From patchwork Fri Feb 14 08:13:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 11381885 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 A2D80138D for ; Fri, 14 Feb 2020 08:14:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77236222C2 for ; Fri, 14 Feb 2020 08:14:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387401AbgBNIOY (ORCPT ); Fri, 14 Feb 2020 03:14:24 -0500 Received: from mx2.suse.de ([195.135.220.15]:46938 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387398AbgBNIOY (ORCPT ); Fri, 14 Feb 2020 03:14:24 -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 6AF2AAC91 for ; Fri, 14 Feb 2020 08:14:21 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 3/3] btrfs: relocation: Use btrfs_backref_iterator infrastructure Date: Fri, 14 Feb 2020 16:13:54 +0800 Message-Id: <20200214081354.56605-4-wqu@suse.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200214081354.56605-1-wqu@suse.com> References: <20200214081354.56605-1-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 In the core function of relocation, build_backref_tree, it needs to iterate all backref items of one tree block. We don't really want to spend our code and reviewers' time to going through tons of supportive code just for the backref walk. Use btrfs_backref_iterator infrastructure to do the loop. The backref items look would be much more easier to read: ret = btrfs_backref_iterator_start(iterator, cur->bytenr); for (; ret == 0; ret = btrfs_backref_iterator_next(iterator)) { /* The really important work */ } Signed-off-by: Qu Wenruo --- fs/btrfs/backref.h | 20 +++++ fs/btrfs/relocation.c | 193 ++++++++++++++---------------------------- 2 files changed, 82 insertions(+), 131 deletions(-) diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index b53301f2147f..016999339be1 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -150,4 +150,24 @@ int btrfs_backref_iterator_start(struct btrfs_backref_iterator *iterator, u64 bytenr); int btrfs_backref_iterator_next(struct btrfs_backref_iterator *iterator); +static inline bool +btrfs_backref_iterator_is_inline_ref(struct btrfs_backref_iterator *iterator) +{ + if (iterator->cur_key.type == BTRFS_EXTENT_ITEM_KEY || + iterator->cur_key.type == BTRFS_METADATA_ITEM_KEY) + return true; + return false; +} + +static inline void +btrfs_backref_iterator_release(struct btrfs_backref_iterator *iterator) +{ + iterator->bytenr = 0; + iterator->item_ptr = 0; + iterator->cur_ptr = 0; + iterator->end_ptr = 0; + btrfs_release_path(iterator->path); + memset(&iterator->cur_key, 0, sizeof(iterator->cur_key)); +} + #endif diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index b1365a516a25..21e4482c8232 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -22,6 +22,7 @@ #include "print-tree.h" #include "delalloc-space.h" #include "block-group.h" +#include "backref.h" /* * backref_node, mapping_node and tree_block start with this @@ -604,48 +605,6 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, return btrfs_get_fs_root(fs_info, &key, false); } -static noinline_for_stack -int find_inline_backref(struct extent_buffer *leaf, int slot, - unsigned long *ptr, unsigned long *end) -{ - struct btrfs_key key; - struct btrfs_extent_item *ei; - struct btrfs_tree_block_info *bi; - u32 item_size; - - btrfs_item_key_to_cpu(leaf, &key, slot); - - item_size = btrfs_item_size_nr(leaf, slot); - if (item_size < sizeof(*ei)) { - btrfs_print_v0_err(leaf->fs_info); - btrfs_handle_fs_error(leaf->fs_info, -EINVAL, NULL); - return 1; - } - ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); - WARN_ON(!(btrfs_extent_flags(leaf, ei) & - BTRFS_EXTENT_FLAG_TREE_BLOCK)); - - if (key.type == BTRFS_EXTENT_ITEM_KEY && - item_size <= sizeof(*ei) + sizeof(*bi)) { - WARN_ON(item_size < sizeof(*ei) + sizeof(*bi)); - return 1; - } - if (key.type == BTRFS_METADATA_ITEM_KEY && - item_size <= sizeof(*ei)) { - WARN_ON(item_size < sizeof(*ei)); - return 1; - } - - if (key.type == BTRFS_EXTENT_ITEM_KEY) { - bi = (struct btrfs_tree_block_info *)(ei + 1); - *ptr = (unsigned long)(bi + 1); - } else { - *ptr = (unsigned long)(ei + 1); - } - *end = (unsigned long)ei + item_size; - return 0; -} - /* * build backref tree for a given tree block. root of the backref tree * corresponds the tree block, leaves of the backref tree correspond @@ -665,10 +624,9 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, struct btrfs_key *node_key, int level, u64 bytenr) { + struct btrfs_backref_iterator *iterator; struct backref_cache *cache = &rc->backref_cache; - struct btrfs_path *path1; /* For searching extent root */ - struct btrfs_path *path2; /* For searching parent of TREE_BLOCK_REF */ - struct extent_buffer *eb; + struct btrfs_path *path; /* For searching parent of TREE_BLOCK_REF */ struct btrfs_root *root; struct backref_node *cur; struct backref_node *upper; @@ -677,9 +635,6 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, struct backref_node *exist = NULL; struct backref_edge *edge; struct rb_node *rb_node; - struct btrfs_key key; - unsigned long end; - unsigned long ptr; LIST_HEAD(list); /* Pending edge list, upper node needs to be checked */ LIST_HEAD(useless); int cowonly; @@ -687,14 +642,14 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, int err = 0; bool need_check = true; - path1 = btrfs_alloc_path(); - path2 = btrfs_alloc_path(); - if (!path1 || !path2) { + iterator = btrfs_backref_iterator_alloc(rc->extent_root->fs_info, + GFP_NOFS); + path = btrfs_alloc_path(); + if (!path) { err = -ENOMEM; goto out; } - path1->reada = READA_FORWARD; - path2->reada = READA_FORWARD; + path->reada = READA_FORWARD; node = alloc_backref_node(cache); if (!node) { @@ -707,25 +662,28 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, node->lowest = 1; cur = node; again: - end = 0; - ptr = 0; - key.objectid = cur->bytenr; - key.type = BTRFS_METADATA_ITEM_KEY; - key.offset = (u64)-1; - - path1->search_commit_root = 1; - path1->skip_locking = 1; - ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1, - 0, 0); + ret = btrfs_backref_iterator_start(iterator, cur->bytenr); if (ret < 0) { err = ret; goto out; } - ASSERT(ret); - ASSERT(path1->slots[0]); - - path1->slots[0]--; + /* + * We skip the first btrfs_tree_block_info, as we don't use the key + * stored in it, but fetch it from the tree block. + */ + if (btrfs_backref_has_tree_block_info(iterator)) { + ret = btrfs_backref_iterator_next(iterator); + if (ret < 0) { + err = ret; + goto out; + } + /* No extra backref? This means the tree block is corrupted */ + if (ret > 0) { + err = -EUCLEAN; + goto out; + } + } WARN_ON(cur->checked); if (!list_empty(&cur->upper)) { /* @@ -747,42 +705,21 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, exist = NULL; } - while (1) { - cond_resched(); - eb = path1->nodes[0]; - - if (ptr >= end) { - if (path1->slots[0] >= btrfs_header_nritems(eb)) { - ret = btrfs_next_leaf(rc->extent_root, path1); - if (ret < 0) { - err = ret; - goto out; - } - if (ret > 0) - break; - eb = path1->nodes[0]; - } + for (; ret == 0; ret = btrfs_backref_iterator_next(iterator)) { + struct extent_buffer *eb; + struct btrfs_key key; + int type; - btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); - if (key.objectid != cur->bytenr) { - WARN_ON(exist); - break; - } + cond_resched(); + eb = btrfs_backref_get_eb(iterator); - if (key.type == BTRFS_EXTENT_ITEM_KEY || - key.type == BTRFS_METADATA_ITEM_KEY) { - ret = find_inline_backref(eb, path1->slots[0], - &ptr, &end); - if (ret) - goto next; - } - } + key.objectid = iterator->bytenr; + if (btrfs_backref_iterator_is_inline_ref(iterator)) { + struct btrfs_extent_inline_ref *iref; - if (ptr < end) { /* update key for inline back ref */ - struct btrfs_extent_inline_ref *iref; - int type; - iref = (struct btrfs_extent_inline_ref *)ptr; + iref = (struct btrfs_extent_inline_ref *) + iterator->cur_ptr; type = btrfs_get_extent_inline_ref_type(eb, iref, BTRFS_REF_TYPE_BLOCK); if (type == BTRFS_REF_TYPE_INVALID) { @@ -791,9 +728,9 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, } key.type = type; key.offset = btrfs_extent_inline_ref_offset(eb, iref); - - WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY && - key.type != BTRFS_SHARED_BLOCK_REF_KEY); + } else { + key.type = iterator->cur_key.type; + key.offset = iterator->cur_key.offset; } /* @@ -806,7 +743,7 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, (key.type == BTRFS_SHARED_BLOCK_REF_KEY && exist->bytenr == key.offset))) { exist = NULL; - goto next; + continue; } /* SHARED_BLOCK_REF means key.offset is the parent bytenr */ @@ -852,7 +789,7 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, edge->node[LOWER] = cur; edge->node[UPPER] = upper; - goto next; + continue; } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) { err = -EINVAL; btrfs_print_v0_err(rc->extent_root->fs_info); @@ -860,7 +797,7 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, NULL); goto out; } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { - goto next; + continue; } /* @@ -891,20 +828,20 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, level = cur->level + 1; /* Search the tree to find parent blocks referring the block. */ - path2->search_commit_root = 1; - path2->skip_locking = 1; - path2->lowest_level = level; - ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0); - path2->lowest_level = 0; + path->search_commit_root = 1; + path->skip_locking = 1; + path->lowest_level = level; + ret = btrfs_search_slot(NULL, root, node_key, path, 0, 0); + path->lowest_level = 0; if (ret < 0) { err = ret; goto out; } - if (ret > 0 && path2->slots[level] > 0) - path2->slots[level]--; + if (ret > 0 && path->slots[level] > 0) + path->slots[level]--; - eb = path2->nodes[level]; - if (btrfs_node_blockptr(eb, path2->slots[level]) != + eb = path->nodes[level]; + if (btrfs_node_blockptr(eb, path->slots[level]) != cur->bytenr) { btrfs_err(root->fs_info, "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)", @@ -920,7 +857,7 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, /* Add all nodes and edges in the path */ for (; level < BTRFS_MAX_LEVEL; level++) { - if (!path2->nodes[level]) { + if (!path->nodes[level]) { ASSERT(btrfs_root_bytenr(&root->root_item) == lower->bytenr); if (should_ignore_root(root)) @@ -936,7 +873,7 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, goto out; } - eb = path2->nodes[level]; + eb = path->nodes[level]; rb_node = tree_search(&cache->rb_root, eb->start); if (!rb_node) { upper = alloc_backref_node(cache); @@ -993,20 +930,14 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, lower = upper; upper = NULL; } - btrfs_release_path(path2); -next: - if (ptr < end) { - ptr += btrfs_extent_inline_ref_size(key.type); - if (ptr >= end) { - WARN_ON(ptr > end); - ptr = 0; - end = 0; - } - } - if (ptr >= end) - path1->slots[0]++; + btrfs_release_path(path); + } + if (ret < 0) { + err = ret; + goto out; } - btrfs_release_path(path1); + ret = 0; + btrfs_backref_iterator_release(iterator); cur->checked = 1; WARN_ON(exist); @@ -1124,8 +1055,8 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, } } out: - btrfs_free_path(path1); - btrfs_free_path(path2); + btrfs_backref_iterator_free(iterator); + btrfs_free_path(path); if (err) { while (!list_empty(&useless)) { lower = list_entry(useless.next,