relay: simplify relay_file_read()

to hell with actors...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/kernel/relay.c b/kernel/relay.c
index d797502140b9a0f1ceb36f5ccbb4b9c66382a44e..6fa398e90eb34aba2370440a50703ba156dafb51 100644 (file)
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1121,51 +1121,23 @@ static size_t relay_file_read_end_pos(struct rchan_buf *buf,
        return end_pos;
 }
 
-/*
- *     subbuf_read_actor - read up to one subbuf's worth of data
- */
-static int subbuf_read_actor(size_t read_start,
-                            struct rchan_buf *buf,
-                            size_t avail,
-                            read_descriptor_t *desc)
-{
-       void *from;
-       int ret = 0;
-
-       from = buf->start + read_start;
-       ret = avail;
-       if (copy_to_user(desc->arg.buf, from, avail)) {
-               desc->error = -EFAULT;
-               ret = 0;
-       }
-       desc->arg.data += ret;
-       desc->written += ret;
-       desc->count -= ret;
-
-       return ret;
-}
-
-typedef int (*subbuf_actor_t) (size_t read_start,
-                              struct rchan_buf *buf,
-                              size_t avail,
-                              read_descriptor_t *desc);
-
-/*
- *     relay_file_read_subbufs - read count bytes, bridging subbuf boundaries
- */
-static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos,
-                                       subbuf_actor_t subbuf_actor,
-                                       read_descriptor_t *desc)
+static ssize_t relay_file_read(struct file *filp,
+                              char __user *buffer,
+                              size_t count,
+                              loff_t *ppos)
 {
        struct rchan_buf *buf = filp->private_data;
        size_t read_start, avail;
+       size_t written = 0;
        int ret;
 
-       if (!desc->count)
+       if (!count)
                return 0;
 
        inode_lock(file_inode(filp));
        do {
+               void *from;
+
                if (!relay_file_read_avail(buf, *ppos))
                        break;
 
@@ -1174,32 +1146,22 @@ static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos,
                if (!avail)
                        break;
 
-               avail = min(desc->count, avail);
-               ret = subbuf_actor(read_start, buf, avail, desc);
-               if (desc->error < 0)
+               avail = min(count, avail);
+               from = buf->start + read_start;
+               ret = avail;
+               if (copy_to_user(buffer, from, avail))
                        break;
 
-               if (ret) {
-                       relay_file_read_consume(buf, read_start, ret);
-                       *ppos = relay_file_read_end_pos(buf, read_start, ret);
-               }
-       } while (desc->count && ret);
-       inode_unlock(file_inode(filp));
+               buffer += ret;
+               written += ret;
+               count -= ret;
 
-       return desc->written;
-}
+               relay_file_read_consume(buf, read_start, ret);
+               *ppos = relay_file_read_end_pos(buf, read_start, ret);
+       } while (count);
+       inode_unlock(file_inode(filp));
 
-static ssize_t relay_file_read(struct file *filp,
-                              char __user *buffer,
-                              size_t count,
-                              loff_t *ppos)
-{
-       read_descriptor_t desc;
-       desc.written = 0;
-       desc.count = count;
-       desc.arg.buf = buffer;
-       desc.error = 0;
-       return relay_file_read_subbufs(filp, ppos, subbuf_read_actor, &desc);
+       return written;
 }
 
 static void relay_consume_bytes(struct rchan_buf *rbuf, int bytes_consumed)