[PATCH] v9fs: new multiplexer implementation

New multiplexer implementation. Decreases the number of kernel threads
required. Better handling when the user process receives a signal.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 46 insertions, 3 deletions

diff --git a/fs/9p/trans_fd.c b/fs/9p/trans_fd.c
index b7ffb9859588..1a28ef97a3d1 100644
--- a/fs/9p/trans_fd.c
+++ b/fs/9p/trans_fd.c
@@ -3,6 +3,7 @@
  *
  * File Descriptor Transport Layer
  *
+ *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
  *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -106,9 +107,6 @@ v9fs_fd_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
                 return -ENOPROTOOPT;
         }
 
-        sema_init(&trans->writelock, 1);
-        sema_init(&trans->readlock, 1);
-
         ts = kmalloc(sizeof(struct v9fs_trans_fd), GFP_KERNEL);
 
         if (!ts)
@@ -163,10 +161,55 @@ static void v9fs_fd_close(struct v9fs_transport *trans)
         kfree(ts);
 }
 
+static unsigned int
+v9fs_fd_poll(struct v9fs_transport *trans, struct poll_table_struct *pt)
+{
+        int ret, n;
+        struct v9fs_trans_fd *ts;
+        mm_segment_t oldfs;
+
+        if (!trans)
+                return -EIO;
+
+        ts = trans->priv;
+        if (trans->status != Connected || !ts)
+                return -EIO;
+
+        oldfs = get_fs();
+        set_fs(get_ds());
+
+        if (!ts->in_file->f_op || !ts->in_file->f_op->poll) {
+                ret = -EIO;
+                goto end;
+        }
+
+        ret = ts->in_file->f_op->poll(ts->in_file, pt);
+
+        if (ts->out_file != ts->in_file) {
+                if (!ts->out_file->f_op || !ts->out_file->f_op->poll) {
+                        ret = -EIO;
+                        goto end;
+                }
+
+                n = ts->out_file->f_op->poll(ts->out_file, pt);
+
+                ret &= ~POLLOUT;
+                n &= ~POLLIN;
+
+                ret |= n;
+        }
+
+end:
+        set_fs(oldfs);
+        return ret;
+}
+
+
 struct v9fs_transport v9fs_trans_fd = {
         .init = v9fs_fd_init,
         .write = v9fs_fd_send,
         .read = v9fs_fd_recv,
         .close = v9fs_fd_close,
+        .poll = v9fs_fd_poll,
 };