[CIFS] when not using unix extensions, check for and set ATTR_READONLY on create and mkdir

When creating a directory on a CIFS share without POSIX extensions,
and the given mode has no write bits set, set the ATTR_READONLY bit.

When creating a file, set ATTR_READONLY if the create mode has no write
bits set and we're not using unix extensions.

There are some comments about this being problematic due to the VFS
splitting creates into 2 parts. I'm not sure what that's actually
talking about, but I'm assuming that it has something to do with how
mknod is implemented. In the simple case where we have no unix
extensions and we're just creating a regular file, there's no reason
we can't set ATTR_READONLY.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 6 insertions, 10 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index cfd9750852b3..95fbba4ea7d4 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1224,11 +1224,8 @@ OldOpenRetry:
         else /* BB FIXME BB */
                 pSMB->FileAttributes = cpu_to_le16(0/*ATTR_NORMAL*/);
 
-        /* if ((omode & S_IWUGO) == 0)
-                pSMB->FileAttributes |= cpu_to_le32(ATTR_READONLY);*/
-        /*  Above line causes problems due to vfs splitting create into two
-            pieces - need to set mode after file created not while it is
-            being created */
+        if (create_options & CREATE_OPTION_READONLY)
+                pSMB->FileAttributes |= cpu_to_le16(ATTR_READONLY);
 
         /* BB FIXME BB */
 /*      pSMB->CreateOptions = cpu_to_le32(create_options &
@@ -1331,17 +1328,16 @@ openRetry:
                 pSMB->FileAttributes = cpu_to_le32(ATTR_SYSTEM);
         else
                 pSMB->FileAttributes = cpu_to_le32(ATTR_NORMAL);
+
         /* XP does not handle ATTR_POSIX_SEMANTICS */
         /* but it helps speed up case sensitive checks for other
         servers such as Samba */
         if (tcon->ses->capabilities & CAP_UNIX)
                 pSMB->FileAttributes |= cpu_to_le32(ATTR_POSIX_SEMANTICS);
 
-        /* if ((omode & S_IWUGO) == 0)
-                pSMB->FileAttributes |= cpu_to_le32(ATTR_READONLY);*/
-        /*  Above line causes problems due to vfs splitting create into two
-                pieces - need to set mode after file created not while it is
-                being created */
+        if (create_options & CREATE_OPTION_READONLY)
+                pSMB->FileAttributes |= cpu_to_le32(ATTR_READONLY);
+
         pSMB->ShareAccess = cpu_to_le32(FILE_SHARE_ALL);
         pSMB->CreateDisposition = cpu_to_le32(openDisposition);
         pSMB->CreateOptions = cpu_to_le32(create_options & CREATE_OPTIONS_MASK);