From 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay.sievers@vrfy.org>
Date: Tue, 6 May 2008 22:31:33 +0200
Subject: block: do_mounts - accept root=<non-existant partition>
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 <neilb@suse.de>
Tested-by: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br>
Cc: stable <stable@kernel.org>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
block/genhd.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
(limited to 'block')
diff --git a/block/genhd.c b/block/genhd.c
index fda9c7a63c29..129ad939f9dd 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)
--
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