[GFS2] No lock_nolock
This patch merges the lock_nolock module into GFS2 itself. As well as removing
some of the overhead of the module, it also means that its now impossible to
build GFS2 without a lock module (which would be a pointless thing to do
anyway).
We also plan to merge lock_dlm into GFS2 in the future, but that is a more
tricky task, and will therefore be a separate patch.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: David Teigland <teigland@redhat.com>
diff --git a/fs/gfs2/locking.c b/fs/gfs2/locking.c
index 663fee7..a4a367a 100644
--- a/fs/gfs2/locking.c
+++ b/fs/gfs2/locking.c
@@ -23,12 +23,54 @@
const struct lm_lockops *lw_ops;
};
+static int nolock_mount(char *table_name, char *host_data,
+ lm_callback_t cb, void *cb_data,
+ unsigned int min_lvb_size, int flags,
+ struct lm_lockstruct *lockstruct,
+ struct kobject *fskobj);
+
/* List of registered low-level locking protocols. A file system selects one
of them by name at mount time, e.g. lock_nolock, lock_dlm. */
+static const struct lm_lockops nolock_ops = {
+ .lm_proto_name = "lock_nolock",
+ .lm_mount = nolock_mount,
+};
+
+static struct lmh_wrapper nolock_proto = {
+ .lw_list = LIST_HEAD_INIT(nolock_proto.lw_list),
+ .lw_ops = &nolock_ops,
+};
+
static LIST_HEAD(lmh_list);
static DEFINE_MUTEX(lmh_lock);
+static int nolock_mount(char *table_name, char *host_data,
+ lm_callback_t cb, void *cb_data,
+ unsigned int min_lvb_size, int flags,
+ struct lm_lockstruct *lockstruct,
+ struct kobject *fskobj)
+{
+ char *c;
+ unsigned int jid;
+
+ c = strstr(host_data, "jid=");
+ if (!c)
+ jid = 0;
+ else {
+ c += 4;
+ sscanf(c, "%u", &jid);
+ }
+
+ lockstruct->ls_jid = jid;
+ lockstruct->ls_first = 1;
+ lockstruct->ls_lvb_size = min_lvb_size;
+ lockstruct->ls_ops = &nolock_ops;
+ lockstruct->ls_flags = LM_LSFLAG_LOCAL;
+
+ return 0;
+}
+
/**
* gfs2_register_lockproto - Register a low-level locking protocol
* @proto: the protocol definition
@@ -116,9 +158,13 @@
int try = 0;
int error, found;
+
retry:
mutex_lock(&lmh_lock);
+ if (list_empty(&nolock_proto.lw_list))
+ list_add(&lmh_list, &nolock_proto.lw_list);
+
found = 0;
list_for_each_entry(lw, &lmh_list, lw_list) {
if (!strcmp(lw->lw_ops->lm_proto_name, proto_name)) {
@@ -139,7 +185,8 @@
goto out;
}
- if (!try_module_get(lw->lw_ops->lm_owner)) {
+ if (lw->lw_ops->lm_owner &&
+ !try_module_get(lw->lw_ops->lm_owner)) {
try = 0;
mutex_unlock(&lmh_lock);
msleep(1000);
@@ -158,7 +205,8 @@
void gfs2_unmount_lockproto(struct lm_lockstruct *lockstruct)
{
mutex_lock(&lmh_lock);
- lockstruct->ls_ops->lm_unmount(lockstruct->ls_lockspace);
+ if (lockstruct->ls_ops->lm_unmount)
+ lockstruct->ls_ops->lm_unmount(lockstruct->ls_lockspace);
if (lockstruct->ls_ops->lm_owner)
module_put(lockstruct->ls_ops->lm_owner);
mutex_unlock(&lmh_lock);