fs: don't allow to complete sync iocbs through aio_complete

The AIO interface is fairly complex because it tries to allow
filesystems to always work async and then wakeup a synchronous
caller through aio_complete.  It turns out that basically no one
was doing this to avoid the complexity and context switches,
and we've already fixed up the remaining users and can now
get rid of this case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 8 insertions, 18 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index f8b8fc1316ab..76e324e8ce8d 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -346,9 +346,7 @@ ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
 
         iter->type |= READ;
         ret = file->f_op->read_iter(&kiocb, iter);
-        if (ret == -EIOCBQUEUED)
-                ret = wait_on_sync_kiocb(&kiocb);
-
+        BUG_ON(ret == -EIOCBQUEUED);
         if (ret > 0)
                 *ppos = kiocb.ki_pos;
         return ret;
@@ -368,9 +366,7 @@ ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
 
         iter->type |= WRITE;
         ret = file->f_op->write_iter(&kiocb, iter);
-        if (ret == -EIOCBQUEUED)
-                ret = wait_on_sync_kiocb(&kiocb);
-
+        BUG_ON(ret == -EIOCBQUEUED);
         if (ret > 0)
                 *ppos = kiocb.ki_pos;
         return ret;
@@ -426,8 +422,7 @@ ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *pp
         kiocb.ki_pos = *ppos;
 
         ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
-        if (-EIOCBQUEUED == ret)
-                ret = wait_on_sync_kiocb(&kiocb);
+        BUG_ON(ret == -EIOCBQUEUED);
         *ppos = kiocb.ki_pos;
         return ret;
 }
@@ -446,8 +441,7 @@ ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *p
         iov_iter_init(&iter, READ, &iov, 1, len);
 
         ret = filp->f_op->read_iter(&kiocb, &iter);
-        if (-EIOCBQUEUED == ret)
-                ret = wait_on_sync_kiocb(&kiocb);
+        BUG_ON(ret == -EIOCBQUEUED);
         *ppos = kiocb.ki_pos;
         return ret;
 }
@@ -508,8 +502,7 @@ ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, lof
         kiocb.ki_pos = *ppos;
 
         ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
-        if (-EIOCBQUEUED == ret)
-                ret = wait_on_sync_kiocb(&kiocb);
+        BUG_ON(ret == -EIOCBQUEUED);
         *ppos = kiocb.ki_pos;
         return ret;
 }
@@ -528,8 +521,7 @@ ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, lo
         iov_iter_init(&iter, WRITE, &iov, 1, len);
 
         ret = filp->f_op->write_iter(&kiocb, &iter);
-        if (-EIOCBQUEUED == ret)
-                ret = wait_on_sync_kiocb(&kiocb);
+        BUG_ON(ret == -EIOCBQUEUED);
         *ppos = kiocb.ki_pos;
         return ret;
 }
@@ -716,8 +708,7 @@ static ssize_t do_iter_readv_writev(struct file *filp, int rw, const struct iove
 
         iov_iter_init(&iter, rw, iov, nr_segs, len);
         ret = fn(&kiocb, &iter);
-        if (ret == -EIOCBQUEUED)
-                ret = wait_on_sync_kiocb(&kiocb);
+        BUG_ON(ret == -EIOCBQUEUED);
         *ppos = kiocb.ki_pos;
         return ret;
 }
@@ -732,8 +723,7 @@ static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,
         kiocb.ki_pos = *ppos;
 
         ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos);
-        if (ret == -EIOCBQUEUED)
-                ret = wait_on_sync_kiocb(&kiocb);
+        BUG_ON(ret == -EIOCBQUEUED);
         *ppos = kiocb.ki_pos;
         return ret;
 }