Clean up: refactor nsm_get_handle() so it is organized the same way that
nsm_reboot_lookup() is, and get rid of the "goto retry".
There is an additional micro-optimization here. This change moves the
"hostname & nsm_use_hostnames" test out of the list_for_each_entry()
clause in nsm_get_handle(), since it is loop-invariant.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/lockd/mon.c | 69 +++++++++++++++++++++++++++++++-------------------------
1 files changed, 38 insertions(+), 31 deletions(-)
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 24857a8..a5f26f3 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -214,6 +214,16 @@ static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
return NULL;
}
+static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
+{
+ struct nsm_handle *nsm;
+
+ list_for_each_entry(nsm, &nsm_handles, sm_link)
+ if (nlm_cmp_addr(nsm_addr(nsm), sap))
+ return nsm;
+ return NULL;
+}
+
static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
{
struct nsm_handle *nsm;
@@ -282,8 +292,7 @@ struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
const size_t salen, const char *hostname,
const size_t hostname_len)
{
- struct nsm_handle *nsm = NULL;
- struct nsm_handle *pos;
+ struct nsm_handle *cached, *new = NULL;
if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
if (printk_ratelimit()) {
@@ -294,39 +303,37 @@ struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
return NULL;
}
-retry:
- spin_lock(&nsm_lock);
- list_for_each_entry(pos, &nsm_handles, sm_link) {
-
- if (hostname && nsm_use_hostnames) {
- if (strlen(pos->sm_name) != hostname_len
- || memcmp(pos->sm_name, hostname, hostname_len))
- continue;
- } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
- continue;
- atomic_inc(&pos->sm_count);
- spin_unlock(&nsm_lock);
- kfree(nsm);
- dprintk("lockd: found nsm_handle for %s (%s), cnt %d\n",
- pos->sm_name, pos->sm_addrbuf,
- atomic_read(&pos->sm_count));
- return pos;
- }
+ do {
+ spin_lock(&nsm_lock);
- if (nsm) {
- list_add(&nsm->sm_link, &nsm_handles);
- spin_unlock(&nsm_lock);
- dprintk("lockd: created nsm_handle for %s (%s)\n",
- nsm->sm_name, nsm->sm_addrbuf);
- return nsm;
- }
+ if (nsm_use_hostnames && hostname != NULL)
+ cached = nsm_lookup_hostname(hostname, hostname_len);
+ else
+ cached = nsm_lookup_addr(sap);
+
+ if (cached != NULL) {
+ atomic_inc(&cached->sm_count);
+ spin_unlock(&nsm_lock);
+ kfree(new);
+ dprintk("lockd: found nsm_handle for %s (%s), "
+ "cnt %d\n", cached->sm_name,
+ cached->sm_addrbuf,
+ atomic_read(&cached->sm_count));
+ return cached;
+ }
- spin_unlock(&nsm_lock);
+ if (new != NULL) {
+ list_add(&new->sm_link, &nsm_handles);
+ spin_unlock(&nsm_lock);
+ dprintk("lockd: created nsm_handle for %s (%s)\n",
+ new->sm_name, new->sm_addrbuf);
+ return new;
+ }
- nsm = nsm_create_handle(sap, salen, hostname, hostname_len);
- if (nsm != NULL)
- goto retry;
+ spin_unlock(&nsm_lock);
+ new = nsm_create_handle(sap, salen, hostname, hostname_len);
+ } while (new != NULL);
return NULL;
}
--
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