Cleaned up the error handling and reporting.

Fixed a race.

1 files changed, 22 insertions, 18 deletions

diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c
index 166ad6f..f745d2c 100644
--- a/arch/um/drivers/ubd_user.c
+++ b/arch/um/drivers/ubd_user.c
@@ -45,7 +45,7 @@ static int same_backing_files(char *from_cmdline, char *from_cow, char *cow)
 		printk("Couldn't stat '%s', err = %d\n", from_cow, -err);
 		return(1);
 	}
-	if((buf1.st_dev == buf2.st_dev) && (buf1.st_ino == buf2.st_ino))
+	if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino))
 		return(1);
 
 	printk("Backing file mismatch - \"%s\" requested,\n"
@@ -79,9 +79,9 @@ static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
 		       "file\n", size, actual);
 		return(-EINVAL);
 	}
-	if(buf.st_mtime != mtime){
+	if(buf.ust_mtime != mtime){
 		printk("mtime mismatch (%ld vs %ld) of COW header vs backing "
-		       "file\n", mtime, buf.st_mtime);
+		       "file\n", mtime, buf.ust_mtime);
 		return(-EINVAL);
 	}
 	return(0);
@@ -317,21 +317,21 @@ int io_thread(void *arg)
 	while(1){
 		n = os_read_file(kernel_fd, &req, sizeof(req));
 		if(n != sizeof(req)){
-			if(n < 0) {
-				printk("io_thread - read failed, err = %d\n", 
-				       -n);
-			} 
+			if(n < 0)
+				printk("io_thread - read failed, fd = %d, "
+				       "err = %d\n", kernel_fd, -n);
 			else {
-				printk("io_thread - short read : length = %d\n",
-				       n);
-				continue;
+				printk("io_thread - short read, fd = %d, "
+				       "length = %d\n", kernel_fd, n);
 			}
+			continue;
 		}
 		io_count++;
 		do_io(&req);
 		n = os_write_file(kernel_fd, &req, sizeof(req));
 		if(n != sizeof(req))
-			printk("io_thread - write failed, err = %d\n", -n);
+			printk("io_thread - write failed, fd = %d, err = %d\n",
+			       kernel_fd, -n);
 	}
 }
 
@@ -342,24 +342,28 @@ int start_io_thread(unsigned long sp, int *fd_out)
 	err = os_pipe(fds, 1, 1);
 	if(err < 0){
 		printk("start_io_thread - os_pipe failed, err = %d\n", -err);
-		return(err);
+		goto out;
 	}
 
+	kernel_fd = fds[0];
+	*fd_out = fds[1];
+
 	pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM | SIGCHLD,
 		    NULL);
 	if(pid < 0){
 		printk("start_io_thread - clone failed : errno = %d\n", errno);
-		goto err;
+		goto out_close;
 	}
 
-	kernel_fd = fds[0];
-	*fd_out = fds[1];
-
 	return(pid);
- err:
+
+ out_close:
 	os_close_file(fds[0]);
 	os_close_file(fds[1]);
-	return(-errno);
+	kernel_fd = -1;
+	*fd_out = -1;
+ out:
+	return(err);
 }
 
 /*