int fd[2]; /* Stdin/stdout of qemu. */
int sock; /* Daemon communications socket. */
- int pid; /* Qemu PID. */
+ pid_t pid; /* Qemu PID. */
+ pid_t recoverypid; /* Recovery process PID. */
time_t start_t; /* The time when we started qemu. */
int stdout_watch; /* Watches qemu stdout for log messages. */
/* Want to give userspace some room, so: */
memsize += 128;
-#if AC_SIZEOF_LONG == 8
+#if SIZEOF_LONG == 8
/* On 64 bit, assume some overhead. */
- memsize += 32;
+ memsize += 64;
#endif
} else
memsize = 512;
/* Parent (library). */
g->pid = r;
+ /* Fork the recovery process off which will kill qemu if the parent
+ * process fails to do so (eg. if the parent segfaults).
+ */
+ r = fork ();
+ if (r == 0) {
+ pid_t qemu_pid = g->pid;
+ pid_t parent_pid = getppid ();
+
+ /* Writing to argv is hideously complicated and error prone. See:
+ * http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/ps_status.c?rev=1.33.2.1;content-type=text%2Fplain
+ */
+
+ /* Loop around waiting for one or both of the other processes to
+ * disappear. It's fair to say this is very hairy. The PIDs that
+ * we are looking at might be reused by another process. We are
+ * effectively polling. Is the cure worse than the disease?
+ */
+ for (;;) {
+ if (kill (qemu_pid, 0) == -1) /* qemu's gone away, we aren't needed */
+ _exit (0);
+ if (kill (parent_pid, 0) == -1) {
+ /* Parent's gone away, qemu still around, so kill qemu. */
+ kill (qemu_pid, 9);
+ _exit (0);
+ }
+ sleep (2);
+ }
+ }
+
+ /* Don't worry, if the fork failed, this will be -1. The recovery
+ * process isn't essential.
+ */
+ g->recoverypid = r;
+
/* Start the clock ... */
time (&g->start_t);
close (wfd[1]);
close (rfd[0]);
kill (g->pid, 9);
+ if (g->recoverypid > 0) kill (g->recoverypid, 9);
waitpid (g->pid, NULL, 0);
+ if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0);
g->fd[0] = -1;
g->fd[1] = -1;
g->sock = -1;
g->pid = 0;
+ g->recoverypid = 0;
g->start_t = 0;
g->stdout_watch = -1;
g->sock_watch = -1;
fprintf (stderr, "sending SIGTERM to process %d\n", g->pid);
kill (g->pid, SIGTERM);
+ if (g->recoverypid > 0) kill (g->recoverypid, 9);
return 0;
}
if (g->verbose)
fprintf (stderr, "stdout_event: %p: child process died\n", g);
/*kill (g->pid, SIGTERM);*/
+ if (g->recoverypid > 0) kill (g->recoverypid, 9);
waitpid (g->pid, NULL, 0);
+ if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0);
if (g->stdout_watch >= 0)
g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch);
if (g->sock_watch >= 0)
g->fd[1] = -1;
g->sock = -1;
g->pid = 0;
+ g->recoverypid = 0;
g->start_t = 0;
g->stdout_watch = -1;
g->sock_watch = -1;
if (g->msg_in_size-4 < len) return; /* Need more of this message. */
/* Got the full message, begin processing it. */
+#if 0
if (g->verbose) {
int i, j;
printf ("|\n");
}
}
+#endif
/* Not in the expected state. */
if (g->state != BUSY)
/* Push the message up to the higher layer. */
if (g->reply_cb)
g->reply_cb (g, g->reply_cb_data, &xdr);
+ else
+ /* This message (probably) should never be printed. */
+ fprintf (stderr, "libguesfs: sock_read_event: !!! dropped message !!!\n");
g->msg_in_size -= len + 4;
memmove (g->msg_in, g->msg_in+len+4, g->msg_in_size);
guestfs__send_sync (guestfs_h *g, int proc_nr,
xdrproc_t xdrp, char *args)
{
- char buffer[GUESTFS_MESSAGE_MAX];
struct guestfs_message_header hdr;
XDR xdr;
unsigned len;
return -1;
}
+ /* This is probably an internal error. Or perhaps we should just
+ * free the buffer anyway?
+ */
+ if (g->msg_out != NULL) {
+ error (g, "guestfs__send_sync: msg_out should be NULL");
+ return -1;
+ }
+
+ /* We have to allocate this message buffer on the heap because
+ * it is quite large (although will be mostly unused). We
+ * can't allocate it on the stack because in some environments
+ * we have quite limited stack space available, notably when
+ * running in the JVM.
+ */
+ g->msg_out = safe_malloc (g, GUESTFS_MESSAGE_MAX + 4);
+ xdrmem_create (&xdr, g->msg_out + 4, GUESTFS_MESSAGE_MAX, XDR_ENCODE);
+
/* Serialize the header. */
hdr.prog = GUESTFS_PROGRAM;
hdr.vers = GUESTFS_PROTOCOL_VERSION;
hdr.serial = serial;
hdr.status = GUESTFS_STATUS_OK;
- xdrmem_create (&xdr, buffer, sizeof buffer, XDR_ENCODE);
if (!xdr_guestfs_message_header (&xdr, &hdr)) {
error (g, "xdr_guestfs_message_header failed");
- return -1;
+ goto cleanup1;
}
/* Serialize the args. If any, because some message types
if (xdrp) {
if (!(*xdrp) (&xdr, args)) {
error (g, "dispatch failed to marshal args");
- return -1;
+ goto cleanup1;
}
}
+ /* Get the actual length of the message, resize the buffer to match
+ * the actual length, and write the length word at the beginning.
+ */
len = xdr_getpos (&xdr);
xdr_destroy (&xdr);
- /* Allocate the outgoing message buffer. */
- g->msg_out = safe_malloc (g, len + 4);
-
+ g->msg_out = safe_realloc (g, g->msg_out, len + 4);
g->msg_out_size = len + 4;
g->msg_out_pos = 0;
xdrmem_create (&xdr, g->msg_out, 4, XDR_ENCODE);
xdr_uint32_t (&xdr, &len);
- memcpy (g->msg_out + 4, buffer, len);
-
if (guestfs__switch_to_sending (g) == -1)
goto cleanup1;
static int check_for_daemon_cancellation (guestfs_h *g);
static int
-send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t len)
+send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t buflen)
{
- char data[GUESTFS_MAX_CHUNK_SIZE + 48];
- unsigned datalen;
+ unsigned len;
int sent;
guestfs_chunk chunk;
XDR xdr;
return -1;
}
+ /* This is probably an internal error. Or perhaps we should just
+ * free the buffer anyway?
+ */
+ if (g->msg_out != NULL) {
+ error (g, "guestfs__send_sync: msg_out should be NULL");
+ return -1;
+ }
+
/* Did the daemon send a cancellation message? */
if (check_for_daemon_cancellation (g)) {
if (g->verbose)
return -2;
}
+ /* Allocate the chunk buffer. Don't use the stack to avoid
+ * excessive stack usage and unnecessary copies.
+ */
+ g->msg_out = safe_malloc (g, GUESTFS_MAX_CHUNK_SIZE + 4 + 48);
+ xdrmem_create (&xdr, g->msg_out + 4, GUESTFS_MAX_CHUNK_SIZE + 48, XDR_ENCODE);
+
/* Serialize the chunk. */
chunk.cancel = cancel;
- chunk.data.data_len = len;
+ chunk.data.data_len = buflen;
chunk.data.data_val = (char *) buf;
- if (g->verbose)
- fprintf (stderr,
- "library sending chunk cancel = %d, len = %zu, buf = %p\n",
- cancel, len, buf);
-
- xdrmem_create (&xdr, data, sizeof data, XDR_ENCODE);
if (!xdr_guestfs_chunk (&xdr, &chunk)) {
- error (g, "xdr_guestfs_chunk failed (buf = %p, len = %zu)", buf, len);
+ error (g, "xdr_guestfs_chunk failed (buf = %p, buflen = %zu)",
+ buf, buflen);
xdr_destroy (&xdr);
- return -1;
+ goto cleanup1;
}
- datalen = xdr_getpos (&xdr);
+ len = xdr_getpos (&xdr);
xdr_destroy (&xdr);
- /* Allocate outgoing message buffer. */
- g->msg_out = safe_malloc (g, datalen + 4);
- g->msg_out_size = datalen + 4;
+ /* Reduce the size of the outgoing message buffer to the real length. */
+ g->msg_out = safe_realloc (g, g->msg_out, len + 4);
+ g->msg_out_size = len + 4;
g->msg_out_pos = 0;
xdrmem_create (&xdr, g->msg_out, 4, XDR_ENCODE);
- xdr_uint32_t (&xdr, &datalen);
-
- memcpy (g->msg_out + 4, data, datalen);
+ xdr_uint32_t (&xdr, &len);
if (guestfs__switch_to_sending (g) == -1)
goto cleanup1;
/* Synchronously receive a file. */
-static int receive_file_data_sync (guestfs_h *g, void **buf);
+/* Returns -1 = error, 0 = EOF, 1 = more data */
+static int receive_file_data_sync (guestfs_h *g, void **buf, int *len);
int
guestfs__receive_file_sync (guestfs_h *g, const char *filename)
{
void *buf;
- int fd, r;
+ int fd, r, len;
fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, 0666);
if (fd == -1) {
}
/* Receive the file in chunked encoding. */
- while ((r = receive_file_data_sync (g, &buf)) > 0) {
- if (xwrite (fd, buf, r) == -1) {
+ while ((r = receive_file_data_sync (g, &buf, &len)) >= 0) {
+ if (xwrite (fd, buf, len) == -1) {
perrorf (g, "%s: write", filename);
free (buf);
goto cancel;
}
free (buf);
+ if (r == 0) break; /* End of file. */
}
if (r == -1) {
return -1;
}
- while ((r = receive_file_data_sync (g, &buf)) > 0)
- free (buf); /* just discard it */
+ while ((r = receive_file_data_sync (g, NULL, NULL)) > 0)
+ ; /* just discard it */
return -1;
}
+/* Note that the reply callback can be called multiple times before
+ * the main loop quits and we get back to the synchronous code. So
+ * we have to be prepared to save multiple chunks on a list here.
+ */
struct receive_file_ctx {
- int code;
- void **buf;
+ int count; /* 0 if receive_file_cb not called, or
+ * else count number of chunks.
+ */
+ guestfs_chunk *chunks; /* Array of chunks. */
};
static void
+free_chunks (struct receive_file_ctx *ctx)
+{
+ int i;
+
+ for (i = 0; i < ctx->count; ++i)
+ free (ctx->chunks[i].data.data_val);
+
+ free (ctx->chunks);
+}
+
+static void
receive_file_cb (guestfs_h *g, void *data, XDR *xdr)
{
guestfs_main_loop *ml = guestfs_get_main_loop (g);
struct receive_file_ctx *ctx = (struct receive_file_ctx *) data;
guestfs_chunk chunk;
+ if (ctx->count == -1) /* Parse error occurred previously. */
+ return;
+
ml->main_loop_quit (ml, g);
memset (&chunk, 0, sizeof chunk);
if (!xdr_guestfs_chunk (xdr, &chunk)) {
error (g, "failed to parse file chunk");
- ctx->code = -1;
- return;
- }
- if (chunk.cancel) {
- error (g, "file receive cancelled by daemon");
- ctx->code = -2;
- return;
- }
- if (chunk.data.data_len == 0) { /* end of transfer */
- ctx->code = 0;
+ free_chunks (ctx);
+ ctx->chunks = NULL;
+ ctx->count = -1;
return;
}
- ctx->code = chunk.data.data_len;
- *ctx->buf = chunk.data.data_val; /* caller frees */
+ /* Copy the chunk to the list. */
+ ctx->chunks = safe_realloc (g, ctx->chunks,
+ sizeof (guestfs_chunk) * (ctx->count+1));
+ ctx->chunks[ctx->count] = chunk;
+ ctx->count++;
}
/* Receive a chunk of file data. */
+/* Returns -1 = error, 0 = EOF, 1 = more data */
static int
-receive_file_data_sync (guestfs_h *g, void **buf)
+receive_file_data_sync (guestfs_h *g, void **buf, int *len_r)
{
struct receive_file_ctx ctx;
guestfs_main_loop *ml = guestfs_get_main_loop (g);
+ int i, len;
- ctx.code = -3;
- ctx.buf = buf;
+ ctx.count = 0;
+ ctx.chunks = NULL;
guestfs_set_reply_callback (g, receive_file_cb, &ctx);
(void) ml->main_loop_run (ml, g);
guestfs_set_reply_callback (g, NULL, NULL);
- if (g->verbose)
- fprintf (stderr, "receive_file_data_sync: code %d\n", ctx.code);
-
- switch (ctx.code) {
- case 0: /* end of file */
- return 0;
- case -1: case -2:
+ if (ctx.count == 0) {
+ error (g, "receive_file_data_sync: reply callback not called\n");
return -1;
- case -3:
- error (g, "failed to call receive_file_cb");
+ }
+
+ if (ctx.count == -1) {
+ error (g, "receive_file_data_sync: parse error in reply callback\n");
+ /* callback already freed the chunks */
return -1;
- default: /* received n bytes of data */
- return ctx.code;
}
+
+ if (g->verbose)
+ fprintf (stderr, "receive_file_data_sync: got %d chunks\n", ctx.count);
+
+ /* Process each chunk in the list. */
+ if (buf) *buf = NULL; /* Accumulate data in this buffer. */
+ len = 0;
+
+ for (i = 0; i < ctx.count; ++i) {
+ if (ctx.chunks[i].cancel) {
+ error (g, "file receive cancelled by daemon");
+ free_chunks (&ctx);
+ if (buf) free (*buf);
+ if (len_r) *len_r = 0;
+ return -1;
+ }
+
+ if (ctx.chunks[i].data.data_len == 0) { /* end of transfer */
+ free_chunks (&ctx);
+ if (len_r) *len_r = len;
+ return 0;
+ }
+
+ if (buf) {
+ *buf = safe_realloc (g, *buf, len + ctx.chunks[i].data.data_len);
+ memcpy (*buf+len, ctx.chunks[i].data.data_val,
+ ctx.chunks[i].data.data_len);
+ }
+ len += ctx.chunks[i].data.data_len;
+ }
+
+ if (len_r) *len_r = len;
+ free_chunks (&ctx);
+ return 1;
}
/* This is the default main loop implementation, using select(2). */
git.annexia.org / libguestfs.git / blobdiff