btrfs: locking: remove all the blocking helpers

Now that we're using a rw_semaphore we no longer need to indicate if a
lock is blocking or not, nor do we need to flip the entire path from
blocking to spinning.  Remove these helpers and all the places they are
called.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/backref.c

@@ -1341,14 +1341,12 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 					goto out;
 				}
 
-				if (!path->skip_locking) {
+				if (!path->skip_locking)
 					btrfs_tree_read_lock(eb);
-					btrfs_set_lock_blocking_read(eb);
-				}
 				ret = find_extent_in_eb(eb, bytenr,
 							*extent_item_pos, &eie, ignore_offset);
 				if (!path->skip_locking)
-					btrfs_tree_read_unlock_blocking(eb);
+					btrfs_tree_read_unlock(eb);
 				free_extent_buffer(eb);
 				if (ret < 0)
 					goto out;
@@ -1685,7 +1683,7 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 					   name_off, name_len);
 		if (eb != eb_in) {
 			if (!path->skip_locking)
-				btrfs_tree_read_unlock_blocking(eb);
+				btrfs_tree_read_unlock(eb);
 			free_extent_buffer(eb);
 		}
 		ret = btrfs_find_item(fs_root, path, parent, 0,
@@ -1705,8 +1703,6 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 		eb = path->nodes[0];
 		/* make sure we can use eb after releasing the path */
 		if (eb != eb_in) {
-			if (!path->skip_locking)
-				btrfs_set_lock_blocking_read(eb);
 			path->nodes[0] = NULL;
 			path->locks[0] = 0;
 		}

fs/btrfs/delayed-inode.c

@@ -740,13 +740,6 @@ static int btrfs_batch_insert_items(struct btrfs_root *root,
 		goto out;
 	}
 
-	/*
-	 * we need allocate some memory space, but it might cause the task
-	 * to sleep, so we set all locked nodes in the path to blocking locks
-	 * first.
-	 */
-	btrfs_set_path_blocking(path);
-
 	keys = kmalloc_array(nitems, sizeof(struct btrfs_key), GFP_NOFS);
 	if (!keys) {
 		ret = -ENOMEM;

fs/btrfs/disk-io.c

@@ -250,10 +250,8 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 	if (atomic)
 		return -EAGAIN;
 
-	if (need_lock) {
+	if (need_lock)
 		btrfs_tree_read_lock(eb);
-		btrfs_set_lock_blocking_read(eb);
-	}
 
 	lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 			 &cached_state);
@@ -282,7 +280,7 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 	unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
 			     &cached_state);
 	if (need_lock)
-		btrfs_tree_read_unlock_blocking(eb);
+		btrfs_tree_read_unlock(eb);
 	return ret;
 }
 
@@ -1013,8 +1011,6 @@ void btrfs_clean_tree_block(struct extent_buffer *buf)
 			percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
 						 -buf->len,
 						 fs_info->dirty_metadata_batch);
-			/* ugh, clear_extent_buffer_dirty needs to lock the page */
-			btrfs_set_lock_blocking_write(buf);
 			clear_extent_buffer_dirty(buf);
 		}
 	}

fs/btrfs/extent-tree.c

@@ -4665,7 +4665,6 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	btrfs_clean_tree_block(buf);
 	clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
 
-	btrfs_set_lock_blocking_write(buf);
 	set_extent_buffer_uptodate(buf);
 
 	memzero_extent_buffer(buf, 0, sizeof(struct btrfs_header));
@@ -5054,7 +5053,6 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 		reada = 1;
 	}
 	btrfs_tree_lock(next);
-	btrfs_set_lock_blocking_write(next);
 
 	ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1,
 				       &wc->refs[level - 1],
@@ -5114,7 +5112,6 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 			return -EIO;
 		}
 		btrfs_tree_lock(next);
-		btrfs_set_lock_blocking_write(next);
 	}
 
 	level--;
@@ -5126,7 +5123,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 	}
 	path->nodes[level] = next;
 	path->slots[level] = 0;
-	path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+	path->locks[level] = BTRFS_WRITE_LOCK;
 	wc->level = level;
 	if (wc->level == 1)
 		wc->reada_slot = 0;
@@ -5254,8 +5251,7 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
 		if (!path->locks[level]) {
 			BUG_ON(level == 0);
 			btrfs_tree_lock(eb);
-			btrfs_set_lock_blocking_write(eb);
-			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+			path->locks[level] = BTRFS_WRITE_LOCK;
 
 			ret = btrfs_lookup_extent_info(trans, fs_info,
 						       eb->start, level, 1,
@@ -5298,8 +5294,7 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
 		if (!path->locks[level] &&
 		    btrfs_header_generation(eb) == trans->transid) {
 			btrfs_tree_lock(eb);
-			btrfs_set_lock_blocking_write(eb);
-			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+			path->locks[level] = BTRFS_WRITE_LOCK;
 		}
 		btrfs_clean_tree_block(eb);
 	}
@@ -5467,9 +5462,8 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
 	if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
 		level = btrfs_header_level(root->node);
 		path->nodes[level] = btrfs_lock_root_node(root);
-		btrfs_set_lock_blocking_write(path->nodes[level]);
 		path->slots[level] = 0;
-		path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+		path->locks[level] = BTRFS_WRITE_LOCK;
 		memset(&wc->update_progress, 0,
 		       sizeof(wc->update_progress));
 	} else {
@@ -5497,8 +5491,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
 		level = btrfs_header_level(root->node);
 		while (1) {
 			btrfs_tree_lock(path->nodes[level]);
-			btrfs_set_lock_blocking_write(path->nodes[level]);
-			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+			path->locks[level] = BTRFS_WRITE_LOCK;
 
 			ret = btrfs_lookup_extent_info(trans, fs_info,
 						path->nodes[level]->start,
@@ -5685,7 +5678,7 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 	level = btrfs_header_level(node);
 	path->nodes[level] = node;
 	path->slots[level] = 0;
-	path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+	path->locks[level] = BTRFS_WRITE_LOCK;
 
 	wc->refs[parent_level] = 1;
 	wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;

fs/btrfs/file.c

@@ -991,8 +991,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
 	 * write lock.
 	 */
 	if (!ret && replace_extent && leafs_visited == 1 &&
-	    (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
-	     path->locks[0] == BTRFS_WRITE_LOCK) &&
+	    path->locks[0] == BTRFS_WRITE_LOCK &&
 	    btrfs_leaf_free_space(leaf) >=
 	    sizeof(struct btrfs_item) + extent_item_size) {
 

fs/btrfs/inode.c

@@ -6789,7 +6789,6 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
 		em->orig_start = em->start;
 		ptr = btrfs_file_extent_inline_start(item) + extent_offset;
 
-		btrfs_set_path_blocking(path);
 		if (!PageUptodate(page)) {
 			if (btrfs_file_extent_compression(leaf, item) !=
 			    BTRFS_COMPRESS_NONE) {

fs/btrfs/locking.c

@@ -50,31 +50,6 @@
  *
  */
 
-/*
- * Mark already held read lock as blocking. Can be nested in write lock by the
- * same thread.
- *
- * Use when there are potentially long operations ahead so other thread waiting
- * on the lock will not actively spin but sleep instead.
- *
- * The rwlock is released and blocking reader counter is increased.
- */
-void btrfs_set_lock_blocking_read(struct extent_buffer *eb)
-{
-}
-
-/*
- * Mark already held write lock as blocking.
- *
- * Use when there are potentially long operations ahead so other threads
- * waiting on the lock will not actively spin but sleep instead.
- *
- * The rwlock is released and blocking writers is set.
- */
-void btrfs_set_lock_blocking_write(struct extent_buffer *eb)
-{
-}
-
 /*
  * __btrfs_tree_read_lock - lock extent buffer for read
  * @eb:		the eb to be locked
@@ -130,17 +105,6 @@ void btrfs_tree_read_lock(struct extent_buffer *eb)
 	__btrfs_tree_read_lock(eb, BTRFS_NESTING_NORMAL, false);
 }
 
-/*
- * Lock extent buffer for read, optimistically expecting that there are no
- * contending blocking writers. If there are, don't wait.
- *
- * Return 1 if the rwlock has been taken, 0 otherwise
- */
-int btrfs_tree_read_lock_atomic(struct extent_buffer *eb)
-{
-	return btrfs_try_tree_read_lock(eb);
-}
-
 /*
  * Try-lock for read.
  *
@@ -192,18 +156,6 @@ void btrfs_tree_read_unlock(struct extent_buffer *eb)
 	up_read(&eb->lock);
 }
 
-/*
- * Release read lock, previously set to blocking by a pairing call to
- * btrfs_set_lock_blocking_read(). Can be nested in write lock by the same
- * thread.
- *
- * State of rwlock is unchanged, last reader wakes waiting threads.
- */
-void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb)
-{
-	btrfs_tree_read_unlock(eb);
-}
-
 /*
  * __btrfs_tree_lock - lock eb for write
  * @eb:		the eb to lock
@@ -239,32 +191,6 @@ void btrfs_tree_unlock(struct extent_buffer *eb)
 	up_write(&eb->lock);
 }
 
-/*
- * Set all locked nodes in the path to blocking locks.  This should be done
- * before scheduling
- */
-void btrfs_set_path_blocking(struct btrfs_path *p)
-{
-	int i;
-
-	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
-		if (!p->nodes[i] || !p->locks[i])
-			continue;
-		/*
-		 * If we currently have a spinning reader or writer lock this
-		 * will bump the count of blocking holders and drop the
-		 * spinlock.
-		 */
-		if (p->locks[i] == BTRFS_READ_LOCK) {
-			btrfs_set_lock_blocking_read(p->nodes[i]);
-			p->locks[i] = BTRFS_READ_LOCK_BLOCKING;
-		} else if (p->locks[i] == BTRFS_WRITE_LOCK) {
-			btrfs_set_lock_blocking_write(p->nodes[i]);
-			p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING;
-		}
-	}
-}
-
 /*
  * This releases any locks held in the path starting at level and going all the
  * way up to the root.

fs/btrfs/locking.h

@@ -13,8 +13,6 @@
 
 #define BTRFS_WRITE_LOCK 1
 #define BTRFS_READ_LOCK 2
-#define BTRFS_WRITE_LOCK_BLOCKING 3
-#define BTRFS_READ_LOCK_BLOCKING 4
 
 /*
  * We are limited in number of subclasses by MAX_LOCKDEP_SUBCLASSES, which at
@@ -93,12 +91,8 @@ void __btrfs_tree_read_lock(struct extent_buffer *eb, enum btrfs_lock_nesting ne
 			    bool recurse);
 void btrfs_tree_read_lock(struct extent_buffer *eb);
 void btrfs_tree_read_unlock(struct extent_buffer *eb);
-void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
-void btrfs_set_lock_blocking_read(struct extent_buffer *eb);
-void btrfs_set_lock_blocking_write(struct extent_buffer *eb);
 int btrfs_try_tree_read_lock(struct extent_buffer *eb);
 int btrfs_try_tree_write_lock(struct extent_buffer *eb);
-int btrfs_tree_read_lock_atomic(struct extent_buffer *eb);
 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root);
 struct extent_buffer *__btrfs_read_lock_root_node(struct btrfs_root *root,
 						  bool recurse);
@@ -116,15 +110,12 @@ static inline void btrfs_assert_tree_locked(struct extent_buffer *eb) {
 static inline void btrfs_assert_tree_locked(struct extent_buffer *eb) { }
 #endif
 
-void btrfs_set_path_blocking(struct btrfs_path *p);
 void btrfs_unlock_up_safe(struct btrfs_path *path, int level);
 
 static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
 {
-	if (rw == BTRFS_WRITE_LOCK || rw == BTRFS_WRITE_LOCK_BLOCKING)
+	if (rw == BTRFS_WRITE_LOCK)
 		btrfs_tree_unlock(eb);
-	else if (rw == BTRFS_READ_LOCK_BLOCKING)
-		btrfs_tree_read_unlock_blocking(eb);
 	else if (rw == BTRFS_READ_LOCK)
 		btrfs_tree_read_unlock(eb);
 	else

fs/btrfs/qgroup.c

@@ -1970,8 +1970,7 @@ static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
 			src_path->nodes[cur_level] = eb;
 
 			btrfs_tree_read_lock(eb);
-			btrfs_set_lock_blocking_read(eb);
-			src_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
+			src_path->locks[cur_level] = BTRFS_READ_LOCK;
 		}
 
 		src_path->slots[cur_level] = dst_path->slots[cur_level];
@@ -2111,8 +2110,7 @@ static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
 		dst_path->slots[cur_level] = 0;
 
 		btrfs_tree_read_lock(eb);
-		btrfs_set_lock_blocking_read(eb);
-		dst_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
+		dst_path->locks[cur_level] = BTRFS_READ_LOCK;
 		need_cleanup = true;
 	}
 
@@ -2286,8 +2284,7 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
 			path->slots[level] = 0;
 
 			btrfs_tree_read_lock(eb);
-			btrfs_set_lock_blocking_read(eb);
-			path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
+			path->locks[level] = BTRFS_READ_LOCK;
 
 			ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
 							fs_info->nodesize,

fs/btrfs/ref-verify.c

@@ -575,10 +575,9 @@ static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path,
 				return -EIO;
 			}
 			btrfs_tree_read_lock(eb);
-			btrfs_set_lock_blocking_read(eb);
 			path->nodes[level-1] = eb;
 			path->slots[level-1] = 0;
-			path->locks[level-1] = BTRFS_READ_LOCK_BLOCKING;
+			path->locks[level-1] = BTRFS_READ_LOCK;
 		} else {
 			ret = process_leaf(root, path, bytenr, num_bytes);
 			if (ret)
@@ -1000,11 +999,10 @@ int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info)
 		return -ENOMEM;
 
 	eb = btrfs_read_lock_root_node(fs_info->extent_root);
-	btrfs_set_lock_blocking_read(eb);
 	level = btrfs_header_level(eb);
 	path->nodes[level] = eb;
 	path->slots[level] = 0;
-	path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
+	path->locks[level] = BTRFS_READ_LOCK;
 
 	while (1) {
 		/*

fs/btrfs/relocation.c

@@ -1196,7 +1196,6 @@ int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc,
 	btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
 
 	eb = btrfs_lock_root_node(dest);
-	btrfs_set_lock_blocking_write(eb);
 	level = btrfs_header_level(eb);
 
 	if (level < lowest_level) {
@@ -1210,7 +1209,6 @@ int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc,
 				      BTRFS_NESTING_COW);
 		BUG_ON(ret);
 	}
-	btrfs_set_lock_blocking_write(eb);
 
 	if (next_key) {
 		next_key->objectid = (u64)-1;
@@ -1279,7 +1277,6 @@ int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc,
 						      BTRFS_NESTING_COW);
 				BUG_ON(ret);
 			}
-			btrfs_set_lock_blocking_write(eb);
 
 			btrfs_tree_unlock(parent);
 			free_extent_buffer(parent);
@@ -2309,7 +2306,6 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 			goto next;
 		}
 		btrfs_tree_lock(eb);
-		btrfs_set_lock_blocking_write(eb);
 
 		if (!node->eb) {
 			ret = btrfs_cow_block(trans, root, eb, upper->eb,

fs/btrfs/transaction.c

@@ -1598,8 +1598,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 		goto fail;
 	}
 
-	btrfs_set_lock_blocking_write(old);
-
 	ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
 	/* clean up in any case */
 	btrfs_tree_unlock(old);

fs/btrfs/tree-defrag.c

@@ -52,7 +52,6 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
 		u32 nritems;
 
 		root_node = btrfs_lock_root_node(root);
-		btrfs_set_lock_blocking_write(root_node);
 		nritems = btrfs_header_nritems(root_node);
 		root->defrag_max.objectid = 0;
 		/* from above we know this is not a leaf */

fs/btrfs/tree-log.c

@@ -2722,7 +2722,6 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 
 				if (trans) {
 					btrfs_tree_lock(next);
-					btrfs_set_lock_blocking_write(next);
 					btrfs_clean_tree_block(next);
 					btrfs_wait_tree_block_writeback(next);
 					btrfs_tree_unlock(next);
@@ -2791,7 +2790,6 @@ static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
 
 				if (trans) {
 					btrfs_tree_lock(next);
-					btrfs_set_lock_blocking_write(next);
 					btrfs_clean_tree_block(next);
 					btrfs_wait_tree_block_writeback(next);
 					btrfs_tree_unlock(next);
@@ -2873,7 +2871,6 @@ static int walk_log_tree(struct btrfs_trans_handle *trans,
 
 			if (trans) {
 				btrfs_tree_lock(next);
-				btrfs_set_lock_blocking_write(next);
 				btrfs_clean_tree_block(next);
 				btrfs_wait_tree_block_writeback(next);
 				btrfs_tree_unlock(next);