/* $NetBSD: external_locking.c,v 1.1.1.2 2009/12/02 00:26:24 haad Exp $ */ /* * Copyright (C) 2002-2004 Sistina Software, Inc. All rights reserved. * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. * * This file is part of LVM2. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions * of the GNU Lesser General Public License v.2.1. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "lib.h" #include "locking_types.h" #include "defaults.h" #include "sharedlib.h" #include "toolcontext.h" static void *_locking_lib = NULL; static void (*_reset_fn) (void) = NULL; static void (*_end_fn) (void) = NULL; static int (*_lock_fn) (struct cmd_context * cmd, const char *resource, uint32_t flags) = NULL; static int (*_init_fn) (int type, struct config_tree * cft, uint32_t *flags) = NULL; static int (*_lock_query_fn) (const char *resource, int *mode) = NULL; static int _lock_resource(struct cmd_context *cmd, const char *resource, uint32_t flags) { if (_lock_fn) return _lock_fn(cmd, resource, flags); else return 0; } static void _fin_external_locking(void) { if (_end_fn) _end_fn(); dlclose(_locking_lib); _locking_lib = NULL; _init_fn = NULL; _end_fn = NULL; _lock_fn = NULL; _reset_fn = NULL; } static void _reset_external_locking(void) { if (_reset_fn) _reset_fn(); } int init_external_locking(struct locking_type *locking, struct cmd_context *cmd) { const char *libname; if (_locking_lib) { log_error("External locking already initialised"); return 1; } locking->lock_resource = _lock_resource; locking->fin_locking = _fin_external_locking; locking->reset_locking = _reset_external_locking; locking->flags = 0; libname = find_config_tree_str(cmd, "global/locking_library", DEFAULT_LOCKING_LIB); if (!(_locking_lib = load_shared_library(cmd, libname, "locking", 1))) return_0; /* Get the functions we need */ if (!(_init_fn = dlsym(_locking_lib, "locking_init")) || !(_lock_fn = dlsym(_locking_lib, "lock_resource")) || !(_reset_fn = dlsym(_locking_lib, "reset_locking")) || !(_end_fn = dlsym(_locking_lib, "locking_end"))) { log_error("Shared library %s does not contain locking " "functions", libname); dlclose(_locking_lib); _locking_lib = NULL; return 0; } if (!(_lock_query_fn = dlsym(_locking_lib, "query_resource"))) log_warn("WARNING: %s: _query_resource() missing: " "Using inferior activation method.", libname); log_verbose("Loaded external locking library %s", libname); return _init_fn(2, cmd->cft, &locking->flags); } |