From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755318Ab2DJH1s (ORCPT ); Tue, 10 Apr 2012 03:27:48 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:41550 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751480Ab2DJH1q (ORCPT ); Tue, 10 Apr 2012 03:27:46 -0400 X-IronPort-AV: E=Sophos;i="4.75,398,1330876800"; d="scan'208";a="4720139" From: Ren Mingxin To: mst@redhat.com, rusty@rustcorp.com.au Cc: axboe@kernel.dk, tj@kernel.org, James.Bottomley@HansenPartnership.com, asamymuthupa@micron.com, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, Ren Mingxin Subject: [PATCH] virtio_blk: Add help function to format mass of disks Date: Tue, 10 Apr 2012 15:28:05 +0800 Message-Id: <1334042885-8330-1-git-send-email-renmx@cn.fujitsu.com> X-Mailer: git-send-email 1.7.1 X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/04/10 15:27:04, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/04/10 15:27:13, Serialize complete at 2012/04/10 15:27:13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current virtio block's naming algorithm just supports 18278 (26^3 + 26^2 + 26) disks. If there are mass of virtio blocks, there will be disks with the same name. Based on commit 3e1a7ff8a0a7b948f2684930166954f9e8e776fe, I add function "virtblk_name_format()" for virtio block to support mass of disks naming. Signed-off-by: Ren Mingxin --- drivers/block/virtio_blk.c | 38 ++++++++++++++++++++++++++------------ 1 files changed, 26 insertions(+), 12 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index c4a60ba..86516c8 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -374,6 +374,31 @@ 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 +467,7 @@ 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); -- 1.7.1