X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fnet%2Fcassini.c;h=f1936d51b458e387e3ba0ffef867f1e388bb8a90;hb=bc173c5789e1fc6065fd378edc815914b40ee86b;hp=83768df27806be9394fb087acac83ee6f87f08a0;hpb=e6b027a398bcfbb8897353a88a2edfcc97fd604d;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/net/cassini.c b/drivers/net/cassini.c
index 83768df2780..f1936d51b45 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;