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Commit cb2e87a6 authored by Eric Van Hensbergen's avatar Eric Van Hensbergen Committed by Linus Torvalds
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[PATCH] v9fs: fix handling of malformed 9P messages 



This patch attempts to do a better job of cleaning up after detecting errors
on the transport.  This should also improve error reporting on broken
connections to servers.

Signed-off-by: default avatarLatchesar Ionkov <lucho@ionkov.net>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b501611a

fs/9p/error.h

+1 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ static struct errormap errmap[] = { 
	{"Operation not permitted", EPERM},

	{"wstat prohibited", EPERM},

	{"No such file or directory", ENOENT},

	{"directory entry not found", ENOENT},

	{"file not found", ENOENT},

	{"Interrupted system call", EINTR},

	{"Input/output error", EIO},

fs/9p/mux.c

+34 −19
Original line number Diff line number Diff line
@@ -162,17 +162,20 @@ static int v9fs_recv(struct v9fs_session_info *v9ses, struct v9fs_rpcreq *req) 
	dprintk(DEBUG_MUX, "waiting for response: %d\n", req->tcall->tag);

	ret = wait_event_interruptible(v9ses->read_wait,

		       ((v9ses->transport->status != Connected) ||

			(req->rcall != 0) || dprintcond(v9ses, req)));

			(req->rcall != 0) || (req->err < 0) ||

			dprintcond(v9ses, req)));



	dprintk(DEBUG_MUX, "got it: rcall %p\n", req->rcall);

	if (v9ses->transport->status == Disconnected)

		return -ECONNRESET;



	if (ret == 0) {

	spin_lock(&v9ses->muxlock);

	list_del(&req->next);

	spin_unlock(&v9ses->muxlock);

	}



	if (req->err < 0)

		return req->err;



	if (v9ses->transport->status == Disconnected)

		return -ECONNRESET;



	return ret;

}
@@ -245,6 +248,9 @@ v9fs_mux_rpc(struct v9fs_session_info *v9ses, struct v9fs_fcall *tcall, 
	if (!v9ses)

		return -EINVAL;



	if (!v9ses->transport || v9ses->transport->status != Connected)

		return -EIO;



	if (rcall)

		*rcall = NULL;
@@ -257,6 +263,7 @@ v9fs_mux_rpc(struct v9fs_session_info *v9ses, struct v9fs_fcall *tcall, 
	tcall->tag = tid;



	req.tcall = tcall;

	req.err = 0;

	req.rcall = NULL;



	ret = v9fs_send(v9ses, &req);
@@ -371,11 +378,15 @@ static int v9fs_recvproc(void *data) 
		}



		err = read_message(v9ses, rcall, v9ses->maxdata + V9FS_IOHDRSZ);

		spin_lock(&v9ses->muxlock);

		if (err < 0) {

			kfree(rcall);

			break;

			list_for_each_entry_safe(rreq, rptr, &v9ses->mux_fcalls, next) {

				rreq->err = err;

			}

		spin_lock(&v9ses->muxlock);

			if(err != -ERESTARTSYS)

				eprintk(KERN_ERR,

					"Transport error while reading message %d\n", err);

		} else {

			list_for_each_entry_safe(rreq, rptr, &v9ses->mux_fcalls, next) {

				if (rreq->tcall->tag == rcall->tag) {

					req = rreq;
@@ -383,6 +394,7 @@ static int v9fs_recvproc(void *data) 
					break;

				}

			}

		}



		if (req && (req->tcall->id == TFLUSH)) {

			struct v9fs_rpcreq *treq = NULL;
@@ -399,6 +411,7 @@ static int v9fs_recvproc(void *data) 
		spin_unlock(&v9ses->muxlock);



		if (!req) {

			if (err >= 0)

				dprintk(DEBUG_ERROR,

					"unexpected response: id %d tag %d\n",

					rcall->id, rcall->tag);
@@ -410,6 +423,8 @@ static int v9fs_recvproc(void *data) 
		set_current_state(TASK_INTERRUPTIBLE);

	}



	v9ses->transport->close(v9ses->transport);



	/* Inform all pending processes about the failure */

	wake_up_all(&v9ses->read_wait);

fs/9p/mux.h

+1 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
struct v9fs_rpcreq {

	struct v9fs_fcall *tcall;

	struct v9fs_fcall *rcall;

	int err;	/* error code if response failed */



	/* XXX - could we put scatter/gather buffers here? */

fs/9p/trans_sock.c

+10 −2
Original line number Diff line number Diff line
@@ -254,7 +254,12 @@ v9fs_unix_init(struct v9fs_session_info *v9ses, const char *dev_name, 


static void v9fs_sock_close(struct v9fs_transport *trans)

{

	struct v9fs_trans_sock *ts = trans ? trans->priv : NULL;

	struct v9fs_trans_sock *ts;



	if (!trans)

		return;



	ts = trans->priv;



	if ((ts) && (ts->s)) {

		dprintk(DEBUG_TRANS, "closing the socket %p\n", ts->s);
@@ -264,7 +269,10 @@ static void v9fs_sock_close(struct v9fs_transport *trans) 
		dprintk(DEBUG_TRANS, "socket closed\n");

	}



	if (ts)

		kfree(ts);



	trans->priv = NULL;

}



struct v9fs_transport v9fs_trans_tcp = {