always call inode_change_ok early in ->setattr

Make sure we call inode_change_ok before doing any changes in ->setattr,
and make sure to call it even if our fs wants to ignore normal UNIX
permissions, but use the ATTR_FORCE to skip those.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 4 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index 3b58ad65d26c..0a43505eeaec 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -767,6 +767,10 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
         loff_t newsize = attr->ia_size;
         int error;
 
+        error = inode_change_ok(inode, attr);
+        if (error)
+                return error;
+
         if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)
                                         && newsize != inode->i_size) {
                 struct page *page = NULL;
@@ -809,11 +813,9 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
                 shmem_truncate_range(inode, newsize, (loff_t)-1);
         }
 
-        error = inode_change_ok(inode, attr);
-        if (!error)
-                setattr_copy(inode, attr);
+        setattr_copy(inode, attr);
 #ifdef CONFIG_TMPFS_POSIX_ACL
-        if (!error && (attr->ia_valid & ATTR_MODE))
+        if (attr->ia_valid & ATTR_MODE)
                 error = generic_acl_chmod(inode);
 #endif
         return error;