Grow: split out code for setting new_data_offset

This will soon be used for more than just RAID10, so
it deserves independent existence.

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

diff --git a/Grow.c b/Grow.c
index f972f22e5a024439378e9427edfaf68bd2484c1a..78563df64f04947c6a5e459fbb0bcf4a78cc5958 100644 (file)
--- a/Grow.c
+++ b/Grow.c
@@ -2149,60 +2149,15 @@ static int verify_reshape_position(struct mdinfo *info, int level)
        return ret_val;
 }
 
-static int raid10_reshape(char *container, int fd, char *devname,
-                         struct supertype *st, struct mdinfo *info,
-                         struct reshape *reshape,
-                         unsigned long long data_offset,
-                         int force, int verbose)
+static int set_new_data_offset(struct mdinfo *sra, struct supertype *st,
+                              char *devname, struct mdinfo *info,
+                              unsigned long long data_offset,
+                              unsigned long long min)
 {
-       /* Changing raid_disks, layout, chunksize or possibly
-        * just data_offset for a RAID10.
-        * We must always change data_offset.  We change by at least
-        * ->backup_blocks which is the largest of the old and new
-        * chunk sizes.
-        * If raid_disks is increasing, then data_offset must decrease
-        * by at least this copy size.
-        * If raid_disks is unchanged, data_offset must increase or
-        * decrease by at least backup_blocks but preferably by much more.
-        * We choose half of the available space.
-        * If raid_disks is decreasing, data_offset must increase by
-        * at least backup_blocks.  To allow of this, component_size
-        * must be decreased by the same amount.
-        *
-        * So we calculate the required minimum and direction, possibly
-        * reduce the component_size, then iterate through the devices
-        * and set the new_data_offset.
-        * If that all works, we set chunk_size, layout, raid_disks, and start
-        * 'reshape'
-        */
-       struct mdinfo *sra, *sd;
-       unsigned long long min;
+       struct mdinfo *sd;
        int dir = 0;
        int err = 0;
 
-       sra = sysfs_read(fd, NULL,
-                        GET_COMPONENT|GET_DEVS|GET_OFFSET|GET_STATE|GET_CHUNK
-               );
-       if (!sra) {
-               fprintf(stderr, Name ": %s: Cannot get array details from sysfs\n",
-                       devname);
-               goto release;
-       }
-       min = reshape->backup_blocks;
-
-       if (info->delta_disks)
-               sysfs_set_str(sra, NULL, "reshape_direction",
-                             info->delta_disks < 0 ? "backwards" : "forwards");
-       if (info->delta_disks < 0 &&
-           info->space_after < reshape->backup_blocks) {
-               int rv = sysfs_set_num(sra, NULL, "component_size",
-                                      (sra->component_size -
-                                       reshape->backup_blocks)/2);
-               if (rv) {
-                       fprintf(stderr, Name ": cannot reduce component size\n");
-                       goto release;
-               }
-       }
        for (sd = sra->devs; sd; sd = sd->next) {
                char *dn;
                int dfd;
@@ -2343,6 +2298,69 @@ static int raid10_reshape(char *container, int fd, char *devname,
                        break;
                }
        }
+       return err;
+release:
+       return -1;
+}
+
+static int raid10_reshape(char *container, int fd, char *devname,
+                         struct supertype *st, struct mdinfo *info,
+                         struct reshape *reshape,
+                         unsigned long long data_offset,
+                         int force, int verbose)
+{
+       /* Changing raid_disks, layout, chunksize or possibly
+        * just data_offset for a RAID10.
+        * We must always change data_offset.  We change by at least
+        * ->backup_blocks which is the largest of the old and new
+        * chunk sizes.
+        * If raid_disks is increasing, then data_offset must decrease
+        * by at least this copy size.
+        * If raid_disks is unchanged, data_offset must increase or
+        * decrease by at least backup_blocks but preferably by much more.
+        * We choose half of the available space.
+        * If raid_disks is decreasing, data_offset must increase by
+        * at least backup_blocks.  To allow of this, component_size
+        * must be decreased by the same amount.
+        *
+        * So we calculate the required minimum and direction, possibly
+        * reduce the component_size, then iterate through the devices
+        * and set the new_data_offset.
+        * If that all works, we set chunk_size, layout, raid_disks, and start
+        * 'reshape'
+        */
+       struct mdinfo *sra;
+       unsigned long long min;
+       int err = 0;
+
+       sra = sysfs_read(fd, NULL,
+                        GET_COMPONENT|GET_DEVS|GET_OFFSET|GET_STATE|GET_CHUNK
+               );
+       if (!sra) {
+               fprintf(stderr, Name ": %s: Cannot get array details from sysfs\n",
+                       devname);
+               goto release;
+       }
+       min = reshape->backup_blocks;
+
+       if (info->delta_disks)
+               sysfs_set_str(sra, NULL, "reshape_direction",
+                             info->delta_disks < 0 ? "backwards" : "forwards");
+       if (info->delta_disks < 0 &&
+           info->space_after < reshape->backup_blocks) {
+               int rv = sysfs_set_num(sra, NULL, "component_size",
+                                      (sra->component_size -
+                                       reshape->backup_blocks)/2);
+               if (rv) {
+                       fprintf(stderr, Name ": cannot reduce component size\n");
+                       goto release;
+               }
+       }
+       err = set_new_data_offset(sra, st, devname, info, data_offset,
+                                 min);
+       if (err < 0)
+               goto release;
+
        if (!err && sysfs_set_num(sra, NULL, "chunk_size", info->new_chunk) < 0)
                err = errno;
        if (!err && sysfs_set_num(sra, NULL, "layout", reshape->after.layout) < 0)