On Tue, 01 Feb 2011 08:57:37 +0100 Adam Kwolek <adam.kwolek@xxxxxxxxx> wrote:
> When get_imsm_map() is called with second_map parameter == '-1'
> and array is not in migration state NULL pointer is returned.
> This is wrong. '-1' means return map as migration record points.
>
> '-1' can be passed to get_imsm_map() from imsm_num_data_members().
> imsm_num_data_members() is called to get current map members based
> on migr_state information
>
> Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx>
> ---
>
> super-intel.c | 7 ++++---
> 1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/super-intel.c b/super-intel.c
> index 84ab47b..ee0d9c4 100644
> --- a/super-intel.c
> +++ b/super-intel.c
> @@ -567,15 +567,16 @@ struct imsm_map *get_imsm_map(struct imsm_dev *dev, int second_map)
> {
> struct imsm_map *map = &dev->vol.map[0];
>
> - if (second_map && !dev->vol.migr_state)
> + if ((second_map == 1) && !dev->vol.migr_state)
> return NULL;
> - else if (second_map) {
> + else if ((second_map == 1) ||
> + ((second_map < 0) && (dev->vol.migr_state))) {
> void *ptr = map;
>
> return ptr + sizeof_imsm_map(map);
> } else
> return map;
> -
> +
> }
>
> /* return the size of the device.
Thanks.
I added some comments and took the opportunity to simplify
get_imsm_ord_tbl_ent. See below.
NeilBrown
commit 5e7b0330669594ee79201d19ff45a7850fa0f951
Author: Adam Kwolek <adam.kwolek@xxxxxxxxx>
Date: Thu Feb 3 17:02:39 2011 +1100
imsm: FIX: crash during getting map
When get_imsm_map() is called with second_map parameter == '-1'
and array is not in migration state NULL pointer is returned.
This is wrong. '-1' means return map as migration record points.
'-1' can be passed to get_imsm_map() from imsm_num_data_members().
imsm_num_data_members() is called to get current map members based
on migr_state information
Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxx>
diff --git a/super-intel.c b/super-intel.c
index 84ab47b..4081071 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -565,17 +565,24 @@ static size_t sizeof_imsm_map(struct imsm_map *map)
struct imsm_map *get_imsm_map(struct imsm_dev *dev, int second_map)
{
+ /* A device can have 2 maps if it is in the middle of a migration.
+ * If second_map is:
+ * 0 - we return the first map
+ * 1 - we return the second map if it exists, else NULL
+ * -1 - we return the second map if it exists, else the first
+ */
struct imsm_map *map = &dev->vol.map[0];
- if (second_map && !dev->vol.migr_state)
+ if (second_map == 1 && !dev->vol.migr_state)
return NULL;
- else if (second_map) {
+ else if (second_map == 1 ||
+ (second_map < 0 && dev->vol.migr_state)) {
void *ptr = map;
return ptr + sizeof_imsm_map(map);
} else
return map;
-
+
}
/* return the size of the device.
@@ -654,14 +661,7 @@ static __u32 get_imsm_ord_tbl_ent(struct imsm_dev *dev,
{
struct imsm_map *map;
- if (second_map == -1) {
- if (dev->vol.migr_state)
- map = get_imsm_map(dev, 1);
- else
- map = get_imsm_map(dev, 0);
- } else {
- map = get_imsm_map(dev, second_map);
- }
+ map = get_imsm_map(dev, second_map);
/* top byte identifies disk under rebuild */
return __le32_to_cpu(map->disk_ord_tbl[slot]);
--
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