From bb922d577dd8dc484d25c29c7c85bf04ecd62256 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@duempel.org>
Date: Wed, 1 Oct 2014 23:57:28 +0200
Subject: storage/nfs: use the libnfs async API
Share the NFS connection with the NFS input plugin.
---
src/storage/plugins/NfsStorage.cxx | 277 ++++++++++++++++++++++++++++++-------
1 file changed, 228 insertions(+), 49 deletions(-)
(limited to 'src/storage')
diff --git a/src/storage/plugins/NfsStorage.cxx b/src/storage/plugins/NfsStorage.cxx
index e28e41a67..8ddb14250 100644
--- a/src/storage/plugins/NfsStorage.cxx
+++ b/src/storage/plugins/NfsStorage.cxx
@@ -23,31 +23,64 @@
#include "storage/StorageInterface.hxx"
#include "storage/FileInfo.hxx"
#include "storage/MemoryDirectoryReader.hxx"
+#include "lib/nfs/Blocking.hxx"
#include "lib/nfs/Domain.hxx"
#include "lib/nfs/Base.hxx"
+#include "lib/nfs/Lease.hxx"
+#include "lib/nfs/Connection.hxx"
+#include "lib/nfs/Glue.hxx"
#include "fs/AllocatedPath.hxx"
#include "util/Error.hxx"
#include "thread/Mutex.hxx"
+#include "thread/Cond.hxx"
+#include "event/Loop.hxx"
+#include "event/Call.hxx"
+#include "event/DeferredMonitor.hxx"
+#include "event/TimeoutMonitor.hxx"
extern "C" {
#include <nfsc/libnfs.h>
#include <nfsc/libnfs-raw-nfs.h>
}
+#include <string>
+
+#include <assert.h>
#include <sys/stat.h>
#include <fcntl.h>
-class NfsStorage final : public Storage {
+class NfsStorage final
+ : public Storage, NfsLease, DeferredMonitor, TimeoutMonitor {
+
+ enum class State {
+ INITIAL, CONNECTING, READY, DELAY,
+ };
+
const std::string base;
- nfs_context *const ctx;
+ const std::string server, export_name;
+
+ NfsConnection *connection;
+
+ Mutex mutex;
+ Cond cond;
+ State state;
+ Error last_error;
public:
- NfsStorage(const char *_base, nfs_context *_ctx)
- :base(_base), ctx(_ctx) {}
+ NfsStorage(EventLoop &_loop, const char *_base,
+ std::string &&_server, std::string &&_export_name)
+ :DeferredMonitor(_loop), TimeoutMonitor(_loop),
+ base(_base),
+ server(std::move(_server)),
+ export_name(std::move(_export_name)),
+ state(State::INITIAL) {
+ nfs_init();
+ }
- virtual ~NfsStorage() {
- nfs_destroy_context(ctx);
+ ~NfsStorage() {
+ BlockingCall(GetEventLoop(), [this](){ Disconnect(); });
+ nfs_finish();
}
/* virtual methods from class Storage */
@@ -60,6 +93,125 @@ public:
std::string MapUTF8(const char *uri_utf8) const override;
const char *MapToRelativeUTF8(const char *uri_utf8) const override;
+
+ /* virtual methods from NfsLease */
+ void OnNfsConnectionReady() final {
+ assert(state == State::CONNECTING);
+
+ SetState(State::READY);
+ }
+
+ void OnNfsConnectionFailed(gcc_unused const Error &error) final {
+ assert(state == State::CONNECTING);
+
+ SetState(State::DELAY, error);
+ TimeoutMonitor::ScheduleSeconds(60);
+ }
+
+ void OnNfsConnectionDisconnected(gcc_unused const Error &error) final {
+ assert(state == State::READY);
+
+ SetState(State::DELAY, error);
+ TimeoutMonitor::ScheduleSeconds(5);
+ }
+
+ /* virtual methods from DeferredMonitor */
+ void RunDeferred() final {
+ if (state == State::INITIAL)
+ Connect();
+ }
+
+ /* virtual methods from TimeoutMonitor */
+ void OnTimeout() final {
+ assert(state == State::DELAY);
+
+ Connect();
+ }
+
+private:
+ EventLoop &GetEventLoop() {
+ return DeferredMonitor::GetEventLoop();
+ }
+
+ void SetState(State _state) {
+ assert(GetEventLoop().IsInside());
+
+ const ScopeLock protect(mutex);
+ state = _state;
+ cond.broadcast();
+ }
+
+ void SetState(State _state, const Error &error) {
+ assert(GetEventLoop().IsInside());
+
+ const ScopeLock protect(mutex);
+ state = _state;
+ last_error.Set(error);
+ cond.broadcast();
+ }
+
+ void Connect() {
+ assert(state != State::READY);
+ assert(GetEventLoop().IsInside());
+
+ connection = &nfs_get_connection(server.c_str(),
+ export_name.c_str());
+ connection->AddLease(*this);
+
+ SetState(State::CONNECTING);
+ }
+
+ void EnsureConnected() {
+ if (state != State::READY)
+ Connect();
+ }
+
+ bool WaitConnected(Error &error) {
+ const ScopeLock protect(mutex);
+
+ while (true) {
+ switch (state) {
+ case State::INITIAL:
+ /* schedule connect */
+ mutex.unlock();
+ DeferredMonitor::Schedule();
+ mutex.lock();
+ break;
+
+ case State::CONNECTING:
+ case State::READY:
+ return true;
+
+ case State::DELAY:
+ assert(last_error.IsDefined());
+ error.Set(last_error);
+ return false;
+ }
+
+ cond.wait(mutex);
+ }
+ }
+
+ void Disconnect() {
+ assert(GetEventLoop().IsInside());
+
+ switch (state) {
+ case State::INITIAL:
+ DeferredMonitor::Cancel();
+ break;
+
+ case State::CONNECTING:
+ case State::READY:
+ connection->RemoveLease(*this);
+ SetState(State::INITIAL);
+ break;
+
+ case State::DELAY:
+ TimeoutMonitor::Cancel();
+ SetState(State::INITIAL);
+ break;
+ }
+ }
};
static std::string
@@ -107,19 +259,24 @@ Copy(FileInfo &info, const struct stat &st)
info.inode = st.st_ino;
}
-static bool
-GetInfo(nfs_context *ctx, const char *path, FileInfo &info, Error &error)
-{
- struct stat st;
- int result = nfs_stat(ctx, path, &st);
- if (result < 0) {
- error.SetErrno(-result, "nfs_stat() failed");
- return false;
+class NfsGetInfoOperation final : public BlockingNfsOperation {
+ const char *const path;
+ FileInfo &info;
+
+public:
+ NfsGetInfoOperation(NfsConnection &_connection, const char *_path,
+ FileInfo &_info)
+ :BlockingNfsOperation(_connection), path(_path), info(_info) {}
+
+protected:
+ bool Start(Error &_error) override {
+ return connection.Stat(path, *this, _error);
}
- Copy(info, st);
- return true;
-}
+ void HandleResult(gcc_unused unsigned status, void *data) override {
+ Copy(info, *(const struct stat *)data);
+ }
+};
bool
NfsStorage::GetInfo(const char *uri_utf8, gcc_unused bool follow,
@@ -129,7 +286,11 @@ NfsStorage::GetInfo(const char *uri_utf8, gcc_unused bool follow,
if (path.empty())
return false;
- return ::GetInfo(ctx, path.c_str(), info, error);
+ if (!WaitConnected(error))
+ return nullptr;
+
+ NfsGetInfoOperation operation(*connection, path.c_str(), info);
+ return operation.Run(error);
}
gcc_pure
@@ -164,24 +325,43 @@ Copy(FileInfo &info, const struct nfsdirent &ent)
info.inode = ent.inode;
}
-StorageDirectoryReader *
-NfsStorage::OpenDirectory(const char *uri_utf8, Error &error)
-{
- const std::string path = UriToNfsPath(uri_utf8, error);
- if (path.empty())
- return nullptr;
+class NfsListDirectoryOperation final : public BlockingNfsOperation {
+ const char *const path;
- nfsdir *dir;
- int result = nfs_opendir(ctx, path.c_str(), &dir);
- if (result < 0) {
- error.SetErrno(-result, "nfs_opendir() failed");
- return nullptr;
+ MemoryStorageDirectoryReader::List entries;
+
+public:
+ NfsListDirectoryOperation(NfsConnection &_connection,
+ const char *_path)
+ :BlockingNfsOperation(_connection), path(_path) {}
+
+ StorageDirectoryReader *ToReader() {
+ return new MemoryStorageDirectoryReader(std::move(entries));
}
- MemoryStorageDirectoryReader::List entries;
+protected:
+ bool Start(Error &_error) override {
+ return connection.OpenDirectory(path, *this, _error);
+ }
+
+ void HandleResult(gcc_unused unsigned status, void *data) override {
+ struct nfsdir *const dir = (struct nfsdir *)data;
+
+ CollectEntries(dir);
+ connection.CloseDirectory(dir);
+ }
+
+private:
+ void CollectEntries(struct nfsdir *dir);
+};
+
+inline void
+NfsListDirectoryOperation::CollectEntries(struct nfsdir *dir)
+{
+ assert(entries.empty());
const struct nfsdirent *ent;
- while ((ent = nfs_readdir(ctx, dir)) != nullptr) {
+ while ((ent = connection.ReadDirectory(dir)) != nullptr) {
const Path name_fs = Path::FromFS(ent->name);
if (SkipNameFS(name_fs.c_str()))
continue;
@@ -195,15 +375,27 @@ NfsStorage::OpenDirectory(const char *uri_utf8, Error &error)
entries.emplace_front(std::move(name_utf8));
Copy(entries.front().info, *ent);
}
+}
- nfs_closedir(ctx, dir);
+StorageDirectoryReader *
+NfsStorage::OpenDirectory(const char *uri_utf8, Error &error)
+{
+ const std::string path = UriToNfsPath(uri_utf8, error);
+ if (path.empty())
+ return nullptr;
- /* don't reverse the list - order does not matter */
- return new MemoryStorageDirectoryReader(std::move(entries));
+ if (!WaitConnected(error))
+ return nullptr;
+
+ NfsListDirectoryOperation operation(*connection, path.c_str());
+ if (!operation.Run(error))
+ return nullptr;
+
+ return operation.ToReader();
}
static Storage *
-CreateNfsStorageURI(gcc_unused EventLoop &event_loop, const char *base,
+CreateNfsStorageURI(EventLoop &event_loop, const char *base,
Error &error)
{
if (memcmp(base, "nfs://", 6) != 0)
@@ -219,22 +411,9 @@ CreateNfsStorageURI(gcc_unused EventLoop &event_loop, const char *base,
const std::string server(p, mount);
- nfs_context *ctx = nfs_init_context();
- if (ctx == nullptr) {
- error.Set(nfs_domain, "nfs_init_context() failed");
- return nullptr;
- }
-
- int result = nfs_mount(ctx, server.c_str(), mount);
- if (result < 0) {
- nfs_destroy_context(ctx);
- error.SetErrno(-result, "nfs_mount() failed");
- return nullptr;
- }
-
nfs_set_base(server.c_str(), mount);
- return new NfsStorage(base, ctx);
+ return new NfsStorage(event_loop, base, server.c_str(), mount);
}
const StoragePlugin nfs_storage_plugin = {
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