[PATCH] smbfs readdir vs signal fix

An old patch designed to fix http://bugme.osdl.org/show_bug.cgi?id=4497,
"getdents gives empty/random result upon signal".

If smbfs's readdir() is interupted by a signal, smb_readdir() failed to
noticed that and proceeded to treat the unread-into page as valid directory
contents.  Fix that up by handling the -ERESTARTSYS.

Thanks to Stian Skjelstad for reporting and testing.

Cc: Stian Skjelstad <stian@nixia.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/fs/smbfs/dir.c b/fs/smbfs/dir.c
index c6c33e15143a..0424d06b147e 100644
--- a/fs/smbfs/dir.c
+++ b/fs/smbfs/dir.c
@@ -209,6 +209,8 @@ init_cache:
         ctl.valid  = 1;
 read_really:
         result = server->ops->readdir(filp, dirent, filldir, &ctl);
+        if (result == -ERESTARTSYS && page)
+                ClearPageUptodate(page);
         if (ctl.idx == -1)
                 goto invalid_cache;     /* retry */
         ctl.head.end = ctl.fpos - 1;
@@ -217,7 +219,8 @@ finished:
         if (page) {
                 cache->head = ctl.head;
                 kunmap(page);
-                SetPageUptodate(page);
+                if (result != -ERESTARTSYS)
+                        SetPageUptodate(page);
                 unlock_page(page);
                 page_cache_release(page);
         }