First steps to supporting auto-spare-add to groups of partitioned devices.

Adding a spare to a group of partitioned devices is quite different
from adding one to an array.  So detect which option is worth trying
based on policy and then try one or the other - or possibly both - as
appropriate.

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

diff --git a/Incremental.c b/Incremental.c
index bcbd78d0b4abe67ec2069922936be39447a609c5..a6c98bdc5a53794f1c66b3de5b13d9022e56e114 100644 (file)
--- a/Incremental.c
+++ b/Incremental.c
@@ -714,8 +714,8 @@ static int count_active(struct supertype *st, int mdfd, char **availp,
        return cnt + cnt1;
 }
 
-static int try_spare(char *devname, int *dfdp, struct dev_policy *pol,
-                    struct supertype *st, int verbose)
+static int array_try_spare(char *devname, int *dfdp, struct dev_policy *pol,
+                          struct supertype *st, int verbose)
 {
        /* This device doesn't have any md metadata
         * If it is 'bare' and theh device policy allows 'spare' look for
@@ -724,47 +724,15 @@ static int try_spare(char *devname, int *dfdp, struct dev_policy *pol,
         * Return 0 on success, or some exit code on failure, probably 1.
         */
        int rv = -1;
-       char bufpad[4096 + 4096];
-       char *buf = (char*)(((long)bufpad + 4096) & ~4095);
        struct stat stb;
        struct map_ent *mp, *map = NULL;
        struct mdinfo *chosen = NULL;
        int dfd = *dfdp;
 
-       /* First check policy */
-       if (!policy_action_allows(pol, st?st->ss->name:NULL, act_spare))
-               return 1;
-
        if (fstat(dfd, &stb) != 0)
                return 1;
-       /* Now check if the device is bare - we don't add non-bare devices
-        * yet even if action=-spare
-        */
 
-       if (lseek(dfd, 0, SEEK_SET) != 0 ||
-           read(dfd, buf, 4096) != 4096) {
-       not_bare:
-               if (verbose > 1)
-                       fprintf(stderr, Name ": %s is not bare, so not considering as a spare\n",
-                               devname);
-               return 1;
-       }
-       if (buf[0] != '\0' && buf[0] != '\x5a' && buf[0] != '\xff')
-               goto not_bare;
-       if (memcmp(buf, buf+1, 4095) != 0)
-               goto not_bare;
-
-       /* OK, first 4K appear blank, try the end. */
-       if (lseek(dfd, -4096, SEEK_END) < 0 ||
-           read(dfd, buf, 4096) != 4096)
-               goto not_bare;
-
-       if (buf[0] != '\0' && buf[0] != '\x5a' && buf[0] != '\xff')
-               goto not_bare;
-       if (memcmp(buf, buf+1, 4095) != 0)
-               goto not_bare;
-
-       /* This device passes our test for 'is bare'.
+       /*
         * Now we need to find a suitable array to add this to.
         * We only accept arrays that:
         *  - match 'st'
@@ -886,6 +854,92 @@ static int try_spare(char *devname, int *dfdp, struct dev_policy *pol,
        return rv ? 0 : 1;
 }
 
+static int partition_try_spare(char *devname, int *dfdp, struct dev_policy *pol,
+                              struct supertype *st, int verbose)
+{
+       return 1;
+}
+
+
+/* adding a spare to a regular array is quite different from adding one to
+ * a set-of-partitions virtual array.
+ * This function determines which is worth trying and tries as appropriate.
+ * Arrays are given priority over partitions.
+ */
+static int try_spare(char *devname, int *dfdp, struct dev_policy *pol,
+                    struct supertype *st, int verbose)
+{
+       int i;
+       int rv;
+       int arrays_ok = 0;
+       int partitions_ok = 0;
+       char bufpad[4096 + 4096];
+       char *buf = (char*)(((long)bufpad + 4096) & ~4095);
+       int dfd = *dfdp;
+
+       /* Can only add a spare if device has at least one domains */
+       if (pol_find(pol, pol_domain) == NULL)
+               return 1;
+       /* And only if some action allows spares */
+       if (!policy_action_allows(pol, st?st->ss->name:NULL, act_spare))
+               return 1;
+
+       /* Now check if the device is bare - we don't add non-bare devices
+        * yet even if action=-spare
+        */
+
+       if (lseek(dfd, 0, SEEK_SET) != 0 ||
+           read(dfd, buf, 4096) != 4096) {
+       not_bare:
+               if (verbose > 1)
+                       fprintf(stderr, Name ": %s is not bare, so not considering as a spare\n",
+                               devname);
+               return 1;
+       }
+       if (buf[0] != '\0' && buf[0] != '\x5a' && buf[0] != '\xff')
+               goto not_bare;
+       if (memcmp(buf, buf+1, 4095) != 0)
+               goto not_bare;
+
+       /* OK, first 4K appear blank, try the end. */
+       if (lseek(dfd, -4096, SEEK_END) < 0 ||
+           read(dfd, buf, 4096) != 4096)
+               goto not_bare;
+
+       if (buf[0] != '\0' && buf[0] != '\x5a' && buf[0] != '\xff')
+               goto not_bare;
+       if (memcmp(buf, buf+1, 4095) != 0)
+               goto not_bare;
+
+       /* This device passes our test for 'is bare'.
+        * Let's see what policy allows for such things.
+        */
+       if (st) {
+               /* just try try 'array' or 'partition' based on this metadata */
+               if (st->ss->add_to_super)
+                       return array_try_spare(devname, dfdp, pol,
+                                              st, verbose);
+               else
+                       return partition_try_spare(devname, dfdp, pol,
+                                                  st, verbose);
+       }
+       /* Now see which metadata type support spare */
+       for (i = 0; (!arrays_ok || !partitions_ok) && superlist[i] ; i++) {
+               if (superlist[i]->add_to_super && !arrays_ok &&
+                   policy_action_allows(pol, superlist[i]->name, act_spare))
+                       arrays_ok = 1;
+               if (superlist[i]->add_to_super == NULL && !partitions_ok &&
+                   policy_action_allows(pol, superlist[i]->name, act_spare))
+                       partitions_ok = 1;
+       }
+       rv = 0;
+       if (arrays_ok)
+               rv = array_try_spare(devname, dfdp, pol, st, verbose);
+       if (rv == 0 && partitions_ok)
+               rv = partition_try_spare(devname, dfdp, pol, st, verbose);
+       return rv;
+}
+
 int IncrementalScan(int verbose)
 {
        /* look at every device listed in the 'map' file.