From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763086AbYENRuw (ORCPT ); Wed, 14 May 2008 13:50:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762850AbYENRuZ (ORCPT ); Wed, 14 May 2008 13:50:25 -0400 Received: from ns.suse.de ([195.135.220.2]:55868 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758453AbYENRuX (ORCPT ); Wed, 14 May 2008 13:50:23 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Kay Sievers , stable , Greg Kroah-Hartman Subject: [PATCH 1/2] block: do_mounts - accept root= Date: Wed, 14 May 2008 10:49:54 -0700 Message-Id: <1210787395-25887-1-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.5.5.1 In-Reply-To: <20080514174920.GA25856@suse.de> References: <20080514174920.GA25856@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kay Sievers Some devices, like md, may create partitions only at first access, so allow root= to be set to a valid non-existant partition of an existing disk. This applies only to non-initramfs root mounting. This fixes a regression from 2.6.24 which did allow this to happen and broke some users machines :( Acked-by: Neil Brown Tested-by: Joao Luis Meloni Assirati Cc: stable Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- block/genhd.c | 9 ++++++--- include/linux/genhd.h | 4 ++-- init/do_mounts.c | 27 ++++++++++++++++++++++++++- 3 files changed, 34 insertions(+), 6 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index fda9c7a..129ad93 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -653,7 +653,7 @@ void genhd_media_change_notify(struct gendisk *disk) EXPORT_SYMBOL_GPL(genhd_media_change_notify); #endif /* 0 */ -dev_t blk_lookup_devt(const char *name) +dev_t blk_lookup_devt(const char *name, int part) { struct device *dev; dev_t devt = MKDEV(0, 0); @@ -661,7 +661,11 @@ dev_t blk_lookup_devt(const char *name) mutex_lock(&block_class_lock); list_for_each_entry(dev, &block_class.devices, node) { if (strcmp(dev->bus_id, name) == 0) { - devt = dev->devt; + struct gendisk *disk = dev_to_disk(dev); + + if (part < disk->minors) + devt = MKDEV(MAJOR(dev->devt), + MINOR(dev->devt) + part); break; } } @@ -669,7 +673,6 @@ dev_t blk_lookup_devt(const char *name) return devt; } - EXPORT_SYMBOL(blk_lookup_devt); struct gendisk *alloc_disk(int minors) diff --git a/include/linux/genhd.h b/include/linux/genhd.h index e9874e7..ae7aec3 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -525,7 +525,7 @@ struct unixware_disklabel { #define ADDPART_FLAG_RAID 1 #define ADDPART_FLAG_WHOLEDISK 2 -extern dev_t blk_lookup_devt(const char *name); +extern dev_t blk_lookup_devt(const char *name, int part); extern char *disk_name (struct gendisk *hd, int part, char *buf); extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev); @@ -553,7 +553,7 @@ static inline struct block_device *bdget_disk(struct gendisk *disk, int index) static inline void printk_all_partitions(void) { } -static inline dev_t blk_lookup_devt(const char *name) +static inline dev_t blk_lookup_devt(const char *name, int part) { dev_t devt = MKDEV(0, 0); return devt; diff --git a/init/do_mounts.c b/init/do_mounts.c index 3885e70..660c1e5 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -76,6 +76,7 @@ dev_t name_to_dev_t(char *name) char s[32]; char *p; dev_t res = 0; + int part; if (strncmp(name, "/dev/", 5) != 0) { unsigned maj, min; @@ -106,7 +107,31 @@ dev_t name_to_dev_t(char *name) for (p = s; *p; p++) if (*p == '/') *p = '!'; - res = blk_lookup_devt(s); + res = blk_lookup_devt(s, 0); + if (res) + goto done; + + /* + * try non-existant, but valid partition, which may only exist + * after revalidating the disk, like partitioned md devices + */ + while (p > s && isdigit(p[-1])) + p--; + if (p == s || !*p || *p == '0') + goto fail; + + /* try disk name without */ + part = simple_strtoul(p, NULL, 10); + *p = '\0'; + res = blk_lookup_devt(s, part); + if (res) + goto done; + + /* try disk name without p */ + if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') + goto fail; + p[-1] = '\0'; + res = blk_lookup_devt(s, part); if (res) goto done; -- 1.5.5.1