Commit 12db770f authored by Jonathan Marten's avatar Jonathan Marten
Browse files

nfs (v3): Allow listing of virtual directories even if they cannot be mounted

When attempting to mount the server's exported filesystems in
NFSProtocolV3::openConnection(), record the export path even if the
mount failed.  This allows them to be listed as virtual directories,
even though any other access needs a file handle.

Detect that situation in NFSProtocol::getFileHandle() and return an error.

Detect and warn about a mount which may have failed due to reserved port

Correct the virtual directory path prefix check in NFSProtocolV3::listDir().
parent 861072cd
......@@ -558,17 +558,36 @@ NFSFileHandle NFSProtocol::getFileHandle(const QString& path)
return NFSFileHandle();
if (m_exportedDirs.contains(path))
// All exported directories should have already been stored in
// m_handleCache by the protocol's openConnection(). If any
// exported directory could not be mounted, then it will be in
// m_exportedDirs but not in m_handleCache. There is nothing more
// that can be done in this case.
// TODO: This situation should really be propagated up to the
// caller as KIO::ERR_CANNOT_MOUNT.
if (!m_handleCache.contains(path)) {
return NFSFileHandle();
if (!isValidPath(path)) {
qCDebug(LOG_KIO_NFS) << path << "is not a valid path";
return NFSFileHandle();
// In theory the root ("/") is a valid path but matches here.
// However, it should never be seen unless the NFS server is
// exporting its entire filesystem (which is very unlikely).
if (path.endsWith('/')) {
qCWarning(LOG_KIO_NFS) << "Passed a path ending with '/'. Fix the caller.";
// The handle may already be in the cache, check it now.
// The exported dirs are always in the cache.
// The exported dirs are always in the cache, unless there was a
// problem mounting them which will have been checked above.
if (m_handleCache.contains(path)) {
return m_handleCache[path];
......@@ -592,6 +611,8 @@ void NFSProtocol::removeFileHandle(const QString& path)
// TODO: this seems to be very similar to isExportedDir() above
bool NFSProtocol::isValidPath(const QString& path)
if (path.isEmpty() || path == QDir::separator()) {
......@@ -248,7 +248,7 @@ void NFSProtocolV3::openConnection()
int exportsCount = 0;
QStringList failList;
bool mountHint = false;
mountres3 fhStatus;
for (; exportlist != nullptr; exportlist = exportlist->ex_next, exportsCount++) {
......@@ -258,30 +258,51 @@ void NFSProtocolV3::openConnection()
(xdrproc_t) xdr_mountres3, reinterpret_cast<caddr_t>(&fhStatus),
if (fhStatus.fhs_status == 0) {
QString fname = QFileInfo(QDir("/"), exportlist->ex_dir).filePath();
QString fname = QFileInfo(QDir::root(), exportlist->ex_dir).filePath();
if (fhStatus.fhs_status == 0) { // mount succeeded
// Check if the dir is already exported
if (NFSProtocol::isExportedDir(fname)) {
// Check if the directory is already noted as exported,
// if so there is no need to add it again.
if (NFSProtocol::isExportedDir(fname)) continue;
// Save the exported directory and its NFS file handle.
addFileHandle(fname, static_cast<NFSFileHandle>(fhStatus.mountres3_u.mountinfo.fhandle));
} else {
if (failList.size() > 0) {
m_slave->error(KIO::ERR_CANNOT_MOUNT, i18n("Failed to mount %1", failList.join(", ")));
// All exports failed to mount, fail
if (failList.size() == exportsCount) {
} else { // mount failed with error
qCDebug(LOG_KIO_NFS) << "Cannot mount" << fname << "- status" << fhStatus.fhs_status;
// Even if the mount failed, record the directory path as exported
// so that it can be listed as a virtual directory. However, do
// not record its (invalid) file handle in the cache. Trying to
// access the directory in any way other than just listing it, or
// accessing anything below it, will be detected in
// NFSProtocol::getFileHandle() and fail with an appropriate
// error.
if (!NFSProtocol::isExportedDir(fname)) addExportedDir(fname);
// Many modern NFS servers by default reject any access attempted to
// them from a non-reserved source port (i.e. above 1024). Since
// this KIO slave runs as a normal user, it is not able to use the
// reserved port numbers and hence the access will be rejected. Show
// a hint if this could possibly be the problem - only once, as the
// server may have many exported directories.
if (fhStatus.fhs_status == MNT3ERR_ACCES) {
if (!mountHint) {
qCDebug(LOG_KIO_NFS) << "Check that the NFS server is exporting the filesystem";
qCDebug(LOG_KIO_NFS) << "with appropriate access permissions. Note that it must";
qCDebug(LOG_KIO_NFS) << "allow mount requests originating from an unprivileged";
qCDebug(LOG_KIO_NFS) << "source port (see exports(5), the 'insecure' option may";
qCDebug(LOG_KIO_NFS) << "be required).";
mountHint = true;
// If nothing can be mounted then there is no point trying to open the
// NFS server connection here. However, call openConnection() anyway
// and pretend that we are connected so that listing virtual directories
// will work.
if ((connErr = NFSProtocol::openConnection(m_currentHost, NFSPROG, NFSVERS, m_nfsClient, m_nfsSock)) != 0) {
m_slave->error(connErr, m_currentHost);
......@@ -296,6 +317,8 @@ void NFSProtocolV3::listDir(const QUrl& url)
qCDebug(LOG_KIO_NFS) << url;
// TODO: this only needs be checked if not listing a virtual directory,
// so it can be moved down to after the 'if (isExportedDir(path))' test.
// We should always be connected if it reaches this point,
// but better safe than sorry!
if (!isConnected()) {
......@@ -312,20 +335,29 @@ void NFSProtocolV3::listDir(const QUrl& url)
if (isExportedDir(path)) {
qCDebug(LOG_KIO_NFS) << "Listing virtual dir" << path;
QString dirPrefix = path;
if (dirPrefix!="/") dirPrefix += QDir::separator();
QStringList virtualList;
for (QStringList::const_iterator it = getExportedDirs().constBegin(); it != getExportedDirs().constEnd(); ++it) {
// When an export is multiple levels deep(/mnt/nfs for example) we only
// want to display one level at a time.
QString name = (*it);
name = name.remove(0, path.length());
if (name.startsWith(QDir::separator())) {
name = name.mid(1);
if (name.indexOf(QDir::separator()) != -1) {
const QStringList exportedDirs = getExportedDirs();
for (QStringList::const_iterator it = exportedDirs.constBegin(); it != exportedDirs.constEnd(); ++it) {
// When an export is multiple levels deep (for example "/export/nfs/dir"
// where "/export" is being listed), we only want to display one level
// ("nfs") at a time. Find all of the exported directories that are
// below the 'dirPrefix', and list the first (or only) path component
// of each.
QString name = (*it); // this exported directory
if (!name.startsWith(dirPrefix)) continue; // not below this prefix
name = name.mid(dirPrefix.length()); // remainder after the prefix
const int idx = name.indexOf(QDir::separator());
if (idx!=-1) name = name.left(idx); // take first path component
if (!virtualList.contains(name)) {
qCDebug(LOG_KIO_NFS) << "Found exported" << name;
......@@ -336,8 +368,6 @@ void NFSProtocolV3::listDir(const QUrl& url)
for (QStringList::const_iterator it = virtualList.constBegin(); it != virtualList.constEnd(); ++it) {
qCDebug(LOG_KIO_NFS) << "Found " << (*it) << "in exported dir";
entry.replace(KIO::UDSEntry::UDS_NAME, (*it));
......@@ -493,6 +523,9 @@ void NFSProtocolV3::listDir(const QUrl& url)
void NFSProtocolV3::listDirCompat(const QUrl& url)
// TODO: the next two checks will have already been
// done in listDir().
// We should always be connected if it reaches this point,
// but better safe than sorry!
if (!isConnected()) {
......@@ -504,6 +537,11 @@ void NFSProtocolV3::listDirCompat(const QUrl& url)
const QString path(url.path());
// TODO: can never get here, if an exported dir it will have been
// checked in listDir() and there will have been no attempt to
// access the NFS server.
// Is it part of an exported (virtual) dir?
if (NFSProtocol::isExportedDir(path)) {
QStringList virtualList;
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