mirror of
git://sourceware.org/git/lvm2.git
synced 2024-12-22 17:35:59 +03:00
170 lines
3.1 KiB
C
170 lines
3.1 KiB
C
/*
|
|
* Copyright (C) 2001 Sistina Software (UK) Limited.
|
|
*
|
|
* This file is released under the LGPL.
|
|
*
|
|
*/
|
|
|
|
#include "log.h"
|
|
#include "locking.h"
|
|
#include "locking_types.h"
|
|
#include "lvm-string.h"
|
|
#include "activate.h"
|
|
|
|
#include <signal.h>
|
|
|
|
static struct locking_type _locking;
|
|
static sigset_t _oldset;
|
|
|
|
static int _lock_count = 0; /* Number of locks held */
|
|
static int _signals_blocked = 0;
|
|
|
|
static void _block_signals(void)
|
|
{
|
|
sigset_t set;
|
|
|
|
if (_signals_blocked)
|
|
return;
|
|
|
|
if (sigfillset(&set)) {
|
|
log_sys_error("sigfillset", "_block_signals");
|
|
return;
|
|
}
|
|
|
|
if (sigprocmask(SIG_SETMASK, &set, &_oldset)) {
|
|
log_sys_error("sigprocmask", "_block_signals");
|
|
return;
|
|
}
|
|
|
|
_signals_blocked = 1;
|
|
|
|
return;
|
|
}
|
|
|
|
static void _unblock_signals(void)
|
|
{
|
|
/* Don't unblock signals while any locks are held */
|
|
if (!_signals_blocked || _lock_count)
|
|
return;
|
|
|
|
if (sigprocmask(SIG_SETMASK, &_oldset, NULL)) {
|
|
log_sys_error("sigprocmask", "_block_signals");
|
|
return;
|
|
}
|
|
|
|
_signals_blocked = 0;
|
|
|
|
return;
|
|
}
|
|
|
|
static inline void _update_lock_count(int flags)
|
|
{
|
|
if ((flags & LCK_TYPE_MASK) == LCK_NONE)
|
|
_lock_count--;
|
|
else
|
|
_lock_count++;
|
|
}
|
|
|
|
/*
|
|
* No locking - currently does nothing.
|
|
*/
|
|
int no_lock_resource(struct cmd_context *cmd, const char *resource, int flags)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
void no_fin_locking(void)
|
|
{
|
|
return;
|
|
}
|
|
|
|
static void _init_no_locking(struct locking_type *locking,
|
|
struct config_file *cf)
|
|
{
|
|
locking->lock_resource = no_lock_resource;
|
|
locking->fin_locking = no_fin_locking;
|
|
}
|
|
|
|
/*
|
|
* Select a locking type
|
|
*/
|
|
int init_locking(int type, struct config_file *cf)
|
|
{
|
|
switch (type) {
|
|
case 0:
|
|
_init_no_locking(&_locking, cf);
|
|
log_print("WARNING: Locking disabled. Be carefui! "
|
|
"This could corrupt your metadata.");
|
|
break;
|
|
case 1:
|
|
if (!init_file_locking(&_locking, cf))
|
|
return 0;
|
|
log_very_verbose("File-based locking enabled.");
|
|
break;
|
|
/******
|
|
case 2:
|
|
if (!init_other_locking(&_locking, cf))
|
|
return 0;
|
|
log_very_verbose("Other locking enabled.");
|
|
break;
|
|
******/
|
|
default:
|
|
log_error("Unknown locking type requested.");
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
void fin_locking(void)
|
|
{
|
|
_locking.fin_locking();
|
|
}
|
|
|
|
/*
|
|
* VG locking is by VG name.
|
|
* FIXME This should become VG uuid.
|
|
*/
|
|
int _lock_vol(struct cmd_context *cmd, const char *resource, int flags)
|
|
{
|
|
_block_signals();
|
|
|
|
if (!(_locking.lock_resource(cmd, resource, flags))) {
|
|
_unblock_signals();
|
|
return 0;
|
|
}
|
|
|
|
_update_lock_count(flags);
|
|
_unblock_signals();
|
|
|
|
return 1;
|
|
}
|
|
|
|
int lock_vol(struct cmd_context *cmd, const char *vol, int flags)
|
|
{
|
|
char resource[258];
|
|
|
|
switch (flags & LCK_SCOPE_MASK) {
|
|
case LCK_VG: /* Lock VG to change on-disk metadata. */
|
|
case LCK_LV: /* Suspends LV if it's active. */
|
|
strncpy(resource, (char *) vol, sizeof(resource));
|
|
break;
|
|
default:
|
|
log_error("Unrecognised lock scope: %d",
|
|
flags & LCK_SCOPE_MASK);
|
|
return 0;
|
|
}
|
|
|
|
if (!_lock_vol(cmd, resource, flags))
|
|
return 0;
|
|
|
|
/* Perform immediate unlock unless LCK_HOLD set */
|
|
if (!(flags & LCK_HOLD) && ((flags & LCK_TYPE_MASK) != LCK_NONE)) {
|
|
if (!_lock_vol(cmd, resource,
|
|
(flags & ~LCK_TYPE_MASK) | LCK_NONE))
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|