From patchwork Wed Jun 24 16:03:03 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: 11623569 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 839CD912 for ; Wed, 24 Jun 2020 16:03:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 687BE2077D for ; Wed, 24 Jun 2020 16:03:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nic.cz header.i=@nic.cz header.b="VlxII1TQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404800AbgFXQDe (ORCPT ); Wed, 24 Jun 2020 12:03:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404783AbgFXQD2 (ORCPT ); Wed, 24 Jun 2020 12:03:28 -0400 Received: from mail.nic.cz (lists.nic.cz [IPv6:2001:1488:800:400::400]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AD68C0617BC for ; Wed, 24 Jun 2020 09:03:27 -0700 (PDT) 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 5323D140649; Wed, 24 Jun 2020 18:03:24 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nic.cz; s=default; t=1593014604; bh=CduAvAQtNKW5Nu7fYOC1TBw0UdJ43jPLLHGrceLu1bQ=; h=From:To:Date; b=VlxII1TQWzlEnxtyAuAWU/9B6yDWbZQ/XnFjOSKdBGk0x6B78E1VnPOsp44ErI1jS PEn9MTClmQBmcP/qzJ9KAJ/+CdfzA14mqzye4LWQDTLAdcxm0pISHF4oDbq4wRDYqG 21VNNvdxT+RdO44Rcc5jPvGPlDjoiDx30frfnXUk= 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 17/30] fs: btrfs: Use btrfs_readlink() to implement __btrfs_readlink() Date: Wed, 24 Jun 2020 18:03:03 +0200 Message-Id: <20200624160316.5001-18-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 The existing __btrfs_readlink() can be easily re-implemented using the extent buffer based btrfs_readlink(). This is the first step to re-implement U-Boot's btrfs code. Signed-off-by: Qu Wenruo Reviewed-by: Marek Behún --- fs/btrfs/btrfs.h | 1 + fs/btrfs/inode.c | 101 ++++++++++++++++++++++++++++++----------------- 2 files changed, 65 insertions(+), 37 deletions(-) diff --git a/fs/btrfs/btrfs.h b/fs/btrfs/btrfs.h index e8197391a2..53d53f310b 100644 --- a/fs/btrfs/btrfs.h +++ b/fs/btrfs/btrfs.h @@ -60,6 +60,7 @@ u64 __btrfs_lookup_inode_ref(struct __btrfs_root *, u64, struct btrfs_inode_ref int __btrfs_lookup_inode(const struct __btrfs_root *, struct btrfs_key *, struct btrfs_inode_item *, struct __btrfs_root *); int __btrfs_readlink(const struct __btrfs_root *, u64, char *); +int btrfs_readlink(struct btrfs_root *root, u64 ino, char *target); u64 __btrfs_lookup_path(struct __btrfs_root *, u64, const char *, u8 *, struct btrfs_inode_item *, int); u64 btrfs_file_read(const struct __btrfs_root *, u64, u64, u64, char *); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index eb34f546b5..007cf32c16 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -5,8 +5,9 @@ * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz */ -#include "btrfs.h" #include +#include "btrfs.h" +#include "disk-io.h" u64 __btrfs_lookup_inode_ref(struct __btrfs_root *root, u64 inr, struct btrfs_inode_ref *refp, char *name) @@ -83,56 +84,82 @@ out: return res; } -int __btrfs_readlink(const struct __btrfs_root *root, u64 inr, char *target) +/* + * Read the content of symlink inode @ino of @root, into @target. + * NOTE: @target will not be \0 termiated, caller should handle it properly. + * + * Return the number of read data. + * Return <0 for error. + */ +int btrfs_readlink(struct btrfs_root *root, u64 ino, char *target) { - struct __btrfs_path path; + struct btrfs_path path; struct btrfs_key key; - struct btrfs_file_extent_item *extent; - const char *data_ptr; - int res = -1; + struct btrfs_file_extent_item *fi; + int ret; - key.objectid = inr; + key.objectid = ino; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = 0; + btrfs_init_path(&path); - if (btrfs_search_tree(root, &key, &path)) - return -1; - - if (__btrfs_comp_keys(&key, btrfs_path_leaf_key(&path))) - goto out; - - extent = btrfs_path_item_ptr(&path, struct btrfs_file_extent_item); - if (extent->type != BTRFS_FILE_EXTENT_INLINE) { - printf("%s: Extent for symlink %llu not of INLINE type\n", - __func__, inr); + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); + if (ret < 0) + return ret; + if (ret > 0) { + ret = -ENOENT; goto out; } - - btrfs_file_extent_item_to_cpu_inl(extent); - - if (extent->compression != BTRFS_COMPRESS_NONE) { - printf("%s: Symlink %llu extent data compressed!\n", __func__, - inr); + fi = btrfs_item_ptr(path.nodes[0], path.slots[0], + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(path.nodes[0], fi) != + BTRFS_FILE_EXTENT_INLINE) { + ret = -EUCLEAN; + error("Extent for symlink %llu must be INLINE type!", ino); goto out; - } else if (extent->encryption != 0) { - printf("%s: Symlink %llu extent data encrypted!\n", __func__, - inr); + } + if (btrfs_file_extent_compression(path.nodes[0], fi) != + BTRFS_COMPRESS_NONE) { + ret = -EUCLEAN; + error("Extent for symlink %llu must not be compressed!", ino); goto out; - } else if (extent->ram_bytes >= btrfs_info.sb.sectorsize) { - printf("%s: Symlink %llu extent data too long (%llu)!\n", - __func__, inr, extent->ram_bytes); + } + if (btrfs_file_extent_ram_bytes(path.nodes[0], fi) >= + root->fs_info->sectorsize) { + ret = -EUCLEAN; + error("Symlink %llu extent data too large (%llu)!\n", + ino, btrfs_file_extent_ram_bytes(path.nodes[0], fi)); goto out; } + read_extent_buffer(path.nodes[0], target, + btrfs_file_extent_inline_start(fi), + btrfs_file_extent_ram_bytes(path.nodes[0], fi)); + ret = btrfs_file_extent_ram_bytes(path.nodes[0], fi); +out: + btrfs_release_path(&path); + return ret; +} - data_ptr = (const char *) extent - + offsetof(struct btrfs_file_extent_item, disk_bytenr); +int __btrfs_readlink(const struct __btrfs_root *root, u64 inr, char *target) +{ + struct btrfs_root *subvolume; + struct btrfs_fs_info *fs_info = current_fs_info; + struct btrfs_key key; + int ret; + + ASSERT(fs_info); + key.objectid = root->objectid; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + subvolume = btrfs_read_fs_root(fs_info, &key); + if (IS_ERR(subvolume)) + return -1; - memcpy(target, data_ptr, extent->ram_bytes); - target[extent->ram_bytes] = '\0'; - res = 0; -out: - __btrfs_free_path(&path); - return res; + ret = btrfs_readlink(subvolume, inr, target); + if (ret < 0) + return -1; + target[ret] = '\0'; + return 0; } /* inr must be a directory (for regular files with multiple hard links this