[AIO] fix io_wait

  When an application is mixing sync and async IO it ends up crashing
later on in the sync path when calling lock_page_slow as the io_wait
queue has been set to NULL in a previous AIO request.

  Therefore after the retry method has been called the task io_wait
queue should be reset to the default queue.

  This patch applies over Suparna's wait-bit patchset:

	- modify-wait-bit-action-args
	- lock_page_wait
	- init-wait-bit-key
	- tsk-default-io-wait
	- aio-wait-bit
	- aio-wait-page

and could be folded into aio-wait-bit.

Signed-off-by: Sébastien Dugué <sebastien.dugue@bull.net>
Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com>
diff -purN --exclude=description 79_fix-io_wait/net/socket.c 80_no_net_aio/net/socket.c
--- 79_fix-io_wait/net/socket.c	2005-08-04 15:56:11.000000000 -0400
+++ 80_no_net_aio/net/socket.c	2005-08-09 17:06:46.000000000 -0400
@@ -108,6 +108,10 @@ static unsigned int sock_poll(struct fil
 static long sock_ioctl(struct file *file,
 		      unsigned int cmd, unsigned long arg);
 static int sock_fasync(int fd, struct file *filp, int on);
+static ssize_t sock_read(struct file *file, char __user *buf,
+			 size_t len, loff_t *ppos);
+static ssize_t sock_write(struct file *file, const char __user *buf,
+			  size_t len, loff_t *ppos);
 static ssize_t sock_readv(struct file *file, const struct iovec *vector,
 			  unsigned long count, loff_t *ppos);
 static ssize_t sock_writev(struct file *file, const struct iovec *vector,
@@ -124,8 +128,12 @@ static ssize_t sock_sendpage(struct file
 static struct file_operations socket_file_ops = {
 	.owner =	THIS_MODULE,
 	.llseek =	no_llseek,
+#if 0
 	.aio_read =	sock_aio_read,
 	.aio_write =	sock_aio_write,
+#endif
+	.read =		sock_read,
+	.write =	sock_write,
 	.poll =		sock_poll,
 	.unlocked_ioctl = sock_ioctl,
 	.mmap =		sock_mmap,
@@ -638,7 +646,6 @@ static void sock_aio_dtor(struct kiocb *
  *	Read data from a socket. ubuf is a user mode pointer. We make sure the user
  *	area ubuf...ubuf+size-1 is writable before asking the protocol.
  */
-
 static ssize_t sock_aio_read(struct kiocb *iocb, char __user *ubuf,
 			 size_t size, loff_t pos)
 {
@@ -772,7 +779,13 @@ static ssize_t sock_readv(struct file *f
 	return sock_readv_writev(VERIFY_WRITE, file->f_dentry->d_inode,
 				 file, vector, count, tot_len);
 }
-	
+
+static ssize_t sock_read(struct file *file, char __user *buf, size_t len, loff_t *ppos)
+{
+	struct iovec local_iov = { .iov_base = buf, .iov_len = len };
+	return sock_readv(file, &local_iov, len, ppos);
+}
+
 static ssize_t sock_writev(struct file *file, const struct iovec *vector,
 			   unsigned long count, loff_t *ppos)
 {
@@ -784,6 +797,13 @@ static ssize_t sock_writev(struct file *
 				 file, vector, count, tot_len);
 }
 
+static ssize_t sock_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos)
+{
+	struct iovec local_iov = { .iov_base = (void __user *)buf,
+					.iov_len = len };
+	return sock_writev(file, &local_iov, len, ppos);
+}
+
 
 /*
  * Atomic setting of ioctl hooks to avoid race