[PATCH 4.4 16/50] jffs2: reduce the breakage on recovery from halfway failed rename()

Greg Kroah-Hartman
2016-03-14T17:54:08Z

From: Al Viro <viro@zeniv.linux.org.uk>

commit f93812846f31381d35c04c6c577d724254355e7f upstream.

d_instantiate(new_dentry, old_inode) is absolutely wrong thing to
do - it will oops if new_dentry used to be positive, for starters.
What we need is d_invalidate() the target and be done with that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/jffs2/dir.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -843,9 +843,14 @@ static int jffs2_rename (struct inode *o

pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
__func__, ret);
- /* Might as well let the VFS know */
- d_instantiate(new_dentry, d_inode(old_dentry));
- ihold(d_inode(old_dentry));
+ /*
+ * We can't keep the target in dcache after that.
+ * For one thing, we can't afford dentry aliases for directories.
+ * For another, if there was a victim, we _can't_ set new inode
+ * for that sucker and we have to trigger mount eviction - the
+ * caller won't do it on its own since we are returning an error.
+ */
+ d_invalidate(new_dentry);
new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
return ret;
}