imsm: trust sector reservation from metadata

On ich6r the option-rom appears to reserve only 432 sectors rather than
the 418+4096 of newer implementations.  For compatibility trust the
metadata in these cases.

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

diff --git a/super-intel.c b/super-intel.c
index e9f90994386a978521dcce9845e6796abe938f64..87cef13a314c3d9cb3d254dbd648258301ef5328 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -389,7 +389,6 @@ static int get_imsm_raid_level(struct imsm_map *map)
        return map->raid_level;
 }
 
-#ifndef MDASSEMBLE
 static int cmp_extent(const void *av, const void *bv)
 {
        const struct extent *a = av;
@@ -407,6 +406,7 @@ static struct extent *get_extents(struct intel_super *super, struct dl *dl)
        struct extent *rv, *e;
        int i, j;
        int memberships = 0;
+       __u32 reservation = MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS;
 
        for (i = 0; i < super->anchor->num_raid_devs; i++) {
                struct imsm_dev *dev = get_imsm_dev(super, i);
@@ -440,12 +440,57 @@ static struct extent *get_extents(struct intel_super *super, struct dl *dl)
        }
        qsort(rv, memberships, sizeof(*rv), cmp_extent);
 
-       e->start = __le32_to_cpu(dl->disk.total_blocks) -
-                  (MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS);
+       /* determine the start of the metadata 
+        * when no raid devices are defined use the default
+        * ...otherwise allow the metadata to truncate the value
+        * as is the case with older versions of imsm
+        */
+       if (memberships) {
+               struct extent *last = &rv[memberships - 1];
+               __u32 remainder;
+
+               remainder = __le32_to_cpu(dl->disk.total_blocks) - 
+                           (last->start + last->size);
+               if (reservation > remainder)
+                       reservation = remainder;
+       }
+       e->start = __le32_to_cpu(dl->disk.total_blocks) - reservation;
        e->size = 0;
        return rv;
 }
 
+/* try to determine how much space is reserved for metadata from
+ * the last get_extents() entry, otherwise fallback to the
+ * default
+ */
+static __u32 imsm_reserved_sectors(struct intel_super *super, struct dl *dl)
+{
+       struct extent *e;
+       int i;
+       __u32 rv;
+
+       /* for spares just return a minimal reservation which will grow
+        * once the spare is picked up by an array
+        */
+       if (dl->index == -1)
+               return MPB_SECTOR_CNT;
+
+       e = get_extents(super, dl);
+       if (!e)
+               return MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS;
+
+       /* scroll to last entry */
+       for (i = 0; e[i].size; i++)
+               continue;
+
+       rv = __le32_to_cpu(dl->disk.total_blocks) - e[i].start;
+
+       free(e);
+
+       return rv;
+}
+
+#ifndef MDASSEMBLE
 static void print_imsm_dev(struct imsm_dev *dev, int index)
 {
        __u64 sz;
@@ -494,7 +539,7 @@ static void print_imsm_dev(struct imsm_dev *dev, int index)
        printf("    Dirty State : %s\n", dev->vol.dirty ? "dirty" : "clean");
 }
 
-static void print_imsm_disk(struct imsm_super *mpb, int index)
+static void print_imsm_disk(struct imsm_super *mpb, int index, __u32 reserved)
 {
        struct imsm_disk *disk = __get_imsm_disk(mpb, index);
        char str[MAX_RAID_SERIAL_LEN + 1];
@@ -513,8 +558,7 @@ static void print_imsm_disk(struct imsm_super *mpb, int index)
                                              s&FAILED_DISK ? " failed" : "",
                                              s&USABLE_DISK ? " usable" : "");
        printf("             Id : %08x\n", __le32_to_cpu(disk->scsi_id));
-       sz = __le32_to_cpu(disk->total_blocks) -
-            (MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS * mpb->num_raid_devs);
+       sz = __le32_to_cpu(disk->total_blocks) - reserved;
        printf("    Usable Size : %llu%s\n", (unsigned long long)sz,
               human_size(sz * 512));
 }
@@ -526,6 +570,7 @@ static void examine_super_imsm(struct supertype *st, char *homehost)
        char str[MAX_SIGNATURE_LENGTH];
        int i;
        __u32 sum;
+       __u32 reserved = imsm_reserved_sectors(super, super->disks);
 
        snprintf(str, MPB_SIG_LEN, "%s", mpb->sig);
        printf("          Magic : %s\n", str);
@@ -539,7 +584,7 @@ static void examine_super_imsm(struct supertype *st, char *homehost)
        printf("    MPB Sectors : %d\n", mpb_sectors(mpb));
        printf("          Disks : %d\n", mpb->num_disks);
        printf("   RAID Devices : %d\n", mpb->num_raid_devs);
-       print_imsm_disk(mpb, super->disks->index);
+       print_imsm_disk(mpb, super->disks->index, reserved);
        if (super->bbm_log) {
                struct bbm_log *log = super->bbm_log;
 
@@ -556,7 +601,7 @@ static void examine_super_imsm(struct supertype *st, char *homehost)
        for (i = 0; i < mpb->num_disks; i++) {
                if (i == super->disks->index)
                        continue;
-               print_imsm_disk(mpb, i);
+               print_imsm_disk(mpb, i, reserved);
        }
 }
 
@@ -760,12 +805,13 @@ static void getinfo_super_imsm(struct supertype *st, struct mdinfo *info)
        info->name[0] = 0;
 
        if (super->disks) {
+               __u32 reserved = imsm_reserved_sectors(super, super->disks);
+
                disk = &super->disks->disk;
                info->disk.number = super->disks->index;
                info->disk.raid_disk = super->disks->index;
-               info->data_offset = __le32_to_cpu(disk->total_blocks) -
-                                   (MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS);
-               info->component_size = MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS;
+               info->data_offset = __le32_to_cpu(disk->total_blocks) - reserved;
+               info->component_size = reserved;
                s = __le32_to_cpu(disk->status);
                info->disk.state  = s & CONFIGURED_DISK ? (1 << MD_DISK_ACTIVE) : 0;
                info->disk.state |= s & FAILED_DISK ? (1 << MD_DISK_FAULTY) : 0;