diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index aad7201ad11b..10db21fa0926 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -330,7 +330,10 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, goto out; } - root_level = btrfs_old_root_level(root, time_seq); + if (path->search_commit_root) + root_level = btrfs_header_level(root->commit_root); + else + root_level = btrfs_old_root_level(root, time_seq); if (root_level + 1 == level) { srcu_read_unlock(&fs_info->subvol_srcu, index); @@ -1099,9 +1102,9 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, * * returns 0 on success, < 0 on error. */ -int btrfs_find_all_roots(struct btrfs_trans_handle *trans, - struct btrfs_fs_info *fs_info, u64 bytenr, - u64 time_seq, struct ulist **roots) +static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, u64 bytenr, + u64 time_seq, struct ulist **roots) { struct ulist *tmp; struct ulist_node *node = NULL; @@ -1137,6 +1140,20 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, return 0; } +int btrfs_find_all_roots(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, u64 bytenr, + u64 time_seq, struct ulist **roots) +{ + int ret; + + if (!trans) + down_read(&fs_info->commit_root_sem); + ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots); + if (!trans) + up_read(&fs_info->commit_root_sem); + return ret; +} + /* * this makes the path point to (inum INODE_ITEM ioff) */ @@ -1516,6 +1533,8 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info, if (IS_ERR(trans)) return PTR_ERR(trans); btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); + } else { + down_read(&fs_info->commit_root_sem); } ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, @@ -1526,8 +1545,8 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info, ULIST_ITER_INIT(&ref_uiter); while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { - ret = btrfs_find_all_roots(trans, fs_info, ref_node->val, - tree_mod_seq_elem.seq, &roots); + ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val, + tree_mod_seq_elem.seq, &roots); if (ret) break; ULIST_ITER_INIT(&root_uiter); @@ -1549,6 +1568,8 @@ out: if (!search_commit_root) { btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); btrfs_end_transaction(trans, fs_info->extent_root); + } else { + up_read(&fs_info->commit_root_sem); } return ret; diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 88d1b1eedc9c..9d89c1648e8e 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -5360,7 +5360,6 @@ int btrfs_compare_trees(struct btrfs_root *left_root, { int ret; int cmp; - struct btrfs_trans_handle *trans = NULL; struct btrfs_path *left_path = NULL; struct btrfs_path *right_path = NULL; struct btrfs_key left_key; @@ -5378,9 +5377,6 @@ int btrfs_compare_trees(struct btrfs_root *left_root, u64 right_blockptr; u64 left_gen; u64 right_gen; - u64 left_start_ctransid; - u64 right_start_ctransid; - u64 ctransid; left_path = btrfs_alloc_path(); if (!left_path) { @@ -5404,21 +5400,6 @@ int btrfs_compare_trees(struct btrfs_root *left_root, right_path->search_commit_root = 1; right_path->skip_locking = 1; - spin_lock(&left_root->root_item_lock); - left_start_ctransid = btrfs_root_ctransid(&left_root->root_item); - spin_unlock(&left_root->root_item_lock); - - spin_lock(&right_root->root_item_lock); - right_start_ctransid = btrfs_root_ctransid(&right_root->root_item); - spin_unlock(&right_root->root_item_lock); - - trans = btrfs_join_transaction(left_root); - if (IS_ERR(trans)) { - ret = PTR_ERR(trans); - trans = NULL; - goto out; - } - /* * Strategy: Go to the first items of both trees. Then do * @@ -5482,67 +5463,6 @@ int btrfs_compare_trees(struct btrfs_root *left_root, advance_left = advance_right = 0; while (1) { - /* - * We need to make sure the transaction does not get committed - * while we do anything on commit roots. This means, we need to - * join and leave transactions for every item that we process. - */ - if (trans && btrfs_should_end_transaction(trans, left_root)) { - btrfs_release_path(left_path); - btrfs_release_path(right_path); - - ret = btrfs_end_transaction(trans, left_root); - trans = NULL; - if (ret < 0) - goto out; - } - /* now rejoin the transaction */ - if (!trans) { - trans = btrfs_join_transaction(left_root); - if (IS_ERR(trans)) { - ret = PTR_ERR(trans); - trans = NULL; - goto out; - } - - spin_lock(&left_root->root_item_lock); - ctransid = btrfs_root_ctransid(&left_root->root_item); - spin_unlock(&left_root->root_item_lock); - if (ctransid != left_start_ctransid) - left_start_ctransid = 0; - - spin_lock(&right_root->root_item_lock); - ctransid = btrfs_root_ctransid(&right_root->root_item); - spin_unlock(&right_root->root_item_lock); - if (ctransid != right_start_ctransid) - right_start_ctransid = 0; - - if (!left_start_ctransid || !right_start_ctransid) { - WARN(1, KERN_WARNING - "BTRFS: btrfs_compare_tree detected " - "a change in one of the trees while " - "iterating. This is probably a " - "bug.\n"); - ret = -EIO; - goto out; - } - - /* - * the commit root may have changed, so start again - * where we stopped - */ - left_path->lowest_level = left_level; - right_path->lowest_level = right_level; - ret = btrfs_search_slot(NULL, left_root, - &left_key, left_path, 0, 0); - if (ret < 0) - goto out; - ret = btrfs_search_slot(NULL, right_root, - &right_key, right_path, 0, 0); - if (ret < 0) - goto out; - } - if (advance_left && !left_end_reached) { ret = tree_advance(left_root, left_path, &left_level, left_root_level, @@ -5672,14 +5592,6 @@ out: btrfs_free_path(left_path); btrfs_free_path(right_path); kfree(tmp_buf); - - if (trans) { - if (!ret) - ret = btrfs_end_transaction(trans, left_root); - else - btrfs_end_transaction(trans, left_root); - } - return ret; } diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 2a9d32e193a5..4253ab257c9c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1440,7 +1440,7 @@ struct btrfs_fs_info { */ struct mutex ordered_extent_flush_mutex; - struct rw_semaphore extent_commit_sem; + struct rw_semaphore commit_root_sem; struct rw_semaphore cleanup_work_sem; @@ -1711,7 +1711,6 @@ struct btrfs_root { struct btrfs_block_rsv *block_rsv; /* free ino cache stuff */ - struct mutex fs_commit_mutex; struct btrfs_free_space_ctl *free_ino_ctl; enum btrfs_caching_type cached; spinlock_t cache_lock; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 98fe70193397..6d1ac7d46f81 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1567,7 +1567,6 @@ int btrfs_init_fs_root(struct btrfs_root *root) root->subv_writers = writers; btrfs_init_free_ino_ctl(root); - mutex_init(&root->fs_commit_mutex); spin_lock_init(&root->cache_lock); init_waitqueue_head(&root->cache_wait); @@ -2345,7 +2344,7 @@ int open_ctree(struct super_block *sb, mutex_init(&fs_info->transaction_kthread_mutex); mutex_init(&fs_info->cleaner_mutex); mutex_init(&fs_info->volume_mutex); - init_rwsem(&fs_info->extent_commit_sem); + init_rwsem(&fs_info->commit_root_sem); init_rwsem(&fs_info->cleanup_work_sem); init_rwsem(&fs_info->subvol_sem); sema_init(&fs_info->uuid_tree_rescan_sem, 1); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index e09db2c2f3b4..4d2508bbf6f0 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -419,7 +419,7 @@ static noinline void caching_thread(struct btrfs_work *work) again: mutex_lock(&caching_ctl->mutex); /* need to make sure the commit_root doesn't disappear */ - down_read(&fs_info->extent_commit_sem); + down_read(&fs_info->commit_root_sem); next: ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); @@ -443,10 +443,10 @@ next: break; if (need_resched() || - rwsem_is_contended(&fs_info->extent_commit_sem)) { + rwsem_is_contended(&fs_info->commit_root_sem)) { caching_ctl->progress = last; btrfs_release_path(path); - up_read(&fs_info->extent_commit_sem); + up_read(&fs_info->commit_root_sem); mutex_unlock(&caching_ctl->mutex); cond_resched(); goto again; @@ -513,7 +513,7 @@ next: err: btrfs_free_path(path); - up_read(&fs_info->extent_commit_sem); + up_read(&fs_info->commit_root_sem); free_excluded_extents(extent_root, block_group); @@ -633,10 +633,10 @@ static int cache_block_group(struct btrfs_block_group_cache *cache, return 0; } - down_write(&fs_info->extent_commit_sem); + down_write(&fs_info->commit_root_sem); atomic_inc(&caching_ctl->count); list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups); - up_write(&fs_info->extent_commit_sem); + up_write(&fs_info->commit_root_sem); btrfs_get_block_group(cache); @@ -5471,7 +5471,7 @@ void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans, struct btrfs_block_group_cache *cache; struct btrfs_space_info *space_info; - down_write(&fs_info->extent_commit_sem); + down_write(&fs_info->commit_root_sem); list_for_each_entry_safe(caching_ctl, next, &fs_info->caching_block_groups, list) { @@ -5490,7 +5490,7 @@ void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans, else fs_info->pinned_extents = &fs_info->freed_extents[0]; - up_write(&fs_info->extent_commit_sem); + up_write(&fs_info->commit_root_sem); list_for_each_entry_rcu(space_info, &fs_info->space_info, list) percpu_counter_set(&space_info->total_bytes_pinned, 0); @@ -8256,14 +8256,14 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info) struct btrfs_caching_control *caching_ctl; struct rb_node *n; - down_write(&info->extent_commit_sem); + down_write(&info->commit_root_sem); while (!list_empty(&info->caching_block_groups)) { caching_ctl = list_entry(info->caching_block_groups.next, struct btrfs_caching_control, list); list_del(&caching_ctl->list); put_caching_control(caching_ctl); } - up_write(&info->extent_commit_sem); + up_write(&info->commit_root_sem); spin_lock(&info->block_group_cache_lock); while ((n = rb_last(&info->block_group_cache_tree)) != NULL) { diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c index ab485e57b6fe..cc8ca193d830 100644 --- a/fs/btrfs/inode-map.c +++ b/fs/btrfs/inode-map.c @@ -55,7 +55,7 @@ static int caching_kthread(void *data) key.type = BTRFS_INODE_ITEM_KEY; again: /* need to make sure the commit_root doesn't disappear */ - mutex_lock(&root->fs_commit_mutex); + down_read(&fs_info->commit_root_sem); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) @@ -88,7 +88,7 @@ again: btrfs_item_key_to_cpu(leaf, &key, 0); btrfs_release_path(path); root->cache_progress = last; - mutex_unlock(&root->fs_commit_mutex); + up_read(&fs_info->commit_root_sem); schedule_timeout(1); goto again; } else @@ -127,7 +127,7 @@ next: btrfs_unpin_free_ino(root); out: wake_up(&root->cache_wait); - mutex_unlock(&root->fs_commit_mutex); + up_read(&fs_info->commit_root_sem); btrfs_free_path(path); @@ -223,11 +223,11 @@ again: * or the caching work is done. */ - mutex_lock(&root->fs_commit_mutex); + down_write(&root->fs_info->commit_root_sem); spin_lock(&root->cache_lock); if (root->cached == BTRFS_CACHE_FINISHED) { spin_unlock(&root->cache_lock); - mutex_unlock(&root->fs_commit_mutex); + up_write(&root->fs_info->commit_root_sem); goto again; } spin_unlock(&root->cache_lock); @@ -240,7 +240,7 @@ again: else __btrfs_add_free_space(pinned, objectid, 1); - mutex_unlock(&root->fs_commit_mutex); + up_write(&root->fs_info->commit_root_sem); } } @@ -250,7 +250,7 @@ again: * and others will just be dropped, because the commit root we were * searching has changed. * - * Must be called with root->fs_commit_mutex held + * Must be called with root->fs_info->commit_root_sem held */ void btrfs_unpin_free_ino(struct btrfs_root *root) { diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index d00534b78382..6b5f13659317 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1268,8 +1268,10 @@ static int find_extent_clone(struct send_ctx *sctx, } logical = disk_byte + btrfs_file_extent_offset(eb, fi); + down_read(&sctx->send_root->fs_info->commit_root_sem); ret = extent_from_logical(sctx->send_root->fs_info, disk_byte, tmp_path, &found_key, &flags); + up_read(&sctx->send_root->fs_info->commit_root_sem); btrfs_release_path(tmp_path); if (ret < 0) @@ -5367,57 +5369,21 @@ out: static int full_send_tree(struct send_ctx *sctx) { int ret; - struct btrfs_trans_handle *trans = NULL; struct btrfs_root *send_root = sctx->send_root; struct btrfs_key key; struct btrfs_key found_key; struct btrfs_path *path; struct extent_buffer *eb; int slot; - u64 start_ctransid; - u64 ctransid; path = alloc_path_for_send(); if (!path) return -ENOMEM; - spin_lock(&send_root->root_item_lock); - start_ctransid = btrfs_root_ctransid(&send_root->root_item); - spin_unlock(&send_root->root_item_lock); - key.objectid = BTRFS_FIRST_FREE_OBJECTID; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; -join_trans: - /* - * We need to make sure the transaction does not get committed - * while we do anything on commit roots. Join a transaction to prevent - * this. - */ - trans = btrfs_join_transaction(send_root); - if (IS_ERR(trans)) { - ret = PTR_ERR(trans); - trans = NULL; - goto out; - } - - /* - * Make sure the tree has not changed after re-joining. We detect this - * by comparing start_ctransid and ctransid. They should always match. - */ - spin_lock(&send_root->root_item_lock); - ctransid = btrfs_root_ctransid(&send_root->root_item); - spin_unlock(&send_root->root_item_lock); - - if (ctransid != start_ctransid) { - WARN(1, KERN_WARNING "BTRFS: the root that you're trying to " - "send was modified in between. This is " - "probably a bug.\n"); - ret = -EIO; - goto out; - } - ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0); if (ret < 0) goto out; @@ -5425,19 +5391,6 @@ join_trans: goto out_finish; while (1) { - /* - * When someone want to commit while we iterate, end the - * joined transaction and rejoin. - */ - if (btrfs_should_end_transaction(trans, send_root)) { - ret = btrfs_end_transaction(trans, send_root); - trans = NULL; - if (ret < 0) - goto out; - btrfs_release_path(path); - goto join_trans; - } - eb = path->nodes[0]; slot = path->slots[0]; btrfs_item_key_to_cpu(eb, &found_key, slot); @@ -5465,12 +5418,6 @@ out_finish: out: btrfs_free_path(path); - if (trans) { - if (!ret) - ret = btrfs_end_transaction(trans, send_root); - else - btrfs_end_transaction(trans, send_root); - } return ret; } diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 038177cfabbb..7579f6d0b854 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -75,10 +75,21 @@ void btrfs_put_transaction(struct btrfs_transaction *transaction) } } -static noinline void switch_commit_root(struct btrfs_root *root) +static noinline void switch_commit_roots(struct btrfs_transaction *trans, + struct btrfs_fs_info *fs_info) { - free_extent_buffer(root->commit_root); - root->commit_root = btrfs_root_node(root); + struct btrfs_root *root, *tmp; + + down_write(&fs_info->commit_root_sem); + list_for_each_entry_safe(root, tmp, &trans->switch_commits, + dirty_list) { + list_del_init(&root->dirty_list); + free_extent_buffer(root->commit_root); + root->commit_root = btrfs_root_node(root); + if (is_fstree(root->objectid)) + btrfs_unpin_free_ino(root); + } + up_write(&fs_info->commit_root_sem); } static inline void extwriter_counter_inc(struct btrfs_transaction *trans, @@ -208,6 +219,7 @@ loop: INIT_LIST_HEAD(&cur_trans->pending_snapshots); INIT_LIST_HEAD(&cur_trans->ordered_operations); INIT_LIST_HEAD(&cur_trans->pending_chunks); + INIT_LIST_HEAD(&cur_trans->switch_commits); list_add_tail(&cur_trans->list, &fs_info->trans_list); extent_io_tree_init(&cur_trans->dirty_pages, fs_info->btree_inode->i_mapping); @@ -920,9 +932,6 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans, return ret; } - if (root != root->fs_info->extent_root) - switch_commit_root(root); - return 0; } @@ -978,15 +987,16 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans, list_del_init(next); root = list_entry(next, struct btrfs_root, dirty_list); + if (root != fs_info->extent_root) + list_add_tail(&root->dirty_list, + &trans->transaction->switch_commits); ret = update_cowonly_root(trans, root); if (ret) return ret; } - down_write(&fs_info->extent_commit_sem); - switch_commit_root(fs_info->extent_root); - up_write(&fs_info->extent_commit_sem); - + list_add_tail(&fs_info->extent_root->dirty_list, + &trans->transaction->switch_commits); btrfs_after_dev_replace_commit(fs_info); return 0; @@ -1043,11 +1053,8 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans, smp_wmb(); if (root->commit_root != root->node) { - mutex_lock(&root->fs_commit_mutex); - switch_commit_root(root); - btrfs_unpin_free_ino(root); - mutex_unlock(&root->fs_commit_mutex); - + list_add_tail(&root->dirty_list, + &trans->transaction->switch_commits); btrfs_set_root_node(&root->root_item, root->node); } @@ -1858,11 +1865,15 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, btrfs_set_root_node(&root->fs_info->tree_root->root_item, root->fs_info->tree_root->node); - switch_commit_root(root->fs_info->tree_root); + list_add_tail(&root->fs_info->tree_root->dirty_list, + &cur_trans->switch_commits); btrfs_set_root_node(&root->fs_info->chunk_root->root_item, root->fs_info->chunk_root->node); - switch_commit_root(root->fs_info->chunk_root); + list_add_tail(&root->fs_info->chunk_root->dirty_list, + &cur_trans->switch_commits); + + switch_commit_roots(cur_trans, root->fs_info); assert_qgroups_uptodate(trans); update_super_roots(root); diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 2bcba89d952e..b57b924e8e03 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -57,6 +57,7 @@ struct btrfs_transaction { struct list_head pending_snapshots; struct list_head ordered_operations; struct list_head pending_chunks; + struct list_head switch_commits; struct btrfs_delayed_ref_root delayed_refs; int aborted; };