coda: cleanup for upcall handling path

Make the code that processes upcall responses more straightforward, uncovered
at least one bad assumption.  We trusted that vc_inuse would be 0 when upcalls
are aborted, however the device may have been reopened.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/coda/upcall.c

@@ -693,21 +693,21 @@ static int coda_upcall(struct coda_sb_info *sbi,
 {
 	struct venus_comm *vcommp;
 	union outputArgs *out;
-	struct upc_req *req;
+	union inputArgs *sig_inputArgs;
+	struct upc_req *req, *sig_req;
 	int error = 0;
 
 	vcommp = sbi->sbi_vcomm;
 	if (!vcommp->vc_inuse) {
-		printk("No pseudo device in upcall comms at %p\n", vcommp);
+		printk(KERN_NOTICE "coda: Venus dead, not sending upcall\n");
 		return -ENXIO;
 	}
 
 	/* Format the request message. */
 	req = upc_alloc();
-	if (!req) {
-		printk("Failed to allocate upc_req structure\n");
+	if (!req)
 		return -ENOMEM;
-	}
+
 	req->uc_data = (void *)buffer;
 	req->uc_flags = 0;
 	req->uc_inSize = inSize;
@@ -720,7 +720,7 @@ static int coda_upcall(struct coda_sb_info *sbi,
 	((union inputArgs *)buffer)->ih.unique = req->uc_unique;
 
 	/* Append msg to pending queue and poke Venus. */
-	list_add_tail(&(req->uc_chain), &vcommp->vc_pending);
+	list_add_tail(&req->uc_chain, &vcommp->vc_pending);
 
 	wake_up_interruptible(&vcommp->vc_waitq);
 	/* We can be interrupted while we wait for Venus to process
@@ -735,7 +735,6 @@ static int coda_upcall(struct coda_sb_info *sbi,
 	/* Go to sleep.  Wake up on signals only after the timeout. */
 	coda_waitfor_upcall(req);
 
-	if (vcommp->vc_inuse) {      /* i.e. Venus is still alive */
 	/* Op went through, interrupt or not... */
 	if (req->uc_flags & REQ_WRITE) {
 		out = (union outputArgs *)req->uc_data;
@@ -744,20 +743,25 @@ static int coda_upcall(struct coda_sb_info *sbi,
 		*outSize = req->uc_outSize;
 		goto exit;
 	}
-	    if ( !(req->uc_flags & REQ_READ) && signal_pending(current)) { 
-		/* Interrupted before venus read it. */
-		list_del(&(req->uc_chain));
-		/* perhaps the best way to convince the app to
-		   give up? */
+
 	error = -EINTR;
+	if ((req->uc_flags & REQ_ABORT) || !signal_pending(current)) {
+		printk(KERN_WARNING "coda: Unexpected interruption.\n");
 		goto exit;
 	}
-	    if ( (req->uc_flags & REQ_READ) && signal_pending(current) ) {
-		    /* interrupted after Venus did its read, send signal */
-		    union inputArgs *sig_inputArgs;
-		    struct upc_req *sig_req;
 
 	list_del(&(req->uc_chain));
+
+	/* Interrupted before venus read it. */
+	if (!(req->uc_flags & REQ_READ))
+		goto exit;
+
+	/* Venus saw the upcall, make sure we can send interrupt signal */
+	if (!vcommp->vc_inuse) {
+		printk(KERN_INFO "coda: Venus dead, not sending signal.\n");
+		goto exit;
+	}
+
 	error = -ENOMEM;
 	sig_req = upc_alloc();
 	if (!sig_req) goto exit;
@@ -782,15 +786,6 @@ static int coda_upcall(struct coda_sb_info *sbi,
 	/* insert at head of queue! */
 	list_add(&(sig_req->uc_chain), &vcommp->vc_pending);
 	wake_up_interruptible(&vcommp->vc_waitq);
-	    } else {
-		    printk("Coda: Strange interruption..\n");
-		    error = -EINTR;
-	    }
-	} else {	/* If venus died i.e. !VC_OPEN(vcommp) */
-	        printk("coda_upcall: Venus dead on (op,un) (%d.%d) flags %d\n",
-		       req->uc_opcode, req->uc_unique, req->uc_flags);
-		error = -ENODEV;
-	}
 
 exit:
 	upc_free(req);