From: NeilBrown <neilb@suse.de>
If you try to assemble an array with too many missing devices, raid10 will now
reject the attempt, instead of allowing it.
Also check when hot-adding a drive and refuse the hot-add if the array is
beyond hope.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
drivers/md/raid10.c | 30 +++++++++++++++++++++++++++---
1 files changed, 27 insertions(+), 3 deletions(-)
diff -puN drivers/md/raid10.c~md-fix-raid10-assembly-when-too-many-devices-are-missing drivers/md/raid10.c
--- devel/drivers/md/raid10.c~md-fix-raid10-assembly-when-too-many-devices-are-missing 2005-09-06 17:10:29.000000000 -0700
+++ devel-akpm/drivers/md/raid10.c 2005-09-06 17:10:29.000000000 -0700
@@ -906,6 +906,27 @@ static void close_sync(conf_t *conf)
conf->r10buf_pool = NULL;
}
+/* check if there are enough drives for
+ * every block to appear on atleast one
+ */
+static int enough(conf_t *conf)
+{
+ int first = 0;
+
+ do {
+ int n = conf->copies;
+ int cnt = 0;
+ while (n--) {
+ if (conf->mirrors[first].rdev)
+ cnt++;
+ first = (first+1) % conf->raid_disks;
+ }
+ if (cnt == 0)
+ return 0;
+ } while (first != 0);
+ return 1;
+}
+
static int raid10_spare_active(mddev_t *mddev)
{
int i;
@@ -944,6 +965,8 @@ static int raid10_add_disk(mddev_t *mdde
* very different from resync
*/
return 0;
+ if (!enough(conf))
+ return 0;
for (mirror=0; mirror < mddev->raid_disks; mirror++)
if ( !(p=conf->mirrors+mirror)->rdev) {
@@ -1684,9 +1707,10 @@ static int run(mddev_t *mddev)
init_waitqueue_head(&conf->wait_idle);
init_waitqueue_head(&conf->wait_resume);
- if (!conf->working_disks) {
- printk(KERN_ERR "raid10: no operational mirrors for %s\n",
- mdname(mddev));
+ /* need to check that every block has at least one working mirror */
+ if (!enough(conf)) {
+ printk(KERN_ERR "raid10: not enough operational mirrors for %s\n",
+ mdname(mddev));
goto out_free_conf;
}
_