From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7476F24EF78; Mon, 24 Feb 2025 14:39:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740407972; cv=none; b=FzU4ilHDI9sxTMLf6un/u2ecRv4u++1JsnscTpKTeXazug1pqEHQimnIxHXkPpUlOtKcPeNd9f52JG+Prb8ziOEZM4x4Dd/2RJtLc4Rqr5CPV0PywdhTA/K4Z9B9jLf7zwthif0VOcKioYUpKIkO0UAT37NZ2FHZyR8Q4eZLsWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740407972; c=relaxed/simple; bh=r8sxdShY72+9IymeVMtkmV1pHdFI7k/4Vb4H66Wsv2w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dkui4w2t1ofxJTVfrqf14IyaSb2BE7kbvQ6Wk5+26Dj4teUZQ2/qEV3Wus8AYJOgM4aoOoZod/4i7cHqziF9+JT30i5q+cAzX1oFhP5EwaHJf8v4W9oWCeI5eFg+4ZaDpgsUdhDBv7l1CZ8PoLDpqpjNN8FfVw4ec4toCsgV4ic= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WKDThrW/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="WKDThrW/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D89F5C4CED6; Mon, 24 Feb 2025 14:39:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1740407972; bh=r8sxdShY72+9IymeVMtkmV1pHdFI7k/4Vb4H66Wsv2w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WKDThrW/IGxyQis0JBjChwJXf05cElXZW13T2w2fDHVBM2nuEvQ8VSF2jdckqk/NL o8SaSXSdwnYz0LP5yzvNPapsnLV4BATt54k+oO5l1f5odCLJOuaT4H1UaKi3iaXVgj mfyD0j+CNgAKnO30xBzfvyQ2yLc/PxjsE238//XI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yu Kuai , Song Liu , Sasha Levin Subject: [PATCH 6.6 030/140] md: simplify md_seq_ops Date: Mon, 24 Feb 2025 15:33:49 +0100 Message-ID: <20250224142604.192843945@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250224142602.998423469@linuxfoundation.org> References: <20250224142602.998423469@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yu Kuai [ Upstream commit cf1b6d4441fffd0ba8ae4ced6a12f578c95ca049 ] Before this patch, the implementation is hacky and hard to understand: 1) md_seq_start set pos to 1; 2) md_seq_show found pos is 1, then print Personalities; 3) md_seq_next found pos is 1, then it update pos to the first mddev; 4) md_seq_show found pos is not 1 or 2, show mddev; 5) md_seq_next found pos is not 1 or 2, update pos to next mddev; 6) loop 4-5 until the last mddev, then md_seq_next update pos to 2; 7) md_seq_show found pos is 2, then print unused devices; 8) md_seq_next found pos is 2, stop; This patch remove the magic value and use seq_list_start/next/stop() directly, and move printing "Personalities" to md_seq_start(), "unsed devices" to md_seq_stop(): 1) md_seq_start print Personalities, and then set pos to first mddev; 2) md_seq_show show mddev; 3) md_seq_next update pos to next mddev; 4) loop 2-3 until the last mddev; 5) md_seq_stop print unsed devices; Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230927061241.1552837-3-yukuai1@huaweicloud.com Stable-dep-of: 8d28d0ddb986 ("md/md-bitmap: Synchronize bitmap_get_stats() with bitmap lifetime") Signed-off-by: Sasha Levin --- drivers/md/md.c | 100 +++++++++++------------------------------------- 1 file changed, 22 insertions(+), 78 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 836e8ed58c8ad..27a6a11b71ee4 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8260,105 +8260,46 @@ static int status_resync(struct seq_file *seq, struct mddev *mddev) } static void *md_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(&all_mddevs_lock) { - struct list_head *tmp; - loff_t l = *pos; - struct mddev *mddev; + struct md_personality *pers; - if (l == 0x10000) { - ++*pos; - return (void *)2; - } - if (l > 0x10000) - return NULL; - if (!l--) - /* header */ - return (void*)1; + seq_puts(seq, "Personalities : "); + spin_lock(&pers_lock); + list_for_each_entry(pers, &pers_list, list) + seq_printf(seq, "[%s] ", pers->name); + + spin_unlock(&pers_lock); + seq_puts(seq, "\n"); + seq->poll_event = atomic_read(&md_event_count); spin_lock(&all_mddevs_lock); - list_for_each(tmp,&all_mddevs) - if (!l--) { - mddev = list_entry(tmp, struct mddev, all_mddevs); - if (!mddev_get(mddev)) - continue; - spin_unlock(&all_mddevs_lock); - return mddev; - } - spin_unlock(&all_mddevs_lock); - if (!l--) - return (void*)2;/* tail */ - return NULL; + + return seq_list_start(&all_mddevs, *pos); } static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos) { - struct list_head *tmp; - struct mddev *next_mddev, *mddev = v; - struct mddev *to_put = NULL; - - ++*pos; - if (v == (void*)2) - return NULL; - - spin_lock(&all_mddevs_lock); - if (v == (void*)1) { - tmp = all_mddevs.next; - } else { - to_put = mddev; - tmp = mddev->all_mddevs.next; - } - - for (;;) { - if (tmp == &all_mddevs) { - next_mddev = (void*)2; - *pos = 0x10000; - break; - } - next_mddev = list_entry(tmp, struct mddev, all_mddevs); - if (mddev_get(next_mddev)) - break; - mddev = next_mddev; - tmp = mddev->all_mddevs.next; - } - spin_unlock(&all_mddevs_lock); - - if (to_put) - mddev_put(to_put); - return next_mddev; - + return seq_list_next(v, &all_mddevs, pos); } static void md_seq_stop(struct seq_file *seq, void *v) + __releases(&all_mddevs_lock) { - struct mddev *mddev = v; - - if (mddev && v != (void*)1 && v != (void*)2) - mddev_put(mddev); + status_unused(seq); + spin_unlock(&all_mddevs_lock); } static int md_seq_show(struct seq_file *seq, void *v) { - struct mddev *mddev = v; + struct mddev *mddev = list_entry(v, struct mddev, all_mddevs); sector_t sectors; struct md_rdev *rdev; - if (v == (void*)1) { - struct md_personality *pers; - seq_printf(seq, "Personalities : "); - spin_lock(&pers_lock); - list_for_each_entry(pers, &pers_list, list) - seq_printf(seq, "[%s] ", pers->name); - - spin_unlock(&pers_lock); - seq_printf(seq, "\n"); - seq->poll_event = atomic_read(&md_event_count); + if (!mddev_get(mddev)) return 0; - } - if (v == (void*)2) { - status_unused(seq); - return 0; - } + spin_unlock(&all_mddevs_lock); spin_lock(&mddev->lock); if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) { seq_printf(seq, "%s : %sactive", mdname(mddev), @@ -8429,6 +8370,9 @@ static int md_seq_show(struct seq_file *seq, void *v) seq_printf(seq, "\n"); } spin_unlock(&mddev->lock); + spin_lock(&all_mddevs_lock); + if (atomic_dec_and_test(&mddev->active)) + __mddev_put(mddev); return 0; } -- 2.39.5