From patchwork Fri Mar 6 02:47:01 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 5949701 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 45E42BF440 for ; Fri, 6 Mar 2015 02:47:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2A09C2035C for ; Fri, 6 Mar 2015 02:47:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B523A2034E for ; Fri, 6 Mar 2015 02:47:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750738AbbCFCrE (ORCPT ); Thu, 5 Mar 2015 21:47:04 -0500 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:35363 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751374AbbCFCrD (ORCPT ); Thu, 5 Mar 2015 21:47:03 -0500 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 2F5108EE0EA; Thu, 5 Mar 2015 18:47:03 -0800 (PST) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RaOfarfhDM0j; Thu, 5 Mar 2015 18:47:03 -0800 (PST) Received: from [153.66.254.242] (unknown [50.46.149.214]) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id BBAD98EE072; Thu, 5 Mar 2015 18:47:02 -0800 (PST) Message-ID: <1425610021.2169.86.camel@HansenPartnership.com> Subject: [PATCH] sd, mmc, virtio_blk, string_helpers: fix block size units From: James Bottomley To: linux-scsi Cc: Andrew Morton , linux-mmc@vger.kernel.org, virtualization@lists.linux-foundation.org Date: Thu, 05 Mar 2015 18:47:01 -0800 X-Mailer: Evolution 3.12.9 Mime-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: James Bottomley The current string_get_size() overflows when the device size goes over 2^64 bytes because the string helper routine computes the suffix from the size in bytes. However, the entirety of Linux thinks in terms of blocks, not bytes, so this will artificially induce an overflow on very large devices. Fix this by making the function string_get_size() take blocks and the block size instead of bytes. This should allow us to keep working until the current SCSI standard overflows. Also fix virtio_blk and mmc (both of which were also artificially multiplying by the block size to pass a byte side to string_get_size()). The mathematics of this is pretty simple: we're taking a product of size in blocks (S) and block size (B) and trying to re-express this in exponential form: S*B = R*N^E (where N, the exponent is either 1000 or 1024) and R < N. Mathematically, S = RS*N^ES and B=RB*N^EB, so if RS*RB < N it's easy to see that S*B = RS*RB*N^(ES+EB). However, if RS*BS > N, we can see that this can be re-expressed as RS*BS = R*N (where R = RS*BS/N < N) so the whole exponent becomes R*N^(ES+EB+1) Signed-off-by: James Bottomley Acked-by: Ulf Hansson --- -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index cdfbd21..26d2440 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -344,7 +344,7 @@ static void virtblk_config_changed_work(struct work_struct *work) struct request_queue *q = vblk->disk->queue; char cap_str_2[10], cap_str_10[10]; char *envp[] = { "RESIZE=1", NULL }; - u64 capacity, size; + u64 capacity; /* Host must always specify the capacity. */ virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); @@ -356,9 +356,10 @@ static void virtblk_config_changed_work(struct work_struct *work) capacity = (sector_t)-1; } - size = capacity * queue_logical_block_size(q); - string_get_size(size, STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); - string_get_size(size, STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); + string_get_size(capacity, queue_logical_block_size(q), + STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); + string_get_size(capacity, queue_logical_block_size(q), + STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); dev_notice(&vdev->dev, "new size: %llu %d-byte logical blocks (%s/%s)\n", diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index c69afb5..2fc4269 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -2230,7 +2230,7 @@ static int mmc_blk_alloc_part(struct mmc_card *card, part_md->part_type = part_type; list_add(&part_md->part, &md->part); - string_get_size((u64)get_capacity(part_md->disk) << 9, STRING_UNITS_2, + string_get_size((u64)get_capacity(part_md->disk), 512, STRING_UNITS_2, cap_str, sizeof(cap_str)); pr_info("%s: %s %s partition %u %s\n", part_md->disk->disk_name, mmc_card_id(card), @@ -2436,7 +2436,7 @@ static int mmc_blk_probe(struct device *dev) if (IS_ERR(md)) return PTR_ERR(md); - string_get_size((u64)get_capacity(md->disk) << 9, STRING_UNITS_2, + string_get_size((u64)get_capacity(md->disk), 512, STRING_UNITS_2, cap_str, sizeof(cap_str)); pr_info("%s: %s %s %s %s\n", md->disk->disk_name, mmc_card_id(card), mmc_card_name(card), diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 6b78476..3c7fe4e 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2235,11 +2235,11 @@ got_data: { char cap_str_2[10], cap_str_10[10]; - u64 sz = (u64)sdkp->capacity << ilog2(sector_size); - string_get_size(sz, STRING_UNITS_2, cap_str_2, - sizeof(cap_str_2)); - string_get_size(sz, STRING_UNITS_10, cap_str_10, + string_get_size(sdkp->capacity, sector_size, + STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); + string_get_size(sdkp->capacity, sector_size, + STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); if (sdkp->first_scan || old_capacity != sdkp->capacity) { diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h index 6575718..2633280 100644 --- a/include/linux/string_helpers.h +++ b/include/linux/string_helpers.h @@ -10,7 +10,7 @@ enum string_size_units { STRING_UNITS_2, /* use binary powers of 2^10 */ }; -void string_get_size(u64 size, enum string_size_units units, +void string_get_size(u64 size, u64 blk_size, enum string_size_units units, char *buf, int len); #define UNESCAPE_SPACE 0x01 diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 8f8c441..6ac8d5a 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -4,6 +4,7 @@ * Copyright 31 August 2008 James Bottomley * Copyright (C) 2013, Intel Corporation */ +#include #include #include #include @@ -14,7 +15,8 @@ /** * string_get_size - get the size in the specified units - * @size: The size to be converted + * @size: The size to be converted in blocks + * @blk_size: Size of the block (use 1 for size in bytes) * @units: units to use (powers of 1000 or 1024) * @buf: buffer to format to * @len: length of buffer @@ -24,14 +26,14 @@ * at least 9 bytes and will always be zero terminated. * */ -void string_get_size(u64 size, const enum string_size_units units, +void string_get_size(u64 size, u64 blk_size, const enum string_size_units units, char *buf, int len) { static const char *const units_10[] = { - "B", "kB", "MB", "GB", "TB", "PB", "EB" + "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" }; static const char *const units_2[] = { - "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB" + "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB" }; static const char *const *const units_str[] = { [STRING_UNITS_10] = units_10, @@ -42,31 +44,58 @@ void string_get_size(u64 size, const enum string_size_units units, [STRING_UNITS_2] = 1024, }; int i, j; - u32 remainder = 0, sf_cap; + u32 remainder = 0, sf_cap, exp; char tmp[8]; + const char *unit; tmp[0] = '\0'; i = 0; - if (size >= divisor[units]) { - while (size >= divisor[units]) { - remainder = do_div(size, divisor[units]); - i++; - } + if (!size) + goto out; - sf_cap = size; - for (j = 0; sf_cap*10 < 1000; j++) - sf_cap *= 10; + while (blk_size >= divisor[units]) { + remainder = do_div(blk_size, divisor[units]); + i++; + } - if (j) { - remainder *= 1000; - remainder /= divisor[units]; - snprintf(tmp, sizeof(tmp), ".%03u", remainder); - tmp[j+1] = '\0'; - } + exp = divisor[units]; + do_div(exp, blk_size); + if (size >= exp) { + remainder = do_div(size, divisor[units]); + remainder *= blk_size; + i++; + } else { + remainder *= size; + } + + size *= blk_size; + size += (remainder/divisor[units]); + remainder %= divisor[units]; + + while (size >= divisor[units]) { + remainder = do_div(size, divisor[units]); + i++; } + sf_cap = size; + for (j = 0; sf_cap*10 < 1000; j++) + sf_cap *= 10; + + if (j) { + remainder *= 1000; + remainder /= divisor[units]; + snprintf(tmp, sizeof(tmp), ".%03u", remainder); + tmp[j+1] = '\0'; + } + + out: + if (i >= ARRAY_SIZE(units_2)) + unit = "UNK"; + else + unit = units_str[units][i]; + snprintf(buf, len, "%u%s %s", (u32)size, - tmp, units_str[units][i]); + tmp, unit); } EXPORT_SYMBOL(string_get_size);