DM RAID: Move 'rebuild' checking code to its own function

DM RAID:  Move chunk of code to it's own function

The code that checks whether device replacements/rebuilds are possible given
a specific RAID type is moved to it's own function.  It will further expand
when the code to check RAID10 is added.  A separate function makes it easier
to read.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 50 insertions, 25 deletions

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 982e3e390c45..10635e965fec 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -338,6 +338,52 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 }
 
 /*
+ * validate_rebuild_devices
+ * @rs
+ *
+ * Determine if the devices specified for rebuild can result in a valid
+ * usable array that is capable of rebuilding the given devices.
+ *
+ * Returns: 0 on success, -EINVAL on failure.
+ */
+static int validate_rebuild_devices(struct raid_set *rs)
+{
+        unsigned i, rebuild_cnt = 0;
+
+        if (!(rs->print_flags & DMPF_REBUILD))
+                return 0;
+
+        for (i = 0; i < rs->md.raid_disks; i++)
+                if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
+                        rebuild_cnt++;
+
+        switch (rs->raid_type->level) {
+        case 1:
+                if (rebuild_cnt >= rs->md.raid_disks)
+                        goto too_many;
+                break;
+        case 4:
+        case 5:
+        case 6:
+                if (rebuild_cnt > rs->raid_type->parity_devs)
+                        goto too_many;
+                break;
+        case 10:
+        default:
+                DMERR("The rebuild parameter is not supported for %s",
+                      rs->raid_type->name);
+                rs->ti->error = "Rebuild not supported for this RAID type";
+                return -EINVAL;
+        }
+
+        return 0;
+
+too_many:
+        rs->ti->error = "Too many rebuild devices specified";
+        return -EINVAL;
+}
+
+/*
  * Possible arguments are...
  *      <chunk_size> [optional_args]
  *
@@ -365,7 +411,7 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
 {
         char *raid10_format = "near";
         unsigned raid10_copies = 2;
-        unsigned i, rebuild_cnt = 0;
+        unsigned i;
         unsigned long value, region_size = 0;
         sector_t sectors_per_dev = rs->ti->len;
         sector_t max_io_len;
@@ -461,30 +507,6 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
 
                 /* Parameters that take a numeric value are checked here */
                 if (!strcasecmp(key, "rebuild")) {
-                        rebuild_cnt++;
-
-                        switch (rs->raid_type->level) {
-                        case 1:
-                                if (rebuild_cnt >= rs->md.raid_disks) {
-                                        rs->ti->error = "Too many rebuild devices specified";
-                                        return -EINVAL;
-                                }
-                                break;
-                        case 4:
-                        case 5:
-                        case 6:
-                                if (rebuild_cnt > rs->raid_type->parity_devs) {
-                                        rs->ti->error = "Too many rebuild devices specified for given RAID type";
-                                        return -EINVAL;
-                                }
-                                break;
-                        case 10:
-                        default:
-                                DMERR("The rebuild parameter is not supported for %s", rs->raid_type->name);
-                                rs->ti->error = "Rebuild not supported for this RAID type";
-                                return -EINVAL;
-                        }
-
                         if (value > rs->md.raid_disks) {
                                 rs->ti->error = "Invalid rebuild index given";
                                 return -EINVAL;
@@ -608,6 +630,9 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
         }
         rs->md.dev_sectors = sectors_per_dev;
 
+        if (validate_rebuild_devices(rs))
+                return -EINVAL;
+
         /* Assume there are no metadata devices until the drives are parsed */
         rs->md.persistent = 0;
         rs->md.external = 1;