Commit e67f0216 authored Apr 22, 2020 by Vivek Goyal Committed by Miklos Szeredi Apr 30, 2020

ovl: clear ATTR_FILE from attr->ia_valid



ovl_setattr() can be passed an attr which has ATTR_FILE set and
attr->ia_file is a file pointer to overlay file. This is done in
open(O_TRUNC) path.

We should either replace with attr->ia_file with underlying file object or
clear ATTR_FILE so that underlying filesystem does not end up using
overlayfs file object pointer.

There are no good use cases yet so for now clear ATTR_FILE. fuse seems to
be one user which can use this. But it can work even without this.  So it
is not mandatory to pass ATTR_FILE to fuse.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Fixes: bccece1e ("ovl: allow remote upper")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

parent ae83d0b4

fs/overlayfs/inode.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,13 @@ int ovl_setattr(struct dentry dentry, struct iattr attr)
		if (attr->ia_valid & (ATTR_KILL_SUID\|ATTR_KILL_SGID))
		attr->ia_valid &= ~ATTR_MODE;

		/*
		* We might have to translate ovl file into underlying file
		* object once some use cases are there. For now, simply don't
		* let underlying filesystem rely on attr->ia_file
		*/
		attr->ia_valid &= ~ATTR_FILE;

		inode_lock(upperdentry->d_inode);
		old_cred = ovl_override_creds(dentry->d_sb);
		err = notify_change(upperdentry, attr, NULL);

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