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/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2014 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/misc/lib.h"
#include "lib/locking/locking.h"
#include "locking_types.h"
#include "lib/config/config.h"
#include "lib/config/defaults.h"
#include "lib/misc/lvm-string.h"
#include "lib/misc/lvm-flock.h"
#include <limits.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <dirent.h>
static char _lock_dir[PATH_MAX];
static void _fin_file_locking(void)
{
release_flocks(1);
free_flocks();
}
static void _reset_file_locking(void)
{
release_flocks(0);
}
static int _file_lock_resource(struct cmd_context *cmd, const char *resource,
uint32_t flags, const struct logical_volume *lv)
{
char lockfile[PATH_MAX];
if (!strcmp(resource, VG_GLOBAL)) {
if (dm_snprintf(lockfile, sizeof(lockfile),
"%s/P_%s", _lock_dir, resource + 1) < 0) {
log_error("Too long locking filename %s/P_%s.", _lock_dir, resource + 1);
return 0;
}
} else {
if (dm_snprintf(lockfile, sizeof(lockfile), "%s/V_%s", _lock_dir, resource) < 0) {
log_error("Too long locking filename %s/V_%s.", _lock_dir, resource);
return 0;
}
}
if (!lock_file(lockfile, flags))
return_0;
return 1;
}
int init_file_locking(struct locking_type *locking, struct cmd_context *cmd,
int suppress_messages)
{
int r;
const char *locking_dir;
init_flock(cmd);
locking->lock_resource = _file_lock_resource;
locking->reset_locking = _reset_file_locking;
locking->fin_locking = _fin_file_locking;
locking->flags = LCK_FLOCK;
/* Get lockfile directory from config file */
locking_dir = find_config_tree_str(cmd, global_locking_dir_CFG, NULL);
if (!dm_strncpy(_lock_dir, locking_dir, sizeof(_lock_dir))) {
log_error("Path for locking_dir %s is invalid.", locking_dir);
return 0;
}
(void) dm_prepare_selinux_context(_lock_dir, S_IFDIR);
r = dm_create_dir(_lock_dir);
(void) dm_prepare_selinux_context(NULL, 0);
if (!r)
return 0;
/* Trap a read-only file system */
if ((access(_lock_dir, R_OK | W_OK | X_OK) == -1) && (errno == EROFS))
return 0;
return 1;
}
/*
* For each file in locking_dir with V_ and no aux,
* stat and save the file time.
*/
void file_lock_save_times(struct cmd_context *cmd)
{
char lockfile[PATH_MAX];
DIR *dir;
struct dirent *de;
char *aux;
if (!(dir = opendir(_lock_dir)))
return;
while ((de = readdir(dir))) {
if (de->d_name[0] != 'V')
continue;
if ((aux = strchr(de->d_name, ':'))) {
if (!strncmp(aux, ":aux", 4))
continue;
}
if (dm_snprintf(lockfile, sizeof(lockfile), "%s/%s", _lock_dir, de->d_name) < 0)
continue;
lock_file_time_init(lockfile);
}
closedir(dir);
}
/*
* Check if the file lock timestamp is unchanged from when it was saved by
* file_lock_save_times. Return true if unchanged. Return false if the
* timestamp is different, or if there's no info to know.
*/
bool file_lock_time_unchanged(struct cmd_context *cmd, const char *resource)
{
char lockfile[PATH_MAX];
/* shouldn't be used with this function */
if (!strcmp(resource, VG_GLOBAL))
return false;
if (dm_snprintf(lockfile, sizeof(lockfile), "%s/V_%s", _lock_dir, resource) < 0) {
log_error("Too long locking filename %s/V_%s.", _lock_dir, resource);
return false;
}
return lock_file_time_unchanged(lockfile);
}
void file_lock_remove_on_unlock(struct cmd_context *cmd, const char *resource)
{
char lockfile[PATH_MAX];
/* shouldn't be used with this function */
if (!strcmp(resource, VG_GLOBAL))
return;
if (dm_snprintf(lockfile, sizeof(lockfile), "%s/V_%s", _lock_dir, resource) < 0) {
log_error("Too long locking filename %s/V_%s.", _lock_dir, resource);
return;
}
lock_file_remove_on_unlock(lockfile);
}
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