[PATCH 08/11] ocfs2: Pass the locking protocol into ocfs2_cluster_connect().

From: Joel Becker
Date: Wed Feb 10 2010 - 04:31:34 EST


Inside the stackglue, the locking protocol structure is hanging off of
the ocfs2_cluster_connection. This takes it one further; the locking
protocol is passed into ocfs2_cluster_connect(). Now different cluster
connections can have different locking protocols with distinct asts.
Note that all locking protocols have to keep their maximum protocol
version in lock-step.

With the protocol structure set in ocfs2_cluster_connect(), there is no
need for the stackglue to have a static pointer to a specific protocol
structure. We can change initialization to only pass in the maximum
protocol version.

Signed-off-by: Joel Becker <joel.becker@xxxxxxxxxx>
---
fs/ocfs2/dlmglue.c | 168 +++++++++++++++++++++++++-------------------------
fs/ocfs2/stackglue.c | 43 ++++++++-----
fs/ocfs2/stackglue.h | 3 +-
3 files changed, 110 insertions(+), 104 deletions(-)

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 4cb3ac2..dde55c4 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -1036,7 +1036,6 @@ static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres)
return lockres->l_pending_gen;
}

-
static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level)
{
struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
@@ -1130,6 +1129,88 @@ out:
spin_unlock_irqrestore(&lockres->l_lock, flags);
}

+static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
+{
+ struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
+ unsigned long flags;
+
+ mlog_entry_void();
+
+ mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name,
+ lockres->l_unlock_action);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (error) {
+ mlog(ML_ERROR, "Dlm passes error %d for lock %s, "
+ "unlock_action %d\n", error, lockres->l_name,
+ lockres->l_unlock_action);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ mlog_exit_void();
+ return;
+ }
+
+ switch(lockres->l_unlock_action) {
+ case OCFS2_UNLOCK_CANCEL_CONVERT:
+ mlog(0, "Cancel convert success for %s\n", lockres->l_name);
+ lockres->l_action = OCFS2_AST_INVALID;
+ /* Downconvert thread may have requeued this lock, we
+ * need to wake it. */
+ if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
+ ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres));
+ break;
+ case OCFS2_UNLOCK_DROP_LOCK:
+ lockres->l_level = DLM_LOCK_IV;
+ break;
+ default:
+ BUG();
+ }
+
+ lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+ lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
+ wake_up(&lockres->l_event);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ mlog_exit_void();
+}
+
+/*
+ * This is the filesystem locking protocol. It provides the lock handling
+ * hooks for the underlying DLM. It has a maximum version number.
+ * The version number allows interoperability with systems running at
+ * the same major number and an equal or smaller minor number.
+ *
+ * Whenever the filesystem does new things with locks (adds or removes a
+ * lock, orders them differently, does different things underneath a lock),
+ * the version must be changed. The protocol is negotiated when joining
+ * the dlm domain. A node may join the domain if its major version is
+ * identical to all other nodes and its minor version is greater than
+ * or equal to all other nodes. When its minor version is greater than
+ * the other nodes, it will run at the minor version specified by the
+ * other nodes.
+ *
+ * If a locking change is made that will not be compatible with older
+ * versions, the major number must be increased and the minor version set
+ * to zero. If a change merely adds a behavior that can be disabled when
+ * speaking to older versions, the minor version must be increased. If a
+ * change adds a fully backwards compatible change (eg, LVB changes that
+ * are just ignored by older versions), the version does not need to be
+ * updated.
+ */
+static struct ocfs2_locking_protocol lproto = {
+ .lp_max_version = {
+ .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
+ .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
+ },
+ .lp_lock_ast = ocfs2_locking_ast,
+ .lp_blocking_ast = ocfs2_blocking_ast,
+ .lp_unlock_ast = ocfs2_unlock_ast,
+};
+
+void ocfs2_set_locking_protocol(void)
+{
+ ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version);
+}
+
static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
int convert)
{
@@ -2959,7 +3040,7 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
status = ocfs2_cluster_connect(osb->osb_cluster_stack,
osb->uuid_str,
strlen(osb->uuid_str),
- ocfs2_do_node_down, osb,
+ &lproto, ocfs2_do_node_down, osb,
&conn);
if (status) {
mlog_errno(status);
@@ -3026,50 +3107,6 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
mlog_exit_void();
}

-static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
-{
- struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
- unsigned long flags;
-
- mlog_entry_void();
-
- mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name,
- lockres->l_unlock_action);
-
- spin_lock_irqsave(&lockres->l_lock, flags);
- if (error) {
- mlog(ML_ERROR, "Dlm passes error %d for lock %s, "
- "unlock_action %d\n", error, lockres->l_name,
- lockres->l_unlock_action);
- spin_unlock_irqrestore(&lockres->l_lock, flags);
- mlog_exit_void();
- return;
- }
-
- switch(lockres->l_unlock_action) {
- case OCFS2_UNLOCK_CANCEL_CONVERT:
- mlog(0, "Cancel convert success for %s\n", lockres->l_name);
- lockres->l_action = OCFS2_AST_INVALID;
- /* Downconvert thread may have requeued this lock, we
- * need to wake it. */
- if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
- ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres));
- break;
- case OCFS2_UNLOCK_DROP_LOCK:
- lockres->l_level = DLM_LOCK_IV;
- break;
- default:
- BUG();
- }
-
- lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
- lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
- wake_up(&lockres->l_event);
- spin_unlock_irqrestore(&lockres->l_lock, flags);
-
- mlog_exit_void();
-}
-
static int ocfs2_drop_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres)
{
@@ -3843,45 +3880,6 @@ void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex)
ocfs2_cluster_unlock(osb, lockres, level);
}

-/*
- * This is the filesystem locking protocol. It provides the lock handling
- * hooks for the underlying DLM. It has a maximum version number.
- * The version number allows interoperability with systems running at
- * the same major number and an equal or smaller minor number.
- *
- * Whenever the filesystem does new things with locks (adds or removes a
- * lock, orders them differently, does different things underneath a lock),
- * the version must be changed. The protocol is negotiated when joining
- * the dlm domain. A node may join the domain if its major version is
- * identical to all other nodes and its minor version is greater than
- * or equal to all other nodes. When its minor version is greater than
- * the other nodes, it will run at the minor version specified by the
- * other nodes.
- *
- * If a locking change is made that will not be compatible with older
- * versions, the major number must be increased and the minor version set
- * to zero. If a change merely adds a behavior that can be disabled when
- * speaking to older versions, the minor version must be increased. If a
- * change adds a fully backwards compatible change (eg, LVB changes that
- * are just ignored by older versions), the version does not need to be
- * updated.
- */
-static struct ocfs2_locking_protocol lproto = {
- .lp_max_version = {
- .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
- .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
- },
- .lp_lock_ast = ocfs2_locking_ast,
- .lp_blocking_ast = ocfs2_blocking_ast,
- .lp_unlock_ast = ocfs2_unlock_ast,
-};
-
-void ocfs2_set_locking_protocol(void)
-{
- ocfs2_stack_glue_set_locking_protocol(&lproto);
-}
-
-
static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres)
{
diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
index fc184c7..31db2e8 100644
--- a/fs/ocfs2/stackglue.c
+++ b/fs/ocfs2/stackglue.c
@@ -36,7 +36,7 @@
#define OCFS2_STACK_PLUGIN_USER "user"
#define OCFS2_MAX_HB_CTL_PATH 256

-static struct ocfs2_locking_protocol *lproto;
+static struct ocfs2_protocol_version locking_max_version;
static DEFINE_SPINLOCK(ocfs2_stack_lock);
static LIST_HEAD(ocfs2_stack_list);
static char cluster_stack_name[OCFS2_STACK_LABEL_LEN + 1];
@@ -176,7 +176,7 @@ int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin)
spin_lock(&ocfs2_stack_lock);
if (!ocfs2_stack_lookup(plugin->sp_name)) {
plugin->sp_count = 0;
- plugin->sp_max_proto = lproto->lp_max_version;
+ plugin->sp_max_proto = locking_max_version;
list_add(&plugin->sp_list, &ocfs2_stack_list);
printk(KERN_INFO "ocfs2: Registered cluster interface %s\n",
plugin->sp_name);
@@ -213,23 +213,23 @@ void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin)
}
EXPORT_SYMBOL_GPL(ocfs2_stack_glue_unregister);

-void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto)
+void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto)
{
struct ocfs2_stack_plugin *p;

- BUG_ON(proto == NULL);
-
spin_lock(&ocfs2_stack_lock);
- BUG_ON(active_stack != NULL);
+ if (memcmp(max_proto, &locking_max_version,
+ sizeof(struct ocfs2_protocol_version))) {
+ BUG_ON(locking_max_version.pv_major != 0);

- lproto = proto;
- list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
- p->sp_max_proto = lproto->lp_max_version;
+ locking_max_version = *max_proto;
+ list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
+ p->sp_max_proto = locking_max_version;
+ }
}
-
spin_unlock(&ocfs2_stack_lock);
}
-EXPORT_SYMBOL_GPL(ocfs2_stack_glue_set_locking_protocol);
+EXPORT_SYMBOL_GPL(ocfs2_stack_glue_set_max_proto_version);


/*
@@ -245,8 +245,6 @@ int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
void *name,
unsigned int namelen)
{
- BUG_ON(lproto == NULL);
-
if (!lksb->lksb_conn)
lksb->lksb_conn = conn;
else
@@ -260,7 +258,6 @@ int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
struct ocfs2_dlm_lksb *lksb,
u32 flags)
{
- BUG_ON(lproto == NULL);
BUG_ON(lksb->lksb_conn == NULL);

return active_stack->sp_ops->dlm_unlock(conn, lksb, flags);
@@ -314,6 +311,7 @@ EXPORT_SYMBOL_GPL(ocfs2_plock);
int ocfs2_cluster_connect(const char *stack_name,
const char *group,
int grouplen,
+ struct ocfs2_locking_protocol *lproto,
void (*recovery_handler)(int node_num,
void *recovery_data),
void *recovery_data,
@@ -331,6 +329,12 @@ int ocfs2_cluster_connect(const char *stack_name,
goto out;
}

+ if (memcmp(&lproto->lp_max_version, &locking_max_version,
+ sizeof(struct ocfs2_protocol_version))) {
+ rc = -EINVAL;
+ goto out;
+ }
+
new_conn = kzalloc(sizeof(struct ocfs2_cluster_connection),
GFP_KERNEL);
if (!new_conn) {
@@ -456,10 +460,10 @@ static ssize_t ocfs2_max_locking_protocol_show(struct kobject *kobj,
ssize_t ret = 0;

spin_lock(&ocfs2_stack_lock);
- if (lproto)
+ if (locking_max_version.pv_major)
ret = snprintf(buf, PAGE_SIZE, "%u.%u\n",
- lproto->lp_max_version.pv_major,
- lproto->lp_max_version.pv_minor);
+ locking_max_version.pv_major,
+ locking_max_version.pv_minor);
spin_unlock(&ocfs2_stack_lock);

return ret;
@@ -688,7 +692,10 @@ static int __init ocfs2_stack_glue_init(void)

static void __exit ocfs2_stack_glue_exit(void)
{
- lproto = NULL;
+ memset(&locking_max_version, 0,
+ sizeof(struct ocfs2_protocol_version));
+ locking_max_version.pv_major = 0;
+ locking_max_version.pv_minor = 0;
ocfs2_sysfs_exit();
if (ocfs2_table_header)
unregister_sysctl_table(ocfs2_table_header);
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index 77a7a9a..b1981ba 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -241,6 +241,7 @@ struct ocfs2_stack_plugin {
int ocfs2_cluster_connect(const char *stack_name,
const char *group,
int grouplen,
+ struct ocfs2_locking_protocol *lproto,
void (*recovery_handler)(int node_num,
void *recovery_data),
void *recovery_data,
@@ -270,7 +271,7 @@ int ocfs2_stack_supports_plocks(void);
int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
struct file *file, int cmd, struct file_lock *fl);

-void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto);
+void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto);


/* Used by stack plugins */
--
1.6.6.1

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