On 09/01/2016 01:52 AM, NeilBrown wrote:
On Thu, Sep 01 2016, Guoqing Jiang wrote:
On 08/26/2016 10:40 AM, Marc Smith wrote:
Hi,
I'm attempting to use md-cluster from Linux 4.5.2 with mdadm 3.4 and
I'm running into this when attempting to create a RAID1 device with
the clustered bitmap:
--snip--
[64782.619968] md: bind<dm-4>
[64782.629336] md: bind<dm-3>
[64782.630008] md/raid1:md127: active with 2 out of 2 mirrors
[64782.630528] md-cluster module not found.
[64782.630530] md127: Could not setup cluster service (-2)
[64782.630531] md127: bitmap file superblock:
[64782.630532] magic: 6d746962
[64782.630533] version: 5
[64782.630534] uuid: 10fee18f.f553d7f2.deb926f1.c7c4bd4b
[64782.630534] events: 0
[64782.630535] events cleared: 0
[64782.630536] state: 00000000
[64782.630537] chunksize: 67108864 B
[64782.630537] daemon sleep: 5s
[64782.630538] sync size: 878956288 KB
[64782.630539] max write behind: 0
[64782.630541] md127: failed to create bitmap (-2)
[64782.630577] md: md127 stopped.
[64782.630581] md: unbind<dm-3>
[64782.635133] md: export_rdev(dm-3)
[64782.635145] md: unbind<dm-4>
[64782.643111] md: export_rdev(dm-4)
--snip--
I'm using md-cluster built-in, not as a module:
# zcat /proc/config.gz | grep MD_CLUSTER
CONFIG_MD_CLUSTER=y
It seems the driver is attempting to load the 'md-cluster' module
(from drivers/md/md.c):
--snip--
err = request_module("md-cluster");
if (err) {
pr_err("md-cluster module not found.\n");
return -ENOENT;
}
--snip--
I think this code is wrong. It should be more like:
diff --git a/drivers/md/md.c b/drivers/md/md.c
index d646f6e444f0..09036add7f33 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7612,15 +7612,13 @@ int md_setup_cluster(struct mddev *mddev, int nodes)
{
int err;
- err = request_module("md-cluster");
- if (err) {
- pr_err("md-cluster module not found.\n");
- return -ENOENT;
- }
+ if (!md_cluster_ops)
+ request_module("md-cluster");
spin_lock(&pers_lock);
if (!md_cluster_ops || !try_module_get(md_cluster_mod)) {
spin_unlock(&pers_lock);
+ pr_err("md-cluster module not found.\n");
return -ENOENT;
}
spin_unlock(&pers_lock);
Thanks, how about below changes?
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7619,20 +7619,19 @@ EXPORT_SYMBOL(unregister_md_cluster_operations);
int md_setup_cluster(struct mddev *mddev, int nodes)
{
- int err;
-
- err = request_module("md-cluster");
- if (err) {
- pr_err("md-cluster module not found.\n");
- return -ENOENT;
- }
-
spin_lock(&pers_lock);
- if (!md_cluster_ops || !try_module_get(md_cluster_mod)) {
- spin_unlock(&pers_lock);
- return -ENOENT;
+ if (!md_cluster_ops) {
+ /* load module and ensure it won't be unloaded */
+ if (!request_module("md-cluster") &&
+ !try_module_get(md_cluster_mod)) {
+ pr_err("md-cluster module found.\n");
+ spin_unlock(&pers_lock);
+ } else {
+ pr_err("md-cluster module not found.\n");
+ spin_unlock(&pers_lock);
+ return -ENODEV;
+ }
}
- spin_unlock(&pers_lock);
return md_cluster_ops->join(mddev, nodes);
}
I looked at linux-next and it appears this code is the same; is there
a test we can do before attempting to load the module in the case that
its built-in, or is there some other requirement that md-cluster needs
to be built as a module?
Yes, we need some additional modules corosync/pacemaker and dlm,
That doesn't explain the error message though.
You are right, I should read carefully :(
If MD_CLUSTER is built in, then DLM must be too.
Sure, then only need to ensure cluster is configured right.
Best Regards,
Guoqing
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