1 files changed, 9 insertions, 2 deletions

diff --git a/kernel/relay.c b/kernel/relay.c
index 4311101b0ca7..95db8c79fe8f 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -812,7 +812,10 @@ static void relay_file_read_consume(struct rchan_buf *buf,
         }
 
         buf->bytes_consumed += bytes_consumed;
-        read_subbuf = read_pos / buf->chan->subbuf_size;
+        if (!read_pos)
+                read_subbuf = buf->subbufs_consumed % n_subbufs;
+        else
+                read_subbuf = read_pos / buf->chan->subbuf_size;
         if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) {
                 if ((read_subbuf == buf->subbufs_produced % n_subbufs) &&
                     (buf->offset == subbuf_size))
@@ -841,8 +844,9 @@ static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
         }
 
         if (unlikely(produced - consumed >= n_subbufs)) {
-                consumed = (produced / n_subbufs) * n_subbufs;
+                consumed = produced - n_subbufs + 1;
                 buf->subbufs_consumed = consumed;
+                buf->bytes_consumed = 0;
         }
         
         produced = (produced % n_subbufs) * subbuf_size + buf->offset;
@@ -899,7 +903,10 @@ static size_t relay_file_read_start_pos(size_t read_pos,
         size_t read_subbuf, padding, padding_start, padding_end;
         size_t subbuf_size = buf->chan->subbuf_size;
         size_t n_subbufs = buf->chan->n_subbufs;
+        size_t consumed = buf->subbufs_consumed % n_subbufs;
 
+        if (!read_pos)
+                read_pos = consumed * subbuf_size + buf->bytes_consumed;
         read_subbuf = read_pos / subbuf_size;
         padding = buf->padding[read_subbuf];
         padding_start = (read_subbuf + 1) * subbuf_size - padding;