From patchwork Fri Sep 6 17:15:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Fasheh X-Patchwork-Id: 11135751 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 A5C3613BD for ; Fri, 6 Sep 2019 17:16:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 643322082C for ; Fri, 6 Sep 2019 17:16:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405963AbfIFRQN (ORCPT ); Fri, 6 Sep 2019 13:16:13 -0400 Received: from mx2.suse.de ([195.135.220.15]:36558 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2404253AbfIFRQN (ORCPT ); Fri, 6 Sep 2019 13:16:13 -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 02F86AD4B for ; Fri, 6 Sep 2019 17:16:04 +0000 (UTC) From: Mark Fasheh To: linux-btrfs@vger.kernel.org Cc: Mark Fasheh Subject: [PATCH 1/3] btrfs: Move backref cache code out of relocation.c Date: Fri, 6 Sep 2019 10:15:31 -0700 Message-Id: <20190906171533.618-2-mfasheh@suse.com> X-Mailer: git-send-email 2.22.1 In-Reply-To: <20190906171533.618-1-mfasheh@suse.com> References: <20190906171533.618-1-mfasheh@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 From: Mark Fasheh No functional changes are made here, we simply move the backref cache out of relocation.c and into it's own file, backref-cache.c. We also add the headers relocation.h and backref-cache.h. Signed-off-by: Mark Fasheh Reviewed-by: Josef Bacik --- fs/btrfs/Makefile | 2 +- fs/btrfs/backref-cache.c | 883 ++++++++++++++++++++++++++++++++ fs/btrfs/backref-cache.h | 113 +++++ fs/btrfs/relocation.c | 1027 +------------------------------------- fs/btrfs/relocation.h | 85 ++++ 5 files changed, 1090 insertions(+), 1020 deletions(-) create mode 100644 fs/btrfs/backref-cache.c create mode 100644 fs/btrfs/backref-cache.h create mode 100644 fs/btrfs/relocation.h diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index 76a843198bcb..197eed65e051 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -11,7 +11,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \ reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \ uuid-tree.o props.o free-space-tree.o tree-checker.o space-info.o \ - block-rsv.o delalloc-space.o + block-rsv.o delalloc-space.o backref-cache.o btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o diff --git a/fs/btrfs/backref-cache.c b/fs/btrfs/backref-cache.c new file mode 100644 index 000000000000..d0f6530f23b8 --- /dev/null +++ b/fs/btrfs/backref-cache.c @@ -0,0 +1,883 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2009 Oracle. All rights reserved. + */ +#include +#include +#include +#include +#include +#include +#include "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "volumes.h" +#include "locking.h" +#include "btrfs_inode.h" +#include "async-thread.h" +#include "free-space-cache.h" +#include "inode-map.h" +#include "qgroup.h" +#include "print-tree.h" +#include "relocation.h" + +#include "backref-cache.h" + +void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr) +{ + + struct btrfs_fs_info *fs_info = NULL; + struct backref_node *bnode = rb_entry(rb_node, struct backref_node, + rb_node); + if (bnode->root) + fs_info = bnode->root->fs_info; + btrfs_panic(fs_info, errno, + "Inconsistency in backref cache found at offset %llu", + bytenr); +} + +void backref_cache_init(struct backref_cache *cache) +{ + int i; + cache->rb_root = RB_ROOT; + for (i = 0; i < BTRFS_MAX_LEVEL; i++) + INIT_LIST_HEAD(&cache->pending[i]); + INIT_LIST_HEAD(&cache->changed); + INIT_LIST_HEAD(&cache->detached); + INIT_LIST_HEAD(&cache->leaves); +} + +void backref_cache_cleanup(struct backref_cache *cache) +{ + struct backref_node *node; + int i; + + while (!list_empty(&cache->detached)) { + node = list_entry(cache->detached.next, + struct backref_node, list); + remove_backref_node(cache, node); + } + + while (!list_empty(&cache->leaves)) { + node = list_entry(cache->leaves.next, + struct backref_node, lower); + remove_backref_node(cache, node); + } + + cache->last_trans = 0; + + for (i = 0; i < BTRFS_MAX_LEVEL; i++) + ASSERT(list_empty(&cache->pending[i])); + ASSERT(list_empty(&cache->changed)); + ASSERT(list_empty(&cache->detached)); + ASSERT(RB_EMPTY_ROOT(&cache->rb_root)); + ASSERT(!cache->nr_nodes); + ASSERT(!cache->nr_edges); +} + +struct backref_node *alloc_backref_node(struct backref_cache *cache) +{ + struct backref_node *node; + + node = kzalloc(sizeof(*node), GFP_NOFS); + if (node) { + INIT_LIST_HEAD(&node->list); + INIT_LIST_HEAD(&node->upper); + INIT_LIST_HEAD(&node->lower); + RB_CLEAR_NODE(&node->rb_node); + cache->nr_nodes++; + } + return node; +} + +void free_backref_node(struct backref_cache *cache, struct backref_node *node) +{ + if (node) { + cache->nr_nodes--; + kfree(node); + } +} + +struct backref_edge *alloc_backref_edge(struct backref_cache *cache) +{ + struct backref_edge *edge; + + edge = kzalloc(sizeof(*edge), GFP_NOFS); + if (edge) + cache->nr_edges++; + return edge; +} + +void free_backref_edge(struct backref_cache *cache, struct backref_edge *edge) +{ + if (edge) { + cache->nr_edges--; + kfree(edge); + } +} + + +void unlock_node_buffer(struct backref_node *node) +{ + if (node->locked) { + btrfs_tree_unlock(node->eb); + node->locked = 0; + } +} + +void drop_node_buffer(struct backref_node *node) +{ + if (node->eb) { + unlock_node_buffer(node); + free_extent_buffer(node->eb); + node->eb = NULL; + } +} + +static void drop_backref_node(struct backref_cache *tree, + struct backref_node *node) +{ + BUG_ON(!list_empty(&node->upper)); + + drop_node_buffer(node); + list_del(&node->list); + list_del(&node->lower); + if (!RB_EMPTY_NODE(&node->rb_node)) + rb_erase(&node->rb_node, &tree->rb_root); + free_backref_node(tree, node); +} + +/* + * remove a backref node from the backref cache + */ +void remove_backref_node(struct backref_cache *cache, struct backref_node *node) +{ + struct backref_node *upper; + struct backref_edge *edge; + + if (!node) + return; + + BUG_ON(!node->lowest && !node->detached); + while (!list_empty(&node->upper)) { + edge = list_entry(node->upper.next, struct backref_edge, + list[LOWER]); + upper = edge->node[UPPER]; + list_del(&edge->list[LOWER]); + list_del(&edge->list[UPPER]); + free_backref_edge(cache, edge); + + if (RB_EMPTY_NODE(&upper->rb_node)) { + BUG_ON(!list_empty(&node->upper)); + drop_backref_node(cache, node); + node = upper; + node->lowest = 1; + continue; + } + /* + * add the node to leaf node list if no other + * child block cached. + */ + if (list_empty(&upper->lower)) { + list_add_tail(&upper->lower, &cache->leaves); + upper->lowest = 1; + } + } + + drop_backref_node(cache, node); +} + +void update_backref_node(struct backref_cache *cache, struct backref_node *node, + u64 bytenr) +{ + struct rb_node *rb_node; + rb_erase(&node->rb_node, &cache->rb_root); + node->bytenr = bytenr; + rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); + if (rb_node) + backref_tree_panic(rb_node, -EEXIST, bytenr); +} + +/* + * update backref cache after a transaction commit + */ +int update_backref_cache(struct btrfs_trans_handle *trans, + struct backref_cache *cache) +{ + struct backref_node *node; + int level = 0; + + if (cache->last_trans == 0) { + cache->last_trans = trans->transid; + return 0; + } + + if (cache->last_trans == trans->transid) + return 0; + + /* + * detached nodes are used to avoid unnecessary backref + * lookup. transaction commit changes the extent tree. + * so the detached nodes are no longer useful. + */ + while (!list_empty(&cache->detached)) { + node = list_entry(cache->detached.next, + struct backref_node, list); + remove_backref_node(cache, node); + } + + while (!list_empty(&cache->changed)) { + node = list_entry(cache->changed.next, + struct backref_node, list); + list_del_init(&node->list); + BUG_ON(node->pending); + update_backref_node(cache, node, node->new_bytenr); + } + + /* + * some nodes can be left in the pending list if there were + * errors during processing the pending nodes. + */ + for (level = 0; level < BTRFS_MAX_LEVEL; level++) { + list_for_each_entry(node, &cache->pending[level], list) { + BUG_ON(!node->pending); + if (node->bytenr == node->new_bytenr) + continue; + update_backref_node(cache, node, node->new_bytenr); + } + } + + cache->last_trans = 0; + return 1; +} + +static int should_ignore_root(struct btrfs_root *root) +{ + struct btrfs_root *reloc_root; + + if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) + return 0; + + reloc_root = root->reloc_root; + if (!reloc_root) + return 0; + + if (btrfs_root_last_snapshot(&reloc_root->root_item) == + root->fs_info->running_transaction->transid - 1) + return 0; + /* + * if there is reloc tree and it was created in previous + * transaction backref lookup can find the reloc tree, + * so backref node for the fs tree root is useless for + * relocation. + */ + return 1; +} + +/* + * find reloc tree by address of tree root + */ +static struct btrfs_root *find_reloc_root(struct reloc_control *rc, + u64 bytenr) +{ + struct rb_node *rb_node; + struct mapping_node *node; + struct btrfs_root *root = NULL; + + spin_lock(&rc->reloc_root_tree.lock); + rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr); + if (rb_node) { + node = rb_entry(rb_node, struct mapping_node, rb_node); + root = (struct btrfs_root *)node->data; + } + spin_unlock(&rc->reloc_root_tree.lock); + return root; +} + +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 + * roots of b-trees that reference the tree block. + * + * the basic idea of this function is check backrefs of a given block + * to find upper level blocks that reference the block, and then check + * backrefs of these upper level blocks recursively. the recursion stop + * when tree root is reached or backrefs for the block is cached. + * + * NOTE: if we find backrefs for a block are cached, we know backrefs + * for all upper level blocks that directly/indirectly reference the + * block are also cached. + */ +struct backref_node *build_backref_tree(struct reloc_control *rc, + struct btrfs_key *node_key, + int level, u64 bytenr) +{ + 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_root *root; + struct backref_node *cur; + struct backref_node *upper; + struct backref_node *lower; + struct backref_node *node = NULL; + 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; + int ret; + int err = 0; + bool need_check = true; + + path1 = btrfs_alloc_path(); + path2 = btrfs_alloc_path(); + if (!path1 || !path2) { + err = -ENOMEM; + goto out; + } + path1->reada = READA_FORWARD; + path2->reada = READA_FORWARD; + + node = alloc_backref_node(cache); + if (!node) { + err = -ENOMEM; + goto out; + } + + node->bytenr = bytenr; + node->level = level; + 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); + if (ret < 0) { + err = ret; + goto out; + } + ASSERT(ret); + ASSERT(path1->slots[0]); + + path1->slots[0]--; + + WARN_ON(cur->checked); + if (!list_empty(&cur->upper)) { + /* + * the backref was added previously when processing + * backref of type BTRFS_TREE_BLOCK_REF_KEY + */ + ASSERT(list_is_singular(&cur->upper)); + edge = list_entry(cur->upper.next, struct backref_edge, + list[LOWER]); + ASSERT(list_empty(&edge->list[UPPER])); + exist = edge->node[UPPER]; + /* + * add the upper level block to pending list if we need + * check its backrefs + */ + if (!exist->checked) + list_add_tail(&edge->list[UPPER], &list); + } else { + 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]; + } + + btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); + if (key.objectid != cur->bytenr) { + WARN_ON(exist); + break; + } + + 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; + } + } + + if (ptr < end) { + /* update key for inline back ref */ + struct btrfs_extent_inline_ref *iref; + int type; + iref = (struct btrfs_extent_inline_ref *)ptr; + type = btrfs_get_extent_inline_ref_type(eb, iref, + BTRFS_REF_TYPE_BLOCK); + if (type == BTRFS_REF_TYPE_INVALID) { + err = -EUCLEAN; + goto out; + } + 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); + } + + /* + * Parent node found and matches current inline ref, no need to + * rebuild this node for this inline ref. + */ + if (exist && + ((key.type == BTRFS_TREE_BLOCK_REF_KEY && + exist->owner == key.offset) || + (key.type == BTRFS_SHARED_BLOCK_REF_KEY && + exist->bytenr == key.offset))) { + exist = NULL; + goto next; + } + + /* SHARED_BLOCK_REF means key.offset is the parent bytenr */ + if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { + if (key.objectid == key.offset) { + /* + * Only root blocks of reloc trees use backref + * pointing to itself. + */ + root = find_reloc_root(rc, cur->bytenr); + ASSERT(root); + cur->root = root; + break; + } + + edge = alloc_backref_edge(cache); + if (!edge) { + err = -ENOMEM; + goto out; + } + rb_node = tree_search(&cache->rb_root, key.offset); + if (!rb_node) { + upper = alloc_backref_node(cache); + if (!upper) { + free_backref_edge(cache, edge); + err = -ENOMEM; + goto out; + } + upper->bytenr = key.offset; + upper->level = cur->level + 1; + /* + * backrefs for the upper level block isn't + * cached, add the block to pending list + */ + list_add_tail(&edge->list[UPPER], &list); + } else { + upper = rb_entry(rb_node, struct backref_node, + rb_node); + ASSERT(upper->checked); + INIT_LIST_HEAD(&edge->list[UPPER]); + } + list_add_tail(&edge->list[LOWER], &cur->upper); + edge->node[LOWER] = cur; + edge->node[UPPER] = upper; + + goto next; + } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) { + err = -EINVAL; + btrfs_print_v0_err(rc->extent_root->fs_info); + btrfs_handle_fs_error(rc->extent_root->fs_info, err, + NULL); + goto out; + } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { + goto next; + } + + /* + * key.type == BTRFS_TREE_BLOCK_REF_KEY, inline ref offset + * means the root objectid. We need to search the tree to get + * its parent bytenr. + */ + root = read_fs_root(rc->extent_root->fs_info, key.offset); + if (IS_ERR(root)) { + err = PTR_ERR(root); + goto out; + } + + if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) + cur->cowonly = 1; + + if (btrfs_root_level(&root->root_item) == cur->level) { + /* tree root */ + ASSERT(btrfs_root_bytenr(&root->root_item) == + cur->bytenr); + if (should_ignore_root(root)) + list_add(&cur->list, &useless); + else + cur->root = root; + break; + } + + 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; + if (ret < 0) { + err = ret; + goto out; + } + if (ret > 0 && path2->slots[level] > 0) + path2->slots[level]--; + + eb = path2->nodes[level]; + if (btrfs_node_blockptr(eb, path2->slots[level]) != + cur->bytenr) { + btrfs_err(root->fs_info, + "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)", + cur->bytenr, level - 1, + root->root_key.objectid, + node_key->objectid, node_key->type, + node_key->offset); + err = -ENOENT; + goto out; + } + lower = cur; + need_check = true; + + /* Add all nodes and edges in the path */ + for (; level < BTRFS_MAX_LEVEL; level++) { + if (!path2->nodes[level]) { + ASSERT(btrfs_root_bytenr(&root->root_item) == + lower->bytenr); + if (should_ignore_root(root)) + list_add(&lower->list, &useless); + else + lower->root = root; + break; + } + + edge = alloc_backref_edge(cache); + if (!edge) { + err = -ENOMEM; + goto out; + } + + eb = path2->nodes[level]; + rb_node = tree_search(&cache->rb_root, eb->start); + if (!rb_node) { + upper = alloc_backref_node(cache); + if (!upper) { + free_backref_edge(cache, edge); + err = -ENOMEM; + goto out; + } + upper->bytenr = eb->start; + upper->owner = btrfs_header_owner(eb); + upper->level = lower->level + 1; + if (!test_bit(BTRFS_ROOT_REF_COWS, + &root->state)) + upper->cowonly = 1; + + /* + * if we know the block isn't shared + * we can void checking its backrefs. + */ + if (btrfs_block_can_be_shared(root, eb)) + upper->checked = 0; + else + upper->checked = 1; + + /* + * add the block to pending list if we + * need check its backrefs, we only do this once + * while walking up a tree as we will catch + * anything else later on. + */ + if (!upper->checked && need_check) { + need_check = false; + list_add_tail(&edge->list[UPPER], + &list); + } else { + if (upper->checked) + need_check = true; + INIT_LIST_HEAD(&edge->list[UPPER]); + } + } else { + upper = rb_entry(rb_node, struct backref_node, + rb_node); + ASSERT(upper->checked); + INIT_LIST_HEAD(&edge->list[UPPER]); + if (!upper->owner) + upper->owner = btrfs_header_owner(eb); + } + list_add_tail(&edge->list[LOWER], &lower->upper); + edge->node[LOWER] = lower; + edge->node[UPPER] = upper; + + if (rb_node) + break; + 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(path1); + + cur->checked = 1; + WARN_ON(exist); + + /* the pending list isn't empty, take the first block to process */ + if (!list_empty(&list)) { + edge = list_entry(list.next, struct backref_edge, list[UPPER]); + list_del_init(&edge->list[UPPER]); + cur = edge->node[UPPER]; + goto again; + } + + /* + * everything goes well, connect backref nodes and insert backref nodes + * into the cache. + */ + ASSERT(node->checked); + cowonly = node->cowonly; + if (!cowonly) { + rb_node = tree_insert(&cache->rb_root, node->bytenr, + &node->rb_node); + if (rb_node) + backref_tree_panic(rb_node, -EEXIST, node->bytenr); + list_add_tail(&node->lower, &cache->leaves); + } + + list_for_each_entry(edge, &node->upper, list[LOWER]) + list_add_tail(&edge->list[UPPER], &list); + + while (!list_empty(&list)) { + edge = list_entry(list.next, struct backref_edge, list[UPPER]); + list_del_init(&edge->list[UPPER]); + upper = edge->node[UPPER]; + if (upper->detached) { + list_del(&edge->list[LOWER]); + lower = edge->node[LOWER]; + free_backref_edge(cache, edge); + if (list_empty(&lower->upper)) + list_add(&lower->list, &useless); + continue; + } + + if (!RB_EMPTY_NODE(&upper->rb_node)) { + if (upper->lowest) { + list_del_init(&upper->lower); + upper->lowest = 0; + } + + list_add_tail(&edge->list[UPPER], &upper->lower); + continue; + } + + if (!upper->checked) { + /* + * Still want to blow up for developers since this is a + * logic bug. + */ + ASSERT(0); + err = -EINVAL; + goto out; + } + if (cowonly != upper->cowonly) { + ASSERT(0); + err = -EINVAL; + goto out; + } + + if (!cowonly) { + rb_node = tree_insert(&cache->rb_root, upper->bytenr, + &upper->rb_node); + if (rb_node) + backref_tree_panic(rb_node, -EEXIST, + upper->bytenr); + } + + list_add_tail(&edge->list[UPPER], &upper->lower); + + list_for_each_entry(edge, &upper->upper, list[LOWER]) + list_add_tail(&edge->list[UPPER], &list); + } + /* + * process useless backref nodes. backref nodes for tree leaves + * are deleted from the cache. backref nodes for upper level + * tree blocks are left in the cache to avoid unnecessary backref + * lookup. + */ + while (!list_empty(&useless)) { + upper = list_entry(useless.next, struct backref_node, list); + list_del_init(&upper->list); + ASSERT(list_empty(&upper->upper)); + if (upper == node) + node = NULL; + if (upper->lowest) { + list_del_init(&upper->lower); + upper->lowest = 0; + } + while (!list_empty(&upper->lower)) { + edge = list_entry(upper->lower.next, + struct backref_edge, list[UPPER]); + list_del(&edge->list[UPPER]); + list_del(&edge->list[LOWER]); + lower = edge->node[LOWER]; + free_backref_edge(cache, edge); + + if (list_empty(&lower->upper)) + list_add(&lower->list, &useless); + } + __mark_block_processed(rc, upper); + if (upper->level > 0) { + list_add(&upper->list, &cache->detached); + upper->detached = 1; + } else { + rb_erase(&upper->rb_node, &cache->rb_root); + free_backref_node(cache, upper); + } + } +out: + btrfs_free_path(path1); + btrfs_free_path(path2); + if (err) { + while (!list_empty(&useless)) { + lower = list_entry(useless.next, + struct backref_node, list); + list_del_init(&lower->list); + } + while (!list_empty(&list)) { + edge = list_first_entry(&list, struct backref_edge, + list[UPPER]); + list_del(&edge->list[UPPER]); + list_del(&edge->list[LOWER]); + lower = edge->node[LOWER]; + upper = edge->node[UPPER]; + free_backref_edge(cache, edge); + + /* + * Lower is no longer linked to any upper backref nodes + * and isn't in the cache, we can free it ourselves. + */ + if (list_empty(&lower->upper) && + RB_EMPTY_NODE(&lower->rb_node)) + list_add(&lower->list, &useless); + + if (!RB_EMPTY_NODE(&upper->rb_node)) + continue; + + /* Add this guy's upper edges to the list to process */ + list_for_each_entry(edge, &upper->upper, list[LOWER]) + list_add_tail(&edge->list[UPPER], &list); + if (list_empty(&upper->upper)) + list_add(&upper->list, &useless); + } + + while (!list_empty(&useless)) { + lower = list_entry(useless.next, + struct backref_node, list); + list_del_init(&lower->list); + if (lower == node) + node = NULL; + free_backref_node(cache, lower); + } + + free_backref_node(cache, node); + return ERR_PTR(err); + } + ASSERT(!node || !node->detached); + return node; +} + +void mark_block_processed(struct reloc_control *rc, u64 bytenr, u32 blocksize) +{ + set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1, + EXTENT_DIRTY); +} + +void __mark_block_processed(struct reloc_control *rc, struct backref_node *node) +{ + u32 blocksize; + if (node->level == 0 || + in_block_group(node->bytenr, rc->block_group)) { + blocksize = rc->extent_root->fs_info->nodesize; + mark_block_processed(rc, node->bytenr, blocksize); + } + node->processed = 1; +} diff --git a/fs/btrfs/backref-cache.h b/fs/btrfs/backref-cache.h new file mode 100644 index 000000000000..549eb891b9f8 --- /dev/null +++ b/fs/btrfs/backref-cache.h @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 SUSE. All rights reserved. + */ + +#ifndef BTRFS_BACKREF_CACHE_H +#define BTRFS_BACKREF_CACHE_H + +/* + * present a tree block in the backref cache + */ +struct backref_node { + struct rb_node rb_node; + u64 bytenr; + + u64 new_bytenr; + /* objectid of tree block owner, can be not uptodate */ + u64 owner; + /* link to pending, changed or detached list */ + struct list_head list; + /* list of upper level blocks reference this block */ + struct list_head upper; + /* list of child blocks in the cache */ + struct list_head lower; + /* NULL if this node is not tree root */ + struct btrfs_root *root; + /* extent buffer got by COW the block */ + struct extent_buffer *eb; + /* level of tree block */ + unsigned int level:8; + /* is the block in non-reference counted tree */ + unsigned int cowonly:1; + /* 1 if no child node in the cache */ + unsigned int lowest:1; + /* is the extent buffer locked */ + unsigned int locked:1; + /* has the block been processed */ + unsigned int processed:1; + /* have backrefs of this block been checked */ + unsigned int checked:1; + /* + * 1 if corresponding block has been cowed but some upper + * level block pointers may not point to the new location + */ + unsigned int pending:1; + /* + * 1 if the backref node isn't connected to any other + * backref node. + */ + unsigned int detached:1; +}; + +/* + * present a block pointer in the backref cache + */ +struct backref_edge { + struct list_head list[2]; + struct backref_node *node[2]; +}; + +#define LOWER 0 +#define UPPER 1 + +struct backref_cache { + /* red black tree of all backref nodes in the cache */ + struct rb_root rb_root; + /* for passing backref nodes to btrfs_reloc_cow_block */ + struct backref_node *path[BTRFS_MAX_LEVEL]; + /* + * list of blocks that have been cowed but some block + * pointers in upper level blocks may not reflect the + * new location + */ + struct list_head pending[BTRFS_MAX_LEVEL]; + /* list of backref nodes with no child node */ + struct list_head leaves; + /* list of blocks that have been cowed in current transaction */ + struct list_head changed; + /* list of detached backref node. */ + struct list_head detached; + + u64 last_trans; + + int nr_nodes; + int nr_edges; +}; + +void backref_cache_init(struct backref_cache *cache); +void backref_cache_cleanup(struct backref_cache *cache); +struct backref_node *alloc_backref_node(struct backref_cache *cache); +void free_backref_node(struct backref_cache *cache, + struct backref_node *node); +struct backref_edge *alloc_backref_edge(struct backref_cache *cache); +void free_backref_edge(struct backref_cache *cache, struct backref_edge *edge); +void unlock_node_buffer(struct backref_node *node); +void drop_node_buffer(struct backref_node *node); +void remove_backref_node(struct backref_cache *cache, struct backref_node *node); +void update_backref_node(struct backref_cache *cache, struct backref_node *node, + u64 bytenr); +int update_backref_cache(struct btrfs_trans_handle *trans, + struct backref_cache *cache); + +/* for relocation.c */ +void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr); +void mark_block_processed(struct reloc_control *rc, u64 bytenr, u32 blocksize); +void __mark_block_processed(struct reloc_control *rc, struct backref_node *node); +struct reloc_control; + +struct backref_node *build_backref_tree(struct reloc_control *rc, + struct btrfs_key *node_key, + int level, u64 bytenr); + +#endif /* BTRFS_BACKREF_CACHE_H */ diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 7f219851fa23..a669f26a504a 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -21,6 +21,8 @@ #include "qgroup.h" #include "print-tree.h" #include "delalloc-space.h" +#include "backref-cache.h" +#include "relocation.h" /* * backref_node, mapping_node and tree_block start with this @@ -29,101 +31,8 @@ struct tree_entry { struct rb_node rb_node; u64 bytenr; }; - -/* - * present a tree block in the backref cache - */ -struct backref_node { - struct rb_node rb_node; - u64 bytenr; - - u64 new_bytenr; - /* objectid of tree block owner, can be not uptodate */ - u64 owner; - /* link to pending, changed or detached list */ - struct list_head list; - /* list of upper level blocks reference this block */ - struct list_head upper; - /* list of child blocks in the cache */ - struct list_head lower; - /* NULL if this node is not tree root */ - struct btrfs_root *root; - /* extent buffer got by COW the block */ - struct extent_buffer *eb; - /* level of tree block */ - unsigned int level:8; - /* is the block in non-reference counted tree */ - unsigned int cowonly:1; - /* 1 if no child node in the cache */ - unsigned int lowest:1; - /* is the extent buffer locked */ - unsigned int locked:1; - /* has the block been processed */ - unsigned int processed:1; - /* have backrefs of this block been checked */ - unsigned int checked:1; - /* - * 1 if corresponding block has been cowed but some upper - * level block pointers may not point to the new location - */ - unsigned int pending:1; - /* - * 1 if the backref node isn't connected to any other - * backref node. - */ - unsigned int detached:1; -}; - -/* - * present a block pointer in the backref cache - */ -struct backref_edge { - struct list_head list[2]; - struct backref_node *node[2]; -}; - -#define LOWER 0 -#define UPPER 1 #define RELOCATION_RESERVED_NODES 256 -struct backref_cache { - /* red black tree of all backref nodes in the cache */ - struct rb_root rb_root; - /* for passing backref nodes to btrfs_reloc_cow_block */ - struct backref_node *path[BTRFS_MAX_LEVEL]; - /* - * list of blocks that have been cowed but some block - * pointers in upper level blocks may not reflect the - * new location - */ - struct list_head pending[BTRFS_MAX_LEVEL]; - /* list of backref nodes with no child node */ - struct list_head leaves; - /* list of blocks that have been cowed in current transaction */ - struct list_head changed; - /* list of detached backref node. */ - struct list_head detached; - - u64 last_trans; - - int nr_nodes; - int nr_edges; -}; - -/* - * map address of tree root to tree - */ -struct mapping_node { - struct rb_node rb_node; - u64 bytenr; - void *data; -}; - -struct mapping_tree { - struct rb_root rb_root; - spinlock_t lock; -}; - /* * present a tree block to process */ @@ -135,151 +44,14 @@ struct tree_block { unsigned int key_ready:1; }; -#define MAX_EXTENTS 128 - -struct file_extent_cluster { - u64 start; - u64 end; - u64 boundary[MAX_EXTENTS]; - unsigned int nr; -}; - -struct reloc_control { - /* block group to relocate */ - struct btrfs_block_group_cache *block_group; - /* extent tree */ - struct btrfs_root *extent_root; - /* inode for moving data */ - struct inode *data_inode; - - struct btrfs_block_rsv *block_rsv; - - struct backref_cache backref_cache; - - struct file_extent_cluster cluster; - /* tree blocks have been processed */ - struct extent_io_tree processed_blocks; - /* map start of tree root to corresponding reloc tree */ - struct mapping_tree reloc_root_tree; - /* list of reloc trees */ - struct list_head reloc_roots; - /* list of subvolume trees that get relocated */ - struct list_head dirty_subvol_roots; - /* size of metadata reservation for merging reloc trees */ - u64 merging_rsv_size; - /* size of relocated tree nodes */ - u64 nodes_relocated; - /* reserved size for block group relocation*/ - u64 reserved_bytes; - - u64 search_start; - u64 extents_found; - - unsigned int stage:8; - unsigned int create_reloc_tree:1; - unsigned int merge_reloc_tree:1; - unsigned int found_file_extent:1; -}; - -/* stages of data relocation */ -#define MOVE_DATA_EXTENTS 0 -#define UPDATE_DATA_PTRS 1 - -static void remove_backref_node(struct backref_cache *cache, - struct backref_node *node); -static void __mark_block_processed(struct reloc_control *rc, - struct backref_node *node); - static void mapping_tree_init(struct mapping_tree *tree) { tree->rb_root = RB_ROOT; spin_lock_init(&tree->lock); } -static void backref_cache_init(struct backref_cache *cache) -{ - int i; - cache->rb_root = RB_ROOT; - for (i = 0; i < BTRFS_MAX_LEVEL; i++) - INIT_LIST_HEAD(&cache->pending[i]); - INIT_LIST_HEAD(&cache->changed); - INIT_LIST_HEAD(&cache->detached); - INIT_LIST_HEAD(&cache->leaves); -} - -static void backref_cache_cleanup(struct backref_cache *cache) -{ - struct backref_node *node; - int i; - - while (!list_empty(&cache->detached)) { - node = list_entry(cache->detached.next, - struct backref_node, list); - remove_backref_node(cache, node); - } - - while (!list_empty(&cache->leaves)) { - node = list_entry(cache->leaves.next, - struct backref_node, lower); - remove_backref_node(cache, node); - } - - cache->last_trans = 0; - - for (i = 0; i < BTRFS_MAX_LEVEL; i++) - ASSERT(list_empty(&cache->pending[i])); - ASSERT(list_empty(&cache->changed)); - ASSERT(list_empty(&cache->detached)); - ASSERT(RB_EMPTY_ROOT(&cache->rb_root)); - ASSERT(!cache->nr_nodes); - ASSERT(!cache->nr_edges); -} - -static struct backref_node *alloc_backref_node(struct backref_cache *cache) -{ - struct backref_node *node; - - node = kzalloc(sizeof(*node), GFP_NOFS); - if (node) { - INIT_LIST_HEAD(&node->list); - INIT_LIST_HEAD(&node->upper); - INIT_LIST_HEAD(&node->lower); - RB_CLEAR_NODE(&node->rb_node); - cache->nr_nodes++; - } - return node; -} - -static void free_backref_node(struct backref_cache *cache, - struct backref_node *node) -{ - if (node) { - cache->nr_nodes--; - kfree(node); - } -} - -static struct backref_edge *alloc_backref_edge(struct backref_cache *cache) -{ - struct backref_edge *edge; - - edge = kzalloc(sizeof(*edge), GFP_NOFS); - if (edge) - cache->nr_edges++; - return edge; -} - -static void free_backref_edge(struct backref_cache *cache, - struct backref_edge *edge) -{ - if (edge) { - cache->nr_edges--; - kfree(edge); - } -} - -static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, - struct rb_node *node) +struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, + struct rb_node *node) { struct rb_node **p = &root->rb_node; struct rb_node *parent = NULL; @@ -302,7 +74,7 @@ static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, return NULL; } -static struct rb_node *tree_search(struct rb_root *root, u64 bytenr) +struct rb_node *tree_search(struct rb_root *root, u64 bytenr) { struct rb_node *n = root->rb_node; struct tree_entry *entry; @@ -320,19 +92,6 @@ static struct rb_node *tree_search(struct rb_root *root, u64 bytenr) return NULL; } -static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr) -{ - - struct btrfs_fs_info *fs_info = NULL; - struct backref_node *bnode = rb_entry(rb_node, struct backref_node, - rb_node); - if (bnode->root) - fs_info = bnode->root->fs_info; - btrfs_panic(fs_info, errno, - "Inconsistency in backref cache found at offset %llu", - bytenr); -} - /* * walk up backref nodes until reach node presents tree root */ @@ -381,185 +140,7 @@ static struct backref_node *walk_down_backref(struct backref_edge *edges[], return NULL; } -static void unlock_node_buffer(struct backref_node *node) -{ - if (node->locked) { - btrfs_tree_unlock(node->eb); - node->locked = 0; - } -} - -static void drop_node_buffer(struct backref_node *node) -{ - if (node->eb) { - unlock_node_buffer(node); - free_extent_buffer(node->eb); - node->eb = NULL; - } -} - -static void drop_backref_node(struct backref_cache *tree, - struct backref_node *node) -{ - BUG_ON(!list_empty(&node->upper)); - - drop_node_buffer(node); - list_del(&node->list); - list_del(&node->lower); - if (!RB_EMPTY_NODE(&node->rb_node)) - rb_erase(&node->rb_node, &tree->rb_root); - free_backref_node(tree, node); -} - -/* - * remove a backref node from the backref cache - */ -static void remove_backref_node(struct backref_cache *cache, - struct backref_node *node) -{ - struct backref_node *upper; - struct backref_edge *edge; - - if (!node) - return; - - BUG_ON(!node->lowest && !node->detached); - while (!list_empty(&node->upper)) { - edge = list_entry(node->upper.next, struct backref_edge, - list[LOWER]); - upper = edge->node[UPPER]; - list_del(&edge->list[LOWER]); - list_del(&edge->list[UPPER]); - free_backref_edge(cache, edge); - - if (RB_EMPTY_NODE(&upper->rb_node)) { - BUG_ON(!list_empty(&node->upper)); - drop_backref_node(cache, node); - node = upper; - node->lowest = 1; - continue; - } - /* - * add the node to leaf node list if no other - * child block cached. - */ - if (list_empty(&upper->lower)) { - list_add_tail(&upper->lower, &cache->leaves); - upper->lowest = 1; - } - } - - drop_backref_node(cache, node); -} - -static void update_backref_node(struct backref_cache *cache, - struct backref_node *node, u64 bytenr) -{ - struct rb_node *rb_node; - rb_erase(&node->rb_node, &cache->rb_root); - node->bytenr = bytenr; - rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, bytenr); -} - -/* - * update backref cache after a transaction commit - */ -static int update_backref_cache(struct btrfs_trans_handle *trans, - struct backref_cache *cache) -{ - struct backref_node *node; - int level = 0; - - if (cache->last_trans == 0) { - cache->last_trans = trans->transid; - return 0; - } - - if (cache->last_trans == trans->transid) - return 0; - - /* - * detached nodes are used to avoid unnecessary backref - * lookup. transaction commit changes the extent tree. - * so the detached nodes are no longer useful. - */ - while (!list_empty(&cache->detached)) { - node = list_entry(cache->detached.next, - struct backref_node, list); - remove_backref_node(cache, node); - } - - while (!list_empty(&cache->changed)) { - node = list_entry(cache->changed.next, - struct backref_node, list); - list_del_init(&node->list); - BUG_ON(node->pending); - update_backref_node(cache, node, node->new_bytenr); - } - - /* - * some nodes can be left in the pending list if there were - * errors during processing the pending nodes. - */ - for (level = 0; level < BTRFS_MAX_LEVEL; level++) { - list_for_each_entry(node, &cache->pending[level], list) { - BUG_ON(!node->pending); - if (node->bytenr == node->new_bytenr) - continue; - update_backref_node(cache, node, node->new_bytenr); - } - } - - cache->last_trans = 0; - return 1; -} - - -static int should_ignore_root(struct btrfs_root *root) -{ - struct btrfs_root *reloc_root; - - if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) - return 0; - - reloc_root = root->reloc_root; - if (!reloc_root) - return 0; - - if (btrfs_root_last_snapshot(&reloc_root->root_item) == - root->fs_info->running_transaction->transid - 1) - return 0; - /* - * if there is reloc tree and it was created in previous - * transaction backref lookup can find the reloc tree, - * so backref node for the fs tree root is useless for - * relocation. - */ - return 1; -} -/* - * find reloc tree by address of tree root - */ -static struct btrfs_root *find_reloc_root(struct reloc_control *rc, - u64 bytenr) -{ - struct rb_node *rb_node; - struct mapping_node *node; - struct btrfs_root *root = NULL; - - spin_lock(&rc->reloc_root_tree.lock); - rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr); - if (rb_node) { - node = rb_entry(rb_node, struct mapping_node, rb_node); - root = (struct btrfs_root *)node->data; - } - spin_unlock(&rc->reloc_root_tree.lock); - return root; -} - -static int is_cowonly_root(u64 root_objectid) +int is_cowonly_root(u64 root_objectid) { if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || root_objectid == BTRFS_EXTENT_TREE_OBJECTID || @@ -574,8 +155,7 @@ static int is_cowonly_root(u64 root_objectid) return 0; } -static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, - u64 root_objectid) +struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, u64 root_objectid) { struct btrfs_key key; @@ -589,577 +169,6 @@ 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 - * roots of b-trees that reference the tree block. - * - * the basic idea of this function is check backrefs of a given block - * to find upper level blocks that reference the block, and then check - * backrefs of these upper level blocks recursively. the recursion stop - * when tree root is reached or backrefs for the block is cached. - * - * NOTE: if we find backrefs for a block are cached, we know backrefs - * for all upper level blocks that directly/indirectly reference the - * block are also cached. - */ -static noinline_for_stack -struct backref_node *build_backref_tree(struct reloc_control *rc, - struct btrfs_key *node_key, - int level, u64 bytenr) -{ - 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_root *root; - struct backref_node *cur; - struct backref_node *upper; - struct backref_node *lower; - struct backref_node *node = NULL; - 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; - int ret; - int err = 0; - bool need_check = true; - - path1 = btrfs_alloc_path(); - path2 = btrfs_alloc_path(); - if (!path1 || !path2) { - err = -ENOMEM; - goto out; - } - path1->reada = READA_FORWARD; - path2->reada = READA_FORWARD; - - node = alloc_backref_node(cache); - if (!node) { - err = -ENOMEM; - goto out; - } - - node->bytenr = bytenr; - node->level = level; - 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); - if (ret < 0) { - err = ret; - goto out; - } - ASSERT(ret); - ASSERT(path1->slots[0]); - - path1->slots[0]--; - - WARN_ON(cur->checked); - if (!list_empty(&cur->upper)) { - /* - * the backref was added previously when processing - * backref of type BTRFS_TREE_BLOCK_REF_KEY - */ - ASSERT(list_is_singular(&cur->upper)); - edge = list_entry(cur->upper.next, struct backref_edge, - list[LOWER]); - ASSERT(list_empty(&edge->list[UPPER])); - exist = edge->node[UPPER]; - /* - * add the upper level block to pending list if we need - * check its backrefs - */ - if (!exist->checked) - list_add_tail(&edge->list[UPPER], &list); - } else { - 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]; - } - - btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); - if (key.objectid != cur->bytenr) { - WARN_ON(exist); - break; - } - - 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; - } - } - - if (ptr < end) { - /* update key for inline back ref */ - struct btrfs_extent_inline_ref *iref; - int type; - iref = (struct btrfs_extent_inline_ref *)ptr; - type = btrfs_get_extent_inline_ref_type(eb, iref, - BTRFS_REF_TYPE_BLOCK); - if (type == BTRFS_REF_TYPE_INVALID) { - err = -EUCLEAN; - goto out; - } - 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); - } - - /* - * Parent node found and matches current inline ref, no need to - * rebuild this node for this inline ref. - */ - if (exist && - ((key.type == BTRFS_TREE_BLOCK_REF_KEY && - exist->owner == key.offset) || - (key.type == BTRFS_SHARED_BLOCK_REF_KEY && - exist->bytenr == key.offset))) { - exist = NULL; - goto next; - } - - /* SHARED_BLOCK_REF means key.offset is the parent bytenr */ - if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { - if (key.objectid == key.offset) { - /* - * Only root blocks of reloc trees use backref - * pointing to itself. - */ - root = find_reloc_root(rc, cur->bytenr); - ASSERT(root); - cur->root = root; - break; - } - - edge = alloc_backref_edge(cache); - if (!edge) { - err = -ENOMEM; - goto out; - } - rb_node = tree_search(&cache->rb_root, key.offset); - if (!rb_node) { - upper = alloc_backref_node(cache); - if (!upper) { - free_backref_edge(cache, edge); - err = -ENOMEM; - goto out; - } - upper->bytenr = key.offset; - upper->level = cur->level + 1; - /* - * backrefs for the upper level block isn't - * cached, add the block to pending list - */ - list_add_tail(&edge->list[UPPER], &list); - } else { - upper = rb_entry(rb_node, struct backref_node, - rb_node); - ASSERT(upper->checked); - INIT_LIST_HEAD(&edge->list[UPPER]); - } - list_add_tail(&edge->list[LOWER], &cur->upper); - edge->node[LOWER] = cur; - edge->node[UPPER] = upper; - - goto next; - } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) { - err = -EINVAL; - btrfs_print_v0_err(rc->extent_root->fs_info); - btrfs_handle_fs_error(rc->extent_root->fs_info, err, - NULL); - goto out; - } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { - goto next; - } - - /* - * key.type == BTRFS_TREE_BLOCK_REF_KEY, inline ref offset - * means the root objectid. We need to search the tree to get - * its parent bytenr. - */ - root = read_fs_root(rc->extent_root->fs_info, key.offset); - if (IS_ERR(root)) { - err = PTR_ERR(root); - goto out; - } - - if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) - cur->cowonly = 1; - - if (btrfs_root_level(&root->root_item) == cur->level) { - /* tree root */ - ASSERT(btrfs_root_bytenr(&root->root_item) == - cur->bytenr); - if (should_ignore_root(root)) - list_add(&cur->list, &useless); - else - cur->root = root; - break; - } - - 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; - if (ret < 0) { - err = ret; - goto out; - } - if (ret > 0 && path2->slots[level] > 0) - path2->slots[level]--; - - eb = path2->nodes[level]; - if (btrfs_node_blockptr(eb, path2->slots[level]) != - cur->bytenr) { - btrfs_err(root->fs_info, - "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)", - cur->bytenr, level - 1, - root->root_key.objectid, - node_key->objectid, node_key->type, - node_key->offset); - err = -ENOENT; - goto out; - } - lower = cur; - need_check = true; - - /* Add all nodes and edges in the path */ - for (; level < BTRFS_MAX_LEVEL; level++) { - if (!path2->nodes[level]) { - ASSERT(btrfs_root_bytenr(&root->root_item) == - lower->bytenr); - if (should_ignore_root(root)) - list_add(&lower->list, &useless); - else - lower->root = root; - break; - } - - edge = alloc_backref_edge(cache); - if (!edge) { - err = -ENOMEM; - goto out; - } - - eb = path2->nodes[level]; - rb_node = tree_search(&cache->rb_root, eb->start); - if (!rb_node) { - upper = alloc_backref_node(cache); - if (!upper) { - free_backref_edge(cache, edge); - err = -ENOMEM; - goto out; - } - upper->bytenr = eb->start; - upper->owner = btrfs_header_owner(eb); - upper->level = lower->level + 1; - if (!test_bit(BTRFS_ROOT_REF_COWS, - &root->state)) - upper->cowonly = 1; - - /* - * if we know the block isn't shared - * we can void checking its backrefs. - */ - if (btrfs_block_can_be_shared(root, eb)) - upper->checked = 0; - else - upper->checked = 1; - - /* - * add the block to pending list if we - * need check its backrefs, we only do this once - * while walking up a tree as we will catch - * anything else later on. - */ - if (!upper->checked && need_check) { - need_check = false; - list_add_tail(&edge->list[UPPER], - &list); - } else { - if (upper->checked) - need_check = true; - INIT_LIST_HEAD(&edge->list[UPPER]); - } - } else { - upper = rb_entry(rb_node, struct backref_node, - rb_node); - ASSERT(upper->checked); - INIT_LIST_HEAD(&edge->list[UPPER]); - if (!upper->owner) - upper->owner = btrfs_header_owner(eb); - } - list_add_tail(&edge->list[LOWER], &lower->upper); - edge->node[LOWER] = lower; - edge->node[UPPER] = upper; - - if (rb_node) - break; - 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(path1); - - cur->checked = 1; - WARN_ON(exist); - - /* the pending list isn't empty, take the first block to process */ - if (!list_empty(&list)) { - edge = list_entry(list.next, struct backref_edge, list[UPPER]); - list_del_init(&edge->list[UPPER]); - cur = edge->node[UPPER]; - goto again; - } - - /* - * everything goes well, connect backref nodes and insert backref nodes - * into the cache. - */ - ASSERT(node->checked); - cowonly = node->cowonly; - if (!cowonly) { - rb_node = tree_insert(&cache->rb_root, node->bytenr, - &node->rb_node); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, node->bytenr); - list_add_tail(&node->lower, &cache->leaves); - } - - list_for_each_entry(edge, &node->upper, list[LOWER]) - list_add_tail(&edge->list[UPPER], &list); - - while (!list_empty(&list)) { - edge = list_entry(list.next, struct backref_edge, list[UPPER]); - list_del_init(&edge->list[UPPER]); - upper = edge->node[UPPER]; - if (upper->detached) { - list_del(&edge->list[LOWER]); - lower = edge->node[LOWER]; - free_backref_edge(cache, edge); - if (list_empty(&lower->upper)) - list_add(&lower->list, &useless); - continue; - } - - if (!RB_EMPTY_NODE(&upper->rb_node)) { - if (upper->lowest) { - list_del_init(&upper->lower); - upper->lowest = 0; - } - - list_add_tail(&edge->list[UPPER], &upper->lower); - continue; - } - - if (!upper->checked) { - /* - * Still want to blow up for developers since this is a - * logic bug. - */ - ASSERT(0); - err = -EINVAL; - goto out; - } - if (cowonly != upper->cowonly) { - ASSERT(0); - err = -EINVAL; - goto out; - } - - if (!cowonly) { - rb_node = tree_insert(&cache->rb_root, upper->bytenr, - &upper->rb_node); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, - upper->bytenr); - } - - list_add_tail(&edge->list[UPPER], &upper->lower); - - list_for_each_entry(edge, &upper->upper, list[LOWER]) - list_add_tail(&edge->list[UPPER], &list); - } - /* - * process useless backref nodes. backref nodes for tree leaves - * are deleted from the cache. backref nodes for upper level - * tree blocks are left in the cache to avoid unnecessary backref - * lookup. - */ - while (!list_empty(&useless)) { - upper = list_entry(useless.next, struct backref_node, list); - list_del_init(&upper->list); - ASSERT(list_empty(&upper->upper)); - if (upper == node) - node = NULL; - if (upper->lowest) { - list_del_init(&upper->lower); - upper->lowest = 0; - } - while (!list_empty(&upper->lower)) { - edge = list_entry(upper->lower.next, - struct backref_edge, list[UPPER]); - list_del(&edge->list[UPPER]); - list_del(&edge->list[LOWER]); - lower = edge->node[LOWER]; - free_backref_edge(cache, edge); - - if (list_empty(&lower->upper)) - list_add(&lower->list, &useless); - } - __mark_block_processed(rc, upper); - if (upper->level > 0) { - list_add(&upper->list, &cache->detached); - upper->detached = 1; - } else { - rb_erase(&upper->rb_node, &cache->rb_root); - free_backref_node(cache, upper); - } - } -out: - btrfs_free_path(path1); - btrfs_free_path(path2); - if (err) { - while (!list_empty(&useless)) { - lower = list_entry(useless.next, - struct backref_node, list); - list_del_init(&lower->list); - } - while (!list_empty(&list)) { - edge = list_first_entry(&list, struct backref_edge, - list[UPPER]); - list_del(&edge->list[UPPER]); - list_del(&edge->list[LOWER]); - lower = edge->node[LOWER]; - upper = edge->node[UPPER]; - free_backref_edge(cache, edge); - - /* - * Lower is no longer linked to any upper backref nodes - * and isn't in the cache, we can free it ourselves. - */ - if (list_empty(&lower->upper) && - RB_EMPTY_NODE(&lower->rb_node)) - list_add(&lower->list, &useless); - - if (!RB_EMPTY_NODE(&upper->rb_node)) - continue; - - /* Add this guy's upper edges to the list to process */ - list_for_each_entry(edge, &upper->upper, list[LOWER]) - list_add_tail(&edge->list[UPPER], &list); - if (list_empty(&upper->upper)) - list_add(&upper->list, &useless); - } - - while (!list_empty(&useless)) { - lower = list_entry(useless.next, - struct backref_node, list); - list_del_init(&lower->list); - if (lower == node) - node = NULL; - free_backref_node(cache, lower); - } - - free_backref_node(cache, node); - return ERR_PTR(err); - } - ASSERT(!node || !node->detached); - return node; -} - /* * helper to add backref node for the newly created snapshot. * the backref node is created by cloning backref node that @@ -1552,8 +561,7 @@ static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid) return NULL; } -static int in_block_group(u64 bytenr, - struct btrfs_block_group_cache *block_group) +int in_block_group(u64 bytenr, struct btrfs_block_group_cache *block_group) { if (bytenr >= block_group->key.objectid && bytenr < block_group->key.objectid + block_group->key.offset) @@ -2926,25 +1934,6 @@ static int finish_pending_nodes(struct btrfs_trans_handle *trans, return err; } -static void mark_block_processed(struct reloc_control *rc, - u64 bytenr, u32 blocksize) -{ - set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1, - EXTENT_DIRTY); -} - -static void __mark_block_processed(struct reloc_control *rc, - struct backref_node *node) -{ - u32 blocksize; - if (node->level == 0 || - in_block_group(node->bytenr, rc->block_group)) { - blocksize = rc->extent_root->fs_info->nodesize; - mark_block_processed(rc, node->bytenr, blocksize); - } - node->processed = 1; -} - /* * mark a block and all blocks directly/indirectly reference the block * as processed. diff --git a/fs/btrfs/relocation.h b/fs/btrfs/relocation.h new file mode 100644 index 000000000000..6f6b0d85ea45 --- /dev/null +++ b/fs/btrfs/relocation.h @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 SUSE. All rights reserved. + */ + +#ifndef BTRFS_RELOCATION_H +#define BTRFS_RELOCATION_H + +#include "backref-cache.h" + +/* + * map address of tree root to tree + */ +struct mapping_node { + struct rb_node rb_node; + u64 bytenr; + void *data; +}; + +struct mapping_tree { + struct rb_root rb_root; + spinlock_t lock; +}; + +#define MAX_EXTENTS 128 + +struct file_extent_cluster { + u64 start; + u64 end; + u64 boundary[MAX_EXTENTS]; + unsigned int nr; +}; + +struct reloc_control { + /* block group to relocate */ + struct btrfs_block_group_cache *block_group; + /* extent tree */ + struct btrfs_root *extent_root; + /* inode for moving data */ + struct inode *data_inode; + + struct btrfs_block_rsv *block_rsv; + + struct backref_cache backref_cache; + + struct file_extent_cluster cluster; + /* tree blocks have been processed */ + struct extent_io_tree processed_blocks; + /* map start of tree root to corresponding reloc tree */ + struct mapping_tree reloc_root_tree; + /* list of reloc trees */ + struct list_head reloc_roots; + /* list of subvolume trees that get relocated */ + struct list_head dirty_subvol_roots; + /* size of metadata reservation for merging reloc trees */ + u64 merging_rsv_size; + /* size of relocated tree nodes */ + u64 nodes_relocated; + /* reserved size for block group relocation*/ + u64 reserved_bytes; + + u64 search_start; + u64 extents_found; + + unsigned int stage:8; + unsigned int create_reloc_tree:1; + unsigned int merge_reloc_tree:1; + unsigned int found_file_extent:1; +}; + +/* stages of data relocation */ +#define MOVE_DATA_EXTENTS 0 +#define UPDATE_DATA_PTRS 1 + +/* for backref-cache.c */ +int is_cowonly_root(u64 root_objectid); +struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, + u64 root_objectid); +int in_block_group(u64 bytenr, struct btrfs_block_group_cache *block_group); + +struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, + struct rb_node *node); +struct rb_node *tree_search(struct rb_root *root, u64 bytenr); + +#endif /* BTRFS_RELOCATION_H */ From patchwork Fri Sep 6 17:15:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Fasheh X-Patchwork-Id: 11135747 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 8F8C114ED for ; Fri, 6 Sep 2019 17:16:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 791C12082C for ; Fri, 6 Sep 2019 17:16:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404411AbfIFRQH (ORCPT ); Fri, 6 Sep 2019 13:16:07 -0400 Received: from mx2.suse.de ([195.135.220.15]:36564 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2404350AbfIFRQH (ORCPT ); Fri, 6 Sep 2019 13:16:07 -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 59BBFADDA for ; Fri, 6 Sep 2019 17:16:05 +0000 (UTC) From: Mark Fasheh To: linux-btrfs@vger.kernel.org Cc: Mark Fasheh Subject: [PATCH 2/3] btrfs: move ref finding machinery out of build_backref_tree() Date: Fri, 6 Sep 2019 10:15:32 -0700 Message-Id: <20190906171533.618-3-mfasheh@suse.com> X-Mailer: git-send-email 2.22.1 In-Reply-To: <20190906171533.618-1-mfasheh@suse.com> References: <20190906171533.618-1-mfasheh@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 From: Mark Fasheh build_backref_tree() is walking extent refs in what is an otherwise self contained chunk of code. We can shrink the total number of lines in build_backref_tree() *and* make it more readable by moving that walk into its own subroutine. Signed-off-by: Mark Fasheh Reviewed-by: Josef Bacik --- fs/btrfs/backref-cache.c | 110 +++++++++++++++++++++++---------------- 1 file changed, 65 insertions(+), 45 deletions(-) diff --git a/fs/btrfs/backref-cache.c b/fs/btrfs/backref-cache.c index d0f6530f23b8..ff0d49ca6e26 100644 --- a/fs/btrfs/backref-cache.c +++ b/fs/btrfs/backref-cache.c @@ -336,6 +336,61 @@ int find_inline_backref(struct extent_buffer *leaf, int slot, return 0; } +#define SEARCH_COMPLETE 1 +#define SEARCH_NEXT 2 +static int find_next_ref(struct btrfs_root *extent_root, u64 cur_bytenr, + struct btrfs_path *path, unsigned long *ptr, + unsigned long *end, struct btrfs_key *key, bool exist) +{ + struct extent_buffer *eb = path->nodes[0]; + int ret; + + if (*ptr >= *end) { + if (path->slots[0] >= btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(extent_root, path); + if (ret < 0) + goto out; + if (ret > 0) + return SEARCH_COMPLETE; + eb = path->nodes[0]; + } + + btrfs_item_key_to_cpu(eb, key, path->slots[0]); + if (key->objectid != cur_bytenr) { + WARN_ON(exist); + return SEARCH_COMPLETE; + } + + if (key->type == BTRFS_EXTENT_ITEM_KEY || + key->type == BTRFS_METADATA_ITEM_KEY) { + ret = find_inline_backref(eb, path->slots[0], + ptr, end); + if (ret) + return SEARCH_NEXT; + } + } + + if (*ptr < *end) { + /* update key for inline back ref */ + struct btrfs_extent_inline_ref *iref; + int type; + iref = (struct btrfs_extent_inline_ref *)(*ptr); + type = btrfs_get_extent_inline_ref_type(eb, iref, + BTRFS_REF_TYPE_BLOCK); + if (type == BTRFS_REF_TYPE_INVALID) { + ret = -EUCLEAN; + goto out; + } + 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); + } + ret = 0; +out: + return ret; +} /* * build backref tree for a given tree block. root of the backref tree @@ -439,52 +494,17 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, 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]; - } - - btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); - if (key.objectid != cur->bytenr) { - WARN_ON(exist); - break; - } - - 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; - } - } - - if (ptr < end) { - /* update key for inline back ref */ - struct btrfs_extent_inline_ref *iref; - int type; - iref = (struct btrfs_extent_inline_ref *)ptr; - type = btrfs_get_extent_inline_ref_type(eb, iref, - BTRFS_REF_TYPE_BLOCK); - if (type == BTRFS_REF_TYPE_INVALID) { - err = -EUCLEAN; - goto out; - } - 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); + ret = find_next_ref(rc->extent_root, cur->bytenr, path1, &ptr, + &end, &key, exist != NULL); + if (ret < 0) { + err = ret; + goto out; } + eb = path1->nodes[0]; + if (ret == SEARCH_COMPLETE) + break; + else if (ret == SEARCH_NEXT) + goto next; /* * Parent node found and matches current inline ref, no need to From patchwork Fri Sep 6 17:15:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Fasheh X-Patchwork-Id: 11135749 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 E4EDF13BD for ; Fri, 6 Sep 2019 17:16:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF1C1206A5 for ; Fri, 6 Sep 2019 17:16:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405843AbfIFRQJ (ORCPT ); Fri, 6 Sep 2019 13:16:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:36572 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2404375AbfIFRQI (ORCPT ); Fri, 6 Sep 2019 13:16:08 -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 76A36AE0C for ; Fri, 6 Sep 2019 17:16:06 +0000 (UTC) From: Mark Fasheh To: linux-btrfs@vger.kernel.org Cc: Mark Fasheh Subject: [PATCH 3/3] btrfs: move useless node processing out of build_backref_cache Date: Fri, 6 Sep 2019 10:15:33 -0700 Message-Id: <20190906171533.618-4-mfasheh@suse.com> X-Mailer: git-send-email 2.22.1 In-Reply-To: <20190906171533.618-1-mfasheh@suse.com> References: <20190906171533.618-1-mfasheh@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 From: Mark Fasheh The backref cache has to clean up nodes referring to tree leaves. It is trivial to pull that code into it's own function, which is what I do here. Signed-off-by: Mark Fasheh Reviewed-by: Josef Bacik --- fs/btrfs/backref-cache.c | 82 +++++++++++++++++++++++----------------- 1 file changed, 47 insertions(+), 35 deletions(-) diff --git a/fs/btrfs/backref-cache.c b/fs/btrfs/backref-cache.c index ff0d49ca6e26..93632480b8d8 100644 --- a/fs/btrfs/backref-cache.c +++ b/fs/btrfs/backref-cache.c @@ -336,6 +336,51 @@ int find_inline_backref(struct extent_buffer *leaf, int slot, return 0; } +/* + * process useless backref nodes. backref nodes for tree leaves are + * deleted from the cache. backref nodes for upper level tree blocks + * are left in the cache to avoid unnecessary backref lookup. + */ +static void process_useless_backrefs(struct reloc_control *rc, + struct backref_node *node, + struct list_head *useless) +{ + struct backref_node *lower; + struct backref_node *upper; + struct backref_edge *edge; + + while (!list_empty(useless)) { + upper = list_entry(useless->next, struct backref_node, list); + list_del_init(&upper->list); + ASSERT(list_empty(&upper->upper)); + if (upper == node) + node = NULL; + if (upper->lowest) { + list_del_init(&upper->lower); + upper->lowest = 0; + } + while (!list_empty(&upper->lower)) { + edge = list_entry(upper->lower.next, + struct backref_edge, list[UPPER]); + list_del(&edge->list[UPPER]); + list_del(&edge->list[LOWER]); + lower = edge->node[LOWER]; + free_backref_edge(&rc->backref_cache, edge); + + if (list_empty(&lower->upper)) + list_add(&lower->list, useless); + } + __mark_block_processed(rc, upper); + if (upper->level > 0) { + list_add(&upper->list, &rc->backref_cache.detached); + upper->detached = 1; + } else { + rb_erase(&upper->rb_node, &rc->backref_cache.rb_root); + free_backref_node(&rc->backref_cache, upper); + } + } +} + #define SEARCH_COMPLETE 1 #define SEARCH_NEXT 2 static int find_next_ref(struct btrfs_root *extent_root, u64 cur_bytenr, @@ -797,42 +842,9 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, list_for_each_entry(edge, &upper->upper, list[LOWER]) list_add_tail(&edge->list[UPPER], &list); } - /* - * process useless backref nodes. backref nodes for tree leaves - * are deleted from the cache. backref nodes for upper level - * tree blocks are left in the cache to avoid unnecessary backref - * lookup. - */ - while (!list_empty(&useless)) { - upper = list_entry(useless.next, struct backref_node, list); - list_del_init(&upper->list); - ASSERT(list_empty(&upper->upper)); - if (upper == node) - node = NULL; - if (upper->lowest) { - list_del_init(&upper->lower); - upper->lowest = 0; - } - while (!list_empty(&upper->lower)) { - edge = list_entry(upper->lower.next, - struct backref_edge, list[UPPER]); - list_del(&edge->list[UPPER]); - list_del(&edge->list[LOWER]); - lower = edge->node[LOWER]; - free_backref_edge(cache, edge); - if (list_empty(&lower->upper)) - list_add(&lower->list, &useless); - } - __mark_block_processed(rc, upper); - if (upper->level > 0) { - list_add(&upper->list, &cache->detached); - upper->detached = 1; - } else { - rb_erase(&upper->rb_node, &cache->rb_root); - free_backref_node(cache, upper); - } - } + process_useless_backrefs(rc, node, &useless); + out: btrfs_free_path(path1); btrfs_free_path(path2);