linux-kernel - Re: [PATCH] fs: fix possible extra iput() in do

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Message-Id: <20230928-piloten-mitkommen-d284c6b5581d@brauner>
Date:   Thu, 28 Sep 2023 16:20:58 +0200
From:   Christian Brauner <brauner@...nel.org>
To:     Luís Henriques <lhenriques@...e.de>@vger.kernel.org
Cc:     Christian Brauner <brauner@...nel.org>,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Mateusz Guzik <mjguzik@...il.com>,
        David Howells <dhowells@...hat.com>
Subject: Re: [PATCH] fs: fix possible extra iput() in do_unlinkat()

On Thu, 28 Sep 2023 14:11:29 +0100, Luís Henriques wrote:
> Because inode is being initialised before checking if dentry is negative,
> and the ihold() is only done if the dentry is *not* negative, the cleanup
> code may end-up doing an extra iput() on that inode.
> 
> 

Not a bug afaict but as Mateusz points out it's confusing.
So I took it with a changed commit message:

    fs: move d_is_negative() further up

    The code is confusing because inode is dereferenced before the
    d_is_negative() check. Make it clear that iput() isn't called further
    below.

---

Applied to the vfs.misc branch of the vfs/vfs.git tree.
Patches in the vfs.misc branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.misc

[1/1] fs: fix possible extra iput() in do_unlinkat()
      https://git.kernel.org/vfs/vfs/c/b99cf757431d