODE_ITEM ioff) */ @@ -1146,16 +1114,16 @@ int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, struct btrfs_path *path) { struct btrfs_key key; - return __inode_info(inum, ioff, BTRFS_INODE_ITEM_KEY, fs_root, path, - &key); + return btrfs_find_item(fs_root, path, inum, ioff, + BTRFS_INODE_ITEM_KEY, &key); } static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, struct btrfs_path *path, struct btrfs_key *found_key) { - return __inode_info(inum, ioff, BTRFS_INODE_REF_KEY, fs_root, path, - found_key); + return btrfs_find_item(fs_root, path, inum, ioff, + BTRFS_INODE_REF_KEY, found_key); } int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 316136b..3828352 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2462,6 +2462,43 @@ static int key_search(struct extent_buffer *b, struct btrfs_key *key, return 0; } +/* Proposed generic search function, meant to take the place of the +* various small search helper functions throughout the code and standardize +* the search interface. Right now, it only replaces the former __inode_info +* in backref.c. +*/ +int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, + u64 inum, u64 ioff, u8 key_type, + struct btrfs_key *found_key) +{ + int ret; + struct btrfs_key key; + struct extent_buffer *eb; + + key.type = key_type; + key.objectid = inum; + key.offset = ioff; + + ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); + if (ret < 0) + return ret; + + eb = path->nodes[0]; + if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(fs_root, path); + if (ret) + return ret; + eb = path->nodes[0]; + } + + btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); + if (found_key->type != key.type || + found_key->objectid != key.objectid) + return 1; + + return 0; +} + /* * look for key in the tree. path is filled in with nodes along the way * if key is found, we return zero and you can find the item in the leaf diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 941019d..aa9993c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3357,6 +3357,8 @@ int btrfs_duplicate_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *new_key); +int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, + u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key); int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *p, int ins_len, int cow); -- 1.8.1.2