btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself

Currently we pass things around to figure out if we maybe freeing data
based on the state of the delayed refs head.  This makes the accounting
sort of confusing and hard to follow, as it's distinctly separate from
the delayed ref heads stuff, but also depends on it entirely.

Fix this by explicitly adjusting the space_info->total_bytes_pinned in
the delayed refs code.  We now have two places where we modify this
counter, once where we create the delayed and destroy the delayed refs,
and once when we pin and unpin the extents.  This means there is a
slight overlap between delayed refs and the pin/unpin mechanisms, but
this is simply used by the ENOSPC infrastructure to determine if we need
to commit the transaction, so there's no adverse affect from this, we
might simply commit thinking it will give us enough space when it might
not.

CC: stable@vger.kernel.org # 5.10
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 12 insertions, 85 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0c335dae5af7..2f591036ffc1 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -82,41 +82,6 @@ void btrfs_free_excluded_extents(struct btrfs_block_group *cache)
 			  EXTENT_UPTODATE);
 }
 
-static u64 generic_ref_to_space_flags(struct btrfs_ref *ref)
-{
-	if (ref->type == BTRFS_REF_METADATA) {
-		if (ref->tree_ref.root == BTRFS_CHUNK_TREE_OBJECTID)
-			return BTRFS_BLOCK_GROUP_SYSTEM;
-		else
-			return BTRFS_BLOCK_GROUP_METADATA;
-	}
-	return BTRFS_BLOCK_GROUP_DATA;
-}
-
-static void add_pinned_bytes(struct btrfs_fs_info *fs_info,
-			     struct btrfs_ref *ref)
-{
-	struct btrfs_space_info *space_info;
-	u64 flags = generic_ref_to_space_flags(ref);
-
-	space_info = btrfs_find_space_info(fs_info, flags);
-	ASSERT(space_info);
-	percpu_counter_add_batch(&space_info->total_bytes_pinned, ref->len,
-		    BTRFS_TOTAL_BYTES_PINNED_BATCH);
-}
-
-static void sub_pinned_bytes(struct btrfs_fs_info *fs_info,
-			     struct btrfs_ref *ref)
-{
-	struct btrfs_space_info *space_info;
-	u64 flags = generic_ref_to_space_flags(ref);
-
-	space_info = btrfs_find_space_info(fs_info, flags);
-	ASSERT(space_info);
-	percpu_counter_add_batch(&space_info->total_bytes_pinned, -ref->len,
-		    BTRFS_TOTAL_BYTES_PINNED_BATCH);
-}
-
 /* simple helper to search for an existing data extent at a given offset */
 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len)
 {
@@ -1388,7 +1353,6 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 			 struct btrfs_ref *generic_ref)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
-	int old_ref_mod, new_ref_mod;
 	int ret;
 
 	ASSERT(generic_ref->type != BTRFS_REF_NOT_SET &&
@@ -1397,17 +1361,12 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 	       generic_ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID);
 
 	if (generic_ref->type == BTRFS_REF_METADATA)
-		ret = btrfs_add_delayed_tree_ref(trans, generic_ref,
-				NULL, &old_ref_mod, &new_ref_mod);
+		ret = btrfs_add_delayed_tree_ref(trans, generic_ref, NULL);
 	else
-		ret = btrfs_add_delayed_data_ref(trans, generic_ref, 0,
-						 &old_ref_mod, &new_ref_mod);
+		ret = btrfs_add_delayed_data_ref(trans, generic_ref, 0);
 
 	btrfs_ref_tree_mod(fs_info, generic_ref);
 
-	if (ret == 0 && old_ref_mod < 0 && new_ref_mod >= 0)
-		sub_pinned_bytes(fs_info, generic_ref);
-
 	return ret;
 }
 
@@ -1796,20 +1755,9 @@ void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
 	int nr_items = 1;	/* Dropping this ref head update. */
 
 	if (head->total_ref_mod < 0) {
-		struct btrfs_space_info *space_info;
-		u64 flags;
+		u64 flags = btrfs_ref_head_to_space_flags(head);
 
-		if (head->is_data)
-			flags = BTRFS_BLOCK_GROUP_DATA;
-		else if (head->is_system)
-			flags = BTRFS_BLOCK_GROUP_SYSTEM;
-		else
-			flags = BTRFS_BLOCK_GROUP_METADATA;
-		space_info = btrfs_find_space_info(fs_info, flags);
-		ASSERT(space_info);
-		percpu_counter_add_batch(&space_info->total_bytes_pinned,
-				   -head->num_bytes,
-				   BTRFS_TOTAL_BYTES_PINNED_BATCH);
+		btrfs_mod_total_bytes_pinned(fs_info, flags, -head->num_bytes);
 
 		/*
 		 * We had csum deletions accounted for in our delayed refs rsv,
@@ -2572,8 +2520,7 @@ static int pin_down_extent(struct btrfs_trans_handle *trans,
 	spin_unlock(&cache->lock);
 	spin_unlock(&cache->space_info->lock);
 
-	percpu_counter_add_batch(&cache->space_info->total_bytes_pinned,
-		    num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH);
+	__btrfs_mod_total_bytes_pinned(cache->space_info, num_bytes);
 	set_extent_dirty(&trans->transaction->pinned_extents, bytenr,
 			 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
 	return 0;
@@ -2784,8 +2731,7 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
 		cache->pinned -= len;
 		btrfs_space_info_update_bytes_pinned(fs_info, space_info, -len);
 		space_info->max_extent_size = 0;
-		percpu_counter_add_batch(&space_info->total_bytes_pinned,
-			    -len, BTRFS_TOTAL_BYTES_PINNED_BATCH);
+		__btrfs_mod_total_bytes_pinned(space_info, -len);
 		if (cache->ro) {
 			space_info->bytes_readonly += len;
 			readonly = true;
@@ -3318,7 +3264,6 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_ref generic_ref = { 0 };
-	int pin = 1;
 	int ret;
 
 	btrfs_init_generic_ref(&generic_ref, BTRFS_DROP_DELAYED_REF,
@@ -3327,13 +3272,9 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 			    root->root_key.objectid);
 
 	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
-		int old_ref_mod, new_ref_mod;
-
 		btrfs_ref_tree_mod(fs_info, &generic_ref);
-		ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL,
-						 &old_ref_mod, &new_ref_mod);
+		ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL);
 		BUG_ON(ret); /* -ENOMEM */
-		pin = old_ref_mod >= 0 && new_ref_mod < 0;
 	}
 
 	if (last_ref && btrfs_header_generation(buf) == trans->transid) {
@@ -3345,7 +3286,6 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 				goto out;
 		}
 
-		pin = 0;
 		cache = btrfs_lookup_block_group(fs_info, buf->start);
 
 		if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
@@ -3362,9 +3302,6 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 		trace_btrfs_reserved_extent_free(fs_info, buf->start, buf->len);
 	}
 out:
-	if (pin)
-		add_pinned_bytes(fs_info, &generic_ref);
-
 	if (last_ref) {
 		/*
 		 * Deleting the buffer, clear the corrupt flag since it doesn't
@@ -3378,7 +3315,6 @@ out:
 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
-	int old_ref_mod, new_ref_mod;
 	int ret;
 
 	if (btrfs_is_testing(fs_info))
@@ -3394,14 +3330,11 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
 	     ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)) {
 		/* unlocks the pinned mutex */
 		btrfs_pin_extent(trans, ref->bytenr, ref->len, 1);
-		old_ref_mod = new_ref_mod = 0;
 		ret = 0;
 	} else if (ref->type == BTRFS_REF_METADATA) {
-		ret = btrfs_add_delayed_tree_ref(trans, ref, NULL,
-						 &old_ref_mod, &new_ref_mod);
+		ret = btrfs_add_delayed_tree_ref(trans, ref, NULL);
 	} else {
-		ret = btrfs_add_delayed_data_ref(trans, ref, 0,
-						 &old_ref_mod, &new_ref_mod);
+		ret = btrfs_add_delayed_data_ref(trans, ref, 0);
 	}
 
 	if (!((ref->type == BTRFS_REF_METADATA &&
@@ -3410,9 +3343,6 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
 	       ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)))
 		btrfs_ref_tree_mod(fs_info, ref);
 
-	if (ret == 0 && old_ref_mod >= 0 && new_ref_mod < 0)
-		add_pinned_bytes(fs_info, ref);
-
 	return ret;
 }
 
@@ -4528,7 +4458,6 @@ int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 				     struct btrfs_key *ins)
 {
 	struct btrfs_ref generic_ref = { 0 };
-	int ret;
 
 	BUG_ON(root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
 
@@ -4536,9 +4465,8 @@ int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 			       ins->objectid, ins->offset, 0);
 	btrfs_init_data_ref(&generic_ref, root->root_key.objectid, owner, offset);
 	btrfs_ref_tree_mod(root->fs_info, &generic_ref);
-	ret = btrfs_add_delayed_data_ref(trans, &generic_ref,
-					 ram_bytes, NULL, NULL);
-	return ret;
+
+	return btrfs_add_delayed_data_ref(trans, &generic_ref, ram_bytes);
 }
 
 /*
@@ -4730,8 +4658,7 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
 		generic_ref.real_root = root->root_key.objectid;
 		btrfs_init_tree_ref(&generic_ref, level, root_objectid);
 		btrfs_ref_tree_mod(fs_info, &generic_ref);
-		ret = btrfs_add_delayed_tree_ref(trans, &generic_ref,
-						 extent_op, NULL, NULL);
+		ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, extent_op);
 		if (ret)
 			goto out_free_delayed;
 	}