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Diffstat (limited to 'src/erasure-code/ErasureCodePlugin.cc')
| -rw-r--r-- | src/erasure-code/ErasureCodePlugin.cc | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/src/erasure-code/ErasureCodePlugin.cc b/src/erasure-code/ErasureCodePlugin.cc new file mode 100644 index 000000000..f189b91fd --- /dev/null +++ b/src/erasure-code/ErasureCodePlugin.cc @@ -0,0 +1,197 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab +/* + * Ceph distributed storage system + * + * Copyright (C) 2013,2014 Cloudwatt <libre.licensing@cloudwatt.com> + * Copyright (C) 2014 Red Hat <contact@redhat.com> + * + * Author: Loic Dachary <loic@dachary.org> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + */ + +#include <errno.h> + +#include "ceph_ver.h" +#include "ErasureCodePlugin.h" +#include "common/errno.h" +#include "include/dlfcn_compat.h" +#include "include/str_list.h" +#include "include/ceph_assert.h" + +using namespace std; + +#define PLUGIN_PREFIX "libec_" +#define PLUGIN_SUFFIX SHARED_LIB_SUFFIX +#define PLUGIN_INIT_FUNCTION "__erasure_code_init" +#define PLUGIN_VERSION_FUNCTION "__erasure_code_version" + +namespace ceph { + +ErasureCodePluginRegistry ErasureCodePluginRegistry::singleton; + +ErasureCodePluginRegistry::ErasureCodePluginRegistry() = default; + +ErasureCodePluginRegistry::~ErasureCodePluginRegistry() +{ + if (disable_dlclose) + return; + + for (std::map<std::string,ErasureCodePlugin*>::iterator i = plugins.begin(); + i != plugins.end(); + ++i) { + void *library = i->second->library; + delete i->second; + dlclose(library); + } +} + +int ErasureCodePluginRegistry::remove(const std::string &name) +{ + ceph_assert(ceph_mutex_is_locked(lock)); + if (plugins.find(name) == plugins.end()) + return -ENOENT; + std::map<std::string,ErasureCodePlugin*>::iterator plugin = plugins.find(name); + void *library = plugin->second->library; + delete plugin->second; + dlclose(library); + plugins.erase(plugin); + return 0; +} + +int ErasureCodePluginRegistry::add(const std::string &name, + ErasureCodePlugin* plugin) +{ + ceph_assert(ceph_mutex_is_locked(lock)); + if (plugins.find(name) != plugins.end()) + return -EEXIST; + plugins[name] = plugin; + return 0; +} + +ErasureCodePlugin *ErasureCodePluginRegistry::get(const std::string &name) +{ + ceph_assert(ceph_mutex_is_locked(lock)); + if (plugins.find(name) != plugins.end()) + return plugins[name]; + else + return 0; +} + +int ErasureCodePluginRegistry::factory(const std::string &plugin_name, + const std::string &directory, + ErasureCodeProfile &profile, + ErasureCodeInterfaceRef *erasure_code, + ostream *ss) +{ + ErasureCodePlugin *plugin; + { + std::lock_guard l{lock}; + plugin = get(plugin_name); + if (plugin == 0) { + loading = true; + int r = load(plugin_name, directory, &plugin, ss); + loading = false; + if (r != 0) + return r; + } + } + + int r = plugin->factory(directory, profile, erasure_code, ss); + if (r) + return r; + if (profile != (*erasure_code)->get_profile()) { + *ss << __func__ << " profile " << profile << " != get_profile() " + << (*erasure_code)->get_profile() << std::endl; + return -EINVAL; + } + return 0; +} + +static const char *an_older_version() { + return "an older version"; +} + +int ErasureCodePluginRegistry::load(const std::string &plugin_name, + const std::string &directory, + ErasureCodePlugin **plugin, + ostream *ss) +{ + ceph_assert(ceph_mutex_is_locked(lock)); + std::string fname = directory + "/" PLUGIN_PREFIX + + plugin_name + PLUGIN_SUFFIX; + void *library = dlopen(fname.c_str(), RTLD_NOW); + if (!library) { + *ss << "load dlopen(" << fname << "): " << dlerror(); + return -EIO; + } + + const char * (*erasure_code_version)() = + (const char *(*)())dlsym(library, PLUGIN_VERSION_FUNCTION); + if (erasure_code_version == NULL) + erasure_code_version = an_older_version; + if (erasure_code_version() != string(CEPH_GIT_NICE_VER)) { + *ss << "expected plugin " << fname << " version " << CEPH_GIT_NICE_VER + << " but it claims to be " << erasure_code_version() << " instead"; + dlclose(library); + return -EXDEV; + } + + int (*erasure_code_init)(const char *, const char *) = + (int (*)(const char *, const char *))dlsym(library, PLUGIN_INIT_FUNCTION); + if (erasure_code_init) { + std::string name = plugin_name; + int r = erasure_code_init(name.c_str(), directory.c_str()); + if (r != 0) { + *ss << "erasure_code_init(" << plugin_name + << "," << directory + << "): " << cpp_strerror(r); + dlclose(library); + return r; + } + } else { + *ss << "load dlsym(" << fname + << ", " << PLUGIN_INIT_FUNCTION + << "): " << dlerror(); + dlclose(library); + return -ENOENT; + } + + *plugin = get(plugin_name); + if (*plugin == 0) { + *ss << "load " << PLUGIN_INIT_FUNCTION << "()" + << "did not register " << plugin_name; + dlclose(library); + return -EBADF; + } + + (*plugin)->library = library; + + *ss << __func__ << ": " << plugin_name << " "; + + return 0; +} + +int ErasureCodePluginRegistry::preload(const std::string &plugins, + const std::string &directory, + ostream *ss) +{ + std::lock_guard l{lock}; + list<string> plugins_list; + get_str_list(plugins, plugins_list); + for (list<string>::iterator i = plugins_list.begin(); + i != plugins_list.end(); + ++i) { + ErasureCodePlugin *plugin; + int r = load(*i, directory, &plugin, ss); + if (r) + return r; + } + return 0; +} +} |