[PATCH] NFS: Ensure we always update inode->i_mode when doing O_EXCL creates

When the client performs an exclusive create and opens the file for writing,
a Netapp filer will first create the file using the mode 01777. It does this
since an NFSv3/v4 exclusive create cannot immediately set the mode bits.
The 01777 mode then gets put into the inode->i_mode. After the file creation
is successful, we then do a setattr to change the mode to the correct value
(as per the NFS spec).

The problem is that nfs_refresh_inode() no longer updates inode->i_mode, so
the latter retains the 01777 mode. A bit later, the VFS notices this, and calls
remove_suid(). This of course now resets the file mode to inode->i_mode & 0777.
Hey presto, the file mode on the server is now magically changed to 0777. Duh...

Fixes http://bugzilla.linux-nfs.org/show_bug.cgi?id=32

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 2 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1b76f80aedb9..0c5a308e4963 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -753,6 +753,7 @@ static int _nfs4_do_setattr(struct nfs_server *server, struct nfs_fattr *fattr,
                 .rpc_argp       = &arg,
                 .rpc_resp       = &res,
         };
+        int status;
 
         fattr->valid = 0;
 
@@ -762,7 +763,8 @@ static int _nfs4_do_setattr(struct nfs_server *server, struct nfs_fattr *fattr,
         } else
                 memcpy(&arg.stateid, &zero_stateid, sizeof(arg.stateid));
 
-        return rpc_call_sync(server->client, &msg, 0);
+        status = rpc_call_sync(server->client, &msg, 0);
+        return status;
 }
 
 static int nfs4_do_setattr(struct nfs_server *server, struct nfs_fattr *fattr,
@@ -1145,6 +1147,8 @@ nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
 
         status = nfs4_do_setattr(NFS_SERVER(inode), fattr,
                         NFS_FH(inode), sattr, state);
+        if (status == 0)
+                nfs_setattr_update_inode(inode, sattr);
         if (state != NULL)
                 nfs4_close_state(state, FMODE_WRITE);
         put_rpccred(cred);
@@ -1449,8 +1453,10 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                 struct nfs_fattr fattr;
                 status = nfs4_do_setattr(NFS_SERVER(dir), &fattr,
                                      NFS_FH(state->inode), sattr, state);
-                if (status == 0)
+                if (status == 0) {
+                        nfs_setattr_update_inode(state->inode, sattr);
                         goto out;
+                }
         } else if (flags != 0)
                 goto out;
         nfs4_close_state(state, flags);