static void virLockSpaceResourceFree(virLockSpaceResourcePtr res)
{
if (!res)
return;
if (res->lockHeld &&
(res->flags & VIR_LOCK_SPACE_ACQUIRE_AUTOCREATE)) {
if (res->flags & VIR_LOCK_SPACE_ACQUIRE_SHARED) {
/* We must upgrade to an exclusive lock to ensure
* no one else still has it before trying to delete */
if (virFileLock(res->fd, false, 0, 1) < 0) {
VIR_DEBUG("Could not upgrade shared lease to exclusive, not deleting");
} else {
if (unlink(res->path) < 0 &&
errno != ENOENT) {
char ebuf[1024];
VIR_WARN("Failed to unlink resource %s: %s",
res->path, virStrerror(errno, ebuf, sizeof(ebuf)));
}
}
} else {
if (unlink(res->path) < 0 &&
errno != ENOENT) {
char ebuf[1024];
VIR_WARN("Failed to unlink resource %s: %s",
res->path, virStrerror(errno, ebuf, sizeof(ebuf)));
}
}
}
VIR_FORCE_CLOSE(res->fd);
VIR_FREE(res->path);
VIR_FREE(res->name);
VIR_FREE(res);
}
static virLockSpaceResourcePtr
virLockSpaceResourceNew(virLockSpacePtr lockspace,
const char *resname,
unsigned int flags,
pid_t owner)
{
virLockSpaceResourcePtr res;
bool shared = !!(flags & VIR_LOCK_SPACE_ACQUIRE_SHARED);
if (VIR_ALLOC(res) < 0)
return NULL;
res->fd = -1;
res->flags = flags;
if (VIR_STRDUP(res->name, resname) < 0)
goto error;
if (!(res->path = virLockSpaceGetResourcePath(lockspace, resname)))
goto error;
if (flags & VIR_LOCK_SPACE_ACQUIRE_AUTOCREATE) {
while (1) {
struct stat a, b;
if ((res->fd = open(res->path, O_RDWR|O_CREAT, 0600)) < 0) {
virReportSystemError(errno,
_("Unable to open/create resource %s"),
res->path);
goto error;
}
if (virSetCloseExec(res->fd) < 0) {
virReportSystemError(errno,
_("Failed to set close-on-exec flag '%s'"),
res->path);
goto error;
}
if (fstat(res->fd, &b) < 0) {
virReportSystemError(errno,
_("Unable to check status of pid file '%s'"),
res->path);
goto error;
}
if (virFileLock(res->fd, shared, 0, 1, false) < 0) {
if (errno == EACCES || errno == EAGAIN) {
virReportError(VIR_ERR_RESOURCE_BUSY,
_("Lockspace resource '%s' is locked"),
resname);
} else {
virReportSystemError(errno,
_("Unable to acquire lock on '%s'"),
res->path);
}
goto error;
}
/* Now make sure the pidfile we locked is the same
* one that now exists on the filesystem
*/
if (stat(res->path, &a) < 0) {
char ebuf[1024] ATTRIBUTE_UNUSED;
VIR_DEBUG("Resource '%s' disappeared: %s",
res->path, virStrerror(errno, ebuf, sizeof(ebuf)));
VIR_FORCE_CLOSE(res->fd);
/* Someone else must be racing with us, so try again */
continue;
}
if (a.st_ino == b.st_ino)
break;
VIR_DEBUG("Resource '%s' was recreated", res->path);
VIR_FORCE_CLOSE(res->fd);
/* Someone else must be racing with us, so try again */
}
} else {
int virPidFileAcquirePath(const char *path,
pid_t pid)
{
int fd = -1;
char pidstr[INT_BUFSIZE_BOUND(pid)];
if (path[0] == '\0')
return 0;
while (1) {
struct stat a, b;
if ((fd = open(path, O_WRONLY|O_CREAT, 0644)) < 0) {
virReportSystemError(errno,
_("Failed to open pid file '%s'"),
path);
return -1;
}
if (virSetCloseExec(fd) < 0) {
virReportSystemError(errno,
_("Failed to set close-on-exec flag '%s'"),
path);
VIR_FORCE_CLOSE(fd);
return -1;
}
if (fstat(fd, &b) < 0) {
virReportSystemError(errno,
_("Unable to check status of pid file '%s'"),
path);
VIR_FORCE_CLOSE(fd);
return -1;
}
if (virFileLock(fd, false, 0, 1) < 0) {
virReportSystemError(errno,
_("Failed to acquire pid file '%s'"),
path);
VIR_FORCE_CLOSE(fd);
return -1;
}
/* Now make sure the pidfile we locked is the same
* one that now exists on the filesystem
*/
if (stat(path, &a) < 0) {
char ebuf[1024] ATTRIBUTE_UNUSED;
VIR_DEBUG("Pid file '%s' disappeared: %s",
path, virStrerror(errno, ebuf, sizeof(ebuf)));
VIR_FORCE_CLOSE(fd);
/* Someone else must be racing with us, so try agin */
continue;
}
if (a.st_ino == b.st_ino)
break;
VIR_DEBUG("Pid file '%s' was recreated", path);
VIR_FORCE_CLOSE(fd);
/* Someone else must be racing with us, so try agin */
}
