imsm: auto layout

In support of auto-layout:

1/ collect and merge all extents to find the largest common-start free region
2/ verify that we meet the "all volumes must use the same set of disks"
2/ mark the disks to be added in add_to_super_imsm_volume

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/super-intel.c b/super-intel.c
index dd69cb133f03961341d89df0b780baa316b9ba17..2ace8a87ad6af9ee0be6bd3ec18ecb994a2fd878 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -233,6 +233,7 @@ struct intel_super {
                int fd;
                int extent_cnt;
                struct extent *e; /* for determining freespace @ create */
+               int raiddisk; /* slot to fill in autolayout */
        } *disks;
        struct dl *add; /* list of disks to add while mdmon active */
        struct dl *missing; /* disks removed while we weren't looking */
@@ -1119,7 +1120,11 @@ static void getinfo_super_imsm_volume(struct supertype *st, struct mdinfo *info)
        struct intel_super *super = st->sb;
        struct imsm_dev *dev = get_imsm_dev(super, super->current_vol);
        struct imsm_map *map = get_imsm_map(dev, 0);
+       struct dl *dl;
 
+       for (dl = super->disks; dl; dl = dl->next)
+               if (dl->raiddisk == info->disk.raid_disk)
+                       break;
        info->container_member    = super->current_vol;
        info->array.raid_disks    = map->num_members;
        info->array.level         = get_imsm_raid_level(map);
@@ -1132,6 +1137,10 @@ static void getinfo_super_imsm_volume(struct supertype *st, struct mdinfo *info)
 
        info->disk.major = 0;
        info->disk.minor = 0;
+       if (dl) {
+               info->disk.major = dl->major;
+               info->disk.minor = dl->minor;
+       }
 
        info->data_offset         = __le32_to_cpu(map->pba_of_lba0);
        info->component_size      = __le32_to_cpu(map->blocks_per_member);
@@ -2398,10 +2407,19 @@ static int add_to_super_imsm_volume(struct supertype *st, mdu_disk_info_t *dk,
                return 1;
        }
 
-       for (dl = super->disks; dl ; dl = dl->next)
-               if (dl->major == dk->major &&
-                   dl->minor == dk->minor)
-                       break;
+       if (fd == -1) {
+               /* we're doing autolayout so grab the pre-marked (in
+                * validate_geometry) raid_disk
+                */
+               for (dl = super->disks; dl; dl = dl->next)
+                       if (dl->raiddisk == dk->raid_disk)
+                               break;
+       } else {
+               for (dl = super->disks; dl ; dl = dl->next)
+                       if (dl->major == dk->major &&
+                           dl->minor == dk->minor)
+                               break;
+       }
 
        if (!dl) {
                fprintf(stderr, Name ": %s is not a member of the same container\n", devname);
@@ -3052,6 +3070,78 @@ static int validate_geometry_imsm_volume(struct supertype *st, int level,
        return 1;
 }
 
+static int reserve_space(struct supertype *st, int raiddisks,
+                        unsigned long long size, int chunk,
+                        unsigned long long *freesize)
+{
+       struct intel_super *super = st->sb;
+       struct imsm_super *mpb = super->anchor;
+       struct dl *dl;
+       int i;
+       int extent_cnt;
+       struct extent *e;
+       unsigned long long maxsize;
+       unsigned long long minsize;
+       int cnt;
+       int used;
+
+       /* find the largest common start free region of the possible disks */
+       used = 0;
+       extent_cnt = 0;
+       cnt = 0;
+       for (dl = super->disks; dl; dl = dl->next) {
+               dl->raiddisk = -1;
+
+               if (dl->index >= 0)
+                       used++;
+
+               /* don't activate new spares if we are orom constrained
+                * and there is already a volume active in the container
+                */
+               if (super->orom && dl->index < 0 && mpb->num_raid_devs)
+                       continue;
+
+               e = get_extents(super, dl);
+               if (!e)
+                       continue;
+               for (i = 1; e[i-1].size; i++)
+                       ;
+               dl->e = e;
+               dl->extent_cnt = i;
+               extent_cnt += i;
+               cnt++;
+       }
+
+       maxsize = merge_extents(super, extent_cnt);
+       minsize = size;
+       if (size == 0)
+               minsize = chunk;
+
+       if (cnt < raiddisks ||
+           (super->orom && used && used != raiddisks) ||
+           maxsize < minsize) {
+               fprintf(stderr, Name ": not enough devices with space to create array.\n");
+               return 0; /* No enough free spaces large enough */
+       }
+
+       if (size == 0) {
+               size = maxsize;
+               if (chunk) {
+                       size /= chunk;
+                       size *= chunk;
+               }
+       }
+
+       cnt = 0;
+       for (dl = super->disks; dl; dl = dl->next)
+               if (dl->e)
+                       dl->raiddisk = cnt++;
+
+       *freesize = size;
+
+       return 1;
+}
+
 static int validate_geometry_imsm(struct supertype *st, int level, int layout,
                                  int raiddisks, int chunk, unsigned long long size,
                                  char *dev, unsigned long long *freesize,
@@ -3073,9 +3163,15 @@ static int validate_geometry_imsm(struct supertype *st, int level, int layout,
        
        if (!dev) {
                if (st->sb && freesize) {
-                       /* Should do auto-layout here */
-                       fprintf(stderr, Name ": IMSM does not support auto-layout yet\n");
-                       return 0;
+                       /* we are being asked to automatically layout a
+                        * new volume based on the current contents of
+                        * the container.  If the the parameters can be
+                        * satisfied reserve_space will record the disks,
+                        * start offset, and size of the volume to be
+                        * created.  add_to_super and getinfo_super
+                        * detect when autolayout is in progress.
+                        */
+                       return reserve_space(st, raiddisks, size, chunk, freesize);
                }
                return 1;
        }