From patchwork Mon Sep 13 16:36:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Coly Li X-Patchwork-Id: 12490121 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) (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 98E2B3FD6 for ; Mon, 13 Sep 2021 16:38:42 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 3D8CE20008; Mon, 13 Sep 2021 16:38:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1631551121; 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=VypkdBFyWgH9xahnzRTdnDLTrVppU0MvmRi4ACLqQ64=; b=txfMhyHm4al/syclT0iNVpDG/uYBTBZnqfGwiRuviaI6KanxILDG4+iKVB9GG8B1fjp+wl Y4DdPVGWsSHs6nVrSbQfjCwrHASYrfxNIEiIL6YHesA9DtU9yFB0uiuOQdKrTiReQHtdzZ pLc7KMEoXdwv05QQVvz/Zefo59dhGBA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1631551121; 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=VypkdBFyWgH9xahnzRTdnDLTrVppU0MvmRi4ACLqQ64=; b=O8G7NJUmktYO65xli1la/jGTklstYI9tra/2wxf3gue0B4GvRJjKJp3Jz+Ig8VD9G9S81b fXTO9w4K3VzkvCDw== Received: from localhost.localdomain (unknown [10.163.16.22]) by relay2.suse.de (Postfix) with ESMTP id DB5BAA3B9D; Mon, 13 Sep 2021 16:38:36 +0000 (UTC) From: Coly Li To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-raid@vger.kernel.org, nvdimm@lists.linux.dev Cc: antlists@youngman.org.uk, Coly Li , Dan Williams , Hannes Reinecke , Jens Axboe , NeilBrown , Richard Fan , Vishal L Verma Subject: [PATCH v3 5/6] badblocks: improve badblocks_check() for multiple ranges handling Date: Tue, 14 Sep 2021 00:36:41 +0800 Message-Id: <20210913163643.10233-6-colyli@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210913163643.10233-1-colyli@suse.de> References: <20210913163643.10233-1-colyli@suse.de> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 divid 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: Hannes Reinecke Cc: Jens Axboe Cc: NeilBrown Cc: Richard Fan Cc: Vishal L Verma --- block/badblocks.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) diff --git a/block/badblocks.c b/block/badblocks.c index b8d466e835da..93d29276ffc2 100644 --- a/block/badblocks.c +++ b/block/badblocks.c @@ -1257,6 +1257,105 @@ 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) +{ + u64 *p; + struct badblocks_context bad; + int prev = -1, hint = -1, set = 0; + int unacked_badblocks, acked_badblocks; + int len, rv; + unsigned int seq; + + 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); + + bad.orig_start = s; + bad.orig_len = sectors; + 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