Merging upstream version 4.19.289.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 8 insertions, 10 deletions

diff --git a/kernel/relay.c b/kernel/relay.c
index b7aa7df43..e6f70f4c4 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -997,14 +997,14 @@ static void relay_file_read_consume(struct rchan_buf *buf,
 /*
  *	relay_file_read_avail - boolean, are there unconsumed bytes available?
  */
-static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
+static int relay_file_read_avail(struct rchan_buf *buf)
 {
 	size_t subbuf_size = buf->chan->subbuf_size;
 	size_t n_subbufs = buf->chan->n_subbufs;
 	size_t produced = buf->subbufs_produced;
 	size_t consumed = buf->subbufs_consumed;
 
-	relay_file_read_consume(buf, read_pos, 0);
+	relay_file_read_consume(buf, 0, 0);
 
 	consumed = buf->subbufs_consumed;
 
@@ -1065,23 +1065,21 @@ static size_t relay_file_read_subbuf_avail(size_t read_pos,
 
 /**
  *	relay_file_read_start_pos - find the first available byte to read
- *	@read_pos: file read position
  *	@buf: relay channel buffer
  *
- *	If the @read_pos is in the middle of padding, return the
+ *	If the read_pos is in the middle of padding, return the
  *	position of the first actually available byte, otherwise
  *	return the original value.
  */
-static size_t relay_file_read_start_pos(size_t read_pos,
-					struct rchan_buf *buf)
+static size_t relay_file_read_start_pos(struct rchan_buf *buf)
 {
 	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;
+	size_t read_pos = (consumed * subbuf_size + buf->bytes_consumed)
+			% (n_subbufs * subbuf_size);
 
-	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;
@@ -1137,10 +1135,10 @@ static ssize_t relay_file_read(struct file *filp,
 	do {
 		void *from;
 
-		if (!relay_file_read_avail(buf, *ppos))
+		if (!relay_file_read_avail(buf))
 			break;
 
-		read_start = relay_file_read_start_pos(*ppos, buf);
+		read_start = relay_file_read_start_pos(buf);
 		avail = relay_file_read_subbuf_avail(read_start, buf);
 		if (!avail)
 			break;