[Ocfs2-devel] [PATCH 1/7] Add dlm operations placeholders
Joel Becker
jlbec at evilplan.org
Fri Sep 27 11:59:37 PDT 2013
On Fri, Sep 27, 2013 at 12:06:47PM -0500, Goldwyn Rodrigues wrote:
> Try locking with the new DLM semantics with the dlm operations.
> If operation fails with EOPNOTSUPP, try the old semantics.
> This would ensure that filesystems are mounted for those who
> are upgrading the kernel but not the tools.
> Users using old tools will be presented with a notice message
> to upgrade the tools.
>
> recover_prep() is called when DLM understands a node is down.
> recover_slot() is called once all nodes have acknowledged recover_prep and
> recovery can begin.
> recover_done() is called once the recovery is complete. It returns the
> new membership.
Can recover_prep() pause? What does the cluster do when not all
nodes acknowledge the prep? When they die during recover_slot()? Which
node recovers the slot?
> ---
> fs/ocfs2/stack_user.c | 70 +++++++++++++++++++++++++++++++++++++--------------
> 1 file changed, 51 insertions(+), 19 deletions(-)
>
> diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
> index 286edf1..b44490b 100644
> --- a/fs/ocfs2/stack_user.c
> +++ b/fs/ocfs2/stack_user.c
> @@ -799,14 +799,63 @@ static int fs_protocol_compare(struct ocfs2_protocol_version *existing,
> return 0;
> }
>
> +static void user_recover_prep(void *arg)
> +{
> +}
> +
> +static void user_recover_slot(void *arg, struct dlm_slot *slot)
> +{
> +}
> +
> +static void user_recover_done(void *arg, struct dlm_slot *slots,
> + int num_slots, int our_slot,
> + uint32_t generation)
> +{
> +}
> +
> +const struct dlm_lockspace_ops ocfs2_ls_ops = {
> + .recover_prep = user_recover_prep,
> + .recover_slot = user_recover_slot,
> + .recover_done = user_recover_done,
> +};
> +
> +static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
> +{
> + dlm_release_lockspace(conn->cc_lockspace, 2);
> + conn->cc_lockspace = NULL;
> + ocfs2_live_connection_drop(conn->cc_private);
> + conn->cc_private = NULL;
> + return 0;
> +}
> +
> static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
> {
> dlm_lockspace_t *fsdlm;
> struct ocfs2_live_connection *uninitialized_var(control);
> - int rc = 0;
> + int rc = 0, ops_rv;
>
> BUG_ON(conn == NULL);
>
> + rc = dlm_new_lockspace(conn->cc_name, NULL, DLM_LSFL_FS, DLM_LVB_LEN,
> + &ocfs2_ls_ops, conn, &ops_rv, &fsdlm);
> +
> + if (rc)
> + goto out;
> +
> + if (!ops_rv) {
> + /* DLM lockspace creation with newer new_lockspace successful */
> + goto out;
> + } else if (ops_rv != -EOPNOTSUPP) {
> + rc = ops_rv;
> + goto out;
> + }
> +
> + conn->cc_lockspace = fsdlm;
This code returns from !ops_rv before setting cc_lockspace, yet tries to
reference it out in user_cluster_disconnect(). That looks like a
crashing bug.
Also, it looks like you call the new form of dlm_new_lockspace() before
the callbacks are even implemented. If I just apply this patch, the
code does not work. Please reorder the patch so that ocfs2 works at
each patch.
Joel
> +
> + printk(KERN_NOTICE "ocfs2: You seem to be using an older version "
> + "of dlm_controld and/or ocfs2-tools. Please consider "
> + "upgrading.\n");
> +
> rc = ocfs2_live_connection_new(conn, &control);
> if (rc)
> goto out;
> @@ -823,32 +872,15 @@ static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
> conn->cc_version.pv_major, conn->cc_version.pv_minor,
> running_proto.pv_major, running_proto.pv_minor);
> rc = -EPROTO;
> - ocfs2_live_connection_drop(control);
> - goto out;
> - }
> -
> - rc = dlm_new_lockspace(conn->cc_name, NULL, DLM_LSFL_FS, DLM_LVB_LEN,
> - NULL, NULL, NULL, &fsdlm);
> - if (rc) {
> - ocfs2_live_connection_drop(control);
> + user_cluster_disconnect(conn);
> goto out;
> }
>
> conn->cc_private = control;
> - conn->cc_lockspace = fsdlm;
> out:
> return rc;
> }
>
> -static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
> -{
> - dlm_release_lockspace(conn->cc_lockspace, 2);
> - conn->cc_lockspace = NULL;
> - ocfs2_live_connection_drop(conn->cc_private);
> - conn->cc_private = NULL;
> - return 0;
> -}
> -
> static int user_cluster_this_node(unsigned int *this_node)
> {
> int rc;
> --
> 1.8.1.4
>
>
> --
> Goldwyn
>
> _______________________________________________
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> Ocfs2-devel at oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
--
"But all my words come back to me
In shades of mediocrity.
Like emptiness in harmony
I need someone to comfort me."
http://www.jlbec.org/
jlbec at evilplan.org
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