fix off-by-one in argument passed by iterate_fd() to callbacks

Noticed by Pavel Roskin; the thing in his patch I disagree with
was compensating for that shite in callbacks instead of fixing
it once in the iterator itself.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/file.c b/fs/file.c
index 7cb71b99260340fe7302d2a8c5dc4f84f8029aff..eff23162485f93176255199b3ed74176534ae489 100644 (file)
--- a/fs/file.c
+++ b/fs/file.c
@@ -994,16 +994,18 @@ int iterate_fd(struct files_struct *files, unsigned n,
                const void *p)
 {
        struct fdtable *fdt;
-       struct file *file;
        int res = 0;
        if (!files)
                return 0;
        spin_lock(&files->file_lock);
-       fdt = files_fdtable(files);
-       while (!res && n < fdt->max_fds) {
-               file = rcu_dereference_check_fdtable(files, fdt->fd[n++]);
-               if (file)
-                       res = f(p, file, n);
+       for (fdt = files_fdtable(files); n < fdt->max_fds; n++) {
+               struct file *file;
+               file = rcu_dereference_check_fdtable(files, fdt->fd[n]);
+               if (!file)
+                       continue;
+               res = f(p, file, n);
+               if (res)
+                       break;
        }
        spin_unlock(&files->file_lock);
        return res;