fs/btrfs/delayed-ref.c

Source file repositories/reference/linux-study-clean/fs/btrfs/delayed-ref.c

File Facts

System
Linux kernel
Corpus path
fs/btrfs/delayed-ref.c
Extension
.c
Size
41158 bytes
Lines
1407
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

if (num_bytes >= needed) {
			block_rsv->reserved += needed;
			block_rsv->full = true;
			to_free = num_bytes - needed;
			refilled_bytes = needed;
		} else {
			block_rsv->reserved += num_bytes;
			to_free = 0;
			refilled_bytes = num_bytes;
		}
	} else {
		to_free = num_bytes;
		refilled_bytes = 0;
	}
	spin_unlock(&block_rsv->lock);

	if (to_free > 0)
		btrfs_space_info_free_bytes_may_use(space_info, to_free);

	if (refilled_bytes > 0)
		trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", 0,
					      refilled_bytes, 1);
	return 0;
}

/*
 * compare two delayed data backrefs with same bytenr and type
 */
static int comp_data_refs(const struct btrfs_delayed_ref_node *ref1,
			  const struct btrfs_delayed_ref_node *ref2)
{
	if (ref1->data_ref.objectid < ref2->data_ref.objectid)
		return -1;
	if (ref1->data_ref.objectid > ref2->data_ref.objectid)
		return 1;
	if (ref1->data_ref.offset < ref2->data_ref.offset)
		return -1;
	if (ref1->data_ref.offset > ref2->data_ref.offset)
		return 1;
	return 0;
}

static int comp_refs(const struct btrfs_delayed_ref_node *ref1,
		     const struct btrfs_delayed_ref_node *ref2,
		     bool check_seq)
{
	int ret = 0;

	if (ref1->type < ref2->type)
		return -1;
	if (ref1->type > ref2->type)
		return 1;
	if (ref1->type == BTRFS_SHARED_BLOCK_REF_KEY ||
	    ref1->type == BTRFS_SHARED_DATA_REF_KEY) {
		if (ref1->parent < ref2->parent)
			return -1;
		if (ref1->parent > ref2->parent)
			return 1;
	} else {
		if (ref1->ref_root < ref2->ref_root)
			return -1;
		if (ref1->ref_root > ref2->ref_root)
			return 1;
		if (ref1->type == BTRFS_EXTENT_DATA_REF_KEY)
			ret = comp_data_refs(ref1, ref2);
	}
	if (ret)
		return ret;
	if (check_seq) {
		if (ref1->seq < ref2->seq)
			return -1;
		if (ref1->seq > ref2->seq)
			return 1;
	}
	return 0;
}

static int cmp_refs_node(const struct rb_node *new, const struct rb_node *exist)
{
	const struct btrfs_delayed_ref_node *new_node =
		rb_entry(new, struct btrfs_delayed_ref_node, ref_node);
	const struct btrfs_delayed_ref_node *exist_node =
		rb_entry(exist, struct btrfs_delayed_ref_node, ref_node);

	return comp_refs(new_node, exist_node, true);
}

static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root,
		struct btrfs_delayed_ref_node *ins)
{

Annotation

Implementation Notes