On Fri, 5 Feb 2016, Yan, Zheng wrote:
> This allows namespace data structure to be shared by cephfs inodes
> with same layout.
>
> Signed-off-by: Yan, Zheng <zyan@xxxxxxxxxx>
> ---
> include/linux/ceph/libceph.h | 1 +
> include/linux/ceph/pool_ns.h | 47 +++++++++++++++
> net/ceph/Makefile | 2 +-
> net/ceph/ceph_common.c | 2 +
> net/ceph/pool_ns.c | 133 +++++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 184 insertions(+), 1 deletion(-)
> create mode 100644 include/linux/ceph/pool_ns.h
> create mode 100644 net/ceph/pool_ns.c
Would it make sense to rename this string_table and make it generic?
There's nothing ceph (or pool ns) specific about it that I can see.
sage
>
> diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
> index e7975e4..40e0d84 100644
> --- a/include/linux/ceph/libceph.h
> +++ b/include/linux/ceph/libceph.h
> @@ -21,6 +21,7 @@
> #include <linux/ceph/mon_client.h>
> #include <linux/ceph/osd_client.h>
> #include <linux/ceph/ceph_fs.h>
> +#include <linux/ceph/pool_ns.h>
>
> /*
> * mount options
> diff --git a/include/linux/ceph/pool_ns.h b/include/linux/ceph/pool_ns.h
> new file mode 100644
> index 0000000..627cf9d
> --- /dev/null
> +++ b/include/linux/ceph/pool_ns.h
> @@ -0,0 +1,47 @@
> +#ifndef _FS_CEPH_POOL_NS_H
> +#define _FS_CEPH_POOL_NS_H
> +
> +#include <linux/types.h>
> +#include <linux/kref.h>
> +#include <linux/rbtree.h>
> +#include <linux/rcupdate.h>
> +
> +struct ceph_pool_ns {
> + struct kref kref;
> + union {
> + struct rb_node node;
> + struct rcu_head rcu;
> + };
> + size_t name_len;
> + char name[];
> +};
> +
> +extern void ceph_release_pool_ns(struct kref *ref);
> +extern struct ceph_pool_ns *ceph_find_or_create_pool_ns(const char *str,
> + size_t len);
> +extern struct ceph_pool_ns *ceph_try_get_pool_ns(struct ceph_pool_ns **pns);
> +extern void ceph_pool_ns_cleanup(void);
> +
> +static inline void ceph_get_pool_ns(struct ceph_pool_ns *ns)
> +{
> + kref_get(&ns->kref);
> +}
> +
> +static inline void ceph_put_pool_ns(struct ceph_pool_ns *ns)
> +{
> + if (!ns)
> + return;
> + kref_put(&ns->kref, ceph_release_pool_ns);
> +}
> +
> +static inline int ceph_compare_pool_ns(struct ceph_pool_ns *ns,
> + const char* str, size_t len)
> +{
> + size_t nsl = ns ? ns->name_len : 0;
> + if (nsl != len)
> + return nsl - len;
> + if (nsl == 0)
> + return 0;
> + return strncmp(ns->name, str, len);
> +}
> +#endif
> diff --git a/net/ceph/Makefile b/net/ceph/Makefile
> index 958d9856..520dab6 100644
> --- a/net/ceph/Makefile
> +++ b/net/ceph/Makefile
> @@ -11,5 +11,5 @@ libceph-y := ceph_common.o messenger.o msgpool.o buffer.o pagelist.o \
> crypto.o armor.o \
> auth_x.o \
> ceph_fs.o ceph_strings.o ceph_hash.o \
> - pagevec.o snapshot.o
> + pagevec.o snapshot.o pool_ns.o
>
> diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
> index dcc18c6..ac60293 100644
> --- a/net/ceph/ceph_common.c
> +++ b/net/ceph/ceph_common.c
> @@ -25,6 +25,7 @@
> #include <linux/ceph/decode.h>
> #include <linux/ceph/mon_client.h>
> #include <linux/ceph/auth.h>
> +#include <linux/ceph/pool_ns.h>
> #include "crypto.h"
>
>
> @@ -751,6 +752,7 @@ static void __exit exit_ceph_lib(void)
> ceph_msgr_exit();
> ceph_crypto_shutdown();
> ceph_debugfs_cleanup();
> + ceph_pool_ns_cleanup();
> }
>
> module_init(init_ceph_lib);
> diff --git a/net/ceph/pool_ns.c b/net/ceph/pool_ns.c
> new file mode 100644
> index 0000000..64ccd77
> --- /dev/null
> +++ b/net/ceph/pool_ns.c
> @@ -0,0 +1,133 @@
> +#include <linux/slab.h>
> +#include <linux/gfp.h>
> +#include <linux/string.h>
> +#include <linux/spinlock.h>
> +#include <linux/ceph/pool_ns.h>
> +
> +static DEFINE_SPINLOCK(pool_ns_lock);
> +static struct rb_root pool_ns_tree = RB_ROOT;
> +
> +struct ceph_pool_ns *ceph_find_or_create_pool_ns(const char* name, size_t len)
> +{
> + struct ceph_pool_ns *ns, *exist;
> + struct rb_node **p, *parent;
> + int ret;
> +
> + exist = NULL;
> + spin_lock(&pool_ns_lock);
> + p = &pool_ns_tree.rb_node;
> + while (*p) {
> + exist = rb_entry(*p, struct ceph_pool_ns, node);
> + ret = ceph_compare_pool_ns(exist, name, len);
> + if (ret > 0)
> + p = &(*p)->rb_left;
> + else if (ret < 0)
> + p = &(*p)->rb_right;
> + else
> + break;
> + exist = NULL;
> + }
> + if (exist && !kref_get_unless_zero(&exist->kref)) {
> + rb_erase(&exist->node, &pool_ns_tree);
> + RB_CLEAR_NODE(&exist->node);
> + exist = NULL;
> + }
> + spin_unlock(&pool_ns_lock);
> + if (exist)
> + return exist;
> +
> + ns = kmalloc(sizeof(*ns) + len + 1, GFP_NOFS);
> + if (!ns)
> + return NULL;
> +
> + kref_init(&ns->kref);
> + ns->name_len = len;
> + memcpy(ns->name, name, len);
> + ns->name[len] = 0;
> +
> +retry:
> + exist = NULL;
> + parent = NULL;
> + p = &pool_ns_tree.rb_node;
> + spin_lock(&pool_ns_lock);
> + while (*p) {
> + parent = *p;
> + exist = rb_entry(*p, struct ceph_pool_ns, node);
> + ret = ceph_compare_pool_ns(exist, name, len);
> + if (ret > 0)
> + p = &(*p)->rb_left;
> + else if (ret < 0)
> + p = &(*p)->rb_right;
> + else
> + break;
> + exist = NULL;
> + }
> + ret = 0;
> + if (!exist) {
> + rb_link_node(&ns->node, parent, p);
> + rb_insert_color(&ns->node, &pool_ns_tree);
> + } else if (!kref_get_unless_zero(&exist->kref)) {
> + rb_erase(&exist->node, &pool_ns_tree);
> + RB_CLEAR_NODE(&exist->node);
> + ret = -EAGAIN;
> + }
> + spin_unlock(&pool_ns_lock);
> + if (ret == -EAGAIN)
> + goto retry;
> +
> + if (exist) {
> + kfree(ns);
> + ns = exist;
> + }
> +
> + return ns;
> +}
> +EXPORT_SYMBOL(ceph_find_or_create_pool_ns);
> +
> +static void ceph_free_pool_ns(struct rcu_head *head)
> +{
> + struct ceph_pool_ns *ns = container_of(head, struct ceph_pool_ns, rcu);
> + kfree(ns);
> +}
> +
> +void ceph_release_pool_ns(struct kref *ref)
> +{
> + struct ceph_pool_ns *ns = container_of(ref, struct ceph_pool_ns, kref);
> +
> + spin_lock(&pool_ns_lock);
> + if (!RB_EMPTY_NODE(&ns->node)) {
> + rb_erase(&ns->node, &pool_ns_tree);
> + RB_CLEAR_NODE(&ns->node);
> + }
> + spin_unlock(&pool_ns_lock);
> +
> + call_rcu(&ns->rcu, ceph_free_pool_ns);
> +}
> +EXPORT_SYMBOL(ceph_release_pool_ns);
> +
> +struct ceph_pool_ns *ceph_try_get_pool_ns(struct ceph_pool_ns **pns)
> +{
> + struct ceph_pool_ns *ns;
> + rcu_read_lock();
> + ns = rcu_dereference(*pns);
> + if (ns && !kref_get_unless_zero(&ns->kref))
> + ns = NULL;
> + rcu_read_unlock();
> + return ns;
> +}
> +EXPORT_SYMBOL(ceph_try_get_pool_ns);
> +
> +void ceph_pool_ns_cleanup(void)
> +{
> + struct rb_node *p;
> + struct ceph_pool_ns *ns;
> + if (RB_EMPTY_ROOT(&pool_ns_tree))
> + return;
> +
> + pr_err("libceph: detect pool ns leaks\n");
> + while ((p = rb_first(&pool_ns_tree))) {
> + ns = rb_entry(p, struct ceph_pool_ns, node);
> + rb_erase(p, &pool_ns_tree);
> + kfree(ns);
> + }
> +}
> --
> 2.5.0
>
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