From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751974Ab2C1Gy3 (ORCPT ); Wed, 28 Mar 2012 02:54:29 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:41186 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751572Ab2C1Gy2 (ORCPT ); Wed, 28 Mar 2012 02:54:28 -0400 X-IronPort-AV: E=Sophos;i="4.75,329,1330876800"; d="scan'208";a="4637671" Message-ID: <4F72B5B3.6020602@cn.fujitsu.com> Date: Wed, 28 Mar 2012 14:54:43 +0800 From: Ren Mingxin User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20110412 CentOS/3.1.3-1.el6.centos Thunderbird/3.1.3 MIME-Version: 1.0 To: Rusty Russell , "Michael S. Tsirkin" CC: LKML Subject: [PATCH] virtio_blk: add helper function to support mass of disks naming X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-03-28 14:52:11, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-03-28 14:52:13, Serialize complete at 2012-03-28 14:52:13 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, The current virtblk's naming algorithm just supports 26^3 disks. If there are mass of virtblks(exceeding 26^3), there will be disks with the same name. According to "sd_format_disk_name()", I add function "virtblk_name_format()" for virtblk to support mass of disks. Signed-off-by: Ren Mingxin --- virtio_blk.c | 37 +++++++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index c4a60ba..07b8bf9 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -374,6 +374,30 @@ static int init_vq(struct virtio_blk *vblk) return err; } +static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) +{ + const int base = 'z' - 'a' + 1; + char *begin = buf + strlen(prefix); + char *begin = buf + strlen(prefix); + char *end = buf + buflen; + char *p; + int unit; + + p = end - 1; + *p = '\0'; + unit = base; + do { + if (p == begin) + return -EINVAL; + *--p = 'a' + (index % unit); + index = (index / unit) - 1; + } while (index >= 0); + + memmove(begin, p, end - p); + memcpy(buf, prefix, strlen(prefix)); + + return 0; +} + static int __devinit virtblk_probe(struct virtio_device *vdev) { struct virtio_blk *vblk; @@ -442,18 +466,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) q->queuedata = vblk; - if (index < 26) { - sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26); - } else if (index < (26 + 1) * 26) { - sprintf(vblk->disk->disk_name, "vd%c%c", - 'a' + index / 26 - 1, 'a' + index % 26); - } else { - const unsigned int m1 = (index / 26 - 1) / 26 - 1; - const unsigned int m2 = (index / 26 - 1) % 26; - const unsigned int m3 = index % 26; - sprintf(vblk->disk->disk_name, "vd%c%c%c", - 'a' + m1, 'a' + m2, 'a' + m3); - } + virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); vblk->disk->major = major; vblk->disk->first_minor = index_to_minor(index);