md/raid10: split out interpretation of layout to separate function.

We will soon be interpreting the layout (and chunksize etc) from
multiple places to support reshape.  So split it out into separate
function.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index ff8c2e28c2ffc86db283484def0f304e1e88b171..4469f52c276e7ad7e7dff9a5279cee1764d65d96 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3223,28 +3223,65 @@ raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks)
        return size << conf->geo.chunk_shift;
 }
 
+enum geo_type {geo_new, geo_old, geo_start};
+static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new)
+{
+       int nc, fc, fo;
+       int layout, chunk, disks;
+       switch (new) {
+       case geo_old:
+               layout = mddev->layout;
+               chunk = mddev->chunk_sectors;
+               disks = mddev->raid_disks - mddev->delta_disks;
+               break;
+       case geo_new:
+               layout = mddev->new_layout;
+               chunk = mddev->new_chunk_sectors;
+               disks = mddev->raid_disks;
+               break;
+       default: /* avoid 'may be unused' warnings */
+       case geo_start: /* new when starting reshape - raid_disks not
+                        * updated yet. */
+               layout = mddev->new_layout;
+               chunk = mddev->new_chunk_sectors;
+               disks = mddev->raid_disks + mddev->delta_disks;
+               break;
+       }
+       if (layout >> 17)
+               return -1;
+       if (chunk < (PAGE_SIZE >> 9) ||
+           !is_power_of_2(chunk))
+               return -2;
+       nc = layout & 255;
+       fc = (layout >> 8) & 255;
+       fo = layout & (1<<16);
+       geo->raid_disks = disks;
+       geo->near_copies = nc;
+       geo->far_copies = fc;
+       geo->far_offset = fo;
+       geo->chunk_mask = chunk - 1;
+       geo->chunk_shift = ffz(~chunk);
+       return nc*fc;
+}
 
 static struct r10conf *setup_conf(struct mddev *mddev)
 {
        struct r10conf *conf = NULL;
-       int nc, fc, fo;
        sector_t stride, size;
        int err = -EINVAL;
+       struct geom geo;
+       int copies;
+
+       copies = setup_geo(&geo, mddev, geo_new);
 
-       if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
-           !is_power_of_2(mddev->new_chunk_sectors)) {
+       if (copies == -2) {
                printk(KERN_ERR "md/raid10:%s: chunk size must be "
                       "at least PAGE_SIZE(%ld) and be a power of 2.\n",
                       mdname(mddev), PAGE_SIZE);
                goto out;
        }
 
-       nc = mddev->new_layout & 255;
-       fc = (mddev->new_layout >> 8) & 255;
-       fo = mddev->new_layout & (1<<16);
-
-       if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
-           (mddev->new_layout >> 17)) {
+       if (copies < 2 || copies > mddev->raid_disks) {
                printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
                       mdname(mddev), mddev->new_layout);
                goto out;
@@ -3264,24 +3301,17 @@ static struct r10conf *setup_conf(struct mddev *mddev)
        if (!conf->tmppage)
                goto out;
 
-
-       conf->geo.raid_disks = mddev->raid_disks;
-       conf->geo.near_copies = nc;
-       conf->geo.far_copies = fc;
-       conf->copies = nc*fc;
-       conf->geo.far_offset = fo;
-       conf->geo.chunk_mask = mddev->new_chunk_sectors - 1;
-       conf->geo.chunk_shift = ffz(~mddev->new_chunk_sectors);
-
+       conf->geo = geo;
+       conf->copies = copies;
        conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
                                           r10bio_pool_free, conf);
        if (!conf->r10bio_pool)
                goto out;
 
        size = mddev->dev_sectors >> conf->geo.chunk_shift;
-       sector_div(size, fc);
+       sector_div(size, geo.far_copies);
        size = size * conf->geo.raid_disks;
-       sector_div(size, nc);
+       sector_div(size, geo.near_copies);
        /* 'size' is now the number of chunks in the array */
        /* calculate "used chunks per device" in 'stride' */
        stride = size * conf->copies;
@@ -3294,10 +3324,10 @@ static struct r10conf *setup_conf(struct mddev *mddev)
 
        conf->dev_sectors = stride << conf->geo.chunk_shift;
 
-       if (fo)
+       if (geo.far_offset)
                stride = 1;
        else
-               sector_div(stride, fc);
+               sector_div(stride, geo.far_copies);
        conf->geo.stride = stride << conf->geo.chunk_shift;
        conf->prev = conf->geo;
        conf->reshape_progress = MaxSector;