1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/net/cassini.c b/drivers/net/cassini.c
index 83768df27806..f1936d51b458 100644
--- a/drivers/net/cassini.c
+++ b/drivers/net/cassini.c
@@ -576,6 +576,18 @@ static void cas_spare_recover(struct cas *cp, const gfp_t flags)
         list_for_each_safe(elem, tmp, &list) {
                 cas_page_t *page = list_entry(elem, cas_page_t, list);
 
+                /*
+                 * With the lockless pagecache, cassini buffering scheme gets
+                 * slightly less accurate: we might find that a page has an
+                 * elevated reference count here, due to a speculative ref,
+                 * and skip it as in-use. Ideally we would be able to reclaim
+                 * it. However this would be such a rare case, it doesn't
+                 * matter too much as we should pick it up the next time round.
+                 *
+                 * Importantly, if we find that the page has a refcount of 1
+                 * here (our refcount), then we know it is definitely not inuse
+                 * so we can reuse it.
+                 */
                 if (page_count(page->buffer) > 1)
                         continue;