| /* |
| * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "lib.h" |
| #include "locking_types.h" |
| #include "defaults.h" |
| #include "sharedlib.h" |
| #include "toolcontext.h" |
| #include "activate.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 dm_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, const struct logical_volume *lv __attribute__((unused))) |
| { |
| if (!_lock_fn) |
| return 0; |
| |
| if (!strcmp(resource, VG_SYNC_NAMES)) { |
| /* Hide this lock request from external locking */ |
| fs_unlock(); |
| return 1; |
| } |
| |
| return _lock_fn(cmd, resource, flags); |
| } |
| |
| 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, |
| int suppress_messages) |
| { |
| const char *libname; |
| |
| if (_locking_lib) { |
| log_error_suppress(suppress_messages, "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; |
| |
| if (!(libname = find_config_tree_str(cmd, global_locking_library_CFG, NULL))) |
| return_0; |
| |
| 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_suppress(suppress_messages, "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_suppress(suppress_messages, "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); |
| } |