mirror of
https://github.com/facebook/sapling.git
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d8d841ae80
Summary: This will enable to gather a bit more debugging regarding what processes are fetching data. The one missing bit on Windows is to collect the process name, for now, a "NOT IMPLEMENTED" placeholder is put in place. Reviewed By: wez Differential Revision: D23946258 fbshipit-source-id: 9f7642c7b9207c5b48ffff0f4eb0333af00bc7d5
1043 lines
32 KiB
C++
1043 lines
32 KiB
C++
/*
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This software may be used and distributed according to the terms of the
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* GNU General Public License version 2.
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*/
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#pragma once
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#include <folly/Portability.h>
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#include <folly/SharedMutex.h>
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#include <folly/Synchronized.h>
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#include <folly/ThreadLocal.h>
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#include <folly/futures/Future.h>
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#include <folly/futures/Promise.h>
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#include <folly/futures/SharedPromise.h>
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#include <folly/logging/Logger.h>
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#include <chrono>
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#include <memory>
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#include <mutex>
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#include <optional>
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#include <shared_mutex>
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#include <stdexcept>
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#include "eden/fs/inodes/CacheHint.h"
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#include "eden/fs/inodes/InodeNumber.h"
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#include "eden/fs/inodes/InodePtrFwd.h"
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#include "eden/fs/inodes/Overlay.h"
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#include "eden/fs/journal/Journal.h"
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#include "eden/fs/model/ParentCommits.h"
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#include "eden/fs/service/gen-cpp2/eden_types.h"
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#include "eden/fs/store/BlobAccess.h"
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#include "eden/fs/takeover/TakeoverData.h"
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#include "eden/fs/utils/PathFuncs.h"
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#ifndef _WIN32
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#include "eden/fs/fuse/Dispatcher.h"
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#include "eden/fs/fuse/FuseChannel.h"
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#include "eden/fs/inodes/OverlayFileAccess.h"
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#else
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#include "eden/fs/prjfs/PrjfsChannel.h"
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#endif
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DECLARE_string(edenfsctlPath);
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namespace apache {
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namespace thrift {
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class ResponseChannelRequest;
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}
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} // namespace apache
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namespace folly {
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class EventBase;
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class File;
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template <typename T>
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class Future;
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} // namespace folly
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namespace facebook {
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namespace eden {
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class BindMount;
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class BlobCache;
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class CheckoutConfig;
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class CheckoutConflict;
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class Clock;
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class DiffContext;
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class EdenDispatcher;
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class FuseChannel;
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class FuseDeviceUnmountedDuringInitialization;
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class DiffCallback;
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class InodeMap;
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class MountPoint;
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struct InodeMetadata;
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template <typename T>
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class InodeTable;
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using InodeMetadataTable = InodeTable<InodeMetadata>;
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class ObjectStore;
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class Overlay;
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class OverlayFileAccess;
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class ServerState;
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class Tree;
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class TreePrefetchLease;
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class UnboundedQueueExecutor;
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struct FileMetadata;
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class RenameLock;
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class SharedRenameLock;
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/**
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* Represents types of keys for some fb303 counters.
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*/
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enum class CounterName {
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/**
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* Represents count of loaded inodes in the current mount.
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*/
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INODEMAP_LOADED,
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/**
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* Represents count of unloaded inodes in the current mount.
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*/
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INODEMAP_UNLOADED,
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/**
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* Represents the amount of memory used by deltas in the change log
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*/
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JOURNAL_MEMORY,
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/**
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* Represents the number of entries in the change log
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*/
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JOURNAL_ENTRIES,
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/**
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* Represents the duration of the journal in seconds end to end
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*/
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JOURNAL_DURATION,
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/**
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* Represents the maximum deltas iterated over in the Journal's forEachDelta
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*/
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JOURNAL_MAX_FILES_ACCUMULATED
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};
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/**
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* Contains the uid and gid of the owner of the files in the mount
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*/
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struct Owner {
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uid_t uid;
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gid_t gid;
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};
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/**
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* Durations of the various stages of checkout.
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*/
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struct CheckoutTimes {
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using duration = std::chrono::steady_clock::duration;
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duration didAcquireParentsLock{};
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duration didLookupTrees{};
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duration didDiff{};
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duration didAcquireRenameLock{};
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duration didCheckout{};
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duration didFinish{};
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};
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struct CheckoutResult {
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std::vector<CheckoutConflict> conflicts;
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CheckoutTimes times;
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};
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/**
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* EdenMount contains all of the data about a specific eden mount point.
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*
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* This contains:
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* - The MountPoint object which manages our FUSE interactions with the kernel.
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* - The ObjectStore object used for retreiving/storing object data.
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* - The Overlay object used for storing local changes (that have not been
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* committed/snapshotted yet).
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*/
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class EdenMount {
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public:
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using State = MountState;
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/**
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* Create a shared_ptr to an EdenMount.
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*
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* The caller must call initialize() after creating the EdenMount to load data
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* required to access the mount's inodes. No inode-related methods may be
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* called on the EdenMount until initialize() has successfully completed.
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*/
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static std::shared_ptr<EdenMount> create(
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std::unique_ptr<CheckoutConfig> config,
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std::shared_ptr<ObjectStore> objectStore,
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std::shared_ptr<BlobCache> blobCache,
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std::shared_ptr<ServerState> serverState,
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std::unique_ptr<Journal> journal);
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/**
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* Asynchronous EdenMount initialization - post instantiation.
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*
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* If takeover data is specified, it is used to initialize the inode map.
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*/
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FOLLY_NODISCARD folly::Future<folly::Unit> initialize(
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OverlayChecker::ProgressCallback&& progressCallback = [](auto) {},
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const std::optional<SerializedInodeMap>& takeover = std::nullopt);
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/**
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* Destroy the EdenMount.
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*
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* This method generally does not need to be invoked directly, and will
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* instead be invoked automatically by the shared_ptr<EdenMount> returned by
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* create(), once it becomes unreferenced.
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*
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* If the EdenMount has not already been explicitly shutdown(), destroy()
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* will trigger the shutdown(). destroy() blocks until the shutdown is
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* complete, so it is advisable for callers to callers to explicitly trigger
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* shutdown() themselves if they want to ensure that the shared_ptr
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* destruction will not block on this operation.
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*/
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void destroy();
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/**
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* Shutdown the EdenMount.
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*
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* This should be called *after* calling unmount() (i.e. after the FUSE mount
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* point has been unmounted from the kernel).
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*
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* This cleans up the in-memory data associated with the EdenMount, and waits
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* for all outstanding InodeBase objects to become unreferenced and be
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* destroyed.
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*
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* If doTakeover is true, this function will return populated
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* SerializedFileHandleMap and SerializedInodeMap instances generated by
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* calling FileHandleMap::serializeMap() and InodeMap::shutdown.
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*
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* If doTakeover is false, this function will return default-constructed
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* SerializedFileHandleMap and SerializedInodeMap instances.
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*/
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folly::SemiFuture<SerializedInodeMap> shutdown(
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bool doTakeover,
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bool allowFuseNotStarted = false);
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/**
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* Call the umount(2) syscall to tell the kernel to remove this filesystem.
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*
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* After umount(2) succeeds, the following operations happen independently and
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* concurrently:
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*
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* * The future returned by unmount() is fulfilled successfully.
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* * The future returned by getChannelCompletionFuture() is fulfilled.
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*
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* If startChannel() is in progress, unmount() can cancel startChannel().
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*
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* If startChannel() is in progress, unmount() might wait for startChannel()
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* to finish before calling umount(2).
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*
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* If neither startChannel() nor takeoverFuse() has been called, unmount()
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* finishes successfully without calling umount(2). Thereafter, startChannel()
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* and takeoverFuse() will both fail with an EdenMountCancelled exception.
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*
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* unmount() is idempotent: If unmount() has already been called, this
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* function immediately returns a Future which will complete at the same time
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* the original call to unmount() completes.
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*/
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FOLLY_NODISCARD folly::Future<folly::Unit> unmount();
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/**
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* Get the current state of this mount.
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*
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* Note that the state may be changed by another thread immediately after this
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* method is called, so this method should primarily only be used for
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* debugging & diagnostics.
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*/
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State getState() const {
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return state_.load(std::memory_order_acquire);
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}
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/**
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* Check if inode operations can be performed on this EdenMount.
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*
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* This returns false for mounts that are still initializing and do not have
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* their root inode loaded yet. This also returns false for mounts that are
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* shutting down.
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*/
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bool isSafeForInodeAccess() const {
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auto state = getState();
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return !(
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state == State::UNINITIALIZED || state == State::INITIALIZING ||
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state == State::SHUTTING_DOWN);
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}
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/**
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* Get the FUSE/Prjfs channel for this mount point.
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*
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* This should only be called after the mount point has been successfully
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* started. (It is the caller's responsibility to perform proper
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* synchronization here with the mount start operation. This method provides
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* no internal synchronization of its own.)
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*/
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#ifdef _WIN32
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PrjfsChannel* getPrjfsChannel() const;
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#else
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FuseChannel* getFuseChannel() const;
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#endif
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ProcessAccessLog& getProcessAccessLog() const {
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#ifdef _WIN32
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return getPrjfsChannel()->getProcessAccessLog();
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#else
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return getFuseChannel()->getProcessAccessLog();
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#endif
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}
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/**
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* Return the path to the mount point.
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*/
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const AbsolutePath& getPath() const;
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/**
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* Get the commit IDs of the working directory's parent commit(s).
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*/
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ParentCommits getParentCommits() const {
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return parentInfo_.rlock()->parents;
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}
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/**
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* Return the ObjectStore used by this mount point.
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*
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* The ObjectStore is guaranteed to be valid for the lifetime of the
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* EdenMount.
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*/
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ObjectStore* getObjectStore() const {
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return objectStore_.get();
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}
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/**
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* Return Eden's blob cache.
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*
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* It is guaranteed to be valid for the lifetime of the EdenMount.
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*/
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BlobCache* getBlobCache() const {
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return blobCache_.get();
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}
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/**
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* Return the BlobAccess used by this mount point.
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*
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* The BlobAccess is guaranteed to be valid for the lifetime of the EdenMount.
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*/
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BlobAccess* getBlobAccess() {
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return &blobAccess_;
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}
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/**
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* Return the EdenDispatcher used for this mount.
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*/
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EdenDispatcher* getDispatcher() const {
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return dispatcher_.get();
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}
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/**
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* Return the InodeMap for this mount.
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*/
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InodeMap* getInodeMap() const {
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return inodeMap_.get();
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}
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/**
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* Return the Overlay for this mount.
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*/
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Overlay* getOverlay() const {
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return overlay_.get();
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}
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#ifndef _WIN32
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OverlayFileAccess* getOverlayFileAccess() {
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return &overlayFileAccess_;
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}
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#endif // !_WIN32
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InodeMetadataTable* getInodeMetadataTable() const;
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/**
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* Return the Journal used by this mount point.
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*
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* The Journal is guaranteed to be valid for the lifetime of the EdenMount.
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*/
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Journal& getJournal() {
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return *journal_;
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}
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uint64_t getMountGeneration() const {
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return mountGeneration_;
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}
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const CheckoutConfig* getConfig() const {
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return config_.get();
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}
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/**
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* Returns the server's thread pool.
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*/
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const std::shared_ptr<UnboundedQueueExecutor>& getThreadPool() const;
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/**
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* Returns the Clock with which this mount was configured.
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*/
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const Clock& getClock() const {
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return *clock_;
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}
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/** Get the TreeInode for the root of the mount. */
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TreeInodePtr getRootInode() const;
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#ifndef _WIN32
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/**
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* Get the inode number for the .eden dir. Returns an empty InodeNumber
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* prior to the .eden directory being set up.
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*/
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InodeNumber getDotEdenInodeNumber() const;
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#endif // !_WIN32
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/** Convenience method for getting the Tree for the root of the mount. */
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folly::Future<std::shared_ptr<const Tree>> getRootTree() const;
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/**
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* Look up the Inode object for the specified path.
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*
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* This may fail with an InodeError containing ENOENT if the path does not
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* exist, or ENOTDIR if one of the intermediate components along the path is
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* not a directory.
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*
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* This may also fail with other exceptions if something else goes wrong
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* besides the path being invalid (for instance, an error loading data from
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* the ObjectStore).
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*/
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folly::Future<InodePtr> getInode(
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RelativePathPiece path,
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ObjectFetchContext& context) const;
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/**
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* Resolves symlinks and loads file contents from the Inode at the given path.
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* This loads the entire file contents into memory, so this can be expensive
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* for large files.
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*
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* The fetchContext object must remain valid until the future is completed.
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*/
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folly::Future<std::string> loadFileContentsFromPath(
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ObjectFetchContext& fetchContext,
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RelativePathPiece path,
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CacheHint cacheHint = CacheHint::LikelyNeededAgain) const;
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/**
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* Resolves symlinks and loads file contents. This loads the entire file
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* contents into memory, so this can be expensive for large files.
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*
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* The fetchContext object must remain valid until the future is completed.
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*
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* TODO: add maxSize parameter to cause the command to fail if the file is
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* over a certain size.
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*/
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folly::Future<std::string> loadFileContents(
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ObjectFetchContext& fetchContext,
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InodePtr fileInodePtr,
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CacheHint cacheHint = CacheHint::LikelyNeededAgain) const;
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/**
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* Chases (to bounded depth) and returns the final non-symlink in the
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* (possibly 0-length) chain of symlinks rooted at pInode. Specifically:
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* If pInode is a file or directory, it is immediately returned.
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* If pInode is a symlink, the chain rooted at it chased down until
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* one of the following conditions:
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* 1) an entity outside this mount is encountered => error (EXDEV);
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* 2) an non-symlink item under this mount is found => this item is returned;
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* 3) a maximum depth is exceeded => error (ELOOP).
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* 4) absolute path entity is encountered => error (EPERM).
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* 5) the input inode refers to an unlinked inode => error (ENOENT).
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* 6) a symlink points to a non-existing entity => error (ENOENT)
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* NOTE: a loop in the chain is handled by max depth length logic.
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*/
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folly::Future<InodePtr> resolveSymlink(
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ObjectFetchContext& fetchContext,
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InodePtr pInode,
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CacheHint cacheHint = CacheHint::LikelyNeededAgain) const;
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/**
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* Check out the specified commit.
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*/
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folly::Future<CheckoutResult> checkout(
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Hash snapshotHash,
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std::optional<pid_t> clientPid,
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folly::StringPiece thriftMethodCaller,
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CheckoutMode checkoutMode = CheckoutMode::NORMAL);
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/**
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* Chown the repository to the given uid and gid
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*/
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folly::Future<folly::Unit> chown(uid_t uid, gid_t gid);
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|
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/**
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* Compute differences between the current commit and the working directory
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* state.
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*
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* @param listIgnored Whether or not to inform the callback of ignored files.
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* When listIgnored is set to false can speed up the diff computation, as
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* the code does not need to descend into ignored directories at all.
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* @param enforceCurrentParent Whether or not to return an error if the
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* specified commitHash does not match the actual current working
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* directory parent. If this is false the code will still compute a diff
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* against the specified commitHash even the working directory parent
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* points elsewhere, or when a checkout is currently in progress.
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* @param request This ResposeChannelRequest is passed from the ServiceHandler
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* and is used to check if the request is still active, because if the
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* request is no longer active we will cancel this diff operation.
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*
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* @return Returns a folly::Future that will be fulfilled when the diff
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* operation is complete. This is marked FOLLY_NODISCARD to
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* make sure callers do not forget to wait for the operation to complete.
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*/
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FOLLY_NODISCARD folly::Future<std::unique_ptr<ScmStatus>> diff(
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Hash commitHash,
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bool listIgnored = false,
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bool enforceCurrentParent = true,
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apache::thrift::ResponseChannelRequest* FOLLY_NULLABLE request = nullptr);
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/**
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* This version of diff is primarily intended for testing.
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* Use diff(DiffCallback* callback, bool listIgnored) instead.
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* The caller must ensure that the DiffContext object ctsPtr points to
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* exists at least until the returned Future completes.
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*/
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FOLLY_NODISCARD folly::Future<folly::Unit> diff(
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DiffContext* ctxPtr,
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Hash commitHash) const;
|
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|
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/**
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* Reset the state to point to the specified parent commit(s), without
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* modifying the working directory contents at all.
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*/
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void resetParents(const ParentCommits& parents);
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/**
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* Reset the state to point to the specified parent commit, without
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* modifying the working directory contents at all.
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*
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* This is a small wrapper around resetParents() for when the code knows at
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* compile time that it will only ever have a single parent commit on this
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* code path.
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*/
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void resetParent(const Hash& parent);
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|
|
/**
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* Acquire the rename lock in exclusive mode.
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*/
|
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RenameLock acquireRenameLock();
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|
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/**
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|
* Acquire the rename lock in shared mode.
|
|
*/
|
|
SharedRenameLock acquireSharedRenameLock();
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|
|
/**
|
|
* Returns a pointer to a stats instance associated with this mountpoint.
|
|
* Today this is the global stats instance, but in the future it will be
|
|
* a mount point specific instance.
|
|
*/
|
|
EdenStats* getStats() const;
|
|
|
|
const folly::Logger& getStraceLogger() const {
|
|
return straceLogger_;
|
|
}
|
|
|
|
const std::shared_ptr<ServerState>& getServerState() const {
|
|
return serverState_;
|
|
}
|
|
|
|
/**
|
|
* Returns the last checkout time in the Eden mount.
|
|
*/
|
|
struct timespec getLastCheckoutTime() const;
|
|
|
|
/**
|
|
* Set the last checkout time.
|
|
*
|
|
* This is intended primarily for use in test code.
|
|
*/
|
|
void setLastCheckoutTime(std::chrono::system_clock::time_point time);
|
|
|
|
/**
|
|
* Returns the key value to an fb303 counter.
|
|
*/
|
|
std::string getCounterName(CounterName name);
|
|
|
|
struct ParentInfo {
|
|
ParentCommits parents;
|
|
};
|
|
|
|
/**
|
|
* Mounts the filesystem in the VFS and spawns worker threads to
|
|
* dispatch the fuse session.
|
|
*
|
|
* Returns a Future that will complete as soon as the filesystem has been
|
|
* successfully mounted, or as soon as the mount fails (state transitions
|
|
* to RUNNING or FUSE_ERROR).
|
|
*
|
|
* If unmount() is called before startChannel() is called, then startChannel()
|
|
* does the following:
|
|
*
|
|
* * startChannel() does not attempt to mount the filesystem
|
|
* * The returned Future is fulfilled with an EdenMountCancelled exception
|
|
*
|
|
* If unmount() is called while startChannel() is in progress, then
|
|
* startChannel() does the following:
|
|
*
|
|
* * The filesystem is unmounted (if it was mounted)
|
|
* * The returned Future is fulfilled with an
|
|
* FuseDeviceUnmountedDuringInitialization exception
|
|
*/
|
|
FOLLY_NODISCARD folly::Future<folly::Unit> startChannel(bool readOnly);
|
|
|
|
#ifndef _WIN32
|
|
/**
|
|
* Take over a FUSE channel for an existing mount point.
|
|
*
|
|
* This spins up worker threads to service the existing FUSE channel and
|
|
* returns immediately, or throws an exception on error.
|
|
*
|
|
* If unmount() is called before takeoverFuse() is called, then takeoverFuse()
|
|
* throws an EdenMountCancelled exception.
|
|
*/
|
|
void takeoverFuse(FuseChannelData takeoverData);
|
|
#endif
|
|
|
|
/**
|
|
* Obtains a future that will complete once the channel has wound down.
|
|
*
|
|
* This method may be called at any time, but the returned future will only be
|
|
* fulfilled if startChannel() completes successfully. If startChannel()
|
|
* fails or is never called, the future returned by
|
|
* getChannelCompletionFuture() will never complete.
|
|
*/
|
|
FOLLY_NODISCARD folly::Future<TakeoverData::MountInfo>
|
|
getChannelCompletionFuture();
|
|
|
|
Owner getOwner() const {
|
|
return *owner_.rlock();
|
|
}
|
|
|
|
void setOwner(uid_t uid, gid_t gid) {
|
|
auto owner = owner_.wlock();
|
|
owner->uid = uid;
|
|
owner->gid = gid;
|
|
}
|
|
|
|
/**
|
|
* Return a new stat structure that has been minimally initialized with
|
|
* data for this mount point.
|
|
*
|
|
* The caller must still initialize all file-specific data (inode number,
|
|
* file mode, size, timestamps, link count, etc).
|
|
*/
|
|
struct stat initStatData() const;
|
|
|
|
/**
|
|
* Given a mode_t, return an initial InodeMetadata. All timestamps are set
|
|
* to the last checkout time and uid and gid are set to the creator of the
|
|
* mount.
|
|
*/
|
|
struct InodeMetadata getInitialInodeMetadata(mode_t mode) const;
|
|
|
|
/**
|
|
* mount any configured bind mounts.
|
|
* This requires that the filesystem already be mounted, and must not
|
|
* be called in the context of a fuseWorkerThread().
|
|
*/
|
|
FOLLY_NODISCARD folly::SemiFuture<folly::Unit> performBindMounts();
|
|
|
|
FOLLY_NODISCARD folly::Future<folly::Unit> addBindMount(
|
|
RelativePathPiece repoPath,
|
|
AbsolutePathPiece targetPath);
|
|
FOLLY_NODISCARD folly::Future<folly::Unit> removeBindMount(
|
|
RelativePathPiece repoPath);
|
|
|
|
/**
|
|
* Ensures the path `fromRoot` is a directory. If it is not, then it creates
|
|
* subdirectories until it is. If creating a subdirectory fails, it throws an
|
|
* exception.
|
|
*/
|
|
FOLLY_NODISCARD folly::Future<folly::Unit> ensureDirectoryExists(
|
|
RelativePathPiece fromRoot);
|
|
|
|
/**
|
|
* Request to start a new tree prefetch.
|
|
*
|
|
* Returns a new TreePrefetchLease if you can start a new prefetch, or
|
|
* std::nullopt if there are too many prefetches already in progress and a new
|
|
* one should not be started. If a TreePrefetchLease object is returned the
|
|
* caller should hold onto it until the prefetch is complete. When the
|
|
* TreePrefetchLease is destroyed this will inform the EdenMount that the
|
|
* prefetch has finished.
|
|
*/
|
|
FOLLY_NODISCARD std::optional<TreePrefetchLease> tryStartTreePrefetch(
|
|
TreeInodePtr treeInode,
|
|
ObjectFetchContext& context);
|
|
|
|
private:
|
|
friend class RenameLock;
|
|
friend class SharedRenameLock;
|
|
class JournalDiffCallback;
|
|
|
|
/**
|
|
* Recursive method used for resolveSymlink() implementation
|
|
*/
|
|
folly::Future<InodePtr> resolveSymlinkImpl(
|
|
ObjectFetchContext& fetchContext,
|
|
InodePtr pInode,
|
|
RelativePath&& path,
|
|
size_t depth,
|
|
CacheHint cacheHint) const;
|
|
|
|
/**
|
|
* Attempt to transition from expected -> newState.
|
|
* If the current state is expected then the state is set to newState
|
|
* and returns boolean.
|
|
* Otherwise the current state is left untouched and returns false.
|
|
*/
|
|
FOLLY_NODISCARD bool tryToTransitionState(State expected, State newState);
|
|
|
|
/**
|
|
* Transition from expected -> newState.
|
|
*
|
|
* Throws an error if the current state does not match the expected state.
|
|
*/
|
|
void transitionState(State expected, State newState);
|
|
|
|
/**
|
|
* Transition from the STARTING state to the FUSE_ERROR state.
|
|
*
|
|
* Preconditions:
|
|
* - `getState()` is STARTING or DESTROYING or SHUTTING_DOWN or SHUT_DOWN.
|
|
*
|
|
* Postconditions:
|
|
* - If `getState()` was STARTING, `getState()` is now FUSE_ERROR.
|
|
* - If `getState()` was not STARTING, `getState()` is unchanged.
|
|
*/
|
|
void transitionToFuseInitializationErrorState();
|
|
|
|
EdenMount(
|
|
std::unique_ptr<CheckoutConfig> config,
|
|
std::shared_ptr<ObjectStore> objectStore,
|
|
std::shared_ptr<BlobCache> blobCache,
|
|
std::shared_ptr<ServerState> serverState,
|
|
std::unique_ptr<Journal> journal);
|
|
|
|
// Forbidden copy constructor and assignment operator
|
|
EdenMount(EdenMount const&) = delete;
|
|
EdenMount& operator=(EdenMount const&) = delete;
|
|
|
|
folly::Future<TreeInodePtr> createRootInode(
|
|
const ParentCommits& parentCommits);
|
|
|
|
FOLLY_NODISCARD folly::Future<folly::Unit> setupDotEden(TreeInodePtr root);
|
|
|
|
folly::SemiFuture<SerializedInodeMap> shutdownImpl(bool doTakeover);
|
|
|
|
/**
|
|
* Create a DiffContext to be passed through the TreeInode diff codepath. This
|
|
* will be used to record differences through the callback (in which
|
|
* listIgnored determines if ignored files will be reported in the callback)
|
|
* and houses the thrift request in order to check to see if the diff() should
|
|
* be short circuited
|
|
*/
|
|
std::unique_ptr<DiffContext> createDiffContext(
|
|
DiffCallback* callback,
|
|
bool listIgnored = false,
|
|
apache::thrift::ResponseChannelRequest* FOLLY_NULLABLE request =
|
|
nullptr) const;
|
|
|
|
/**
|
|
* This accepts a callback which will be invoked as differences are found.
|
|
* Note that the callback methods may be invoked simultaneously from multiple
|
|
* different threads, and the callback is responsible for performing
|
|
* synchronization (if it is needed). It will be packaged into a DiffContext
|
|
* and passed through the TreeInode diff() codepath
|
|
*/
|
|
FOLLY_NODISCARD folly::Future<folly::Unit> diff(
|
|
DiffCallback* callback,
|
|
Hash commitHash,
|
|
bool listIgnored,
|
|
bool enforceCurrentParent,
|
|
apache::thrift::ResponseChannelRequest* FOLLY_NULLABLE request) const;
|
|
|
|
/**
|
|
* Signal to unmount() that fuseMount() or takeoverFuse() has started.
|
|
*
|
|
* beginMount() returns a reference to
|
|
* *mountingUnmountingState_->channelMountPromise. To signal that the
|
|
* fuseMount() has completed, set the promise's value (or exception) without
|
|
* mountingUnmountingState_'s lock held.
|
|
*
|
|
* If unmount() was called in the past, beginMount() throws
|
|
* EdenMountCancelled.
|
|
*
|
|
* Preconditions:
|
|
* - `beginMount()` has not been called before.
|
|
*/
|
|
FOLLY_NODISCARD folly::Promise<folly::Unit>& beginMount();
|
|
|
|
#ifdef _WIN32
|
|
using channelType = PrjfsChannel*;
|
|
using ChannelStopData = PrjfsChannel::StopData;
|
|
#else
|
|
using channelType = folly::File;
|
|
using ChannelStopData = FuseChannel::StopData;
|
|
#endif
|
|
|
|
using StopFuture = folly::SemiFuture<ChannelStopData>;
|
|
|
|
/**
|
|
* Open the platform specific device and mount it.
|
|
*/
|
|
folly::Future<channelType> channelMount(bool readOnly);
|
|
|
|
/**
|
|
* Construct the channel_ member variable.
|
|
*/
|
|
void createChannel(channelType fuseDevice);
|
|
|
|
/**
|
|
* Once the channel has been initialized, set up callbacks to clean up
|
|
* correctly when it shuts down.
|
|
*/
|
|
void channelInitSuccessful(EdenMount::StopFuture&& channelCompleteFuture);
|
|
|
|
/**
|
|
* Private destructor.
|
|
*
|
|
* This should not be invoked by callers directly. Use the destroy() method
|
|
* above (or the EdenMountDeleter if you plan to store the EdenMount in a
|
|
* std::unique_ptr or std::shared_ptr).
|
|
*/
|
|
~EdenMount();
|
|
|
|
friend class TreePrefetchLease;
|
|
void treePrefetchFinished() noexcept;
|
|
|
|
static constexpr int kMaxSymlinkChainDepth = 40; // max depth of symlink chain
|
|
|
|
const std::unique_ptr<const CheckoutConfig> config_;
|
|
|
|
/**
|
|
* A promise associated with the future returned from
|
|
* EdenMount::getChannelCompletionFuture() that completes when the
|
|
* fuseChannel has no work remaining and can be torn down.
|
|
* The future yields the underlying fuseDevice descriptor; it can
|
|
* be passed on during graceful restart or simply closed if we're
|
|
* unmounting and shutting down completely. In the unmount scenario
|
|
* the device should be closed prior to calling EdenMount::shutdown()
|
|
* so that the subsequent privilegedFuseUnmount() call won't block
|
|
* waiting on us for a response.
|
|
*/
|
|
folly::Promise<TakeoverData::MountInfo> channelCompletionPromise_;
|
|
|
|
/**
|
|
* Eden server state shared across multiple mount points.
|
|
*/
|
|
std::shared_ptr<ServerState> serverState_;
|
|
|
|
std::unique_ptr<InodeMap> inodeMap_;
|
|
|
|
std::unique_ptr<EdenDispatcher> dispatcher_;
|
|
|
|
std::shared_ptr<ObjectStore> objectStore_;
|
|
std::shared_ptr<BlobCache> blobCache_;
|
|
BlobAccess blobAccess_;
|
|
std::shared_ptr<Overlay> overlay_;
|
|
|
|
#ifndef _WIN32
|
|
OverlayFileAccess overlayFileAccess_;
|
|
#endif // !_WIN32
|
|
InodeNumber dotEdenInodeNumber_{};
|
|
|
|
/**
|
|
* A mutex around all name-changing operations in this mount point.
|
|
*
|
|
* This includes rename() operations as well as unlink() and rmdir().
|
|
* Any operation that modifies an existing InodeBase's location_ data must
|
|
* hold the rename lock.
|
|
*/
|
|
folly::SharedMutex renameMutex_;
|
|
|
|
/**
|
|
* The IDs of the parent commit(s) of the working directory.
|
|
*
|
|
* In most circumstances there will only be a single parent, but there
|
|
* will be two parents when in the middle of resolving a merge conflict.
|
|
*/
|
|
|
|
folly::Synchronized<ParentInfo> parentInfo_;
|
|
|
|
std::unique_ptr<Journal> journal_;
|
|
|
|
/**
|
|
* A number to uniquely identify this particular incarnation of this mount.
|
|
* We use bits from the process id and the time at which we were mounted.
|
|
*/
|
|
const uint64_t mountGeneration_;
|
|
|
|
/**
|
|
* The path to the unix socket that can be used to address us via thrift
|
|
*/
|
|
AbsolutePath socketPath_;
|
|
|
|
/**
|
|
* A log category for logging strace-events for this mount point.
|
|
*
|
|
* All FUSE operations to this mount point will get logged to this category.
|
|
* The category name is of the following form: "eden.strace.<mount_path>"
|
|
*/
|
|
folly::Logger straceLogger_;
|
|
|
|
/**
|
|
* The timestamp of the last time that a checkout operation was performed in
|
|
* this mount. This is used to initialize the timestamps of newly loaded
|
|
* inodes. (Since the file contents might have logically been update by the
|
|
* checkout operation.)
|
|
*
|
|
* We store this as a struct timespec rather than a std::chrono::time_point
|
|
* since this is primarily used by FUSE APIs which need a timespec.
|
|
*
|
|
* This is managed with its own Synchronized lock separate from other state
|
|
* since it needs to be accessed when constructing inodes. This is a very
|
|
* low level lock in our lock ordering hierarchy: No other locks should be
|
|
* acquired while holding this lock.
|
|
*/
|
|
folly::Synchronized<struct timespec> lastCheckoutTime_;
|
|
|
|
struct MountingUnmountingState {
|
|
bool channelMountStarted() const noexcept;
|
|
bool channelUnmountStarted() const noexcept;
|
|
|
|
/**
|
|
* Whether or not the mount(2) syscall has been called (via fuseMount).
|
|
*
|
|
* Use this promise to wait for fuseMount to finish.
|
|
*
|
|
* * Empty optional: fuseMount/mount(2) has not been called yet.
|
|
* (startChannel/fuseMount can be called.)
|
|
* * Unfulfilled: fuseMount is in progress.
|
|
* * Fulfilled with Unit: fuseMount completed successfully (via
|
|
* startChannel), or we took over the FUSE device from another process
|
|
* (via takeoverFuse). (startChannel or takeoverFuse can still be in
|
|
* progress.)
|
|
* * Fulfilled with error: fuseMount failed, or fuseMount was cancelled.
|
|
*
|
|
* The state of this variable might not reflect whether the file system is
|
|
* mounted. For example, if this promise is fulfilled with Unit, then
|
|
* umount(8) is called by another process, the file system will not be
|
|
* mounted.
|
|
*/
|
|
std::optional<folly::Promise<folly::Unit>> channelMountPromise;
|
|
|
|
/**
|
|
* Whether or not unmount has been called.
|
|
*
|
|
* * Empty optional: unmount has not been called yet. (unmount can be
|
|
* called.)
|
|
* * Unfulfilled: unmount is in progress, either waiting for a concurrent
|
|
* fuseMount to complete or waiting for fuseUnmount to complete.
|
|
* * Fulfilled with Unit: unmount was called. fuseUnmount completed
|
|
* successfully, or fuseMount was never called for this EdenMount.
|
|
* * Fulfilled with error: unmount was called, but fuseUnmount failed.
|
|
*
|
|
* The state of this variable might not reflect whether the file system is
|
|
* unmounted.
|
|
*/
|
|
std::optional<folly::SharedPromise<folly::Unit>> channelUnmountPromise;
|
|
};
|
|
|
|
folly::Synchronized<MountingUnmountingState> mountingUnmountingState_;
|
|
|
|
/**
|
|
* The current state of the mount point.
|
|
*/
|
|
std::atomic<State> state_{State::UNINITIALIZED};
|
|
|
|
/**
|
|
* uid and gid that we'll set as the owners in the stat information
|
|
* returned via initStatData().
|
|
*/
|
|
folly::Synchronized<Owner> owner_;
|
|
|
|
/**
|
|
* The number of tree prefetches in progress for this mount point.
|
|
*/
|
|
std::atomic<uint64_t> numPrefetchesInProgress_{0};
|
|
|
|
#ifdef _WIN32
|
|
/**
|
|
* This is the channel between ProjectedFS and rest of Eden.
|
|
*/
|
|
std::unique_ptr<PrjfsChannel> channel_;
|
|
#else
|
|
/**
|
|
* The associated fuse channel to the kernel.
|
|
*/
|
|
std::unique_ptr<FuseChannel, FuseChannelDeleter> channel_;
|
|
#endif // !_WIN32
|
|
|
|
/**
|
|
* The clock. This is also available as serverState_->getClock().
|
|
* We still keep it as a separate member variable for now so that getClock()
|
|
* can be inline without having to include ServerState.h in this file.
|
|
*/
|
|
std::shared_ptr<Clock> clock_;
|
|
};
|
|
|
|
/**
|
|
* RenameLock is a holder for an EdenMount's rename mutex.
|
|
*
|
|
* This is primarily useful so it can be forward declared easily,
|
|
* but it also provides a helper method to ensure that it is currently holding
|
|
* a lock on the desired mount.
|
|
*/
|
|
class RenameLock : public std::unique_lock<folly::SharedMutex> {
|
|
public:
|
|
RenameLock() {}
|
|
explicit RenameLock(EdenMount* mount)
|
|
: std::unique_lock<folly::SharedMutex>{mount->renameMutex_} {}
|
|
|
|
bool isHeld(EdenMount* mount) const {
|
|
return owns_lock() && (mutex() == &mount->renameMutex_);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* SharedRenameLock is a holder for an EdenMount's rename mutex in shared mode.
|
|
*/
|
|
class SharedRenameLock : public std::shared_lock<folly::SharedMutex> {
|
|
public:
|
|
explicit SharedRenameLock(EdenMount* mount)
|
|
: std::shared_lock<folly::SharedMutex>{mount->renameMutex_} {}
|
|
|
|
bool isHeld(EdenMount* mount) const {
|
|
return owns_lock() && (mutex() == &mount->renameMutex_);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* EdenMountDeleter acts as a deleter argument for std::shared_ptr or
|
|
* std::unique_ptr.
|
|
*/
|
|
class EdenMountDeleter {
|
|
public:
|
|
void operator()(EdenMount* mount) {
|
|
mount->destroy();
|
|
}
|
|
};
|
|
|
|
class EdenMountCancelled : public std::runtime_error {
|
|
public:
|
|
explicit EdenMountCancelled();
|
|
};
|
|
|
|
} // namespace eden
|
|
} // namespace facebook
|