Patchwork [3/3] mtd: cmdlinepart: fix the wrong partitions number when truncating occurs

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Submitter Huang Shijie
Date Aug. 26, 2012, 5:21 p.m.
Message ID <1346001700-26895-3-git-send-email-shijie8@gmail.com>
Download mbox | patch
Permalink /patch/180024/
State New
Headers show

Comments

Huang Shijie - Aug. 26, 2012, 5:21 p.m.
This patch is based on the assumption that all the partitions are
in the right offset order.

Assume we have a 1GB(8Gb) nand chip, and we set the partitions
in the command line like this:
    #gpmi-nand:100m(boot),100m(kernel),1g(rootfs)

In this case, the partition truncating occurs. The current code will
get the following result:

     ----------------------------------
	root@freescale ~$ cat /proc/mtd
	dev:    size   erasesize  name
	mtd0: 06400000 00040000 "boot"
	mtd1: 06400000 00040000 "kernel"
     ----------------------------------

It is obvious that we lost the truncated partition `rootfs` which should
be 824M in this case.

Why? The old code sets the wrong partitions number when the truncating
occurs. This patch fixes it. Alao add a `break` to shortcut the code in this
case.

After apply this patch, the result becomes:
     ----------------------------------
	root@freescale ~$ cat /proc/mtd
	dev:    size   erasesize  name
	mtd0: 06400000 00040000 "boot"
	mtd1: 06400000 00040000 "kernel"
	mtd2: 33800000 00040000 "rootfs"
     ----------------------------------

We get the right result.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
---
 drivers/mtd/cmdlinepart.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
Huang Shijie - Aug. 30, 2012, 6:39 a.m.
On Thu, Aug 30, 2012 at 2:43 PM, Artem Bityutskiy <dedekind1@gmail.com> wrote:
> On Sun, 2012-08-26 at 13:21 -0400, Huang Shijie wrote:
>> This patch is based on the assumption that all the partitions are
>> in the right offset order.
>>
>> Assume we have a 1GB(8Gb) nand chip, and we set the partitions
>> in the command line like this:
>>     #gpmi-nand:100m(boot),100m(kernel),1g(rootfs)
>>
>> In this case, the partition truncating occurs. The current code will
>> get the following result:
>>
>>      ----------------------------------
>>       root@freescale ~$ cat /proc/mtd
>>       dev:    size   erasesize  name
>>       mtd0: 06400000 00040000 "boot"
>>       mtd1: 06400000 00040000 "kernel"
>>      ----------------------------------
>>
>> It is obvious that we lost the truncated partition `rootfs` which should
>> be 824M in this case.
>>
>> Why? The old code sets the wrong partitions number when the truncating
>> occurs. This patch fixes it. Alao add a `break` to shortcut the code in this
>> case.
>>
>> After apply this patch, the result becomes:
>>      ----------------------------------
>>       root@freescale ~$ cat /proc/mtd
>>       dev:    size   erasesize  name
>>       mtd0: 06400000 00040000 "boot"
>>       mtd1: 06400000 00040000 "kernel"
>>       mtd2: 33800000 00040000 "rootfs"
>>      ----------------------------------
>>
>> We get the right result.
>>
>> Signed-off-by: Huang Shijie <shijie8@gmail.com>
>
> Should this have CC to -stable?

It's ok to CC to stable.


thanks
Huang Shijie
>
> --
> Best Regards,
> Artem Bityutskiy
Artem Bityutskiy - Aug. 30, 2012, 6:43 a.m.
On Sun, 2012-08-26 at 13:21 -0400, Huang Shijie wrote:
> This patch is based on the assumption that all the partitions are
> in the right offset order.
> 
> Assume we have a 1GB(8Gb) nand chip, and we set the partitions
> in the command line like this:
>     #gpmi-nand:100m(boot),100m(kernel),1g(rootfs)
> 
> In this case, the partition truncating occurs. The current code will
> get the following result:
> 
>      ----------------------------------
> 	root@freescale ~$ cat /proc/mtd
> 	dev:    size   erasesize  name
> 	mtd0: 06400000 00040000 "boot"
> 	mtd1: 06400000 00040000 "kernel"
>      ----------------------------------
> 
> It is obvious that we lost the truncated partition `rootfs` which should
> be 824M in this case.
> 
> Why? The old code sets the wrong partitions number when the truncating
> occurs. This patch fixes it. Alao add a `break` to shortcut the code in this
> case.
> 
> After apply this patch, the result becomes:
>      ----------------------------------
> 	root@freescale ~$ cat /proc/mtd
> 	dev:    size   erasesize  name
> 	mtd0: 06400000 00040000 "boot"
> 	mtd1: 06400000 00040000 "kernel"
> 	mtd2: 33800000 00040000 "rootfs"
>      ----------------------------------
> 
> We get the right result.
> 
> Signed-off-by: Huang Shijie <shijie8@gmail.com>

Should this have CC to -stable?

Patch

diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index f40d390..9f0afe5 100644
--- a/drivers/mtd/cmdlinepart.c
+++ b/drivers/mtd/cmdlinepart.c
@@ -382,7 +382,8 @@  static int parse_cmdline_partitions(struct mtd_info *master,
 					       "%s: partitioning exceeds flash size, truncating\n",
 					       part->mtd_id);
 					part->parts[i].size = master->size - offset;
-					part->num_parts = i;
+					part->num_parts = i + 1;
+					break;
 				}
 				offset += part->parts[i].size;
 			}