diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 9d7621f271ff..08e0b11ba0a1 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -420,12 +420,6 @@ void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, } spin_unlock(&fs_info->tree_mod_seq_lock); - /* - * we removed the lowest blocker from the blocker list, so there may be - * more processible delayed refs. - */ - wake_up(&fs_info->tree_mod_seq_wait); - /* * anything that's lower than the lowest existing (read: blocked) * sequence number can be removed from the tree. diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 348196350bf0..c38734a07a65 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1252,7 +1252,6 @@ struct btrfs_fs_info { atomic_t tree_mod_seq; struct list_head tree_mod_seq_list; struct seq_list tree_mod_seq_elem; - wait_queue_head_t tree_mod_seq_wait; /* this protects tree_mod_log */ rwlock_t tree_mod_log_lock; diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index da7419ed01bb..7561431af50d 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -662,9 +662,6 @@ int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info, add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr, num_bytes, parent, ref_root, level, action, for_cow); - if (!need_ref_seq(for_cow, ref_root) && - waitqueue_active(&fs_info->tree_mod_seq_wait)) - wake_up(&fs_info->tree_mod_seq_wait); spin_unlock(&delayed_refs->lock); if (need_ref_seq(for_cow, ref_root)) btrfs_qgroup_record_ref(trans, &ref->node, extent_op); @@ -713,9 +710,6 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, add_delayed_data_ref(fs_info, trans, &ref->node, bytenr, num_bytes, parent, ref_root, owner, offset, action, for_cow); - if (!need_ref_seq(for_cow, ref_root) && - waitqueue_active(&fs_info->tree_mod_seq_wait)) - wake_up(&fs_info->tree_mod_seq_wait); spin_unlock(&delayed_refs->lock); if (need_ref_seq(for_cow, ref_root)) btrfs_qgroup_record_ref(trans, &ref->node, extent_op); @@ -744,8 +738,6 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info, num_bytes, BTRFS_UPDATE_DELAYED_HEAD, extent_op->is_data); - if (waitqueue_active(&fs_info->tree_mod_seq_wait)) - wake_up(&fs_info->tree_mod_seq_wait); spin_unlock(&delayed_refs->lock); return 0; } diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 502b20c56e84..a7ad8fc8dc53 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2035,8 +2035,6 @@ int open_ctree(struct super_block *sb, fs_info->free_chunk_space = 0; fs_info->tree_mod_log = RB_ROOT; - init_waitqueue_head(&fs_info->tree_mod_seq_wait); - /* readahead state */ INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT); spin_lock_init(&fs_info->reada_lock); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 45c69c4184c9..d3df65f83b5c 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2318,12 +2318,6 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans, ref->in_tree = 0; rb_erase(&ref->rb_node, &delayed_refs->root); delayed_refs->num_entries--; - /* - * we modified num_entries, but as we're currently running - * delayed refs, skip - * wake_up(&delayed_refs->seq_wait); - * here. - */ spin_unlock(&delayed_refs->lock); ret = run_one_delayed_ref(trans, root, ref, extent_op, @@ -2350,22 +2344,6 @@ next: return count; } -static void wait_for_more_refs(struct btrfs_fs_info *fs_info, - struct btrfs_delayed_ref_root *delayed_refs, - unsigned long num_refs, - struct list_head *first_seq) -{ - spin_unlock(&delayed_refs->lock); - pr_debug("waiting for more refs (num %ld, first %p)\n", - num_refs, first_seq); - wait_event(fs_info->tree_mod_seq_wait, - num_refs != delayed_refs->num_entries || - fs_info->tree_mod_seq_list.next != first_seq); - pr_debug("done waiting for more refs (num %ld, first %p)\n", - delayed_refs->num_entries, fs_info->tree_mod_seq_list.next); - spin_lock(&delayed_refs->lock); -} - #ifdef SCRAMBLE_DELAYED_REFS /* * Normally delayed refs get processed in ascending bytenr order. This @@ -2460,13 +2438,11 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_ref_node *ref; struct list_head cluster; - struct list_head *first_seq = NULL; int ret; u64 delayed_start; int run_all = count == (unsigned long)-1; int run_most = 0; - unsigned long num_refs = 0; - int consider_waiting; + int loops; /* We'll clean this up in btrfs_cleanup_transaction */ if (trans->aborted) @@ -2484,7 +2460,7 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, delayed_refs = &trans->transaction->delayed_refs; INIT_LIST_HEAD(&cluster); again: - consider_waiting = 0; + loops = 0; spin_lock(&delayed_refs->lock); #ifdef SCRAMBLE_DELAYED_REFS @@ -2512,31 +2488,6 @@ again: if (ret) break; - if (delayed_start >= delayed_refs->run_delayed_start) { - if (consider_waiting == 0) { - /* - * btrfs_find_ref_cluster looped. let's do one - * more cycle. if we don't run any delayed ref - * during that cycle (because we can't because - * all of them are blocked) and if the number of - * refs doesn't change, we avoid busy waiting. - */ - consider_waiting = 1; - num_refs = delayed_refs->num_entries; - first_seq = root->fs_info->tree_mod_seq_list.next; - } else { - wait_for_more_refs(root->fs_info, delayed_refs, - num_refs, first_seq); - /* - * after waiting, things have changed. we - * dropped the lock and someone else might have - * run some refs, built new clusters and so on. - * therefore, we restart staleness detection. - */ - consider_waiting = 0; - } - } - ret = run_clustered_refs(trans, root, &cluster); if (ret < 0) { spin_unlock(&delayed_refs->lock); @@ -2549,9 +2500,26 @@ again: if (count == 0) break; - if (ret || delayed_refs->run_delayed_start == 0) { + if (delayed_start >= delayed_refs->run_delayed_start) { + if (loops == 0) { + /* + * btrfs_find_ref_cluster looped. let's do one + * more cycle. if we don't run any delayed ref + * during that cycle (because we can't because + * all of them are blocked), bail out. + */ + loops = 1; + } else { + /* + * no runnable refs left, stop trying + */ + BUG_ON(run_all); + break; + } + } + if (ret) { /* refs were run, let's reset staleness detection */ - consider_waiting = 0; + loops = 0; } } @@ -5296,9 +5264,6 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, rb_erase(&head->node.rb_node, &delayed_refs->root); delayed_refs->num_entries--; - smp_mb(); - if (waitqueue_active(&root->fs_info->tree_mod_seq_wait)) - wake_up(&root->fs_info->tree_mod_seq_wait); /* * we don't take a ref on the node because we're removing it from the