Validate size of potential spare disk for external metadata (with containers)

mdinfo read with sysfs_read do not contain information about the space
needed to store data of all volumes created in that container, so that
spare can be used as replacement for existing subarrays in the future.

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

diff --git a/Incremental.c b/Incremental.c
index 2b6ba91c1b2c1b0a0189e7923405461f269350eb..90fc3739d9dbb11d5a0fd39396fa8406b3eedd9e 100644 (file)
--- a/Incremental.c
+++ b/Incremental.c
@@ -888,6 +888,7 @@ static int array_try_spare(char *devname, int *dfdp, struct dev_policy *pol,
                struct domainlist *dl = NULL;
                struct mdinfo *sra;
                unsigned long long devsize;
+               unsigned long long component_size;
 
                if (is_subarray(mp->metadata))
                        continue;
@@ -946,7 +947,25 @@ static int array_try_spare(char *devname, int *dfdp, struct dev_policy *pol,
                        sra->array.failed_disks = container_members_max_degradation(map, mp);
 
                get_dev_size(dfd, NULL, &devsize);
-               if (st2->ss->avail_size(st2, devsize) < sra->component_size) {
+               if (sra->component_size == 0) {
+                       /* true for containers, here we must read superblock
+                        * to obtain minimum spare size */
+                       struct supertype *st3 = dup_super(st2);
+                       int mdfd = open_dev(mp->devnum);
+                       if (!mdfd)
+                               goto next;
+                       if (st3->ss->load_container &&
+                           !st3->ss->load_container(st3, mdfd, mp->path)) {
+                               component_size = st3->ss->min_acceptable_spare_size(st3);
+                               st3->ss->free_super(st3);
+                       }
+                       free(st3);
+                       close(mdfd);
+               }
+               if ((sra->component_size > 0 &&
+                    st2->ss->avail_size(st2, devsize) < sra->component_size)
+                   ||
+                   (sra->component_size == 0 && devsize < component_size)) {
                        if (verbose > 1)
                                fprintf(stderr, Name ": not adding %s to %s as it is too small\n",
                                        devname, mp->path);