Patch "jffs2: reduce the breakage on recovery from halfway failed rename()" has been added to the 4.4-stable tree

Patch "jffs2: reduce the breakage on recovery from halfway failed rename()" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    jffs2: reduce the breakage on recovery from halfway failed rename()

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     jffs2-reduce-the-breakage-on-recovery-from-halfway-failed-rename.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f93812846f31381d35c04c6c577d724254355e7f Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 7 Mar 2016 23:07:10 -0500
Subject: jffs2: reduce the breakage on recovery from halfway failed rename()

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;
 	}


Patches currently in stable-queue which might be from viro@zeniv.linux.org.uk are

queue-4.4/jffs2-reduce-the-breakage-on-recovery-from-halfway-failed-rename.patch
queue-4.4/ncpfs-fix-a-braino-in-oom-handling-in-ncp_fill_cache.patch