1 files changed, 59 insertions, 47 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index ea3ec1e761e8..2801c991814f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2220,6 +2220,12 @@ static noinline int check_delayed_ref(struct btrfs_root *root,
 	}
 
 	if (!mutex_trylock(&head->mutex)) {
+		if (path->nowait) {
+			spin_unlock(&delayed_refs->lock);
+			btrfs_put_transaction(cur_trans);
+			return -EAGAIN;
+		}
+
 		refcount_inc(&head->refs);
 		spin_unlock(&delayed_refs->lock);
 
@@ -2551,17 +2557,10 @@ int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
 		return -EINVAL;
 
 	/*
-	 * pull in the free space cache (if any) so that our pin
-	 * removes the free space from the cache.  We have load_only set
-	 * to one because the slow code to read in the free extents does check
-	 * the pinned extents.
+	 * Fully cache the free space first so that our pin removes the free space
+	 * from the cache.
 	 */
-	btrfs_cache_block_group(cache, 1);
-	/*
-	 * Make sure we wait until the cache is completely built in case it is
-	 * missing or is invalid and therefore needs to be rebuilt.
-	 */
-	ret = btrfs_wait_block_group_cache_done(cache);
+	ret = btrfs_cache_block_group(cache, true);
 	if (ret)
 		goto out;
 
@@ -2584,12 +2583,7 @@ static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
 	if (!block_group)
 		return -EINVAL;
 
-	btrfs_cache_block_group(block_group, 1);
-	/*
-	 * Make sure we wait until the cache is completely built in case it is
-	 * missing or is invalid and therefore needs to be rebuilt.
-	 */
-	ret = btrfs_wait_block_group_cache_done(block_group);
+	ret = btrfs_cache_block_group(block_group, true);
 	if (ret)
 		goto out;
 
@@ -2698,13 +2692,8 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
 		len = cache->start + cache->length - start;
 		len = min(len, end + 1 - start);
 
-		down_read(&fs_info->commit_root_sem);
-		if (start < cache->last_byte_to_unpin && return_free_space) {
-			u64 add_len = min(len, cache->last_byte_to_unpin - start);
-
-			btrfs_add_free_space(cache, start, add_len);
-		}
-		up_read(&fs_info->commit_root_sem);
+		if (return_free_space)
+			btrfs_add_free_space(cache, start, len);
 
 		start += len;
 		total_unpinned += len;
@@ -3306,21 +3295,22 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 		}
 
 		/*
-		 * If this is a leaf and there are tree mod log users, we may
-		 * have recorded mod log operations that point to this leaf.
-		 * So we must make sure no one reuses this leaf's extent before
-		 * mod log operations are applied to a node, otherwise after
-		 * rewinding a node using the mod log operations we get an
-		 * inconsistent btree, as the leaf's extent may now be used as
-		 * a node or leaf for another different btree.
+		 * If there are tree mod log users we may have recorded mod log
+		 * operations for this node.  If we re-allocate this node we
+		 * could replay operations on this node that happened when it
+		 * existed in a completely different root.  For example if it
+		 * was part of root A, then was reallocated to root B, and we
+		 * are doing a btrfs_old_search_slot(root b), we could replay
+		 * operations that happened when the block was part of root A,
+		 * giving us an inconsistent view of the btree.
+		 *
 		 * We are safe from races here because at this point no other
 		 * node or root points to this extent buffer, so if after this
-		 * check a new tree mod log user joins, it will not be able to
-		 * find a node pointing to this leaf and record operations that
-		 * point to this leaf.
+		 * check a new tree mod log user joins we will not have an
+		 * existing log of operations on this node that we have to
+		 * contend with.
 		 */
-		if (btrfs_header_level(buf) == 0 &&
-		    test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags))
+		if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags))
 			must_pin = true;
 
 		if (must_pin || btrfs_is_zoned(fs_info)) {
@@ -3816,7 +3806,8 @@ static int do_allocation_zoned(struct btrfs_block_group *block_group,
 	       block_group->start == fs_info->data_reloc_bg ||
 	       fs_info->data_reloc_bg == 0);
 
-	if (block_group->ro || block_group->zoned_data_reloc_ongoing) {
+	if (block_group->ro ||
+	    test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags)) {
 		ret = 1;
 		goto out;
 	}
@@ -3893,7 +3884,7 @@ out:
 		 * regular extents) at the same time to the same zone, which
 		 * easily break the write pointer.
 		 */
-		block_group->zoned_data_reloc_ongoing = 1;
+		set_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags);
 		fs_info->data_reloc_bg = 0;
 	}
 	spin_unlock(&fs_info->relocation_bg_lock);
@@ -4399,7 +4390,7 @@ have_block_group:
 		ffe_ctl->cached = btrfs_block_group_done(block_group);
 		if (unlikely(!ffe_ctl->cached)) {
 			ffe_ctl->have_caching_bg = true;
-			ret = btrfs_cache_block_group(block_group, 0);
+			ret = btrfs_cache_block_group(block_group, false);
 
 			/*
 			 * If we get ENOMEM here or something else we want to
@@ -4867,6 +4858,7 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_buffer *buf;
+	u64 lockdep_owner = owner;
 
 	buf = btrfs_find_create_tree_block(fs_info, bytenr, owner, level);
 	if (IS_ERR(buf))
@@ -4886,11 +4878,29 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	}
 
 	/*
+	 * The reloc trees are just snapshots, so we need them to appear to be
+	 * just like any other fs tree WRT lockdep.
+	 *
+	 * The exception however is in replace_path() in relocation, where we
+	 * hold the lock on the original fs root and then search for the reloc
+	 * root.  At that point we need to make sure any reloc root buffers are
+	 * set to the BTRFS_TREE_RELOC_OBJECTID lockdep class in order to make
+	 * lockdep happy.
+	 */
+	if (lockdep_owner == BTRFS_TREE_RELOC_OBJECTID &&
+	    !test_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &root->state))
+		lockdep_owner = BTRFS_FS_TREE_OBJECTID;
+
+	/* btrfs_clean_tree_block() accesses generation field. */
+	btrfs_set_header_generation(buf, trans->transid);
+
+	/*
 	 * This needs to stay, because we could allocate a freed block from an
 	 * old tree into a new tree, so we need to make sure this new block is
 	 * set to the appropriate level and owner.
 	 */
-	btrfs_set_buffer_lockdep_class(owner, buf, level);
+	btrfs_set_buffer_lockdep_class(lockdep_owner, buf, level);
+
 	__btrfs_tree_lock(buf, nest);
 	btrfs_clean_tree_block(buf);
 	clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
@@ -5635,6 +5645,8 @@ static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
  */
 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
 {
+	const bool is_reloc_root = (root->root_key.objectid ==
+				    BTRFS_TREE_RELOC_OBJECTID);
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_path *path;
 	struct btrfs_trans_handle *trans;
@@ -5794,6 +5806,9 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
 				goto out_end_trans;
 			}
 
+			if (!is_reloc_root)
+				btrfs_set_last_root_drop_gen(fs_info, trans->transid);
+
 			btrfs_end_transaction_throttle(trans);
 			if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) {
 				btrfs_debug(fs_info,
@@ -5828,7 +5843,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
 		goto out_end_trans;
 	}
 
-	if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
+	if (!is_reloc_root) {
 		ret = btrfs_find_root(tree_root, &root->root_key, path,
 				      NULL, NULL);
 		if (ret < 0) {
@@ -5860,6 +5875,9 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
 		btrfs_put_root(root);
 	root_dropped = true;
 out_end_trans:
+	if (!is_reloc_root)
+		btrfs_set_last_root_drop_gen(fs_info, trans->transid);
+
 	btrfs_end_transaction_throttle(trans);
 out_free:
 	kfree(wc);
@@ -6153,13 +6171,7 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
 
 		if (end - start >= range->minlen) {
 			if (!btrfs_block_group_done(cache)) {
-				ret = btrfs_cache_block_group(cache, 0);
-				if (ret) {
-					bg_failed++;
-					bg_ret = ret;
-					continue;
-				}
-				ret = btrfs_wait_block_group_cache_done(cache);
+				ret = btrfs_cache_block_group(cache, true);
 				if (ret) {
 					bg_failed++;
 					bg_ret = ret;