ocfs2: oldmle should be put while -EEXIST returned, and the new mle should not be get once at that time.
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Message ID 71604351584F6A4EBAE558C676F37CA4A3D35566@H3CMLB12-EX.srv.huawei-3com.com
State New
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Commit Message

Guozhonghua Sept. 14, 2016, 2:30 a.m. UTC
In the function dlm_migrate_lockres, while calling dlm_add_migration_mle, and the ret is --EEXIST.
At this time, the oldmle should be put one time for it had been get once in dlm_find_mle.
And the new mle should not get once for it had not been initialized before goto fail.

Signed-off-by: Guozhonghua <guozhonghua@h3c.com>



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Comments

Joseph Qi Sept. 14, 2016, 2:54 a.m. UTC | #1
NAK. This has already been fixed by commit 32e493265b2b ("ocfs2/dlm:
do not insert a new mle when another process is already migrating").
Please submit patch based on the latest kernel.

Thanks,
Joseph

On 2016/9/14 10:30, Guozhonghua wrote:
> 
> In the function dlm_migrate_lockres, while calling dlm_add_migration_mle, and the ret is --EEXIST.
> At this time, the oldmle should be put one time for it had been get once in dlm_find_mle.
> And the new mle should not get once for it had not been initialized before goto fail.
> 
> Signed-off-by: Guozhonghua <guozhonghua@h3c.com>
> 
> --- ocfs2.orig/dlm/dlmmaster.c  2016-09-13 15:18:13.602684325 +0800
> +++ ocfs2/dlm/dlmmaster.c       2016-09-14 10:15:10.496873879 +0800
> @@ -2573,8 +2573,6 @@ static int dlm_is_lockres_migrateable(st
>  /*
>   * DLM_MIGRATE_LOCKRES
>   */
> -
> -
>  static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
>                                struct dlm_lock_resource *res, u8 target)
>  {
> @@ -2621,20 +2619,26 @@ static int dlm_migrate_lockres(struct dl
>         spin_lock(&dlm->master_lock);
>         ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
>                                     namelen, target, dlm->node_num);
> +       if (ret == -EEXIST) {
> +               if(oldmle)
> +                       __dlm_put_mle(oldmle);
> +
> +               spin_unlock(&dlm->master_lock);
> +               spin_unlock(&dlm->spinlock);
> +               mlog(0, "another process is already migrating it\n");
> +               goto fail;
> +       }
> +
>         /* get an extra reference on the mle.
>          * otherwise the assert_master from the new
>          * master will destroy this.
>          */
>         dlm_get_mle_inuse(mle);
> +       mle_added = 1;
> +
>         spin_unlock(&dlm->master_lock);
>         spin_unlock(&dlm->spinlock);
> 
> -       if (ret == -EEXIST) {
> -               mlog(0, "another process is already migrating it\n");
> -               goto fail;
> -       }
> -       mle_added = 1;
> -
>         /*
>          * set the MIGRATING flag and flush asts
>          * if we fail after this we need to re-dirty the lockres
> 
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Guozhonghua Sept. 14, 2016, 3:41 a.m. UTC | #2
Hi, Joseph

I reviewed the patch of 32e493265b2b.
If the ret is --EEXIST, the oldmle will not be put.

As the fucntion dlm_add_migration_mle called, the return value is -EEXIST.
The oldmle had been gotten once and goto fail.

The fail code, ret is -EEXIST, so there is not anyway for the oldmle to be put.
fail:
        if (ret != -EEXIST && oldmle) {
                /* master is known, detach if not already detached */
                dlm_mle_detach_hb_events(dlm, oldmle);
                dlm_put_mle(oldmle);
        }

Same thing, the new mle is allocated
It will not initialized with the ret --EEXIST while call dlm_add_migration_mle.
So it is wrong to call dlm_get_mle_inuse(mle) for the new mle before goto fail.

I review these code and find that is not well.
Please have a check, and your comments will be good for me.
Thank You.

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或散发)本邮件中的信息。如果您错收了本邮件,请您立即电话或邮件通知发件人并删除本
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Patch
diff mbox

--- ocfs2.orig/dlm/dlmmaster.c  2016-09-13 15:18:13.602684325 +0800
+++ ocfs2/dlm/dlmmaster.c       2016-09-14 10:15:10.496873879 +0800
@@ -2573,8 +2573,6 @@  static int dlm_is_lockres_migrateable(st
 /*
  * DLM_MIGRATE_LOCKRES
  */
-
-
 static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
                               struct dlm_lock_resource *res, u8 target)
 {
@@ -2621,20 +2619,26 @@  static int dlm_migrate_lockres(struct dl
        spin_lock(&dlm->master_lock);
        ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
                                    namelen, target, dlm->node_num);
+       if (ret == -EEXIST) {
+               if(oldmle)
+                       __dlm_put_mle(oldmle);
+
+               spin_unlock(&dlm->master_lock);
+               spin_unlock(&dlm->spinlock);
+               mlog(0, "another process is already migrating it\n");
+               goto fail;
+       }
+
        /* get an extra reference on the mle.
         * otherwise the assert_master from the new
         * master will destroy this.
         */
        dlm_get_mle_inuse(mle);
+       mle_added = 1;
+
        spin_unlock(&dlm->master_lock);
        spin_unlock(&dlm->spinlock);

-       if (ret == -EEXIST) {
-               mlog(0, "another process is already migrating it\n");
-               goto fail;
-       }
-       mle_added = 1;
-
        /*
         * set the MIGRATING flag and flush asts
         * if we fail after this we need to re-dirty the lockres