/* VM_IDENTIFY -- Identify the current process to the VM cache server when
* opening a new client connection.
*/
static void
vm_identify (void)
{
char buf[SZ_CMDBUF];
if (vm_write (vm_server, vm_client, strlen(vm_client)) < 0)
vm_shutdown();
if (read (vm_server, buf, SZ_CMDBUF) <= 0) {
if (vm_debug)
fprintf (stderr,
"vmclient (%s): server not responding\n", vm_client);
vm_shutdown();
}
}
/*
* Shutdown sequence. Opposite to boot().
*/
static
void
shutdown(void)
{
kprintf("Shutting down.\n");
vfs_clearbootfs();
vfs_clearcurdir();
vfs_unmountall();
#if OPT_A3
vmstats_print();
#endif
splhigh();
#if OPT_A3
vm_shutdown();
shutdownSwapOps();
#endif
scheduler_shutdown();
thread_shutdown();
}
/* VM_RESERVESPACE -- Reserve VM space for file data. This directive is
* useful if VM is being used but the VM space could not be preallocated
* at file access time, e.g., when opening a new file.
*/
int
vm_reservespace (long nbytes)
{
char buf[SZ_CMDBUF];
int status;
if (!vm_initialized)
vm_initialize();
if (!vm_enabled || vm_dioenabled)
return (-1);
if (vm_connect() < 0)
return (-1);
/* Format and send the file access directive to the VMcache daemon.
* The status from the server is returned as an ascii integer value
* on the same socket.
*/
sprintf (buf, "reservespace %ld\n", nbytes);
if (vm_debug)
fprintf (stderr, "vmclient (%s): %s", vm_client, buf);
if (vm_write (vm_server, buf, strlen(buf)) < 0) {
vm_shutdown();
return (-1);
}
if (read (vm_server, buf, SZ_CMDBUF) <= 0) {
if (vm_debug)
fprintf (stderr,
"vmclient (%s): server not responding\n", vm_client);
vm_shutdown();
return (-1);
}
status = atoi (buf);
return (status);
}
void vm_error(enum error_code err, char *fmt, ...)
{
char *myfmt = (char*)malloc(32 + strlen(fmt));
sprintf(myfmt, "Error: %s", fmt);
va_list args;
va_start(args, fmt);
vprintf(myfmt, args);
va_end(args);
switch(err) {
case VM_ERR_FATAL:
vm_shutdown(EXIT_FAILURE);
break;
}
}
/*
* Class: java/lang/Runtime
* Method: exitInternal
* Signature: (I)V
*/
JNIEXPORT void JNICALL Java_java_lang_Runtime_exitInternal(JNIEnv *env, jobject _this, jint status)
{
vm_shutdown(status);
}
void vm_shutdown_during_initialization(const char* error, const char* message) {
vm_notify_during_shutdown(error, message);
vm_shutdown();
}
/* VM_DELETE -- Delete any VM space used by a file, e.g., because the file
* is being physically deleted. This should be called before the file is
* actually deleted so that the cache can determine its device and inode
* values.
*/
int
vm_delete (char *fname, int force)
{
struct stat st;
char buf[SZ_COMMAND];
char pathname[SZ_PATHNAME];
int status = 0;
/* One-time process initialization. */
if (!vm_initialized)
vm_initialize();
if (stat (fname, &st) < 0) {
status = -1;
goto done;
}
/* If VMcache is not being used we are done. */
if (vm_dioenabled && (st.st_size >= dio_threshold))
goto done;
else if (!vm_enabled || st.st_size < vm_threshold)
goto done;
/* Don't delete the VM space used by the file if it has hard links
* and only a link is being deleted (force flag will override).
*/
if (st.st_nlink > 1 && !force)
goto done;
/* Connect to the VMcache server if not already connected. */
if (!vm_server)
if (vm_connect() < 0) {
status = -1;
goto done;
}
/* Format and send the delete directive to the VMcache daemon.
* The status from the server is returned as an ascii integer value
* on the same socket.
*/
sprintf (buf, "delete %s\n", realpath(fname,pathname));
if (vm_write (vm_server, buf, strlen(buf)) < 0) {
vm_shutdown();
status = -1;
goto done;
}
if (read (vm_server, buf, SZ_CMDBUF) <= 0) {
if (vm_debug)
fprintf (stderr,
"vmclient (%s): server not responding\n", vm_client);
vm_shutdown();
status = -1;
goto done;
}
status = atoi (buf);
done:
if (vm_debug)
fprintf (stderr, "vmclient (%s): delete `%s' -> %d\n",
vm_client, fname, status);
return (status < 0 ? -1 : status);
}
/* VM_ACCESS -- Access a file via the VM subsystem. A return value of 1
* indicates that the file is (or will be) "cached" in virtual memory, i.e.,
* that normal virtual memory file system (normal file i/o) should be used
* to access the file. A return value of 0 indicates that direct i/o should
* be used to access the file, bypassing the virtual memory file system.
*/
int
vm_access (char *fname, int mode)
{
struct stat st;
char *modestr = NULL, buf[SZ_COMMAND];
char pathname[SZ_PATHNAME];
int status;
/* One-time process initialization. */
if (!vm_initialized)
vm_initialize();
if (stat (fname, &st) < 0) {
status = DEF_ACCESSVAL;
goto done;
}
/* If directio is enabled and the file exceeds the directio threshold
* use directio to access the file (access=0). If vmcache is
* disabled use normal VM-based i/o to access the file (access=1).
* If VMcache is enabled we still only use it if the file size
* exceeds vm_threshold.
*/
if (vm_dioenabled) {
status = (st.st_size >= dio_threshold) ? 0 : 1;
goto done;
} else if (!vm_enabled || st.st_size < vm_threshold) {
status = DEF_ACCESSVAL;
goto done;
}
/* Use of VMcache is enabled and the file equals or exceeds the
* minimum size threshold. Initialization has already been performed.
* Open a VMcache daemon server connection if we don't already have
* one. If the server connection fails we are done, but we will try
* to open a connection again in the next file access.
*/
if (!vm_server)
if (vm_connect() < 0) {
status = DEF_ACCESSVAL;
goto done;
}
/* Compute the mode string for the server request. */
switch (mode) {
case READ_ONLY:
modestr = "ro";
break;
case NEW_FILE:
case READ_WRITE:
case APPEND:
modestr = "rw";
break;
}
/* Format and send the file access directive to the VMcache daemon.
* The status from the server is returned as an ascii integer value
* on the same socket.
*/
sprintf (buf, "access %s %s\n", realpath(fname,pathname), modestr);
if (vm_write (vm_server, buf, strlen(buf)) < 0) {
vm_shutdown();
status = DEF_ACCESSVAL;
goto done;
}
if (read (vm_server, buf, SZ_CMDBUF) <= 0) {
if (vm_debug)
fprintf (stderr,
"vmclient (%s): server not responding\n", vm_client);
vm_shutdown();
status = DEF_ACCESSVAL;
goto done;
}
status = atoi (buf);
done:
if (vm_debug)
fprintf (stderr, "vmclient (%s): access `%s' -> %d\n",
vm_client, fname, status);
return (status < 0 ? DEF_ACCESSVAL : status);
}
