On Fri, 26 Nov 2010 09:08:16 +0100 Adam Kwolek <adam.kwolek@xxxxxxxxx> wrote:
> number of backup blocks evaluation is put in to function for code reuse.
Applied, thanks.
NeilBrown
>
> Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx>
> ---
>
> Grow.c | 44 +++++++++++++++++++++++++++-----------------
> mdadm.h | 4 +++-
> 2 files changed, 30 insertions(+), 18 deletions(-)
>
> diff --git a/Grow.c b/Grow.c
> index 8cba82b..8cc17d5 100644
> --- a/Grow.c
> +++ b/Grow.c
> @@ -929,6 +929,31 @@ release:
> return d;
> }
>
> +unsigned long compute_backup_blocks(int nchunk, int ochunk,
> + unsigned int ndata, unsigned int odata)
> +{
> + unsigned long a, b, blocks;
> + /* So how much do we need to backup.
> + * We need an amount of data which is both a whole number of
> + * old stripes and a whole number of new stripes.
> + * So LCM for (chunksize*datadisks).
> + */
> + a = (ochunk/512) * odata;
> + b = (nchunk/512) * ndata;
> + /* Find GCD */
> + while (a != b) {
> + if (a < b)
> + b -= a;
> + if (b < a)
> + a -= b;
> + }
> + /* LCM == product / GCD */
> + blocks = (ochunk/512) * (nchunk/512) * odata * ndata / a;
> +
> + return blocks;
> +}
> +
> +
> int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
> long long size,
> int level, char *layout_str, int chunksize, int raid_disks)
> @@ -967,7 +992,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
> int nrdisks;
> int err;
> int frozen;
> - unsigned long a,b, blocks, stripes;
> + unsigned long blocks, stripes;
> unsigned long cache;
> unsigned long long array_size;
> int changed = 0;
> @@ -1587,22 +1612,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
> break;
> }
>
> - /* So how much do we need to backup.
> - * We need an amount of data which is both a whole number of
> - * old stripes and a whole number of new stripes.
> - * So LCM for (chunksize*datadisks).
> - */
> - a = (ochunk/512) * odata;
> - b = (nchunk/512) * ndata;
> - /* Find GCD */
> - while (a != b) {
> - if (a < b)
> - b -= a;
> - if (b < a)
> - a -= b;
> - }
> - /* LCM == product / GCD */
> - blocks = (ochunk/512) * (nchunk/512) * odata * ndata / a;
> + blocks = compute_backup_blocks(nchunk, ochunk, ndata, odata);
>
> sysfs_free(sra);
> sra = sysfs_read(fd, 0,
> diff --git a/mdadm.h b/mdadm.h
> index 698f1bf..06195c8 100644
> --- a/mdadm.h
> +++ b/mdadm.h
> @@ -459,7 +459,8 @@ extern int reshape_prepare_fdlist(char *devname,
> extern void reshape_free_fdlist(int **fdlist_in,
> unsigned long long **offsets_in,
> int size);
> -
> +extern unsigned long compute_backup_blocks(int nchunk, int ochunk,
> + unsigned int ndata, unsigned int odata);
>
> extern int save_stripes(int *source, unsigned long long *offsets,
> int raid_disks, int chunk_size, int level, int layout,
> @@ -471,6 +472,7 @@ extern int restore_stripes(int *dest, unsigned long long *offsets,
> int source, unsigned long long read_offset,
> unsigned long long start, unsigned long long length);
>
> +
> #ifndef Sendmail
> #define Sendmail "/usr/lib/sendmail -t"
> #endif
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