Btrfs: truncate space reservation fixes

index 6d16bea..8f8ed7d 100644
@@ -489,11 +489,13 @@ update_existing_ref(struct btrfs_trans_handle *trans,
  * existing and update must have the same bytenr
  */
 static noinline void
-update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
+update_existing_head_ref(struct btrfs_delayed_ref_root *delayed_refs,
+			 struct btrfs_delayed_ref_node *existing,
 			 struct btrfs_delayed_ref_node *update)
 {
 	struct btrfs_delayed_ref_head *existing_ref;
 	struct btrfs_delayed_ref_head *ref;
+	int old_ref_mod;
 
 	existing_ref = btrfs_delayed_node_to_head(existing);
 	ref = btrfs_delayed_node_to_head(update);

@@ -541,7 +543,20 @@ update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
 	 * only need the lock for this case cause we could be processing it
 	 * currently, for refs we just added we know we're a-ok.
 	 */
+	old_ref_mod = existing_ref->total_ref_mod;
 	existing->ref_mod += update->ref_mod;
+	existing_ref->total_ref_mod += update->ref_mod;
+
+	/*
+	 * If we are going to from a positive ref mod to a negative or vice
+	 * versa we need to make sure to adjust pending_csums accordingly.
+	 */
+	if (existing_ref->is_data) {
+		if (existing_ref->total_ref_mod >= 0 && old_ref_mod < 0)
+			delayed_refs->pending_csums -= existing->num_bytes;
+		if (existing_ref->total_ref_mod < 0 && old_ref_mod >= 0)
+			delayed_refs->pending_csums += existing->num_bytes;
+	}
 	spin_unlock(&existing_ref->lock);
 }
 

@@ -605,6 +620,7 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info,
 	head_ref->is_data = is_data;
 	head_ref->ref_root = RB_ROOT;
 	head_ref->processing = 0;
+	head_ref->total_ref_mod = count_mod;
 
 	spin_lock_init(&head_ref->lock);
 	mutex_init(&head_ref->mutex);

@@ -614,7 +630,7 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info,
 	existing = htree_insert(&delayed_refs->href_root,
 				&head_ref->href_node);
 	if (existing) {
-		update_existing_head_ref(&existing->node, ref);
+		update_existing_head_ref(delayed_refs, &existing->node, ref);
 		/*
 		 * we've updated the existing ref, free the newly
 		 * allocated ref

@@ -622,6 +638,8 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info,
 		kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
 		head_ref = existing;
 	} else {
+		if (is_data && count_mod < 0)
+			delayed_refs->pending_csums += num_bytes;
 		delayed_refs->num_heads++;
 		delayed_refs->num_heads_ready++;
 		atomic_inc(&delayed_refs->num_entries);

index a764e23..5eb0892 100644
@@ -88,6 +88,14 @@ struct btrfs_delayed_ref_head {
 	struct rb_node href_node;
 
 	struct btrfs_delayed_extent_op *extent_op;
+
+	/*
+	 * This is used to track the final ref_mod from all the refs associated
+	 * with this head ref, this is not adjusted as delayed refs are run,
+	 * this is meant to track if we need to do the csum accounting or not.
+	 */
+	int total_ref_mod;
+
 	/*
 	 * when a new extent is allocated, it is just reserved in memory
 	 * The actual extent isn't inserted into the extent allocation tree

@@ -138,6 +146,8 @@ struct btrfs_delayed_ref_root {
 	/* total number of head nodes ready for processing */
 	unsigned long num_heads_ready;
 
+	u64 pending_csums;
+
 	/*
 	 * set when the tree is flushing before a transaction commit,
 	 * used by the throttling code to decide if new updates need

84 lines not on this page · raw message

index e3fe137f..cec23cf 100644
@@ -4197,9 +4197,10 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 	int extent_type = -1;
 	int ret;
 	int err = 0;
-	int be_nice = 0;
 	u64 ino = btrfs_ino(inode);
 	u64 bytes_deleted = 0;
+	bool be_nice = 0;
+	bool should_throttle = 0;
 
 	BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
 

@@ -4405,19 +4406,20 @@ delete:
 						btrfs_header_owner(leaf),
 						ino, extent_offset, 0);
 			BUG_ON(ret);
-			if (be_nice && pending_del_nr &&
-			    (pending_del_nr % 16 == 0) &&
-			    bytes_deleted > 1024 * 1024) {
+			if (btrfs_should_throttle_delayed_refs(trans, root))
 				btrfs_async_run_delayed_refs(root,
 					trans->delayed_ref_updates * 2, 0);
-			}
 		}
 
 		if (found_type == BTRFS_INODE_ITEM_KEY)
 			break;
 
+		should_throttle =
+			btrfs_should_throttle_delayed_refs(trans, root);
+
 		if (path->slots[0] == 0 ||
-		    path->slots[0] != pending_del_slot) {
+		    path->slots[0] != pending_del_slot ||
+		    (be_nice && should_throttle)) {
 			if (pending_del_nr) {
 				ret = btrfs_del_items(trans, root, path,
 						pending_del_slot,

@@ -4430,6 +4432,15 @@ delete:
 				pending_del_nr = 0;
 			}
 			btrfs_release_path(path);
+			if (be_nice && should_throttle) {
+				unsigned long updates = trans->delayed_ref_updates;
+				if (updates) {
+					trans->delayed_ref_updates = 0;
+					ret = btrfs_run_delayed_refs(trans, root, updates * 2);
+					if (ret && !err)
+						err = ret;
+				}
+			}
 			goto search_again;
 		} else {
 			path->slots[0]--;

@@ -4449,7 +4460,7 @@ error:
 
 	btrfs_free_path(path);
 
-	if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
+	if (be_nice && btrfs_should_throttle_delayed_refs(trans, root)) {
 		unsigned long updates = trans->delayed_ref_updates;
 		if (updates) {
 			trans->delayed_ref_updates = 0;

index ba831ee..8b9eea8 100644
@@ -64,6 +64,9 @@ void btrfs_put_transaction(struct btrfs_transaction *transaction)
 	if (atomic_dec_and_test(&transaction->use_count)) {
 		BUG_ON(!list_empty(&transaction->list));
 		WARN_ON(!RB_EMPTY_ROOT(&transaction->delayed_refs.href_root));
+		if (transaction->delayed_refs.pending_csums)
+			printk(KERN_ERR "pending csums is %llu\n",
+			       transaction->delayed_refs.pending_csums);
 		while (!list_empty(&transaction->pending_chunks)) {
 			struct extent_map *em;
 

@@ -223,6 +226,7 @@ loop:
 	cur_trans->delayed_refs.href_root = RB_ROOT;
 	atomic_set(&cur_trans->delayed_refs.num_entries, 0);
 	cur_trans->delayed_refs.num_heads_ready = 0;
+	cur_trans->delayed_refs.pending_csums = 0;
 	cur_trans->delayed_refs.num_heads = 0;
 	cur_trans->delayed_refs.flushing = 0;
 	cur_trans->delayed_refs.run_delayed_start = 0;

index 95944b8..6bf16d5 100644
@@ -3297,6 +3297,9 @@ static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
 }
 
 /* extent-tree.c */
+
+u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes);
+
 static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
 						 unsigned num_items)
 {

index a6f88eb..75f4bed 100644
@@ -2636,7 +2636,7 @@ static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads)
  * Takes the number of bytes to be csumm'ed and figures out how many leaves it
  * would require to store the csums for that many bytes.
  */
-static u64 csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes)
+u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes)
 {
 	u64 csum_size;
 	u64 num_csums_per_leaf;

@@ -2665,7 +2665,7 @@ int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
 	if (num_heads > 1)
 		num_bytes += (num_heads - 1) * root->nodesize;
 	num_bytes <<= 1;
-	num_bytes += csum_bytes_to_leaves(root, csum_bytes) * root->nodesize;
+	num_bytes += btrfs_csum_bytes_to_leaves(root, csum_bytes) * root->nodesize;
 	global_rsv = &root->fs_info->global_block_rsv;
 
 	/*

@@ -5098,13 +5098,12 @@ static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
 	    BTRFS_I(inode)->csum_bytes == 0)
 		return 0;
 
-	old_csums = csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
-
+	old_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
 	if (reserve)
 		BTRFS_I(inode)->csum_bytes += num_bytes;
 	else
 		BTRFS_I(inode)->csum_bytes -= num_bytes;
-	num_csums = csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
+	num_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
 
 	/* No change, no need to reserve more */
 	if (old_csums == num_csums)

94 lines not on this page · raw message

index 75f4bed..ae8db3ba 100644
@@ -2657,7 +2657,8 @@ int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
 	struct btrfs_block_rsv *global_rsv;
 	u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
 	u64 csum_bytes = trans->transaction->delayed_refs.pending_csums;
-	u64 num_bytes;
+	u64 num_dirty_bgs = trans->transaction->num_dirty_bgs;
+	u64 num_bytes, num_dirty_bgs_bytes;
 	int ret = 0;
 
 	num_bytes = btrfs_calc_trans_metadata_size(root, 1);

@@ -2666,17 +2667,21 @@ int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
 		num_bytes += (num_heads - 1) * root->nodesize;
 	num_bytes <<= 1;
 	num_bytes += btrfs_csum_bytes_to_leaves(root, csum_bytes) * root->nodesize;
+	num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(root,
+							     num_dirty_bgs);
 	global_rsv = &root->fs_info->global_block_rsv;
 
 	/*
 	 * If we can't allocate any more chunks lets make sure we have _lots_ of
 	 * wiggle room since running delayed refs can create more delayed refs.
 	 */
-	if (global_rsv->space_info->full)
+	if (global_rsv->space_info->full) {
+		num_dirty_bgs_bytes <<= 1;
 		num_bytes <<= 1;
+	}
 
 	spin_lock(&global_rsv->lock);
-	if (global_rsv->reserved <= num_bytes)
+	if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes)
 		ret = 1;
 	spin_unlock(&global_rsv->lock);
 	return ret;

@@ -5408,6 +5413,7 @@ static int update_block_group(struct btrfs_trans_handle *trans,
 		if (list_empty(&cache->dirty_list)) {
 			list_add_tail(&cache->dirty_list,
 				      &trans->transaction->dirty_bgs);
+				trans->transaction->num_dirty_bgs++;
 			btrfs_get_block_group(cache);
 		}
 		spin_unlock(&trans->transaction->dirty_bgs_lock);

index 8b9eea8..234d606 100644
@@ -251,6 +251,7 @@ loop:
 	INIT_LIST_HEAD(&cur_trans->switch_commits);
 	INIT_LIST_HEAD(&cur_trans->pending_ordered);
 	INIT_LIST_HEAD(&cur_trans->dirty_bgs);
+	cur_trans->num_dirty_bgs = 0;
 	spin_lock_init(&cur_trans->dirty_bgs_lock);
 	list_add_tail(&cur_trans->list, &fs_info->trans_list);
 	extent_io_tree_init(&cur_trans->dirty_pages,

index 96b189b..4cb0ae2 100644
@@ -64,6 +64,7 @@ struct btrfs_transaction {
 	struct list_head pending_ordered;
 	struct list_head switch_commits;
 	struct list_head dirty_bgs;
+	u64 num_dirty_bgs;
 	spinlock_t dirty_bgs_lock;
 	struct btrfs_delayed_ref_root delayed_refs;
 	int aborted;

index ae8db3ba..3d4b3d680 100644
@@ -4329,8 +4329,13 @@ out:
 static inline int need_do_async_reclaim(struct btrfs_space_info *space_info,
 					struct btrfs_fs_info *fs_info, u64 used)
 {
-	return (used >= div_factor_fine(space_info->total_bytes, 98) &&
-		!btrfs_fs_closing(fs_info) &&
+	u64 thresh = div_factor_fine(space_info->total_bytes, 98);
+
+	/* If we're just plain full then async reclaim just slows us down. */
+	if (space_info->bytes_used >= thresh)
+		return 0;
+
+	return (used >= thresh && !btrfs_fs_closing(fs_info) &&
 		!test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
 }
 

@@ -4385,10 +4390,7 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
 		if (!btrfs_need_do_async_reclaim(space_info, fs_info,
 						 flush_state))
 			return;
-	} while (flush_state <= COMMIT_TRANS);
-
-	if (btrfs_need_do_async_reclaim(space_info, fs_info, flush_state))
-		queue_work(system_unbound_wq, work);
+	} while (flush_state < COMMIT_TRANS);
 }
 
 void btrfs_init_async_reclaim_work(struct work_struct *work)

index 88537c5..141df0c 100644
@@ -5010,6 +5010,7 @@ void btrfs_evict_inode(struct inode *inode)
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_block_rsv *rsv, *global_rsv;
+	int steal_from_global = 0;
 	u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
 	int ret;
 

@@ -5077,9 +5078,20 @@ void btrfs_evict_inode(struct inode *inode)
 		 * hard as possible to get this to work.
 		 */
 		if (ret)
-			ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
+			steal_from_global++;
+		else
+			steal_from_global = 0;
+		ret = 0;
 
-		if (ret) {
+		/*
+		 * steal_from_global == 0: we reserved stuff, hooray!
+		 * steal_from_global == 1: we didn't reserve stuff, boo!
+		 * steal_from_global == 2: we've committed, still not a lot of
+		 * room but maybe we'll have room in the global reserve this
+		 * time.
+		 * steal_from_global == 3: abandon all hope!
+		 */
+		if (steal_from_global > 2) {
 			btrfs_warn(root->fs_info,
 				"Could not get space for a delete, will truncate on mount %d",
 				ret);

@@ -5095,6 +5107,36 @@ void btrfs_evict_inode(struct inode *inode)
 			goto no_delete;
 		}
 
+		/*
+		 * We can't just steal from the global reserve, we need tomake
+		 * sure there is room to do it, if not we need to commit and try
+		 * again.
+		 */
+		if (steal_from_global) {
+			if (!btrfs_check_space_for_delayed_refs(trans, root))
+				ret = btrfs_block_rsv_migrate(global_rsv, rsv,
+							      min_size);
+			else
+				ret = -ENOSPC;
+		}
+
+		/*
+		 * Couldn't steal from the global reserve, we have too much
+		 * pending stuff built up, commit the transaction and try it
+		 * again.
+		 */
+		if (ret) {
+			ret = btrfs_commit_transaction(trans, root);
+			if (ret) {
+				btrfs_orphan_del(NULL, inode);
+				btrfs_free_block_rsv(root, rsv);
+				goto no_delete;
+			}
+			continue;
+		} else {
+			steal_from_global = 0;
+		}
+
 		trans->block_rsv = rsv;
 
 		ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);