From patchwork Wed Jun 24 16:03:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 11623577 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 EF01C618 for ; Wed, 24 Jun 2020 16:03:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3CA22073E for ; Wed, 24 Jun 2020 16:03:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nic.cz header.i=@nic.cz header.b="MsPs6J2E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404796AbgFXQDc (ORCPT ); Wed, 24 Jun 2020 12:03:32 -0400 Received: from lists.nic.cz ([217.31.204.67]:48136 "EHLO mail.nic.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404755AbgFXQD2 (ORCPT ); Wed, 24 Jun 2020 12:03:28 -0400 Received: from dellmb.labs.office.nic.cz (unknown [IPv6:2001:1488:fffe:6:cac7:3539:7f1f:463]) by mail.nic.cz (Postfix) with ESMTP id 7BD1A1409E9; Wed, 24 Jun 2020 18:03:25 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nic.cz; s=default; t=1593014605; bh=Bh4I9/tTAxn2LMU4sk0YOCbgBWavgtmZf3nSPHMYQ1A=; h=From:To:Date; b=MsPs6J2EKDvLPYTmGF06rfo0BextbqhXC0N83jY+WbJZ231a+v8R/m88oIISP0abL a1kZMSa+8w99ZNsU6bZVTd/cCnJcLnGU4ToXLsTuTZ+D6xXu34QUzM/d8JWC1koFs3 yPJqOGc8+0zEctItIkuzf107pXe9g2J7OPoG6C7A= From: =?utf-8?q?Marek_Beh=C3=BAn?= To: u-boot@lists.denx.de Cc: =?utf-8?q?Alberto_S=C3=A1nchez_Molero?= , Marek Vasut , Pierre Bourdon , Simon Glass , Tom Rini , Yevgeny Popovych , linux-btrfs@vger.kernel.org, Qu Wenruo , =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH U-BOOT v3 24/30] fs: btrfs: Introduce lookup_data_extent() for later use Date: Wed, 24 Jun 2020 18:03:10 +0200 Message-Id: <20200624160316.5001-25-marek.behun@nic.cz> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200624160316.5001-1-marek.behun@nic.cz> References: <20200624160316.5001-1-marek.behun@nic.cz> MIME-Version: 1.0 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on mail.nic.cz X-Spam-Status: No, score=0.00 X-Spamd-Bar: / X-Virus-Scanned: clamav-milter 0.102.2 at mail X-Virus-Status: Clean Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Qu Wenruo This implements lookup_data_extent() function for the incoming new implementation of btrfs_file_read(). Signed-off-by: Qu Wenruo Reviewed-by: Marek Behún --- fs/btrfs/inode.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index ab45db87a6..11eb30c27a 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -825,3 +825,104 @@ out: free(dbuf); return ret; } + +/* + * Get the first file extent that covers bytenr @file_offset. + * + * @file_offset must be aligned to sectorsize. + * + * return 0 for found, and path points to the file extent. + * return >0 for not found, and fill @next_offset. + * @next_offset can be 0 if there is no next file extent. + * return <0 for error. + */ +static int lookup_data_extent(struct btrfs_root *root, struct btrfs_path *path, + u64 ino, u64 file_offset, u64 *next_offset) +{ + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + u8 extent_type; + int ret = 0; + + ASSERT(IS_ALIGNED(file_offset, root->fs_info->sectorsize)); + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = file_offset; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + /* Error or we're already at the file extent */ + if (ret <= 0) + return ret; + if (ret > 0) { + /* Check previous file extent */ + ret = btrfs_previous_item(root, path, ino, + BTRFS_EXTENT_DATA_KEY); + if (ret < 0) + return ret; + if (ret > 0) + goto check_next; + } + /* Now the key.offset must be smaller than @file_offset */ + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.objectid != ino || + key.type != BTRFS_EXTENT_DATA_KEY) + goto check_next; + + fi = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(path->nodes[0], fi); + if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + if (file_offset == 0) + return 0; + /* Inline extent should be the only extent, no next extent. */ + *next_offset = 0; + return 1; + } + + /* This file extent covers @file_offset */ + if (key.offset <= file_offset && key.offset + + btrfs_file_extent_num_bytes(path->nodes[0], fi) > file_offset) + return 0; +check_next: + ret = btrfs_next_item(root, path); + if (ret < 0) + return ret; + if (ret > 0) { + *next_offset = 0; + return 1; + } + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + fi = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_file_extent_item); + /* Next next data extent */ + if (key.objectid != ino || + key.type != BTRFS_EXTENT_DATA_KEY) { + *next_offset = 0; + return 1; + } + /* Current file extent already beyond @file_offset */ + if (key.offset > file_offset) { + *next_offset = key.offset; + return 1; + } + /* This file extent covers @file_offset */ + if (key.offset <= file_offset && key.offset + + btrfs_file_extent_num_bytes(path->nodes[0], fi) > file_offset) + return 0; + /* This file extent ends before @file_offset, check next */ + ret = btrfs_next_item(root, path); + if (ret < 0) + return ret; + if (ret > 0) { + *next_offset = 0; + return 1; + } + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.type != BTRFS_EXTENT_DATA_KEY || key.objectid != ino) { + *next_offset = 0; + return 1; + } + *next_offset = key.offset; + return 1; +}