Explain the read-balancing algorithm for RAID1 better in md.4

[thirdparty/mdadm.git] / super0.c

diff --git a/super0.c b/super0.c
index 8f328436b86a8667b189f87a00bc32c98b875f92..0396c2cd81b4e26074de176c00444d1f818e45c9 100644 (file)
--- a/super0.c
+++ b/super0.c
@@ -280,6 +280,18 @@ static void brief_detail_super0(void *sbv)
        else
                printf("%08x", sb->set_uuid0);
 }
+
+static void export_super0(void *sbv)
+{
+       mdp_super_t *sb = sbv;
+       printf("MD_UUID=");
+       if (sb->minor_version >= 90)
+               printf("%08x:%08x:%08x:%08x", sb->set_uuid0, sb->set_uuid1,
+                      sb->set_uuid2, sb->set_uuid3);
+       else
+               printf("%08x", sb->set_uuid0);
+       printf("\n");
+}
 #endif
 
 static int match_home0(void *sbv, char *homehost)
@@ -447,7 +459,16 @@ static int update_super0(struct mdinfo *info, void *sbv, char *update,
                        rv = 1;
                }
        }
-       if (strcmp(update, "grow") == 0) {
+       if (strcmp(update, "linear-grow-new") == 0) {
+               memset(&sb->disks[info->disk.number], 0, sizeof(sb->disks[0]));
+               sb->disks[info->disk.number].number = info->disk.number;
+               sb->disks[info->disk.number].major = info->disk.major;
+               sb->disks[info->disk.number].minor = info->disk.minor;
+               sb->disks[info->disk.number].raid_disk = info->disk.raid_disk;
+               sb->disks[info->disk.number].state = info->disk.state;
+               sb->this_disk = sb->disks[info->disk.number];
+       }
+       if (strcmp(update, "linear-grow-update") == 0) {
                sb->raid_disks = info->array.raid_disks;
                sb->nr_disks = info->array.nr_disks;
                sb->active_disks = info->array.active_disks;
@@ -458,8 +479,6 @@ static int update_super0(struct mdinfo *info, void *sbv, char *update,
                sb->disks[info->disk.number].minor = info->disk.minor;
                sb->disks[info->disk.number].raid_disk = info->disk.raid_disk;
                sb->disks[info->disk.number].state = info->disk.state;
-               if (sb->this_disk.number == info->disk.number)
-                       sb->this_disk = sb->disks[info->disk.number];
        }
        if (strcmp(update, "resync") == 0) {
                /* make sure resync happens */
@@ -605,7 +624,7 @@ static int store_super0(struct supertype *st, int fd, void *sbv)
        if (!get_dev_size(fd, NULL, &dsize))
                return 1;
 
-       if (dsize < MD_RESERVED_SECTORS*2*512)
+       if (dsize < MD_RESERVED_SECTORS*512)
                return 2;
 
        offset = MD_NEW_SIZE_SECTORS(dsize>>9);
@@ -703,7 +722,6 @@ static int load_super0(struct supertype *st, int fd, void **sbp, char *devname)
         *  1 on cannot get superblock
         *  2 on superblock meaningless
         */
-       unsigned long size;
        unsigned long long dsize;
        unsigned long long offset;
        mdp_super_t *super;
@@ -713,10 +731,11 @@ static int load_super0(struct supertype *st, int fd, void **sbp, char *devname)
        if (!get_dev_size(fd, devname, &dsize))
                return 1;
 
-       if (dsize < MD_RESERVED_SECTORS*512 * 2) {
+       if (dsize < MD_RESERVED_SECTORS*512) {
                if (devname)
-                       fprintf(stderr, Name ": %s is too small for md: size is %ld sectors.\n",
-                               devname, size);
+                       fprintf(stderr, Name
+                           ": %s is too small for md: size is %llu sectors.\n",
+                               devname, dsize);
                return 1;
        }
 
@@ -816,7 +835,7 @@ static struct supertype *match_metadata_desc0(char *arg)
 
 static __u64 avail_size0(struct supertype *st, __u64 devsize)
 {
-       if (devsize < MD_RESERVED_SECTORS*2)
+       if (devsize < MD_RESERVED_SECTORS)
                return 0ULL;
        return MD_NEW_SIZE_SECTORS(devsize);
 }
@@ -874,7 +893,7 @@ void locate_bitmap0(struct supertype *st, int fd, void *sbv)
        if (!get_dev_size(fd, NULL, &dsize))
                return;
 
-       if (dsize < MD_RESERVED_SECTORS*512 * 2)
+       if (dsize < MD_RESERVED_SECTORS*512)
                return;
 
        offset = MD_NEW_SIZE_SECTORS(dsize>>9);
@@ -901,8 +920,8 @@ int write_bitmap0(struct supertype *st, int fd, void *sbv)
                return 1;
 
 
-       if (dsize < MD_RESERVED_SECTORS*512 * 2)
-       return -1;
+       if (dsize < MD_RESERVED_SECTORS*512)
+               return -1;
 
        offset = MD_NEW_SIZE_SECTORS(dsize>>9);
 
@@ -940,6 +959,7 @@ struct superswitch super0 = {
        .brief_examine_super = brief_examine_super0,
        .detail_super = detail_super0,
        .brief_detail_super = brief_detail_super0,
+       .export_super = export_super0,
 #endif
        .match_home = match_home0,
        .uuid_from_super = uuid_from_super0,