From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 156F1369204; Fri, 4 Sep 2026 06:13:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788502381; cv=none; b=dqNgUk9jKGttUjjWWxkw5RvNVVHAOa32XlWjxIRymuDqy21Xq85BTfMVmLkZGTB89cq1EXDsgZdHkozxRROqbSqMZtLSH0zbS9CCXJoslm9YYimNo3z+FbnFXwHKPw6Vtbr8w0Jq/p7cuLYe//cTQEZlTXB7X6iBiofqEQZIa8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788502381; c=relaxed/simple; bh=S9el//VHcjIrwKKSt+ooUjvWGTGKKIKMrhXueZaGAM0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MTtF+hg8TURqE6zgWWml61cGCJEfOMcX9vhzRvOula5akbq7TdLYVPgGVT/NEwKhWMJ8CDmPO+pkmz/D2usyidmBMO4PIrcZLsU016Gge8Uv1YKQ90m8FPWDuQ0XrRNrUHZvgFuYnXpttBJk/3KmloCt3lsgkv3k/t7gwm/lAos= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1GE99cJl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1GE99cJl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F65C1F00A3D; Fri, 4 Sep 2026 06:12:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788502380; bh=AudlkPqfiWTDpLnrby04T6hB7gDKraTAziVp5k4g9C0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1GE99cJlmZlQZN0DpZ2cNvSrHjrHN4TxzDMTuxBdeGN411VoAjHiRnn7eh/ORl8Vw lWjGOkeMLqC4jsAsPqshPZV1wPZ6Be8Z6IRxqCXf3fhLnPiG9OOOqDAOWe5AzTae8U hhTeg+InHX9sVJNd2vLRVe6e0ZhLoXu18UnBsUeU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Max Kellermann , Zhang Yi , Jan Kara , Theodore Tso Subject: [PATCH 6.12 188/403] jbd2: check need_resched() when skipping busy checkpoint buffers Date: Fri, 4 Sep 2026 06:59:51 +0200 Message-ID: <20260904045739.132731968@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045734.806166532@linuxfoundation.org> References: <20260904045734.806166532@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Max Kellermann commit f213e12ff5c9590b1034ae8da0e6d09665c772d0 upstream. journal_shrink_one_cp_list() skips busy checkpoint buffers when called with JBD2_SHRINK_BUSY_SKIP. The continue statement on this path also skips the need_resched() check at the end of the loop body. Consequently, when a checkpoint list contains mostly busy buffers, the shrinker can walk the entire list while holding journal->j_list_lock, even when a reschedule has been requested. Large checkpoint lists under memory pressure can therefore cause long lock hold times and leave other CPUs spinning on j_list_lock, resulting in soft lockups or RCU stalls. Route the busy-buffer path through the need_resched() check so that the shrinker can release j_list_lock and reschedule promptly, restoring parity with the clean-buffer path, which already checks need_resched(). This does not change which checkpoint buffers are eligible for removal. Fixes: b98dba273a0e ("jbd2: remove journal_clean_one_cp_list()") Cc: stable@vger.kernel.org Signed-off-by: Max Kellermann Reviewed-by: Zhang Yi Reviewed-by: Jan Kara Link: https://patch.msgid.link/20260713102229.1598812-2-max.kellermann@ionos.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/jbd2/checkpoint.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -392,7 +392,7 @@ static unsigned long journal_shrink_one_ ret = jbd2_journal_try_remove_checkpoint(jh); if (ret < 0) { if (type == JBD2_SHRINK_BUSY_SKIP) - continue; + goto next; break; } } @@ -403,6 +403,7 @@ static unsigned long journal_shrink_one_ break; } +next: if (need_resched()) break; } while (jh != last_jh && (!nr_to_scan || *nr_to_scan));