[PATCH] Always return last partition end address in 512B blocks

[PATCH] Always return last partition end address in 512B blocks

[Mariusz Dabrowski]

For 4K disks 'endofpart' is an index of the last 4K sector used by partition.
mdadm is using number of 512-byte sectors, so value returned by
get_last_partition_end must be multiplied by 8 for devices with 4K sectors.
Also, unused 'ret' variable has been removed.

Signed-off-by: Mariusz Dabrowski <mariusz.dabrowski@intel.com>
---
 util.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/util.c b/util.c
index 883eaa4..46c1280 100644
--- a/util.c
+++ b/util.c
@@ -1430,6 +1430,7 @@ static int get_last_partition_end(int fd, unsigned long long *endofpart)
 	struct MBR boot_sect;
 	unsigned long long curr_part_end;
 	unsigned part_nr;
+	unsigned int sector_size;
 	int retval = 0;
 
 	*endofpart = 0;
@@ -1469,6 +1470,9 @@ static int get_last_partition_end(int fd, unsigned long long *endofpart)
 		/* Unknown partition table */
 		retval = -1;
 	}
+	/* calculate number of 512-byte blocks */
+	if (get_dev_sector_size(fd, NULL, &sector_size))
+		*endofpart *= sector_size/512;
  abort:
 	return retval;
 }
@@ -1480,9 +1484,8 @@ int check_partitions(int fd, char *dname, unsigned long long freesize,
 	 * Check where the last partition ends
 	 */
 	unsigned long long endofpart;
-	int ret;
 
-	if ((ret = get_last_partition_end(fd, &endofpart)) > 0) {
+	if (get_last_partition_end(fd, &endofpart) > 0) {
 		/* There appears to be a partition table here */
 		if (freesize == 0) {
 			/* partitions will not be visible in new device */
-- 
1.8.3.1

Re: [PATCH] Always return last partition end address in 512B blocks

[Jes Sorensen]

Mariusz Dabrowski <mariusz.dabrowski@intel.com> writes:
> For 4K disks 'endofpart' is an index of the last 4K sector used by partition.
> mdadm is using number of 512-byte sectors, so value returned by
> get_last_partition_end must be multiplied by 8 for devices with 4K sectors.
> Also, unused 'ret' variable has been removed.
>
> Signed-off-by: Mariusz Dabrowski <mariusz.dabrowski@intel.com>
> ---
>  util.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)

I am a little wary of this since I don't have any 4k sector drivers to
test with, so I will come yelling at you if this breaks something :)

> diff --git a/util.c b/util.c
> index 883eaa4..46c1280 100644
> --- a/util.c
> +++ b/util.c
> @@ -1430,6 +1430,7 @@ static int get_last_partition_end(int fd, unsigned long long *endofpart)
>  	struct MBR boot_sect;
>  	unsigned long long curr_part_end;
>  	unsigned part_nr;
> +	unsigned int sector_size;
>  	int retval = 0;
>  
>  	*endofpart = 0;
> @@ -1469,6 +1470,9 @@ static int get_last_partition_end(int fd, unsigned long long *endofpart)
>  		/* Unknown partition table */
>  		retval = -1;
>  	}
> +	/* calculate number of 512-byte blocks */
> +	if (get_dev_sector_size(fd, NULL, &sector_size))
> +		*endofpart *= sector_size/512;

I really would prefer to see a parenthesis around this here and use of
proper spacing.

Thanks,
Jes