[PATCH 4.4 53/86] ring-buffer: Return 0 on success from ring_buffer_resize()

[Greg Kroah-Hartman]

From: Qiujun Huang <hqjag...@gmail.com>

commit 0a1754b2a97efa644aa6e84d1db5b17c42251483 upstream.
We don't need to check the new buffer size, and the return value
had confused resize_buffer_duplicate_size().
...
        ret = ring_buffer_resize(trace_buf->buffer,
                per_cpu_ptr(size_buf->data,cpu_id)->entries, cpu_id);
        if (ret == 0)
                per_cpu_ptr(trace_buf->data, cpu_id)->entries =
                        per_cpu_ptr(size_buf->data, cpu_id)->entries;
...

Link: https://lkml.kernel.org/r/20201019142242.11560-1-hqjag...@gmail.com

Cc: sta...@vger.kernel.org
Fixes: d60da506cbeb3 ("tracing: Add a resize function to make one buffer 
equivalent to another buffer")
Signed-off-by: Qiujun Huang <hqjag...@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 kernel/trace/ring_buffer.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1659,18 +1659,18 @@ int ring_buffer_resize(struct ring_buffe
 {
        struct ring_buffer_per_cpu *cpu_buffer;
        unsigned long nr_pages;
-       int cpu, err = 0;
+       int cpu, err;
 
        /*
         * Always succeed at resizing a non-existent buffer:
         */
        if (!buffer)
-               return size;
+               return 0;
 
        /* Make sure the requested buffer exists */
        if (cpu_id != RING_BUFFER_ALL_CPUS &&
            !cpumask_test_cpu(cpu_id, buffer->cpumask))
-               return size;
+               return 0;
 
        nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
 
@@ -1810,7 +1810,7 @@ int ring_buffer_resize(struct ring_buffe
        }
 
        mutex_unlock(&buffer->mutex);
-       return size;
+       return 0;
 
  out_err:
        for_each_buffer_cpu(buffer, cpu) {