171 lines
3.2 KiB
C
171 lines
3.2 KiB
C
|
|
#include "system.h"
|
|
|
|
#include <errno.h>
|
|
|
|
#include <rpm/rpmlog.h>
|
|
#include <rpm/rpmfileutil.h>
|
|
|
|
#include "lib/rpmlock.h"
|
|
|
|
#include "debug.h"
|
|
|
|
/* Internal interface */
|
|
|
|
struct rpmlock_s {
|
|
int fd;
|
|
int openmode;
|
|
char *path;
|
|
char *descr;
|
|
int fdrefs;
|
|
};
|
|
|
|
static rpmlock rpmlock_new(const char *lock_path, const char *descr)
|
|
{
|
|
rpmlock lock = (rpmlock) malloc(sizeof(*lock));
|
|
|
|
if (lock != NULL) {
|
|
mode_t oldmask = umask(022);
|
|
lock->fd = open(lock_path, O_RDWR|O_CREAT, 0644);
|
|
(void) umask(oldmask);
|
|
|
|
if (lock->fd == -1) {
|
|
if (errno == EACCES)
|
|
lock->fd = open(lock_path, O_RDONLY);
|
|
if (lock->fd == -1) {
|
|
free(lock);
|
|
lock = NULL;
|
|
} else {
|
|
lock->openmode = RPMLOCK_READ;
|
|
}
|
|
} else {
|
|
lock->openmode = RPMLOCK_WRITE | RPMLOCK_READ;
|
|
}
|
|
if (lock) {
|
|
lock->path = xstrdup(lock_path);
|
|
lock->descr = xstrdup(descr);
|
|
lock->fdrefs = 1;
|
|
}
|
|
}
|
|
return lock;
|
|
}
|
|
|
|
static void rpmlock_free(rpmlock lock)
|
|
{
|
|
if (--lock->fdrefs == 0) {
|
|
free(lock->path);
|
|
free(lock->descr);
|
|
(void) close(lock->fd);
|
|
free(lock);
|
|
}
|
|
}
|
|
|
|
static int rpmlock_acquire(rpmlock lock, int mode)
|
|
{
|
|
int res = 0;
|
|
|
|
if (!(mode & lock->openmode))
|
|
return res;
|
|
|
|
if (lock->fdrefs > 1) {
|
|
res = 1;
|
|
} else {
|
|
struct flock info;
|
|
int cmd;
|
|
if (mode & RPMLOCK_WAIT)
|
|
cmd = F_SETLKW;
|
|
else
|
|
cmd = F_SETLK;
|
|
if (mode & RPMLOCK_READ)
|
|
info.l_type = F_RDLCK;
|
|
else
|
|
info.l_type = F_WRLCK;
|
|
info.l_whence = SEEK_SET;
|
|
info.l_start = 0;
|
|
info.l_len = 0;
|
|
info.l_pid = 0;
|
|
if (fcntl(lock->fd, cmd, &info) != -1)
|
|
res = 1;
|
|
}
|
|
|
|
lock->fdrefs += res;
|
|
|
|
return res;
|
|
}
|
|
|
|
static void rpmlock_release(rpmlock lock)
|
|
{
|
|
/* if not locked then we must not release */
|
|
if (lock->fdrefs <= 1)
|
|
return;
|
|
|
|
if (--lock->fdrefs == 1) {
|
|
struct flock info;
|
|
info.l_type = F_UNLCK;
|
|
info.l_whence = SEEK_SET;
|
|
info.l_start = 0;
|
|
info.l_len = 0;
|
|
info.l_pid = 0;
|
|
(void) fcntl(lock->fd, F_SETLK, &info);
|
|
}
|
|
}
|
|
|
|
|
|
/* External interface */
|
|
rpmlock rpmlockNew(const char *lock_path, const char *descr)
|
|
{
|
|
rpmlock lock = rpmlock_new(lock_path, descr);
|
|
if (!lock) {
|
|
rpmlog(RPMLOG_ERR, _("can't create %s lock on %s (%s)\n"),
|
|
descr, lock_path, strerror(errno));
|
|
}
|
|
return lock;
|
|
}
|
|
|
|
int rpmlockAcquire(rpmlock lock)
|
|
{
|
|
int locked = 0; /* assume failure */
|
|
int myerrno = errno;
|
|
int maywait = isatty(STDIN_FILENO); /* dont wait within scriptlets */
|
|
errno = myerrno;
|
|
|
|
if (lock) {
|
|
locked = rpmlock_acquire(lock, RPMLOCK_WRITE);
|
|
if (!locked && (lock->openmode & RPMLOCK_WRITE) && maywait) {
|
|
rpmlog(RPMLOG_WARNING, _("waiting for %s lock on %s\n"),
|
|
lock->descr, lock->path);
|
|
locked = rpmlock_acquire(lock, (RPMLOCK_WRITE|RPMLOCK_WAIT));
|
|
}
|
|
if (!locked) {
|
|
rpmlog(RPMLOG_ERR, _("can't create %s lock on %s (%s)\n"),
|
|
lock->descr, lock->path, strerror(errno));
|
|
}
|
|
}
|
|
return locked;
|
|
}
|
|
|
|
void rpmlockRelease(rpmlock lock)
|
|
{
|
|
if (lock)
|
|
rpmlock_release(lock);
|
|
}
|
|
|
|
rpmlock rpmlockNewAcquire(const char *lock_path, const char *descr)
|
|
{
|
|
rpmlock lock = rpmlockNew(lock_path, descr);
|
|
if (!rpmlockAcquire(lock))
|
|
lock = rpmlockFree(lock);
|
|
return lock;
|
|
}
|
|
|
|
rpmlock rpmlockFree(rpmlock lock)
|
|
{
|
|
if (lock) {
|
|
rpmlock_release(lock);
|
|
rpmlock_free(lock);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
|