linux-kernel - [PATCH v2] mtd: cmdlinepart: fix the wrong partitions number when truncating occurs

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Date:	Sat, 25 Aug 2012 10:26:07 -0400
From:	Huang Shijie <shijie8@...il.com>
To:	dwmw2@...radead.org
Cc:	linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org,
	dedekind1@...il.com, Huang Shijie <shijie8@...il.com>
Subject: [PATCH v2] mtd: cmdlinepart: fix the wrong partitions number when truncating occurs

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@...escale ~$ 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@...escale ~$ 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@...il.com>
---
v1 --> v2:
	[1] add more commit info.
---
 drivers/mtd/cmdlinepart.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index 4558e0f..fc960a3 100644
--- a/drivers/mtd/cmdlinepart.c
+++ b/drivers/mtd/cmdlinepart.c
@@ -344,7 +344,8 @@ 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;
 			}
-- 
1.7.4.4

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