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 d797502..6fa398e 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1121,51 +1121,23 @@
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 @@
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);
+ buffer += ret;
+ written += ret;
+ count -= ret;
+
+ 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));
- return desc->written;
-}
-
-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)