From patchwork Fri Dec 10 16:04:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Coly Li X-Patchwork-Id: 12670107 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB1CFC433EF for ; Fri, 10 Dec 2021 16:05:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239677AbhLJQJK (ORCPT ); Fri, 10 Dec 2021 11:09:10 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:44688 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239447AbhLJQJK (ORCPT ); Fri, 10 Dec 2021 11:09:10 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 1B9A21F3A1; Fri, 10 Dec 2021 16:05:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1639152334; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pOQDspdQRgypQYJ8/E9DgfShctPpK1D3+y/umdDkkWQ=; b=dRSnSG/od2keXXTlNX7LRxhxZ8cDGbLB9h2ahG76tvVoK3GuvJ87yNx31b70BAUlUNQ4k4 wpEoBBs94/ipzrE5c5nYPvb+nl+mCvK7hDKouOxorrikFCWcWvX0dSbkTNbTlVAfEWzSv9 F9yftZWA5YCztMiS48tFR21vjfgwCgM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1639152334; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pOQDspdQRgypQYJ8/E9DgfShctPpK1D3+y/umdDkkWQ=; b=4+Pa2/gP8Plm2WkGyVuOT6ms9AMvpDSCE2e07NUSUGQrKnGD2PLhlDsGp0YdW/qoInVBeh szUMQFp8chxYeKCw== Received: from suse.localdomain (colyli.tcp.ovpn1.nue.suse.de [10.163.16.22]) by relay2.suse.de (Postfix) with ESMTP id 13DB4A3B92; Fri, 10 Dec 2021 16:05:28 +0000 (UTC) From: Coly Li To: nvdimm@lists.linux.dev, linux-raid@vger.kernel.org Cc: linux-block@vger.kernel.org, Coly Li , Dan Williams , Geliang Tang , Hannes Reinecke , Jens Axboe , NeilBrown , Vishal L Verma Subject: [PATCH v5 5/6] badblocks: improve badblocks_check() for multiple ranges handling Date: Sat, 11 Dec 2021 00:04:54 +0800 Message-Id: <20211210160456.56816-6-colyli@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211210160456.56816-1-colyli@suse.de> References: <20211210160456.56816-1-colyli@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org This patch rewrites badblocks_check() with similar coding style as _badblocks_set() and _badblocks_clear(). The only difference is bad blocks checking may handle multiple ranges in bad tables now. If a checking range covers multiple bad blocks range in bad block table, like the following condition (C is the checking range, E1, E2, E3 are three bad block ranges in bad block table), +------------------------------------+ | C | +------------------------------------+ +----+ +----+ +----+ | E1 | | E2 | | E3 | +----+ +----+ +----+ The improved badblocks_check() algorithm will divide checking range C into multiple parts, and handle them in 7 runs of a while-loop, +--+ +----+ +----+ +----+ +----+ +----+ +----+ |C1| | C2 | | C3 | | C4 | | C5 | | C6 | | C7 | +--+ +----+ +----+ +----+ +----+ +----+ +----+ +----+ +----+ +----+ | E1 | | E2 | | E3 | +----+ +----+ +----+ And the start LBA and length of range E1 will be set as first_bad and bad_sectors for the caller. The return value rule is consistent for multiple ranges. For example if there are following bad block ranges in bad block table, Index No. Start Len Ack 0 400 20 1 1 500 50 1 2 650 20 0 the return value, first_bad, bad_sectors by calling badblocks_set() with different checking range can be the following values, Checking Start, Len Return Value first_bad bad_sectors 100, 100 0 N/A N/A 100, 310 1 400 10 100, 440 1 400 10 100, 540 1 400 10 100, 600 -1 400 10 100, 800 -1 400 10 In order to make code review easier, this patch names the improved bad block range checking routine as _badblocks_check() and does not change existing badblock_check() code yet. Later patch will delete old code of badblocks_check() and make it as a wrapper to call _badblocks_check(). Then the new added code won't mess up with the old deleted code, it will be more clear and easier for code review. Signed-off-by: Coly Li Cc: Dan Williams Cc: Geliang Tang Cc: Hannes Reinecke Cc: Jens Axboe Cc: NeilBrown Cc: Vishal L Verma --- block/badblocks.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) diff --git a/block/badblocks.c b/block/badblocks.c index 3e1bb593a2bb..bfade2434c74 100644 --- a/block/badblocks.c +++ b/block/badblocks.c @@ -1256,6 +1256,103 @@ static int _badblocks_clear(struct badblocks *bb, sector_t s, int sectors) return rv; } +/* Do the exact work to check bad blocks range from the bad block table */ +static int _badblocks_check(struct badblocks *bb, sector_t s, int sectors, + sector_t *first_bad, int *bad_sectors) +{ + int unacked_badblocks, acked_badblocks; + int prev = -1, hint = -1, set = 0; + struct badblocks_context bad; + unsigned int seq; + int len, rv; + u64 *p; + + WARN_ON(bb->shift < 0 || sectors == 0); + + if (bb->shift > 0) { + sector_t target; + + /* round the start down, and the end up */ + target = s + sectors; + rounddown(s, bb->shift); + roundup(target, bb->shift); + sectors = target - s; + } + +retry: + seq = read_seqbegin(&bb->lock); + + p = bb->page; + unacked_badblocks = 0; + acked_badblocks = 0; + +re_check: + bad.start = s; + bad.len = sectors; + + if (badblocks_empty(bb)) { + len = sectors; + goto update_sectors; + } + + prev = prev_badblocks(bb, &bad, hint); + + /* start after all badblocks */ + if ((prev + 1) >= bb->count && !overlap_front(bb, prev, &bad)) { + len = sectors; + goto update_sectors; + } + + if (overlap_front(bb, prev, &bad)) { + if (BB_ACK(p[prev])) + acked_badblocks++; + else + unacked_badblocks++; + + if (BB_END(p[prev]) >= (s + sectors)) + len = sectors; + else + len = BB_END(p[prev]) - s; + + if (set == 0) { + *first_bad = BB_OFFSET(p[prev]); + *bad_sectors = BB_LEN(p[prev]); + set = 1; + } + goto update_sectors; + } + + /* Not front overlap, but behind overlap */ + if ((prev + 1) < bb->count && overlap_behind(bb, &bad, prev + 1)) { + len = BB_OFFSET(p[prev + 1]) - bad.start; + hint = prev + 1; + goto update_sectors; + } + + /* not cover any badblocks range in the table */ + len = sectors; + +update_sectors: + s += len; + sectors -= len; + + if (sectors > 0) + goto re_check; + + WARN_ON(sectors < 0); + + if (unacked_badblocks > 0) + rv = -1; + else if (acked_badblocks > 0) + rv = 1; + else + rv = 0; + + if (read_seqretry(&bb->lock, seq)) + goto retry; + + return rv; +} /** * badblocks_check() - check a given range for bad sectors