AFS: fix interminable loop in afs_write_back_from_locked_page()

Following bug was uncovered by compiling with '-W' flag:

  CC [M]  fs/afs/write.o
fs/afs/write.c: In function â\80\98afs_write_back_from_locked_pageâ\80\99:
fs/afs/write.c:398: warning: comparison of unsigned expression >= 0 is always true

Loop variable 'n' is unsigned, so wraps around happily as far as I can
see. Trival fix attached (compile tested only).

Signed-off-by: Mika Kukkonen <mikukkon@iki.fi>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 67ae4db..28f3751 100644 (file)
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -395,8 +395,9 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
                if (n == 0)
                        goto no_more;
                if (pages[0]->index != start) {
-                       for (n--; n >= 0; n--)
-                               put_page(pages[n]);
+                       do {
+                               put_page(pages[--n]);
+                       } while (n > 0);
                        goto no_more;
                }