relay: simplify relay_file_read()

to hell with actors...

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

1 files changed, 20 insertions, 58 deletions

diff --git a/kernel/relay.c b/kernel/relay.c
index d797502140b9..6fa398e90eb3 100644
--- 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)