From 1f7ba3311530993801d6877889efff0382bcd641 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Fri, 10 Aug 2012 13:12:07 -0700 Subject: [PATCH] rbd: handle locking inside __rbd_client_find() There is only caller of __rbd_client_find(), and it somewhat clumsily gets the appropriate lock and gets a reference to the existing ceph_client structure if it's found. Instead, have that function handle its own locking, and acquire the reference if found while it holds the lock. Drop the underscores from the name because there's no need to signify anything special about this function. Signed-off-by: Alex Elder Reviewed-by: Yehuda Sadeh --- drivers/block/rbd.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 2b40a4af4d17..15bd3ecbcf34 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -322,19 +322,28 @@ out_opt: } /* - * Find a ceph client with specific addr and configuration. + * Find a ceph client with specific addr and configuration. If + * found, bump its reference count. */ -static struct rbd_client *__rbd_client_find(struct ceph_options *ceph_opts) +static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts) { struct rbd_client *client_node; + bool found = false; if (ceph_opts->flags & CEPH_OPT_NOSHARE) return NULL; - list_for_each_entry(client_node, &rbd_client_list, node) - if (!ceph_compare_options(ceph_opts, client_node->client)) - return client_node; - return NULL; + spin_lock(&rbd_client_list_lock); + list_for_each_entry(client_node, &rbd_client_list, node) { + if (!ceph_compare_options(ceph_opts, client_node->client)) { + kref_get(&client_node->kref); + found = true; + break; + } + } + spin_unlock(&rbd_client_list_lock); + + return found ? client_node : NULL; } /* @@ -416,22 +425,16 @@ static struct rbd_client *rbd_get_client(const char *mon_addr, return ERR_CAST(ceph_opts); } - spin_lock(&rbd_client_list_lock); - rbdc = __rbd_client_find(ceph_opts); + rbdc = rbd_client_find(ceph_opts); if (rbdc) { /* using an existing client */ - kref_get(&rbdc->kref); - spin_unlock(&rbd_client_list_lock); - ceph_destroy_options(ceph_opts); kfree(rbd_opts); return rbdc; } - spin_unlock(&rbd_client_list_lock); rbdc = rbd_client_create(ceph_opts, rbd_opts); - if (IS_ERR(rbdc)) kfree(rbd_opts);