hw/9pfs/virtio-9p-coth.c

   1 /*
   2  * Virtio 9p backend
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  *  Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
   8  *  Venkateswararao Jujjuri(JV) <jvrao@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2.  See
  11  * the COPYING file in the top-level directory.
  12  *
  13  */
  14
  15 #include "fsdev/qemu-fsdev.h"
  16 #include "qemu/thread.h"
  17 #include "block/coroutine.h"
  18 #include "virtio-9p-coth.h"
  19
  20 /* v9fs glib thread pool */
  21 static V9fsThPool v9fs_pool;
  22
  23 void co_run_in_worker_bh(void *opaque)
  24 {
  25     Coroutine *co = opaque;
  26     g_thread_pool_push(v9fs_pool.pool, co, NULL);
  27 }
  28
  29 static void v9fs_qemu_process_req_done(void *arg)
  30 {
  31     char byte;
  32     ssize_t len;
  33     Coroutine *co;
  34
  35     do {
  36         len = read(v9fs_pool.rfd, &byte, sizeof(byte));
  37     } while (len == -1 &&  errno == EINTR);
  38
  39     while ((co = g_async_queue_try_pop(v9fs_pool.completed)) != NULL) {
  40         qemu_coroutine_enter(co, NULL);
  41     }
  42 }
  43
  44 static void v9fs_thread_routine(gpointer data, gpointer user_data)
  45 {
  46     ssize_t len;
  47     char byte = 0;
  48     Coroutine *co = data;
  49
  50     qemu_coroutine_enter(co, NULL);
  51
  52     g_async_queue_push(v9fs_pool.completed, co);
  53     do {
  54         len = write(v9fs_pool.wfd, &byte, sizeof(byte));
  55     } while (len == -1 && errno == EINTR);
  56 }
  57
  58 int v9fs_init_worker_threads(void)
  59 {
  60     int ret = 0;
  61     int notifier_fds[2];
  62     V9fsThPool *p = &v9fs_pool;
  63     sigset_t set, oldset;
  64
  65     sigfillset(&set);
  66     /* Leave signal handling to the iothread.  */
  67     pthread_sigmask(SIG_SETMASK, &set, &oldset);
  68
  69     if (qemu_pipe(notifier_fds) == -1) {
  70         ret = -1;
  71         goto err_out;
  72     }
  73     p->pool = g_thread_pool_new(v9fs_thread_routine, p, -1, FALSE, NULL);
  74     if (!p->pool) {
  75         ret = -1;
  76         goto err_out;
  77     }
  78     p->completed = g_async_queue_new();
  79     if (!p->completed) {
  80         /*
  81          * We are going to terminate.
  82          * So don't worry about cleanup
  83          */
  84         ret = -1;
  85         goto err_out;
  86     }
  87     p->rfd = notifier_fds[0];
  88     p->wfd = notifier_fds[1];
  89
  90     fcntl(p->rfd, F_SETFL, O_NONBLOCK);
  91     fcntl(p->wfd, F_SETFL, O_NONBLOCK);
  92
  93     qemu_set_fd_handler(p->rfd, v9fs_qemu_process_req_done, NULL, NULL);
  94 err_out:
  95     pthread_sigmask(SIG_SETMASK, &oldset, NULL);
  96     return ret;
  97 }