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>

1 files changed, 8 insertions, 6 deletions

diff --git a/fs/file.c b/fs/file.c
index 7cb71b992603..eff23162485f 100644
--- 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;