From patchwork Wed Feb 26 05:56:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 11405305 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7B1D113A4 for ; Wed, 26 Feb 2020 05:57:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 640E121556 for ; Wed, 26 Feb 2020 05:57:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726407AbgBZF5G (ORCPT ); Wed, 26 Feb 2020 00:57:06 -0500 Received: from mx2.suse.de ([195.135.220.15]:36576 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725789AbgBZF5G (ORCPT ); Wed, 26 Feb 2020 00:57:06 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id EAC69AC65; Wed, 26 Feb 2020 05:57:03 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: Johannes Thumshirn Subject: [PATCH 02/10] btrfs: backref: Implement btrfs_backref_iter_next() Date: Wed, 26 Feb 2020 13:56:44 +0800 Message-Id: <20200226055652.24857-3-wqu@suse.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200226055652.24857-1-wqu@suse.com> References: <20200226055652.24857-1-wqu@suse.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This function will go next inline/keyed backref for btrfs_backref_iter infrastructure. Signed-off-by: Qu Wenruo Reviewed-by: Johannes Thumshirn --- fs/btrfs/backref.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/backref.h | 34 +++++++++++++++++++++++++++ 2 files changed, 92 insertions(+) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index c78d15bb999d..dd82e243d95b 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -2339,3 +2339,61 @@ int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr) btrfs_backref_iter_release(iter); return ret; } + +/* + * Go to next backref item of current bytenr, can be either inlined or keyed. + * + * Caller need to check whether it's inline ref or not by iter->cur_key. + * + * Return 0 if we get next backref without problem. + * Return >0 if there is no extra backref for this bytenr. + * Return <0 if there is something wrong happened. + */ +int btrfs_backref_iter_next(struct btrfs_backref_iter *iter) +{ + struct extent_buffer *eb = btrfs_backref_get_eb(iter); + struct btrfs_path *path = iter->path; + struct btrfs_extent_inline_ref *iref; + int ret; + u32 size; + + if (btrfs_backref_iter_is_inline_ref(iter)) { + /* We're still inside the inline refs */ + ASSERT(iter->cur_ptr < iter->end_ptr); + + if (btrfs_backref_has_tree_block_info(iter)) { + /* First tree block info */ + size = sizeof(struct btrfs_tree_block_info); + } else { + /* Use inline ref type to determine the size */ + int type; + + iref = (struct btrfs_extent_inline_ref *) + (iter->cur_ptr); + type = btrfs_extent_inline_ref_type(eb, iref); + + size = btrfs_extent_inline_ref_size(type); + } + iter->cur_ptr += size; + if (iter->cur_ptr < iter->end_ptr) + return 0; + + /* All inline items iterated, fall through */ + } + /* We're at keyed items, there is no inline item, just go next item */ + ret = btrfs_next_item(iter->fs_info->extent_root, iter->path); + if (ret) + return ret; + + btrfs_item_key_to_cpu(path->nodes[0], &iter->cur_key, path->slots[0]); + if (iter->cur_key.objectid != iter->bytenr || + (iter->cur_key.type != BTRFS_TREE_BLOCK_REF_KEY && + iter->cur_key.type != BTRFS_SHARED_BLOCK_REF_KEY)) + return 1; + iter->item_ptr = btrfs_item_ptr_offset(path->nodes[0], + path->slots[0]); + iter->cur_ptr = iter->item_ptr; + iter->end_ptr = iter->item_ptr + btrfs_item_size_nr(path->nodes[0], + path->slots[0]); + return 0; +} diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index 8b1ec11d4b28..42fd76dfe553 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -121,8 +121,42 @@ static inline void btrfs_backref_iter_free(struct btrfs_backref_iter *iter) kfree(iter); } +static inline struct extent_buffer * +btrfs_backref_get_eb(struct btrfs_backref_iter *iter) +{ + if (!iter) + return NULL; + return iter->path->nodes[0]; +} + +/* + * For metadata with EXTENT_ITEM key (non-skinny) case, the first inline data + * is btrfs_tree_block_info, without a btrfs_extent_inline_ref header. + * + * This helper is here to determine if that's the case. + */ +static inline bool btrfs_backref_has_tree_block_info( + struct btrfs_backref_iter *iter) +{ + if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY && + iter->cur_ptr - iter->item_ptr == sizeof(struct btrfs_extent_item)) + return true; + return false; +} + int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr); +int btrfs_backref_iter_next(struct btrfs_backref_iter *iter); + +static inline bool +btrfs_backref_iter_is_inline_ref(struct btrfs_backref_iter *iter) +{ + if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY || + iter->cur_key.type == BTRFS_METADATA_ITEM_KEY) + return true; + return false; +} + static inline void btrfs_backref_iter_release(struct btrfs_backref_iter *iter) {