From nobody Fri Apr 3 22:31:49 2026 Received: from mail-pf1-f175.google.com (mail-pf1-f175.google.com [209.85.210.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB1A729992B for ; Mon, 23 Mar 2026 07:27:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774250841; cv=none; b=Gq2kCio5yLLR91Ne3Y2x0N2+v33YY09WwcxcwzZHl9cM68eAV/pSk5vIm03wjgW7jrEidKk0aCOmdkhOeK0dkwnyVmX9Dl24FkLNOqNedDu28ne5DzUiLkhwi3NNfUFtAR+t7en0pmXHvyRVXgMeIL1R9Xg5MVzGP1uUB/pnzVg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774250841; c=relaxed/simple; bh=7WPWs1Sp1g3Vl1AoHyo6/B00u7Vy9BnNDHYKrKY47ok=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=O6xHPVMxckpHht+WYwKP8l/4xKGdd9/TR9Kylsqwh95Dk8EXwEgJ/OTFONxCngFr6Xi/ZVKPaIhEga/sZ3PfHGOgJLxJG2wXXzsU+2qDxBctlmlmnfPEdY66p5HFFR4yCWLueCnCYMENVA4IP05doxjTNn7V5KhT4g/bMIxkabw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=dHbLkvav; arc=none smtp.client-ip=209.85.210.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dHbLkvav" Received: by mail-pf1-f175.google.com with SMTP id d2e1a72fcca58-823c56765fdso1992965b3a.1 for ; Mon, 23 Mar 2026 00:27:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1774250839; x=1774855639; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=HyN15G+MEDzt2QKd8l7H0bzTezImqr3C5TjJ8HaJLCg=; b=dHbLkvavK8hiB0mZq62JFtDHaaCwcZTq2ar5ujnBjh8qfQ1yAoOn+RZhXM/hEYGWEr KtTq7RizxKxt56I8rCXaiBbbPj+MeISlutNH478JKy9M9phykRjdnDii+2VQcK2lFEUf VBGjtCKOX96Sgh9DKFwRuaXKzHcLuRfnuh89NcxYlip6rnDit2PNxRGaRnz2GMTxVyRm rcwqk8wiXK7eEZcOlUxfnKwfaC/k9VEysxhmOxyMj5xYhVfkepb5Dr1dTwDA3rhMIYqq wnd+KX/7R+OWSzpe3v8Uoc87xBTdECrZdE90p86BkzOgWUgyzBEnyG4rACVfpQMsa4sP M9Xg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774250839; x=1774855639; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=HyN15G+MEDzt2QKd8l7H0bzTezImqr3C5TjJ8HaJLCg=; b=Op05SGlldm1SXOe0GTb9+dBFCZrGkGq+6bsW2IoWbkM5hm2ftR6eX+8pEWmEU0zrHO dOTv2k0OmN5cCrtvzHmYfpbdolseF9CKPcUd2pYX7EtO1txhMCouQa/BJaV7qm94rMhB WRSpTZz3rDg2DzJSv23jh1UmizOBVt1exyNyaSxsHxMkRW/6Jr58+5QTsBDp8JtWbomy zp68XqTWzXUyUyeq1loUkW7QHz+eCnaiS1ncVpvsadwsjmEbkOezgU4qIlNcxmv8U0Ef ft3cUs5dsRWVJCahBJeZ3fFLKb1nI/VXDqCt8v811Kn1vsDZP2iTMjbFloY+Cl1JHFzL nKUg== X-Forwarded-Encrypted: i=1; AJvYcCWLH32iWYX/je5yS0b5hCwlR5gtwMozO/vxv9WuEavnmHtkpXGuEylUdHQIv5pNmU7vPBijkqounmwPRVA=@vger.kernel.org X-Gm-Message-State: AOJu0YyKS1NDDCsh9q3LyZsvFv88K+b4y8pGeF/q6euYVIsxEZdLNFEI mHoO8suEm3j6tFWg/0Pz1VTOkDitVpQ6kQEUM7Wep6DRBQd8kaXSLs7r X-Gm-Gg: ATEYQzzWOROLTaPo6LZRCZrDHEEalbCjLTupGAbLNIB6PRCdvfRaqHrDkjKKJJ5m/Uv smrfW3nsjolbqIma3ibIDPd9FITJ6M2hWbS77SdR8Gr0dYvvce2aR9+el7Cj3SwwQrLcZUa7j6W J0p1S74s4n4uGnP+8rPDbmbyhEyAV0F/B7uoefH14rIVxQn5I7bU6Z30bfxepD3qn3+PdJwWBNj 1adNIBqJsNnKiUxqNhzDHLDYI9qVGH/HT4T2G2D6Um1QaLOMUj1d/xETXK5goCV06L3d433lu/C 3xPcZcQZfPhL+lQaLrlrZfq+0K0A96+NiBSACLFXm16Zh+2EJhpF101qctlTpinvy9hUKnXz6U9 /8Jb6X7SPo/+cmMzMtt4pIXq7Vga+vxutuHa3vuOkriMGeCmOjpif7snNKel2n868XB9XUQgMZM oARdETw8gPtpH+2kBiwQ== X-Received: by 2002:a05:6a00:2349:b0:824:4a22:ec02 with SMTP id d2e1a72fcca58-82a8c3878camr9366286b3a.42.1774250839210; Mon, 23 Mar 2026 00:27:19 -0700 (PDT) Received: from localhost ([111.228.63.84]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82b03aa5aa7sm8476962b3a.1.2026.03.23.00.27.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Mar 2026 00:27:18 -0700 (PDT) From: Cen Zhang To: cem@kernel.org Cc: linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, baijiaju1990@gmail.com, Cen Zhang , stable@vger.kernel.org Subject: [PATCH v2] xfs: use xfs_trans_ail_copy_lsn for lockless li_lsn read in CIL formatting Date: Mon, 23 Mar 2026 15:09:49 +0800 Message-Id: <20260323070949.3769170-1-zzzccc427@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" xfs_inode_item_format_core() reads lip->li_lsn without holding any lock to embed the last on-disk LSN into the log dinode during CIL commit: xfs_inode_to_log_dinode(ip, dic, ip->i_itemp->ili_item.li_lsn); Concurrently, xfs_trans_ail_update_bulk() writes lip->li_lsn under ail_lock when inserting items into the AIL after log IO completion: lip->li_lsn =3D lsn; The CIL context lock (xc_ctx_lock) and the AIL lock (ail_lock) are independent and provide no mutual exclusion between these paths. On 64-bit architectures this is benign since li_lsn monotonically increases and both old/new values are valid checkpoint LSNs. On 32-bit architectures the 64-bit xfs_lsn_t can be torn into two 32-bit loads, producing a bogus LSN that could cause log recovery to make incorrect replay decisions. Use xfs_trans_ail_copy_lsn() to safely snapshot li_lsn, which takes ail_lock on 32-bit architectures to prevent torn reads. Fixes: 93f958f9c41f ("xfs: cull unnecessary icdinode fields") Cc: stable@vger.kernel.org Signed-off-by: Cen Zhang Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_inode_item.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c index 8913036b8024..0171f4527f40 100644 --- a/fs/xfs/xfs_inode_item.c +++ b/fs/xfs/xfs_inode_item.c @@ -622,9 +622,12 @@ xfs_inode_item_format_core( struct xlog_format_buf *lfb) { struct xfs_log_dinode *dic; + xfs_lsn_t lsn; =20 + xfs_trans_ail_copy_lsn(ip->i_mount->m_ail, &lsn, + &ip->i_itemp->ili_item.li_lsn); dic =3D xlog_format_start(lfb, XLOG_REG_TYPE_ICORE); - xfs_inode_to_log_dinode(ip, dic, ip->i_itemp->ili_item.li_lsn); + xfs_inode_to_log_dinode(ip, dic, lsn); xlog_format_commit(lfb, xfs_log_dinode_size(ip->i_mount)); } =20 --=20 2.34.1