[PATCH] uml: revert block driver use of host AIO

The patch to use host AIO support that I submitted early after 2.6.13 exposed
some problems in the block driver.  I have fixes for these, but am not
comfortable putting them into 2.6.14 at this late date.  So, this patch reverts
the use of host AIO.

I will resubmit the original patch, plus fixes to the driver after 2.6.14
in order to get a reasonable amount of testing before they're exposed to
the general public.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/drivers/Makefile

@@ -13,7 +13,7 @@ mcast-objs := mcast_kern.o mcast_user.o
 net-objs := net_kern.o net_user.o
 mconsole-objs := mconsole_kern.o mconsole_user.o
 hostaudio-objs := hostaudio_kern.o
-ubd-objs := ubd_kern.o
+ubd-objs := ubd_kern.o ubd_user.o
 port-objs := port_kern.o port_user.o
 harddog-objs := harddog_kern.o harddog_user.o
 

arch/um/drivers/ubd_user.c

+/* 
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com)
+ * Licensed under the GPL
+ */
+
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#include "asm/types.h"
+#include "user_util.h"
+#include "kern_util.h"
+#include "user.h"
+#include "ubd_user.h"
+#include "os.h"
+#include "cow.h"
+
+#include <endian.h>
+#include <byteswap.h>
+
+void ignore_sigwinch_sig(void)
+{
+	signal(SIGWINCH, SIG_IGN);
+}
+
+int start_io_thread(unsigned long sp, int *fd_out)
+{
+	int pid, fds[2], err;
+
+	err = os_pipe(fds, 1, 1);
+	if(err < 0){
+		printk("start_io_thread - os_pipe failed, err = %d\n", -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);
+		err = -errno;
+		goto out_close;
+	}
+
+	return(pid);
+
+ out_close:
+	os_close_file(fds[0]);
+	os_close_file(fds[1]);
+	kernel_fd = -1;
+	*fd_out = -1;
+ out:
+	return(err);
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */

arch/um/include/aio.h

@@ -14,27 +14,15 @@ struct aio_thread_reply {
 };
 
 struct aio_context {
-	enum aio_type type;
-	int fd;
-	void *data;
-	int len;
-	unsigned long long offset;
 	int reply_fd;
 	struct aio_context *next;
 };
 
-#define INIT_AIO(aio_type, aio_fd, aio_data, aio_len, aio_offset, \
-		 aio_reply_fd) \
-	{ .type 	= aio_type, \
-	  .fd		= aio_fd, \
-	  .data		= aio_data, \
-	  .len		= aio_len, \
-	  .offset	= aio_offset, \
-	  .reply_fd	= aio_reply_fd }
-
 #define INIT_AIO_CONTEXT { .reply_fd	= -1, \
 			   .next	= NULL }
 
-extern int submit_aio(struct aio_context *aio);
+extern int submit_aio(enum aio_type type, int fd, char *buf, int len,
+		      unsigned long long offset, int reply_fd,
+                      struct aio_context *aio);
 
 #endif