From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 636A4ECE588 for ; Tue, 15 Oct 2019 15:42:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4302A2086A for ; Tue, 15 Oct 2019 15:42:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730237AbfJOPmd (ORCPT ); Tue, 15 Oct 2019 11:42:33 -0400 Received: from mx2.suse.de ([195.135.220.15]:44312 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729578AbfJOPmb (ORCPT ); Tue, 15 Oct 2019 11:42:31 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id BA350B51A; Tue, 15 Oct 2019 15:42:29 +0000 (UTC) From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov Subject: [PATCH 4/8] btrfs: Factor out tree roots initialization during mount Date: Tue, 15 Oct 2019 18:42:20 +0300 Message-Id: <20191015154224.21537-5-nborisov@suse.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191015154224.21537-1-nborisov@suse.com> References: <20191015154224.21537-1-nborisov@suse.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The code responsible for reading and initilizing tree roots is scattered in open_ctree among 2 labels, emulating a loop. This is rather confusing to reason about. Instead, factor the code in a new function, init_tree_roots which implements the same logical flow. There are a couple of notable differences, namely: * Instead of using next_backup_root it's using the newly introduced read_backup_root. * If read_backup_root returns an error init_tree_roots propagates the error and there is no special handling of that case e.g. the code jumps straight to 'fail_tree_roots' label. The old code, however, was (erroneously) jumping to 'fail_block_groups' label if next_backup_root did fail, this was unnecessary since the tree roots init logic doesn't modify the state of block groups. --- fs/btrfs/disk-io.c | 140 +++++++++++++++++++++++++++------------------ 1 file changed, 83 insertions(+), 57 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 9ed3b40aa10d..a82e3acca765 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2581,6 +2581,87 @@ static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info, return ret; } +int __cold init_tree_roots(struct btrfs_fs_info *fs_info) +{ + struct btrfs_super_block *sb = fs_info->super_copy; + struct btrfs_root *tree_root = fs_info->tree_root; + bool handle_error = false; + int ret = 0; + int i; + + for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) { + u64 generation; + int level; + + if (handle_error) { + if (!IS_ERR(tree_root->node)) + free_extent_buffer(tree_root->node); + tree_root->node = NULL; + + if (!btrfs_test_opt(fs_info, USEBACKUPROOT)) + break; + + free_root_pointers(fs_info, 0); + + /* don't use the log in recovery mode, it won't be valid */ + btrfs_set_super_log_root(sb, 0); + + /* we can't trust the free space cache either */ + btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE); + + ret = read_backup_root(fs_info, i); + if (ret < 0) + return ret; + } + generation = btrfs_super_generation(sb); + level = btrfs_super_root_level(sb); + tree_root->node = read_tree_block(fs_info, btrfs_super_root(sb), + generation, level, NULL); + if (IS_ERR(tree_root->node) || + !extent_buffer_uptodate(tree_root->node)) { + handle_error = true; + + if (IS_ERR(tree_root->node)) + ret = PTR_ERR(tree_root->node); + else if (!extent_buffer_uptodate(tree_root->node)) + ret = -EUCLEAN; + + btrfs_warn(fs_info, "failed to read tree root"); + continue; + } + + btrfs_set_root_node(&tree_root->root_item, tree_root->node); + tree_root->commit_root = btrfs_root_node(tree_root); + btrfs_set_root_refs(&tree_root->root_item, 1); + + mutex_lock(&tree_root->objectid_mutex); + ret = btrfs_find_highest_objectid(tree_root, + &tree_root->highest_objectid); + if (ret < 0) { + mutex_unlock(&tree_root->objectid_mutex); + handle_error = true; + continue; + } + + ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID); + mutex_unlock(&tree_root->objectid_mutex); + + ret = btrfs_read_roots(fs_info); + if (ret < 0) { + handle_error = true; + continue; + } + + /* All successful */ + fs_info->generation = generation; + fs_info->last_trans_committed = generation; + break; + + } + + return ret; +} + int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices, char *options) @@ -2599,8 +2680,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_root *chunk_root; int ret; int err = -EINVAL; - int num_backups_tried = 0; - int backup_index = 0; int clear_free_space_tree = 0; int level; @@ -3022,44 +3101,9 @@ int __cold open_ctree(struct super_block *sb, goto fail_tree_roots; } -retry_root_backup: - generation = btrfs_super_generation(disk_super); - level = btrfs_super_root_level(disk_super); - - tree_root->node = read_tree_block(fs_info, - btrfs_super_root(disk_super), - generation, level, NULL); - if (IS_ERR(tree_root->node) || - !extent_buffer_uptodate(tree_root->node)) { - btrfs_warn(fs_info, "failed to read tree root"); - if (!IS_ERR(tree_root->node)) - free_extent_buffer(tree_root->node); - tree_root->node = NULL; - goto recovery_tree_root; - } - - btrfs_set_root_node(&tree_root->root_item, tree_root->node); - tree_root->commit_root = btrfs_root_node(tree_root); - btrfs_set_root_refs(&tree_root->root_item, 1); - - mutex_lock(&tree_root->objectid_mutex); - ret = btrfs_find_highest_objectid(tree_root, - &tree_root->highest_objectid); - if (ret) { - mutex_unlock(&tree_root->objectid_mutex); - goto recovery_tree_root; - } - - ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID); - - mutex_unlock(&tree_root->objectid_mutex); - - ret = btrfs_read_roots(fs_info); + ret = init_tree_roots(fs_info); if (ret) - goto recovery_tree_root; - - fs_info->generation = generation; - fs_info->last_trans_committed = generation; + goto fail_tree_roots; ret = btrfs_verify_dev_extents(fs_info); if (ret) { @@ -3354,24 +3398,6 @@ int __cold open_ctree(struct super_block *sb, btrfs_free_stripe_hash_table(fs_info); btrfs_close_devices(fs_info->fs_devices); return err; - -recovery_tree_root: - if (!btrfs_test_opt(fs_info, USEBACKUPROOT)) - goto fail_tree_roots; - - free_root_pointers(fs_info, false); - - /* don't use the log in recovery mode, it won't be valid */ - btrfs_set_super_log_root(disk_super, 0); - - /* we can't trust the free space cache either */ - btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE); - - ret = next_root_backup(fs_info, fs_info->super_copy, - &num_backups_tried, &backup_index); - if (ret == -1) - goto fail_block_groups; - goto retry_root_backup; } ALLOW_ERROR_INJECTION(open_ctree, ERRNO); -- 2.17.1