From 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Tue, 6 May 2008 22:31:33 +0200 Subject: [PATCH] block: do_mounts - accept root= 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 fda9c7a63c..129ad939f9 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 e9874e7fcd..ae7aec3cab 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 3885e70e77..660c1e50c9 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; -- 2.39.5