blob: 274011d4a9cb121b0ba0039f7d08523372f0480f [file] [log] [blame]
// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/storage/lib/vfs/cpp/paged_vnode.h"
#include "src/storage/lib/vfs/cpp/vfs_types.h"
#include "src/storage/lib/vfs/cpp/vnode.h"
#include "src/storage/memfs/memfs.h"
namespace memfs {
class Dnode;
class Vnode : public fs::PagedVnode {
fs::VnodeAttributesQuery SupportedMutableAttributes() const override;
zx::result<> UpdateAttributes(const fs::VnodeAttributesUpdate& attributes) override;
void Sync(SyncCallback closure) override;
// To be more specific: Is this vnode connected into the directory hierarchy?
// VnodeDirs can be unlinked, and this method will subsequently return false.
bool IsDirectory() const { return dnode_ != nullptr; }
void UpdateModified() const;
~Vnode() override;
uint64_t ino() const { return ino_; }
static uint64_t GetInoCounter() { return ino_ctr_.load(std::memory_order_relaxed); }
static uint64_t GetDeletedInoCounter() {
return deleted_ino_ctr_.load(std::memory_order_relaxed);
// TODO(smklein): Move member into the VnodeDir subclass.
// Directories contain a raw reference to their location in the filesystem hierarchy.
// Although this would have safer memory semantics with an actual weak pointer, it is
// currently raw to avoid circular dependencies from Vnode -> Dnode -> Vnode.
// Caution must be taken when detaching Dnodes from their parents to avoid leaving
// this reference dangling.
Dnode* dnode_ = nullptr;
// The Dnode to parent pointer is always set for both directory and file.
Dnode* dnode_parent_ = nullptr;
uint32_t link_count_ = 0;
explicit Vnode(Memfs& memfs);
uint64_t ino_ = 0;
uint64_t create_time_ = 0;
// Mutable so we can update the vnode's modified time when attributes are queried.
// The modification time might need to be synchronized with writes to the paged VMO.
mutable uint64_t modify_time_ = 0;
void VmoRead(uint64_t offset, uint64_t length) final { ZX_PANIC("Not supported"); }
void VmoDirty(uint64_t offset, uint64_t length) final { ZX_PANIC("Not supported"); }
static std::atomic<uint64_t> ino_ctr_;
static std::atomic<uint64_t> deleted_ino_ctr_;
} // namespace memfs