iarv/znc
1
0
Fork 0
mirror of https://github.com/znc/znc.git synced 2026-05-04 04:22:37 +02:00
Code Issues Packages Projects Releases Wiki Activity

Improve lock file error handling

Browse Source 
When we have an error during rehashing / config writing, we continue keeping the
old lock around since we haven't gotten rid of that one yet.

Signed-off-by: Uli Schlachter <psychon@znc.in>
This commit is contained in:
Uli Schlachter
2011-03-31 19:07:36 +02:00
parent 7f3e55e72f
commit a4d388b56d
2 changed files with 50 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

84
znc.cpp
View File

@@ -35,6 +35,7 @@ CZNC::CZNC() {
m_eConfigState = ECONFIG_NOTHING;
m_TimeStarted = time(NULL);
m_sConnectThrottle.SetTTL(30000);
m_pLockFile = NULL;
}
CZNC::~CZNC() {
@@ -405,28 +406,28 @@ bool CZNC::WriteConfig() {
return false;
}
// Close the old handle to the config file, we are replacing that file.
m_LockFile.Close();
// We first write to a temporary file and then move it to the right place
m_LockFile.SetFileName(GetConfigFile() + "~");
CFile *pFile = new CFile(GetConfigFile() + "~");
if (!m_LockFile.Open(O_WRONLY | O_CREAT | O_TRUNC, 0600)) {
if (!pFile->Open(O_WRONLY | O_CREAT | O_TRUNC, 0600)) {
delete pFile;
return false;
}
// We have to "transfer" our lock on the config to the new file.
// The old file (= inode) is going away and thus a lock on it would be
// useless. These lock should always succeed (races, anyone?).
if (!m_LockFile.TryExLock()) {
if (!pFile->TryExLock()) {
pFile->Delete();
delete pFile;
return false;
}
m_LockFile.Write(MakeConfigHeader() + "\n");
pFile->Write(MakeConfigHeader() + "\n");
m_LockFile.Write("AnonIPLimit = " + CString(m_uiAnonIPLimit) + "\n");
m_LockFile.Write("MaxBufferSize= " + CString(m_uiMaxBufferSize) + "\n");
m_LockFile.Write("SSLCertFile = " + CString(m_sSSLCertFile) + "\n");
pFile->Write("AnonIPLimit = " + CString(m_uiAnonIPLimit) + "\n");
pFile->Write("MaxBufferSize= " + CString(m_uiMaxBufferSize) + "\n");
pFile->Write("SSLCertFile = " + CString(m_sSSLCertFile) + "\n");
for (size_t l = 0; l < m_vpListeners.size(); l++) {
CListener* pListener = m_vpListeners[l];
@@ -455,31 +456,31 @@ bool CZNC::WriteConfig() {
break;
}
m_LockFile.Write("Listener" + s6 + " = " + sAcceptProtocol + sHostPortion +
pFile->Write("Listener" + s6 + " = " + sAcceptProtocol + sHostPortion +
CString((pListener->IsSSL()) ? "+" : "") + CString(pListener->GetPort()) + "\n");
}
m_LockFile.Write("ConnectDelay = " + CString(m_uiConnectDelay) + "\n");
m_LockFile.Write("ServerThrottle = " + CString(m_sConnectThrottle.GetTTL()/1000) + "\n");
pFile->Write("ConnectDelay = " + CString(m_uiConnectDelay) + "\n");
pFile->Write("ServerThrottle = " + CString(m_sConnectThrottle.GetTTL()/1000) + "\n");
if (!m_sPidFile.empty()) {
m_LockFile.Write("PidFile = " + m_sPidFile.FirstLine() + "\n");
pFile->Write("PidFile = " + m_sPidFile.FirstLine() + "\n");
}
if (!m_sSkinName.empty()) {
m_LockFile.Write("Skin = " + m_sSkinName.FirstLine() + "\n");
pFile->Write("Skin = " + m_sSkinName.FirstLine() + "\n");
}
if (!m_sStatusPrefix.empty()) {
m_LockFile.Write("StatusPrefix = " + m_sStatusPrefix.FirstLine() + "\n");
pFile->Write("StatusPrefix = " + m_sStatusPrefix.FirstLine() + "\n");
}
for (unsigned int m = 0; m < m_vsMotd.size(); m++) {
m_LockFile.Write("Motd = " + m_vsMotd[m].FirstLine() + "\n");
pFile->Write("Motd = " + m_vsMotd[m].FirstLine() + "\n");
}
for (unsigned int v = 0; v < m_vsBindHosts.size(); v++) {
m_LockFile.Write("BindHost = " + m_vsBindHosts[v].FirstLine() + "\n");
pFile->Write("BindHost = " + m_vsBindHosts[v].FirstLine() + "\n");
}
CGlobalModules& Mods = GetModules();
@@ -492,7 +493,7 @@ bool CZNC::WriteConfig() {
sArgs = " " + sArgs.FirstLine();
}
m_LockFile.Write("LoadModule = " + sName.FirstLine() + sArgs + "\n");
pFile->Write("LoadModule = " + sName.FirstLine() + sArgs + "\n");
}
for (map<CString,CUser*>::iterator it = m_msUsers.begin(); it != m_msUsers.end(); ++it) {
@@ -503,27 +504,37 @@ bool CZNC::WriteConfig() {
continue;
}
m_LockFile.Write("\n");
pFile->Write("\n");
if (!it->second->WriteConfig(m_LockFile)) {
if (!it->second->WriteConfig(*pFile)) {
DEBUG("** Error writing config for user [" << it->first << "]");
}
}
// If Sync() fails... well, let's hope nothing important breaks..
m_LockFile.Sync();
pFile->Sync();
if (m_LockFile.HadError()) {
if (pFile->HadError()) {
DEBUG("Error while writing the config, errno says: " + CString(strerror(errno)));
pFile->Delete();
delete pFile;
return false;
}
// We wrote to a temporary name, move it to the right place
if (!m_LockFile.Move(GetConfigFile(), true))
if (!pFile->Move(GetConfigFile(), true)) {
DEBUG("Error while replacing the config file with a new version");
pFile->Delete();
delete pFile;
return false;
}
// Everything went fine, just need to update the saved path.
m_LockFile.SetFileName(GetConfigFile());
pFile->SetFileName(GetConfigFile());
// Make sure the lock is kept alive as long as we need it.
delete m_pLockFile;
m_pLockFile = pFile;
return true;
}
@@ -816,11 +827,11 @@ bool CZNC::WriteNewConfig(const CString& sConfigFile) {
bFileOK = true;
if (CFile::Exists(m_sConfigFile)) {
if (!m_LockFile.TryExLock(m_sConfigFile)) {
if (!File.TryExLock(m_sConfigFile)) {
CUtils::PrintStatus(false, "ZNC is currently running on this config.");
bFileOK = false;
} else {
m_LockFile.Close();
File.Close();
CUtils::PrintStatus(false, "This config already exists.");
if (CUtils::GetBoolInput("Would you like to overwrite it?", false))
CUtils::PrintAction("Overwriting config [" + m_sConfigFile + "]");
@@ -894,7 +905,7 @@ bool CZNC::WriteNewConfig(const CString& sConfigFile) {
CUtils::PrintMessage(sProtocol + "://<znc_server_ip>:" + CString(uListenPort) + "/", true);
CUtils::PrintMessage("");
m_LockFile.UnLock();
File.UnLock();
return bFileOpen && CUtils::GetBoolInput("Launch ZNC now?", true);
}
@@ -973,25 +984,28 @@ bool CZNC::DoRehash(CString& sError)
return false;
}
// (re)open the config file
if (m_LockFile.IsOpen())
m_LockFile.Close();
CFile *pFile = new CFile(m_sConfigFile);
// need to open the config file Read/Write for fcntl()
// exclusive locking to work properly!
if (!m_LockFile.Open(m_sConfigFile, O_RDWR)) {
if (!pFile->Open(m_sConfigFile, O_RDWR)) {
sError = "Can not open config file";
CUtils::PrintStatus(false, sError);
delete pFile;
return false;
}
if (!m_LockFile.TryExLock()) {
if (!pFile->TryExLock()) {
sError = "ZNC is already running on this config.";
CUtils::PrintStatus(false, sError);
delete pFile;
return false;
}
CFile &File = m_LockFile;
// (re)open the config file
delete m_pLockFile;
m_pLockFile = pFile;
CFile &File = *pFile;
// This fd is re-used for rehashing, so we must seek back to the beginning!
if (!File.Seek(0)) {
@@ -1991,5 +2005,5 @@ void CZNC::LeakConnectUser(CConnectUserTimer *pTimer) {
}
bool CZNC::WaitForChildLock() {
return m_LockFile.ExLock();
return m_pLockFile && m_pLockFile->ExLock();
}