check ATTR_SIZE contraints in inode_change_ok

Make sure we check the truncate constraints early on in ->setattr by adding
those checks to inode_change_ok.  Also clean up and document inode_change_ok
to make this obvious.

As a fallout we don't have to call inode_newsize_ok from simple_setsize and
simplify it down to a truncate_setsize which doesn't return an error.  This
simplifies a lot of setattr implementations and means we use truncate_setsize
almost everywhere.  Get rid of fat_setsize now that it's trivial and mark
ext2_setsize static to make the calling convention obvious.

Keep the inode_newsize_ok in vmtruncate for now as all callers need an
audit for its removal anyway.

Note: setattr code in ecryptfs doesn't call inode_change_ok at all and
needs a deeper audit, but that is left for later.

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

1 files changed, 2 insertions, 4 deletions

diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index d7d410a4ca42..1009be2c9737 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -1072,7 +1072,7 @@ int gfs2_permission(struct inode *inode, int mask)
 }
 
 /*
- * XXX: should be changed to have proper ordering by opencoding simple_setsize
+ * XXX(truncate): the truncate_setsize calls should be moved to the end.
  */
 static int setattr_size(struct inode *inode, struct iattr *attr)
 {
@@ -1084,10 +1084,8 @@ static int setattr_size(struct inode *inode, struct iattr *attr)
                 error = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
                 if (error)
                         return error;
-                error = simple_setsize(inode, attr->ia_size);
+                truncate_setsize(inode, attr->ia_size);
                 gfs2_trans_end(sdp);
-                if (error) 
-                        return error;
         }
 
         error = gfs2_truncatei(ip, attr->ia_size);