linux-kernel - Re: [PATCH] fs/dax: Fix "don't skip locked entries when scanning entries"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20250530-gekreische-rauben-91838ad7cb45@brauner>
Date: Fri, 30 May 2025 07:10:08 +0200
From: Christian Brauner <brauner@...nel.org>
To: Alistair Popple <apopple@...dia.com>
Cc: Christian Brauner <brauner@...nel.org>,
	linux-kernel@...r.kernel.org,
	Alison Schofield <alison.schofield@...el.com>,
	Balbir Singh <balbirs@...dia.com>,
	"Darrick J. Wong" <djwong@...nel.org>,
	Dave Chinner <david@...morbit.com>,
	David Hildenbrand <david@...hat.com>,
	Jan Kara <jack@...e.cz>,
	John Hubbard <jhubbard@...dia.com>,
	Ted Ts'o <tytso@....edu>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	akpm@...ux-foundation.org,
	linux-fsdevel@...r.kernel.org,
	nvdimm@...ts.linux.dev,
	dan.j.williams@...el.com,
	willy@...radead.org
Subject: Re: [PATCH] fs/dax: Fix "don't skip locked entries when scanning entries"

On Fri, 23 May 2025 14:37:49 +1000, Alistair Popple wrote:
> Commit 6be3e21d25ca ("fs/dax: don't skip locked entries when scanning
> entries") introduced a new function, wait_entry_unlocked_exclusive(),
> which waits for the current entry to become unlocked without advancing
> the XArray iterator state.
> 
> Waiting for the entry to become unlocked requires dropping the XArray
> lock. This requires calling xas_pause() prior to dropping the lock
> which leaves the xas in a suitable state for the next iteration. However
> this has the side-effect of advancing the xas state to the next index.
> Normally this isn't an issue because xas_for_each() contains code to
> detect this state and thus avoid advancing the index a second time on
> the next loop iteration.
> 
> [...]

Applied to the vfs.fixes branch of the vfs/vfs.git tree.
Patches in the vfs.fixes 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.fixes

[1/1] fs/dax: Fix "don't skip locked entries when scanning entries"
      https://git.kernel.org/vfs/vfs/c/dd59137bfe70